1 /* RTL simplification functions for GNU compiler.
2 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
25 #include "coretypes.h"
31 #include "hard-reg-set.h"
34 #include "insn-config.h"
43 /* Simplification and canonicalization of RTL. */
45 /* Much code operates on (low, high) pairs; the low value is an
46 unsigned wide int, the high value a signed wide int. We
47 occasionally need to sign extend from low to high as if low were a
49 #define HWI_SIGN_EXTEND(low) \
50 ((((HOST_WIDE_INT) low) < 0) ? ((HOST_WIDE_INT) -1) : ((HOST_WIDE_INT) 0))
52 static rtx neg_const_int (enum machine_mode, const_rtx);
53 static bool plus_minus_operand_p (const_rtx);
54 static bool simplify_plus_minus_op_data_cmp (rtx, rtx);
55 static rtx simplify_plus_minus (enum rtx_code, enum machine_mode, rtx, rtx);
56 static rtx simplify_immed_subreg (enum machine_mode, rtx, enum machine_mode,
58 static rtx simplify_associative_operation (enum rtx_code, enum machine_mode,
60 static rtx simplify_relational_operation_1 (enum rtx_code, enum machine_mode,
61 enum machine_mode, rtx, rtx);
62 static rtx simplify_unary_operation_1 (enum rtx_code, enum machine_mode, rtx);
63 static rtx simplify_binary_operation_1 (enum rtx_code, enum machine_mode,
66 /* Negate a CONST_INT rtx, truncating (because a conversion from a
67 maximally negative number can overflow). */
69 neg_const_int (enum machine_mode mode, const_rtx i)
71 return gen_int_mode (- INTVAL (i), mode);
74 /* Test whether expression, X, is an immediate constant that represents
75 the most significant bit of machine mode MODE. */
78 mode_signbit_p (enum machine_mode mode, const_rtx x)
80 unsigned HOST_WIDE_INT val;
83 if (GET_MODE_CLASS (mode) != MODE_INT)
86 width = GET_MODE_BITSIZE (mode);
90 if (width <= HOST_BITS_PER_WIDE_INT
91 && GET_CODE (x) == CONST_INT)
93 else if (width <= 2 * HOST_BITS_PER_WIDE_INT
94 && GET_CODE (x) == CONST_DOUBLE
95 && CONST_DOUBLE_LOW (x) == 0)
97 val = CONST_DOUBLE_HIGH (x);
98 width -= HOST_BITS_PER_WIDE_INT;
103 if (width < HOST_BITS_PER_WIDE_INT)
104 val &= ((unsigned HOST_WIDE_INT) 1 << width) - 1;
105 return val == ((unsigned HOST_WIDE_INT) 1 << (width - 1));
108 /* Make a binary operation by properly ordering the operands and
109 seeing if the expression folds. */
112 simplify_gen_binary (enum rtx_code code, enum machine_mode mode, rtx op0,
117 /* If this simplifies, do it. */
118 tem = simplify_binary_operation (code, mode, op0, op1);
122 /* Put complex operands first and constants second if commutative. */
123 if (GET_RTX_CLASS (code) == RTX_COMM_ARITH
124 && swap_commutative_operands_p (op0, op1))
125 tem = op0, op0 = op1, op1 = tem;
127 return gen_rtx_fmt_ee (code, mode, op0, op1);
130 /* If X is a MEM referencing the constant pool, return the real value.
131 Otherwise return X. */
133 avoid_constant_pool_reference (rtx x)
136 enum machine_mode cmode;
137 HOST_WIDE_INT offset = 0;
139 switch (GET_CODE (x))
145 /* Handle float extensions of constant pool references. */
147 c = avoid_constant_pool_reference (tmp);
148 if (c != tmp && GET_CODE (c) == CONST_DOUBLE)
152 REAL_VALUE_FROM_CONST_DOUBLE (d, c);
153 return CONST_DOUBLE_FROM_REAL_VALUE (d, GET_MODE (x));
161 if (GET_MODE (x) == BLKmode)
166 /* Call target hook to avoid the effects of -fpic etc.... */
167 addr = targetm.delegitimize_address (addr);
169 /* Split the address into a base and integer offset. */
170 if (GET_CODE (addr) == CONST
171 && GET_CODE (XEXP (addr, 0)) == PLUS
172 && GET_CODE (XEXP (XEXP (addr, 0), 1)) == CONST_INT)
174 offset = INTVAL (XEXP (XEXP (addr, 0), 1));
175 addr = XEXP (XEXP (addr, 0), 0);
178 if (GET_CODE (addr) == LO_SUM)
179 addr = XEXP (addr, 1);
181 /* If this is a constant pool reference, we can turn it into its
182 constant and hope that simplifications happen. */
183 if (GET_CODE (addr) == SYMBOL_REF
184 && CONSTANT_POOL_ADDRESS_P (addr))
186 c = get_pool_constant (addr);
187 cmode = get_pool_mode (addr);
189 /* If we're accessing the constant in a different mode than it was
190 originally stored, attempt to fix that up via subreg simplifications.
191 If that fails we have no choice but to return the original memory. */
192 if (offset != 0 || cmode != GET_MODE (x))
194 rtx tem = simplify_subreg (GET_MODE (x), c, cmode, offset);
195 if (tem && CONSTANT_P (tem))
205 /* Make a unary operation by first seeing if it folds and otherwise making
206 the specified operation. */
209 simplify_gen_unary (enum rtx_code code, enum machine_mode mode, rtx op,
210 enum machine_mode op_mode)
214 /* If this simplifies, use it. */
215 if ((tem = simplify_unary_operation (code, mode, op, op_mode)) != 0)
218 return gen_rtx_fmt_e (code, mode, op);
221 /* Likewise for ternary operations. */
224 simplify_gen_ternary (enum rtx_code code, enum machine_mode mode,
225 enum machine_mode op0_mode, rtx op0, rtx op1, rtx op2)
229 /* If this simplifies, use it. */
230 if (0 != (tem = simplify_ternary_operation (code, mode, op0_mode,
234 return gen_rtx_fmt_eee (code, mode, op0, op1, op2);
237 /* Likewise, for relational operations.
238 CMP_MODE specifies mode comparison is done in. */
241 simplify_gen_relational (enum rtx_code code, enum machine_mode mode,
242 enum machine_mode cmp_mode, rtx op0, rtx op1)
246 if (0 != (tem = simplify_relational_operation (code, mode, cmp_mode,
250 return gen_rtx_fmt_ee (code, mode, op0, op1);
253 /* Replace all occurrences of OLD_RTX in X with NEW_RTX and try to simplify the
254 resulting RTX. Return a new RTX which is as simplified as possible. */
257 simplify_replace_rtx (rtx x, const_rtx old_rtx, rtx new_rtx)
259 enum rtx_code code = GET_CODE (x);
260 enum machine_mode mode = GET_MODE (x);
261 enum machine_mode op_mode;
264 /* If X is OLD_RTX, return NEW_RTX. Otherwise, if this is an expression, try
265 to build a new expression substituting recursively. If we can't do
266 anything, return our input. */
271 switch (GET_RTX_CLASS (code))
275 op_mode = GET_MODE (op0);
276 op0 = simplify_replace_rtx (op0, old_rtx, new_rtx);
277 if (op0 == XEXP (x, 0))
279 return simplify_gen_unary (code, mode, op0, op_mode);
283 op0 = simplify_replace_rtx (XEXP (x, 0), old_rtx, new_rtx);
284 op1 = simplify_replace_rtx (XEXP (x, 1), old_rtx, new_rtx);
285 if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1))
287 return simplify_gen_binary (code, mode, op0, op1);
290 case RTX_COMM_COMPARE:
293 op_mode = GET_MODE (op0) != VOIDmode ? GET_MODE (op0) : GET_MODE (op1);
294 op0 = simplify_replace_rtx (op0, old_rtx, new_rtx);
295 op1 = simplify_replace_rtx (op1, old_rtx, new_rtx);
296 if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1))
298 return simplify_gen_relational (code, mode, op_mode, op0, op1);
301 case RTX_BITFIELD_OPS:
303 op_mode = GET_MODE (op0);
304 op0 = simplify_replace_rtx (op0, old_rtx, new_rtx);
305 op1 = simplify_replace_rtx (XEXP (x, 1), old_rtx, new_rtx);
306 op2 = simplify_replace_rtx (XEXP (x, 2), old_rtx, new_rtx);
307 if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1) && op2 == XEXP (x, 2))
309 if (op_mode == VOIDmode)
310 op_mode = GET_MODE (op0);
311 return simplify_gen_ternary (code, mode, op_mode, op0, op1, op2);
314 /* The only case we try to handle is a SUBREG. */
317 op0 = simplify_replace_rtx (SUBREG_REG (x), old_rtx, new_rtx);
318 if (op0 == SUBREG_REG (x))
320 op0 = simplify_gen_subreg (GET_MODE (x), op0,
321 GET_MODE (SUBREG_REG (x)),
323 return op0 ? op0 : x;
330 op0 = simplify_replace_rtx (XEXP (x, 0), old_rtx, new_rtx);
331 if (op0 == XEXP (x, 0))
333 return replace_equiv_address_nv (x, op0);
335 else if (code == LO_SUM)
337 op0 = simplify_replace_rtx (XEXP (x, 0), old_rtx, new_rtx);
338 op1 = simplify_replace_rtx (XEXP (x, 1), old_rtx, new_rtx);
340 /* (lo_sum (high x) x) -> x */
341 if (GET_CODE (op0) == HIGH && rtx_equal_p (XEXP (op0, 0), op1))
344 if (op0 == XEXP (x, 0) && op1 == XEXP (x, 1))
346 return gen_rtx_LO_SUM (mode, op0, op1);
348 else if (code == REG)
350 if (rtx_equal_p (x, old_rtx))
361 /* Try to simplify a unary operation CODE whose output mode is to be
362 MODE with input operand OP whose mode was originally OP_MODE.
363 Return zero if no simplification can be made. */
365 simplify_unary_operation (enum rtx_code code, enum machine_mode mode,
366 rtx op, enum machine_mode op_mode)
370 if (GET_CODE (op) == CONST)
373 trueop = avoid_constant_pool_reference (op);
375 tem = simplify_const_unary_operation (code, mode, trueop, op_mode);
379 return simplify_unary_operation_1 (code, mode, op);
382 /* Perform some simplifications we can do even if the operands
385 simplify_unary_operation_1 (enum rtx_code code, enum machine_mode mode, rtx op)
387 enum rtx_code reversed;
393 /* (not (not X)) == X. */
394 if (GET_CODE (op) == NOT)
397 /* (not (eq X Y)) == (ne X Y), etc. if BImode or the result of the
398 comparison is all ones. */
399 if (COMPARISON_P (op)
400 && (mode == BImode || STORE_FLAG_VALUE == -1)
401 && ((reversed = reversed_comparison_code (op, NULL_RTX)) != UNKNOWN))
402 return simplify_gen_relational (reversed, mode, VOIDmode,
403 XEXP (op, 0), XEXP (op, 1));
405 /* (not (plus X -1)) can become (neg X). */
406 if (GET_CODE (op) == PLUS
407 && XEXP (op, 1) == constm1_rtx)
408 return simplify_gen_unary (NEG, mode, XEXP (op, 0), mode);
410 /* Similarly, (not (neg X)) is (plus X -1). */
411 if (GET_CODE (op) == NEG)
412 return plus_constant (XEXP (op, 0), -1);
414 /* (not (xor X C)) for C constant is (xor X D) with D = ~C. */
415 if (GET_CODE (op) == XOR
416 && GET_CODE (XEXP (op, 1)) == CONST_INT
417 && (temp = simplify_unary_operation (NOT, mode,
418 XEXP (op, 1), mode)) != 0)
419 return simplify_gen_binary (XOR, mode, XEXP (op, 0), temp);
421 /* (not (plus X C)) for signbit C is (xor X D) with D = ~C. */
422 if (GET_CODE (op) == PLUS
423 && GET_CODE (XEXP (op, 1)) == CONST_INT
424 && mode_signbit_p (mode, XEXP (op, 1))
425 && (temp = simplify_unary_operation (NOT, mode,
426 XEXP (op, 1), mode)) != 0)
427 return simplify_gen_binary (XOR, mode, XEXP (op, 0), temp);
430 /* (not (ashift 1 X)) is (rotate ~1 X). We used to do this for
431 operands other than 1, but that is not valid. We could do a
432 similar simplification for (not (lshiftrt C X)) where C is
433 just the sign bit, but this doesn't seem common enough to
435 if (GET_CODE (op) == ASHIFT
436 && XEXP (op, 0) == const1_rtx)
438 temp = simplify_gen_unary (NOT, mode, const1_rtx, mode);
439 return simplify_gen_binary (ROTATE, mode, temp, XEXP (op, 1));
442 /* (not (ashiftrt foo C)) where C is the number of bits in FOO
443 minus 1 is (ge foo (const_int 0)) if STORE_FLAG_VALUE is -1,
444 so we can perform the above simplification. */
446 if (STORE_FLAG_VALUE == -1
447 && GET_CODE (op) == ASHIFTRT
448 && GET_CODE (XEXP (op, 1)) == CONST_INT
449 && INTVAL (XEXP (op, 1)) == GET_MODE_BITSIZE (mode) - 1)
450 return simplify_gen_relational (GE, mode, VOIDmode,
451 XEXP (op, 0), const0_rtx);
454 if (GET_CODE (op) == SUBREG
455 && subreg_lowpart_p (op)
456 && (GET_MODE_SIZE (GET_MODE (op))
457 < GET_MODE_SIZE (GET_MODE (SUBREG_REG (op))))
458 && GET_CODE (SUBREG_REG (op)) == ASHIFT
459 && XEXP (SUBREG_REG (op), 0) == const1_rtx)
461 enum machine_mode inner_mode = GET_MODE (SUBREG_REG (op));
464 x = gen_rtx_ROTATE (inner_mode,
465 simplify_gen_unary (NOT, inner_mode, const1_rtx,
467 XEXP (SUBREG_REG (op), 1));
468 return rtl_hooks.gen_lowpart_no_emit (mode, x);
471 /* Apply De Morgan's laws to reduce number of patterns for machines
472 with negating logical insns (and-not, nand, etc.). If result has
473 only one NOT, put it first, since that is how the patterns are
476 if (GET_CODE (op) == IOR || GET_CODE (op) == AND)
478 rtx in1 = XEXP (op, 0), in2 = XEXP (op, 1);
479 enum machine_mode op_mode;
481 op_mode = GET_MODE (in1);
482 in1 = simplify_gen_unary (NOT, op_mode, in1, op_mode);
484 op_mode = GET_MODE (in2);
485 if (op_mode == VOIDmode)
487 in2 = simplify_gen_unary (NOT, op_mode, in2, op_mode);
489 if (GET_CODE (in2) == NOT && GET_CODE (in1) != NOT)
492 in2 = in1; in1 = tem;
495 return gen_rtx_fmt_ee (GET_CODE (op) == IOR ? AND : IOR,
501 /* (neg (neg X)) == X. */
502 if (GET_CODE (op) == NEG)
505 /* (neg (plus X 1)) can become (not X). */
506 if (GET_CODE (op) == PLUS
507 && XEXP (op, 1) == const1_rtx)
508 return simplify_gen_unary (NOT, mode, XEXP (op, 0), mode);
510 /* Similarly, (neg (not X)) is (plus X 1). */
511 if (GET_CODE (op) == NOT)
512 return plus_constant (XEXP (op, 0), 1);
514 /* (neg (minus X Y)) can become (minus Y X). This transformation
515 isn't safe for modes with signed zeros, since if X and Y are
516 both +0, (minus Y X) is the same as (minus X Y). If the
517 rounding mode is towards +infinity (or -infinity) then the two
518 expressions will be rounded differently. */
519 if (GET_CODE (op) == MINUS
520 && !HONOR_SIGNED_ZEROS (mode)
521 && !HONOR_SIGN_DEPENDENT_ROUNDING (mode))
522 return simplify_gen_binary (MINUS, mode, XEXP (op, 1), XEXP (op, 0));
524 if (GET_CODE (op) == PLUS
525 && !HONOR_SIGNED_ZEROS (mode)
526 && !HONOR_SIGN_DEPENDENT_ROUNDING (mode))
528 /* (neg (plus A C)) is simplified to (minus -C A). */
529 if (GET_CODE (XEXP (op, 1)) == CONST_INT
530 || GET_CODE (XEXP (op, 1)) == CONST_DOUBLE)
532 temp = simplify_unary_operation (NEG, mode, XEXP (op, 1), mode);
534 return simplify_gen_binary (MINUS, mode, temp, XEXP (op, 0));
537 /* (neg (plus A B)) is canonicalized to (minus (neg A) B). */
538 temp = simplify_gen_unary (NEG, mode, XEXP (op, 0), mode);
539 return simplify_gen_binary (MINUS, mode, temp, XEXP (op, 1));
542 /* (neg (mult A B)) becomes (mult (neg A) B).
543 This works even for floating-point values. */
544 if (GET_CODE (op) == MULT
545 && !HONOR_SIGN_DEPENDENT_ROUNDING (mode))
547 temp = simplify_gen_unary (NEG, mode, XEXP (op, 0), mode);
548 return simplify_gen_binary (MULT, mode, temp, XEXP (op, 1));
551 /* NEG commutes with ASHIFT since it is multiplication. Only do
552 this if we can then eliminate the NEG (e.g., if the operand
554 if (GET_CODE (op) == ASHIFT)
556 temp = simplify_unary_operation (NEG, mode, XEXP (op, 0), mode);
558 return simplify_gen_binary (ASHIFT, mode, temp, XEXP (op, 1));
561 /* (neg (ashiftrt X C)) can be replaced by (lshiftrt X C) when
562 C is equal to the width of MODE minus 1. */
563 if (GET_CODE (op) == ASHIFTRT
564 && GET_CODE (XEXP (op, 1)) == CONST_INT
565 && INTVAL (XEXP (op, 1)) == GET_MODE_BITSIZE (mode) - 1)
566 return simplify_gen_binary (LSHIFTRT, mode,
567 XEXP (op, 0), XEXP (op, 1));
569 /* (neg (lshiftrt X C)) can be replaced by (ashiftrt X C) when
570 C is equal to the width of MODE minus 1. */
571 if (GET_CODE (op) == LSHIFTRT
572 && GET_CODE (XEXP (op, 1)) == CONST_INT
573 && INTVAL (XEXP (op, 1)) == GET_MODE_BITSIZE (mode) - 1)
574 return simplify_gen_binary (ASHIFTRT, mode,
575 XEXP (op, 0), XEXP (op, 1));
577 /* (neg (xor A 1)) is (plus A -1) if A is known to be either 0 or 1. */
578 if (GET_CODE (op) == XOR
579 && XEXP (op, 1) == const1_rtx
580 && nonzero_bits (XEXP (op, 0), mode) == 1)
581 return plus_constant (XEXP (op, 0), -1);
583 /* (neg (lt x 0)) is (ashiftrt X C) if STORE_FLAG_VALUE is 1. */
584 /* (neg (lt x 0)) is (lshiftrt X C) if STORE_FLAG_VALUE is -1. */
585 if (GET_CODE (op) == LT
586 && XEXP (op, 1) == const0_rtx
587 && SCALAR_INT_MODE_P (GET_MODE (XEXP (op, 0))))
589 enum machine_mode inner = GET_MODE (XEXP (op, 0));
590 int isize = GET_MODE_BITSIZE (inner);
591 if (STORE_FLAG_VALUE == 1)
593 temp = simplify_gen_binary (ASHIFTRT, inner, XEXP (op, 0),
594 GEN_INT (isize - 1));
597 if (GET_MODE_BITSIZE (mode) > isize)
598 return simplify_gen_unary (SIGN_EXTEND, mode, temp, inner);
599 return simplify_gen_unary (TRUNCATE, mode, temp, inner);
601 else if (STORE_FLAG_VALUE == -1)
603 temp = simplify_gen_binary (LSHIFTRT, inner, XEXP (op, 0),
604 GEN_INT (isize - 1));
607 if (GET_MODE_BITSIZE (mode) > isize)
608 return simplify_gen_unary (ZERO_EXTEND, mode, temp, inner);
609 return simplify_gen_unary (TRUNCATE, mode, temp, inner);
615 /* We can't handle truncation to a partial integer mode here
616 because we don't know the real bitsize of the partial
618 if (GET_MODE_CLASS (mode) == MODE_PARTIAL_INT)
621 /* (truncate:SI ({sign,zero}_extend:DI foo:SI)) == foo:SI. */
622 if ((GET_CODE (op) == SIGN_EXTEND
623 || GET_CODE (op) == ZERO_EXTEND)
624 && GET_MODE (XEXP (op, 0)) == mode)
627 /* (truncate:SI (OP:DI ({sign,zero}_extend:DI foo:SI))) is
628 (OP:SI foo:SI) if OP is NEG or ABS. */
629 if ((GET_CODE (op) == ABS
630 || GET_CODE (op) == NEG)
631 && (GET_CODE (XEXP (op, 0)) == SIGN_EXTEND
632 || GET_CODE (XEXP (op, 0)) == ZERO_EXTEND)
633 && GET_MODE (XEXP (XEXP (op, 0), 0)) == mode)
634 return simplify_gen_unary (GET_CODE (op), mode,
635 XEXP (XEXP (op, 0), 0), mode);
637 /* (truncate:A (subreg:B (truncate:C X) 0)) is
639 if (GET_CODE (op) == SUBREG
640 && GET_CODE (SUBREG_REG (op)) == TRUNCATE
641 && subreg_lowpart_p (op))
642 return simplify_gen_unary (TRUNCATE, mode, XEXP (SUBREG_REG (op), 0),
643 GET_MODE (XEXP (SUBREG_REG (op), 0)));
645 /* If we know that the value is already truncated, we can
646 replace the TRUNCATE with a SUBREG. Note that this is also
647 valid if TRULY_NOOP_TRUNCATION is false for the corresponding
648 modes we just have to apply a different definition for
649 truncation. But don't do this for an (LSHIFTRT (MULT ...))
650 since this will cause problems with the umulXi3_highpart
652 if ((TRULY_NOOP_TRUNCATION (GET_MODE_BITSIZE (mode),
653 GET_MODE_BITSIZE (GET_MODE (op)))
654 ? (num_sign_bit_copies (op, GET_MODE (op))
655 > (unsigned int) (GET_MODE_BITSIZE (GET_MODE (op))
656 - GET_MODE_BITSIZE (mode)))
657 : truncated_to_mode (mode, op))
658 && ! (GET_CODE (op) == LSHIFTRT
659 && GET_CODE (XEXP (op, 0)) == MULT))
660 return rtl_hooks.gen_lowpart_no_emit (mode, op);
662 /* A truncate of a comparison can be replaced with a subreg if
663 STORE_FLAG_VALUE permits. This is like the previous test,
664 but it works even if the comparison is done in a mode larger
665 than HOST_BITS_PER_WIDE_INT. */
666 if (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
668 && ((HOST_WIDE_INT) STORE_FLAG_VALUE & ~GET_MODE_MASK (mode)) == 0)
669 return rtl_hooks.gen_lowpart_no_emit (mode, op);
673 if (DECIMAL_FLOAT_MODE_P (mode))
676 /* (float_truncate:SF (float_extend:DF foo:SF)) = foo:SF. */
677 if (GET_CODE (op) == FLOAT_EXTEND
678 && GET_MODE (XEXP (op, 0)) == mode)
681 /* (float_truncate:SF (float_truncate:DF foo:XF))
682 = (float_truncate:SF foo:XF).
683 This may eliminate double rounding, so it is unsafe.
685 (float_truncate:SF (float_extend:XF foo:DF))
686 = (float_truncate:SF foo:DF).
688 (float_truncate:DF (float_extend:XF foo:SF))
689 = (float_extend:SF foo:DF). */
690 if ((GET_CODE (op) == FLOAT_TRUNCATE
691 && flag_unsafe_math_optimizations)
692 || GET_CODE (op) == FLOAT_EXTEND)
693 return simplify_gen_unary (GET_MODE_SIZE (GET_MODE (XEXP (op,
695 > GET_MODE_SIZE (mode)
696 ? FLOAT_TRUNCATE : FLOAT_EXTEND,
700 /* (float_truncate (float x)) is (float x) */
701 if (GET_CODE (op) == FLOAT
702 && (flag_unsafe_math_optimizations
703 || (SCALAR_FLOAT_MODE_P (GET_MODE (op))
704 && ((unsigned)significand_size (GET_MODE (op))
705 >= (GET_MODE_BITSIZE (GET_MODE (XEXP (op, 0)))
706 - num_sign_bit_copies (XEXP (op, 0),
707 GET_MODE (XEXP (op, 0))))))))
708 return simplify_gen_unary (FLOAT, mode,
710 GET_MODE (XEXP (op, 0)));
712 /* (float_truncate:SF (OP:DF (float_extend:DF foo:sf))) is
713 (OP:SF foo:SF) if OP is NEG or ABS. */
714 if ((GET_CODE (op) == ABS
715 || GET_CODE (op) == NEG)
716 && GET_CODE (XEXP (op, 0)) == FLOAT_EXTEND
717 && GET_MODE (XEXP (XEXP (op, 0), 0)) == mode)
718 return simplify_gen_unary (GET_CODE (op), mode,
719 XEXP (XEXP (op, 0), 0), mode);
721 /* (float_truncate:SF (subreg:DF (float_truncate:SF X) 0))
722 is (float_truncate:SF x). */
723 if (GET_CODE (op) == SUBREG
724 && subreg_lowpart_p (op)
725 && GET_CODE (SUBREG_REG (op)) == FLOAT_TRUNCATE)
726 return SUBREG_REG (op);
730 if (DECIMAL_FLOAT_MODE_P (mode))
733 /* (float_extend (float_extend x)) is (float_extend x)
735 (float_extend (float x)) is (float x) assuming that double
736 rounding can't happen.
738 if (GET_CODE (op) == FLOAT_EXTEND
739 || (GET_CODE (op) == FLOAT
740 && SCALAR_FLOAT_MODE_P (GET_MODE (op))
741 && ((unsigned)significand_size (GET_MODE (op))
742 >= (GET_MODE_BITSIZE (GET_MODE (XEXP (op, 0)))
743 - num_sign_bit_copies (XEXP (op, 0),
744 GET_MODE (XEXP (op, 0)))))))
745 return simplify_gen_unary (GET_CODE (op), mode,
747 GET_MODE (XEXP (op, 0)));
752 /* (abs (neg <foo>)) -> (abs <foo>) */
753 if (GET_CODE (op) == NEG)
754 return simplify_gen_unary (ABS, mode, XEXP (op, 0),
755 GET_MODE (XEXP (op, 0)));
757 /* If the mode of the operand is VOIDmode (i.e. if it is ASM_OPERANDS),
759 if (GET_MODE (op) == VOIDmode)
762 /* If operand is something known to be positive, ignore the ABS. */
763 if (GET_CODE (op) == FFS || GET_CODE (op) == ABS
764 || ((GET_MODE_BITSIZE (GET_MODE (op))
765 <= HOST_BITS_PER_WIDE_INT)
766 && ((nonzero_bits (op, GET_MODE (op))
768 << (GET_MODE_BITSIZE (GET_MODE (op)) - 1)))
772 /* If operand is known to be only -1 or 0, convert ABS to NEG. */
773 if (num_sign_bit_copies (op, mode) == GET_MODE_BITSIZE (mode))
774 return gen_rtx_NEG (mode, op);
779 /* (ffs (*_extend <X>)) = (ffs <X>) */
780 if (GET_CODE (op) == SIGN_EXTEND
781 || GET_CODE (op) == ZERO_EXTEND)
782 return simplify_gen_unary (FFS, mode, XEXP (op, 0),
783 GET_MODE (XEXP (op, 0)));
787 switch (GET_CODE (op))
791 /* (popcount (zero_extend <X>)) = (popcount <X>) */
792 return simplify_gen_unary (POPCOUNT, mode, XEXP (op, 0),
793 GET_MODE (XEXP (op, 0)));
797 /* Rotations don't affect popcount. */
798 if (!side_effects_p (XEXP (op, 1)))
799 return simplify_gen_unary (POPCOUNT, mode, XEXP (op, 0),
800 GET_MODE (XEXP (op, 0)));
809 switch (GET_CODE (op))
815 return simplify_gen_unary (PARITY, mode, XEXP (op, 0),
816 GET_MODE (XEXP (op, 0)));
820 /* Rotations don't affect parity. */
821 if (!side_effects_p (XEXP (op, 1)))
822 return simplify_gen_unary (PARITY, mode, XEXP (op, 0),
823 GET_MODE (XEXP (op, 0)));
832 /* (bswap (bswap x)) -> x. */
833 if (GET_CODE (op) == BSWAP)
838 /* (float (sign_extend <X>)) = (float <X>). */
839 if (GET_CODE (op) == SIGN_EXTEND)
840 return simplify_gen_unary (FLOAT, mode, XEXP (op, 0),
841 GET_MODE (XEXP (op, 0)));
845 /* (sign_extend (truncate (minus (label_ref L1) (label_ref L2))))
846 becomes just the MINUS if its mode is MODE. This allows
847 folding switch statements on machines using casesi (such as
849 if (GET_CODE (op) == TRUNCATE
850 && GET_MODE (XEXP (op, 0)) == mode
851 && GET_CODE (XEXP (op, 0)) == MINUS
852 && GET_CODE (XEXP (XEXP (op, 0), 0)) == LABEL_REF
853 && GET_CODE (XEXP (XEXP (op, 0), 1)) == LABEL_REF)
856 /* Check for a sign extension of a subreg of a promoted
857 variable, where the promotion is sign-extended, and the
858 target mode is the same as the variable's promotion. */
859 if (GET_CODE (op) == SUBREG
860 && SUBREG_PROMOTED_VAR_P (op)
861 && ! SUBREG_PROMOTED_UNSIGNED_P (op)
862 && GET_MODE (XEXP (op, 0)) == mode)
865 #if defined(POINTERS_EXTEND_UNSIGNED) && !defined(HAVE_ptr_extend)
866 if (! POINTERS_EXTEND_UNSIGNED
867 && mode == Pmode && GET_MODE (op) == ptr_mode
869 || (GET_CODE (op) == SUBREG
870 && REG_P (SUBREG_REG (op))
871 && REG_POINTER (SUBREG_REG (op))
872 && GET_MODE (SUBREG_REG (op)) == Pmode)))
873 return convert_memory_address (Pmode, op);
878 /* Check for a zero extension of a subreg of a promoted
879 variable, where the promotion is zero-extended, and the
880 target mode is the same as the variable's promotion. */
881 if (GET_CODE (op) == SUBREG
882 && SUBREG_PROMOTED_VAR_P (op)
883 && SUBREG_PROMOTED_UNSIGNED_P (op) > 0
884 && GET_MODE (XEXP (op, 0)) == mode)
887 #if defined(POINTERS_EXTEND_UNSIGNED) && !defined(HAVE_ptr_extend)
888 if (POINTERS_EXTEND_UNSIGNED > 0
889 && mode == Pmode && GET_MODE (op) == ptr_mode
891 || (GET_CODE (op) == SUBREG
892 && REG_P (SUBREG_REG (op))
893 && REG_POINTER (SUBREG_REG (op))
894 && GET_MODE (SUBREG_REG (op)) == Pmode)))
895 return convert_memory_address (Pmode, op);
906 /* Try to compute the value of a unary operation CODE whose output mode is to
907 be MODE with input operand OP whose mode was originally OP_MODE.
908 Return zero if the value cannot be computed. */
910 simplify_const_unary_operation (enum rtx_code code, enum machine_mode mode,
911 rtx op, enum machine_mode op_mode)
913 unsigned int width = GET_MODE_BITSIZE (mode);
915 if (code == VEC_DUPLICATE)
917 gcc_assert (VECTOR_MODE_P (mode));
918 if (GET_MODE (op) != VOIDmode)
920 if (!VECTOR_MODE_P (GET_MODE (op)))
921 gcc_assert (GET_MODE_INNER (mode) == GET_MODE (op));
923 gcc_assert (GET_MODE_INNER (mode) == GET_MODE_INNER
926 if (GET_CODE (op) == CONST_INT || GET_CODE (op) == CONST_DOUBLE
927 || GET_CODE (op) == CONST_VECTOR)
929 int elt_size = GET_MODE_SIZE (GET_MODE_INNER (mode));
930 unsigned n_elts = (GET_MODE_SIZE (mode) / elt_size);
931 rtvec v = rtvec_alloc (n_elts);
934 if (GET_CODE (op) != CONST_VECTOR)
935 for (i = 0; i < n_elts; i++)
936 RTVEC_ELT (v, i) = op;
939 enum machine_mode inmode = GET_MODE (op);
940 int in_elt_size = GET_MODE_SIZE (GET_MODE_INNER (inmode));
941 unsigned in_n_elts = (GET_MODE_SIZE (inmode) / in_elt_size);
943 gcc_assert (in_n_elts < n_elts);
944 gcc_assert ((n_elts % in_n_elts) == 0);
945 for (i = 0; i < n_elts; i++)
946 RTVEC_ELT (v, i) = CONST_VECTOR_ELT (op, i % in_n_elts);
948 return gen_rtx_CONST_VECTOR (mode, v);
952 if (VECTOR_MODE_P (mode) && GET_CODE (op) == CONST_VECTOR)
954 int elt_size = GET_MODE_SIZE (GET_MODE_INNER (mode));
955 unsigned n_elts = (GET_MODE_SIZE (mode) / elt_size);
956 enum machine_mode opmode = GET_MODE (op);
957 int op_elt_size = GET_MODE_SIZE (GET_MODE_INNER (opmode));
958 unsigned op_n_elts = (GET_MODE_SIZE (opmode) / op_elt_size);
959 rtvec v = rtvec_alloc (n_elts);
962 gcc_assert (op_n_elts == n_elts);
963 for (i = 0; i < n_elts; i++)
965 rtx x = simplify_unary_operation (code, GET_MODE_INNER (mode),
966 CONST_VECTOR_ELT (op, i),
967 GET_MODE_INNER (opmode));
970 RTVEC_ELT (v, i) = x;
972 return gen_rtx_CONST_VECTOR (mode, v);
975 /* The order of these tests is critical so that, for example, we don't
976 check the wrong mode (input vs. output) for a conversion operation,
977 such as FIX. At some point, this should be simplified. */
979 if (code == FLOAT && GET_MODE (op) == VOIDmode
980 && (GET_CODE (op) == CONST_DOUBLE || GET_CODE (op) == CONST_INT))
982 HOST_WIDE_INT hv, lv;
985 if (GET_CODE (op) == CONST_INT)
986 lv = INTVAL (op), hv = HWI_SIGN_EXTEND (lv);
988 lv = CONST_DOUBLE_LOW (op), hv = CONST_DOUBLE_HIGH (op);
990 REAL_VALUE_FROM_INT (d, lv, hv, mode);
991 d = real_value_truncate (mode, d);
992 return CONST_DOUBLE_FROM_REAL_VALUE (d, mode);
994 else if (code == UNSIGNED_FLOAT && GET_MODE (op) == VOIDmode
995 && (GET_CODE (op) == CONST_DOUBLE
996 || GET_CODE (op) == CONST_INT))
998 HOST_WIDE_INT hv, lv;
1001 if (GET_CODE (op) == CONST_INT)
1002 lv = INTVAL (op), hv = HWI_SIGN_EXTEND (lv);
1004 lv = CONST_DOUBLE_LOW (op), hv = CONST_DOUBLE_HIGH (op);
1006 if (op_mode == VOIDmode)
1008 /* We don't know how to interpret negative-looking numbers in
1009 this case, so don't try to fold those. */
1013 else if (GET_MODE_BITSIZE (op_mode) >= HOST_BITS_PER_WIDE_INT * 2)
1016 hv = 0, lv &= GET_MODE_MASK (op_mode);
1018 REAL_VALUE_FROM_UNSIGNED_INT (d, lv, hv, mode);
1019 d = real_value_truncate (mode, d);
1020 return CONST_DOUBLE_FROM_REAL_VALUE (d, mode);
1023 if (GET_CODE (op) == CONST_INT
1024 && width <= HOST_BITS_PER_WIDE_INT && width > 0)
1026 HOST_WIDE_INT arg0 = INTVAL (op);
1040 val = (arg0 >= 0 ? arg0 : - arg0);
1044 /* Don't use ffs here. Instead, get low order bit and then its
1045 number. If arg0 is zero, this will return 0, as desired. */
1046 arg0 &= GET_MODE_MASK (mode);
1047 val = exact_log2 (arg0 & (- arg0)) + 1;
1051 arg0 &= GET_MODE_MASK (mode);
1052 if (arg0 == 0 && CLZ_DEFINED_VALUE_AT_ZERO (mode, val))
1055 val = GET_MODE_BITSIZE (mode) - floor_log2 (arg0) - 1;
1059 arg0 &= GET_MODE_MASK (mode);
1062 /* Even if the value at zero is undefined, we have to come
1063 up with some replacement. Seems good enough. */
1064 if (! CTZ_DEFINED_VALUE_AT_ZERO (mode, val))
1065 val = GET_MODE_BITSIZE (mode);
1068 val = exact_log2 (arg0 & -arg0);
1072 arg0 &= GET_MODE_MASK (mode);
1075 val++, arg0 &= arg0 - 1;
1079 arg0 &= GET_MODE_MASK (mode);
1082 val++, arg0 &= arg0 - 1;
1091 for (s = 0; s < width; s += 8)
1093 unsigned int d = width - s - 8;
1094 unsigned HOST_WIDE_INT byte;
1095 byte = (arg0 >> s) & 0xff;
1106 /* When zero-extending a CONST_INT, we need to know its
1108 gcc_assert (op_mode != VOIDmode);
1109 if (GET_MODE_BITSIZE (op_mode) == HOST_BITS_PER_WIDE_INT)
1111 /* If we were really extending the mode,
1112 we would have to distinguish between zero-extension
1113 and sign-extension. */
1114 gcc_assert (width == GET_MODE_BITSIZE (op_mode));
1117 else if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT)
1118 val = arg0 & ~((HOST_WIDE_INT) (-1) << GET_MODE_BITSIZE (op_mode));
1124 if (op_mode == VOIDmode)
1126 if (GET_MODE_BITSIZE (op_mode) == HOST_BITS_PER_WIDE_INT)
1128 /* If we were really extending the mode,
1129 we would have to distinguish between zero-extension
1130 and sign-extension. */
1131 gcc_assert (width == GET_MODE_BITSIZE (op_mode));
1134 else if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT)
1137 = arg0 & ~((HOST_WIDE_INT) (-1) << GET_MODE_BITSIZE (op_mode));
1139 & ((HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (op_mode) - 1)))
1140 val -= (HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (op_mode);
1148 case FLOAT_TRUNCATE:
1159 return gen_int_mode (val, mode);
1162 /* We can do some operations on integer CONST_DOUBLEs. Also allow
1163 for a DImode operation on a CONST_INT. */
1164 else if (GET_MODE (op) == VOIDmode
1165 && width <= HOST_BITS_PER_WIDE_INT * 2
1166 && (GET_CODE (op) == CONST_DOUBLE
1167 || GET_CODE (op) == CONST_INT))
1169 unsigned HOST_WIDE_INT l1, lv;
1170 HOST_WIDE_INT h1, hv;
1172 if (GET_CODE (op) == CONST_DOUBLE)
1173 l1 = CONST_DOUBLE_LOW (op), h1 = CONST_DOUBLE_HIGH (op);
1175 l1 = INTVAL (op), h1 = HWI_SIGN_EXTEND (l1);
1185 neg_double (l1, h1, &lv, &hv);
1190 neg_double (l1, h1, &lv, &hv);
1202 lv = HOST_BITS_PER_WIDE_INT + exact_log2 (h1 & -h1) + 1;
1205 lv = exact_log2 (l1 & -l1) + 1;
1211 lv = GET_MODE_BITSIZE (mode) - floor_log2 (h1) - 1
1212 - HOST_BITS_PER_WIDE_INT;
1214 lv = GET_MODE_BITSIZE (mode) - floor_log2 (l1) - 1;
1215 else if (! CLZ_DEFINED_VALUE_AT_ZERO (mode, lv))
1216 lv = GET_MODE_BITSIZE (mode);
1222 lv = exact_log2 (l1 & -l1);
1224 lv = HOST_BITS_PER_WIDE_INT + exact_log2 (h1 & -h1);
1225 else if (! CTZ_DEFINED_VALUE_AT_ZERO (mode, lv))
1226 lv = GET_MODE_BITSIZE (mode);
1254 for (s = 0; s < width; s += 8)
1256 unsigned int d = width - s - 8;
1257 unsigned HOST_WIDE_INT byte;
1259 if (s < HOST_BITS_PER_WIDE_INT)
1260 byte = (l1 >> s) & 0xff;
1262 byte = (h1 >> (s - HOST_BITS_PER_WIDE_INT)) & 0xff;
1264 if (d < HOST_BITS_PER_WIDE_INT)
1267 hv |= byte << (d - HOST_BITS_PER_WIDE_INT);
1273 /* This is just a change-of-mode, so do nothing. */
1278 gcc_assert (op_mode != VOIDmode);
1280 if (GET_MODE_BITSIZE (op_mode) > HOST_BITS_PER_WIDE_INT)
1284 lv = l1 & GET_MODE_MASK (op_mode);
1288 if (op_mode == VOIDmode
1289 || GET_MODE_BITSIZE (op_mode) > HOST_BITS_PER_WIDE_INT)
1293 lv = l1 & GET_MODE_MASK (op_mode);
1294 if (GET_MODE_BITSIZE (op_mode) < HOST_BITS_PER_WIDE_INT
1295 && (lv & ((HOST_WIDE_INT) 1
1296 << (GET_MODE_BITSIZE (op_mode) - 1))) != 0)
1297 lv -= (HOST_WIDE_INT) 1 << GET_MODE_BITSIZE (op_mode);
1299 hv = HWI_SIGN_EXTEND (lv);
1310 return immed_double_const (lv, hv, mode);
1313 else if (GET_CODE (op) == CONST_DOUBLE
1314 && SCALAR_FLOAT_MODE_P (mode))
1316 REAL_VALUE_TYPE d, t;
1317 REAL_VALUE_FROM_CONST_DOUBLE (d, op);
1322 if (HONOR_SNANS (mode) && real_isnan (&d))
1324 real_sqrt (&t, mode, &d);
1328 d = REAL_VALUE_ABS (d);
1331 d = REAL_VALUE_NEGATE (d);
1333 case FLOAT_TRUNCATE:
1334 d = real_value_truncate (mode, d);
1337 /* All this does is change the mode. */
1340 real_arithmetic (&d, FIX_TRUNC_EXPR, &d, NULL);
1347 real_to_target (tmp, &d, GET_MODE (op));
1348 for (i = 0; i < 4; i++)
1350 real_from_target (&d, tmp, mode);
1356 return CONST_DOUBLE_FROM_REAL_VALUE (d, mode);
1359 else if (GET_CODE (op) == CONST_DOUBLE
1360 && SCALAR_FLOAT_MODE_P (GET_MODE (op))
1361 && GET_MODE_CLASS (mode) == MODE_INT
1362 && width <= 2*HOST_BITS_PER_WIDE_INT && width > 0)
1364 /* Although the overflow semantics of RTL's FIX and UNSIGNED_FIX
1365 operators are intentionally left unspecified (to ease implementation
1366 by target backends), for consistency, this routine implements the
1367 same semantics for constant folding as used by the middle-end. */
1369 /* This was formerly used only for non-IEEE float.
1370 eggert@twinsun.com says it is safe for IEEE also. */
1371 HOST_WIDE_INT xh, xl, th, tl;
1372 REAL_VALUE_TYPE x, t;
1373 REAL_VALUE_FROM_CONST_DOUBLE (x, op);
1377 if (REAL_VALUE_ISNAN (x))
1380 /* Test against the signed upper bound. */
1381 if (width > HOST_BITS_PER_WIDE_INT)
1383 th = ((unsigned HOST_WIDE_INT) 1
1384 << (width - HOST_BITS_PER_WIDE_INT - 1)) - 1;
1390 tl = ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1;
1392 real_from_integer (&t, VOIDmode, tl, th, 0);
1393 if (REAL_VALUES_LESS (t, x))
1400 /* Test against the signed lower bound. */
1401 if (width > HOST_BITS_PER_WIDE_INT)
1403 th = (HOST_WIDE_INT) -1 << (width - HOST_BITS_PER_WIDE_INT - 1);
1409 tl = (HOST_WIDE_INT) -1 << (width - 1);
1411 real_from_integer (&t, VOIDmode, tl, th, 0);
1412 if (REAL_VALUES_LESS (x, t))
1418 REAL_VALUE_TO_INT (&xl, &xh, x);
1422 if (REAL_VALUE_ISNAN (x) || REAL_VALUE_NEGATIVE (x))
1425 /* Test against the unsigned upper bound. */
1426 if (width == 2*HOST_BITS_PER_WIDE_INT)
1431 else if (width >= HOST_BITS_PER_WIDE_INT)
1433 th = ((unsigned HOST_WIDE_INT) 1
1434 << (width - HOST_BITS_PER_WIDE_INT)) - 1;
1440 tl = ((unsigned HOST_WIDE_INT) 1 << width) - 1;
1442 real_from_integer (&t, VOIDmode, tl, th, 1);
1443 if (REAL_VALUES_LESS (t, x))
1450 REAL_VALUE_TO_INT (&xl, &xh, x);
1456 return immed_double_const (xl, xh, mode);
1462 /* Subroutine of simplify_binary_operation to simplify a commutative,
1463 associative binary operation CODE with result mode MODE, operating
1464 on OP0 and OP1. CODE is currently one of PLUS, MULT, AND, IOR, XOR,
1465 SMIN, SMAX, UMIN or UMAX. Return zero if no simplification or
1466 canonicalization is possible. */
1469 simplify_associative_operation (enum rtx_code code, enum machine_mode mode,
1474 /* Linearize the operator to the left. */
1475 if (GET_CODE (op1) == code)
1477 /* "(a op b) op (c op d)" becomes "((a op b) op c) op d)". */
1478 if (GET_CODE (op0) == code)
1480 tem = simplify_gen_binary (code, mode, op0, XEXP (op1, 0));
1481 return simplify_gen_binary (code, mode, tem, XEXP (op1, 1));
1484 /* "a op (b op c)" becomes "(b op c) op a". */
1485 if (! swap_commutative_operands_p (op1, op0))
1486 return simplify_gen_binary (code, mode, op1, op0);
1493 if (GET_CODE (op0) == code)
1495 /* Canonicalize "(x op c) op y" as "(x op y) op c". */
1496 if (swap_commutative_operands_p (XEXP (op0, 1), op1))
1498 tem = simplify_gen_binary (code, mode, XEXP (op0, 0), op1);
1499 return simplify_gen_binary (code, mode, tem, XEXP (op0, 1));
1502 /* Attempt to simplify "(a op b) op c" as "a op (b op c)". */
1503 tem = simplify_binary_operation (code, mode, XEXP (op0, 1), op1);
1505 return simplify_gen_binary (code, mode, XEXP (op0, 0), tem);
1507 /* Attempt to simplify "(a op b) op c" as "(a op c) op b". */
1508 tem = simplify_binary_operation (code, mode, XEXP (op0, 0), op1);
1510 return simplify_gen_binary (code, mode, tem, XEXP (op0, 1));
1517 /* Simplify a binary operation CODE with result mode MODE, operating on OP0
1518 and OP1. Return 0 if no simplification is possible.
1520 Don't use this for relational operations such as EQ or LT.
1521 Use simplify_relational_operation instead. */
1523 simplify_binary_operation (enum rtx_code code, enum machine_mode mode,
1526 rtx trueop0, trueop1;
1529 /* Relational operations don't work here. We must know the mode
1530 of the operands in order to do the comparison correctly.
1531 Assuming a full word can give incorrect results.
1532 Consider comparing 128 with -128 in QImode. */
1533 gcc_assert (GET_RTX_CLASS (code) != RTX_COMPARE);
1534 gcc_assert (GET_RTX_CLASS (code) != RTX_COMM_COMPARE);
1536 /* Make sure the constant is second. */
1537 if (GET_RTX_CLASS (code) == RTX_COMM_ARITH
1538 && swap_commutative_operands_p (op0, op1))
1540 tem = op0, op0 = op1, op1 = tem;
1543 trueop0 = avoid_constant_pool_reference (op0);
1544 trueop1 = avoid_constant_pool_reference (op1);
1546 tem = simplify_const_binary_operation (code, mode, trueop0, trueop1);
1549 return simplify_binary_operation_1 (code, mode, op0, op1, trueop0, trueop1);
1552 /* Subroutine of simplify_binary_operation. Simplify a binary operation
1553 CODE with result mode MODE, operating on OP0 and OP1. If OP0 and/or
1554 OP1 are constant pool references, TRUEOP0 and TRUEOP1 represent the
1555 actual constants. */
1558 simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode,
1559 rtx op0, rtx op1, rtx trueop0, rtx trueop1)
1561 rtx tem, reversed, opleft, opright;
1563 unsigned int width = GET_MODE_BITSIZE (mode);
1565 /* Even if we can't compute a constant result,
1566 there are some cases worth simplifying. */
1571 /* Maybe simplify x + 0 to x. The two expressions are equivalent
1572 when x is NaN, infinite, or finite and nonzero. They aren't
1573 when x is -0 and the rounding mode is not towards -infinity,
1574 since (-0) + 0 is then 0. */
1575 if (!HONOR_SIGNED_ZEROS (mode) && trueop1 == CONST0_RTX (mode))
1578 /* ((-a) + b) -> (b - a) and similarly for (a + (-b)). These
1579 transformations are safe even for IEEE. */
1580 if (GET_CODE (op0) == NEG)
1581 return simplify_gen_binary (MINUS, mode, op1, XEXP (op0, 0));
1582 else if (GET_CODE (op1) == NEG)
1583 return simplify_gen_binary (MINUS, mode, op0, XEXP (op1, 0));
1585 /* (~a) + 1 -> -a */
1586 if (INTEGRAL_MODE_P (mode)
1587 && GET_CODE (op0) == NOT
1588 && trueop1 == const1_rtx)
1589 return simplify_gen_unary (NEG, mode, XEXP (op0, 0), mode);
1591 /* Handle both-operands-constant cases. We can only add
1592 CONST_INTs to constants since the sum of relocatable symbols
1593 can't be handled by most assemblers. Don't add CONST_INT
1594 to CONST_INT since overflow won't be computed properly if wider
1595 than HOST_BITS_PER_WIDE_INT. */
1597 if (CONSTANT_P (op0) && GET_MODE (op0) != VOIDmode
1598 && GET_CODE (op1) == CONST_INT)
1599 return plus_constant (op0, INTVAL (op1));
1600 else if (CONSTANT_P (op1) && GET_MODE (op1) != VOIDmode
1601 && GET_CODE (op0) == CONST_INT)
1602 return plus_constant (op1, INTVAL (op0));
1604 /* See if this is something like X * C - X or vice versa or
1605 if the multiplication is written as a shift. If so, we can
1606 distribute and make a new multiply, shift, or maybe just
1607 have X (if C is 2 in the example above). But don't make
1608 something more expensive than we had before. */
1610 if (SCALAR_INT_MODE_P (mode))
1612 HOST_WIDE_INT coeff0h = 0, coeff1h = 0;
1613 unsigned HOST_WIDE_INT coeff0l = 1, coeff1l = 1;
1614 rtx lhs = op0, rhs = op1;
1616 if (GET_CODE (lhs) == NEG)
1620 lhs = XEXP (lhs, 0);
1622 else if (GET_CODE (lhs) == MULT
1623 && GET_CODE (XEXP (lhs, 1)) == CONST_INT)
1625 coeff0l = INTVAL (XEXP (lhs, 1));
1626 coeff0h = INTVAL (XEXP (lhs, 1)) < 0 ? -1 : 0;
1627 lhs = XEXP (lhs, 0);
1629 else if (GET_CODE (lhs) == ASHIFT
1630 && GET_CODE (XEXP (lhs, 1)) == CONST_INT
1631 && INTVAL (XEXP (lhs, 1)) >= 0
1632 && INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT)
1634 coeff0l = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1));
1636 lhs = XEXP (lhs, 0);
1639 if (GET_CODE (rhs) == NEG)
1643 rhs = XEXP (rhs, 0);
1645 else if (GET_CODE (rhs) == MULT
1646 && GET_CODE (XEXP (rhs, 1)) == CONST_INT)
1648 coeff1l = INTVAL (XEXP (rhs, 1));
1649 coeff1h = INTVAL (XEXP (rhs, 1)) < 0 ? -1 : 0;
1650 rhs = XEXP (rhs, 0);
1652 else if (GET_CODE (rhs) == ASHIFT
1653 && GET_CODE (XEXP (rhs, 1)) == CONST_INT
1654 && INTVAL (XEXP (rhs, 1)) >= 0
1655 && INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT)
1657 coeff1l = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1));
1659 rhs = XEXP (rhs, 0);
1662 if (rtx_equal_p (lhs, rhs))
1664 rtx orig = gen_rtx_PLUS (mode, op0, op1);
1666 unsigned HOST_WIDE_INT l;
1669 add_double (coeff0l, coeff0h, coeff1l, coeff1h, &l, &h);
1670 coeff = immed_double_const (l, h, mode);
1672 tem = simplify_gen_binary (MULT, mode, lhs, coeff);
1673 return rtx_cost (tem, SET) <= rtx_cost (orig, SET)
1678 /* (plus (xor X C1) C2) is (xor X (C1^C2)) if C2 is signbit. */
1679 if ((GET_CODE (op1) == CONST_INT
1680 || GET_CODE (op1) == CONST_DOUBLE)
1681 && GET_CODE (op0) == XOR
1682 && (GET_CODE (XEXP (op0, 1)) == CONST_INT
1683 || GET_CODE (XEXP (op0, 1)) == CONST_DOUBLE)
1684 && mode_signbit_p (mode, op1))
1685 return simplify_gen_binary (XOR, mode, XEXP (op0, 0),
1686 simplify_gen_binary (XOR, mode, op1,
1689 /* Canonicalize (plus (mult (neg B) C) A) to (minus A (mult B C)). */
1690 if (!HONOR_SIGN_DEPENDENT_ROUNDING (mode)
1691 && GET_CODE (op0) == MULT
1692 && GET_CODE (XEXP (op0, 0)) == NEG)
1696 in1 = XEXP (XEXP (op0, 0), 0);
1697 in2 = XEXP (op0, 1);
1698 return simplify_gen_binary (MINUS, mode, op1,
1699 simplify_gen_binary (MULT, mode,
1703 /* (plus (comparison A B) C) can become (neg (rev-comp A B)) if
1704 C is 1 and STORE_FLAG_VALUE is -1 or if C is -1 and STORE_FLAG_VALUE
1706 if (COMPARISON_P (op0)
1707 && ((STORE_FLAG_VALUE == -1 && trueop1 == const1_rtx)
1708 || (STORE_FLAG_VALUE == 1 && trueop1 == constm1_rtx))
1709 && (reversed = reversed_comparison (op0, mode)))
1711 simplify_gen_unary (NEG, mode, reversed, mode);
1713 /* If one of the operands is a PLUS or a MINUS, see if we can
1714 simplify this by the associative law.
1715 Don't use the associative law for floating point.
1716 The inaccuracy makes it nonassociative,
1717 and subtle programs can break if operations are associated. */
1719 if (INTEGRAL_MODE_P (mode)
1720 && (plus_minus_operand_p (op0)
1721 || plus_minus_operand_p (op1))
1722 && (tem = simplify_plus_minus (code, mode, op0, op1)) != 0)
1725 /* Reassociate floating point addition only when the user
1726 specifies associative math operations. */
1727 if (FLOAT_MODE_P (mode)
1728 && flag_associative_math)
1730 tem = simplify_associative_operation (code, mode, op0, op1);
1738 /* Convert (compare FOO (const_int 0)) to FOO unless we aren't
1739 using cc0, in which case we want to leave it as a COMPARE
1740 so we can distinguish it from a register-register-copy.
1742 In IEEE floating point, x-0 is not the same as x. */
1744 if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
1745 || ! FLOAT_MODE_P (mode) || flag_unsafe_math_optimizations)
1746 && trueop1 == CONST0_RTX (mode))
1750 /* Convert (compare (gt (flags) 0) (lt (flags) 0)) to (flags). */
1751 if (((GET_CODE (op0) == GT && GET_CODE (op1) == LT)
1752 || (GET_CODE (op0) == GTU && GET_CODE (op1) == LTU))
1753 && XEXP (op0, 1) == const0_rtx && XEXP (op1, 1) == const0_rtx)
1755 rtx xop00 = XEXP (op0, 0);
1756 rtx xop10 = XEXP (op1, 0);
1759 if (GET_CODE (xop00) == CC0 && GET_CODE (xop10) == CC0)
1761 if (REG_P (xop00) && REG_P (xop10)
1762 && GET_MODE (xop00) == GET_MODE (xop10)
1763 && REGNO (xop00) == REGNO (xop10)
1764 && GET_MODE_CLASS (GET_MODE (xop00)) == MODE_CC
1765 && GET_MODE_CLASS (GET_MODE (xop10)) == MODE_CC)
1772 /* We can't assume x-x is 0 even with non-IEEE floating point,
1773 but since it is zero except in very strange circumstances, we
1774 will treat it as zero with -ffinite-math-only. */
1775 if (rtx_equal_p (trueop0, trueop1)
1776 && ! side_effects_p (op0)
1777 && (!FLOAT_MODE_P (mode) || !HONOR_NANS (mode)))
1778 return CONST0_RTX (mode);
1780 /* Change subtraction from zero into negation. (0 - x) is the
1781 same as -x when x is NaN, infinite, or finite and nonzero.
1782 But if the mode has signed zeros, and does not round towards
1783 -infinity, then 0 - 0 is 0, not -0. */
1784 if (!HONOR_SIGNED_ZEROS (mode) && trueop0 == CONST0_RTX (mode))
1785 return simplify_gen_unary (NEG, mode, op1, mode);
1787 /* (-1 - a) is ~a. */
1788 if (trueop0 == constm1_rtx)
1789 return simplify_gen_unary (NOT, mode, op1, mode);
1791 /* Subtracting 0 has no effect unless the mode has signed zeros
1792 and supports rounding towards -infinity. In such a case,
1794 if (!(HONOR_SIGNED_ZEROS (mode)
1795 && HONOR_SIGN_DEPENDENT_ROUNDING (mode))
1796 && trueop1 == CONST0_RTX (mode))
1799 /* See if this is something like X * C - X or vice versa or
1800 if the multiplication is written as a shift. If so, we can
1801 distribute and make a new multiply, shift, or maybe just
1802 have X (if C is 2 in the example above). But don't make
1803 something more expensive than we had before. */
1805 if (SCALAR_INT_MODE_P (mode))
1807 HOST_WIDE_INT coeff0h = 0, negcoeff1h = -1;
1808 unsigned HOST_WIDE_INT coeff0l = 1, negcoeff1l = -1;
1809 rtx lhs = op0, rhs = op1;
1811 if (GET_CODE (lhs) == NEG)
1815 lhs = XEXP (lhs, 0);
1817 else if (GET_CODE (lhs) == MULT
1818 && GET_CODE (XEXP (lhs, 1)) == CONST_INT)
1820 coeff0l = INTVAL (XEXP (lhs, 1));
1821 coeff0h = INTVAL (XEXP (lhs, 1)) < 0 ? -1 : 0;
1822 lhs = XEXP (lhs, 0);
1824 else if (GET_CODE (lhs) == ASHIFT
1825 && GET_CODE (XEXP (lhs, 1)) == CONST_INT
1826 && INTVAL (XEXP (lhs, 1)) >= 0
1827 && INTVAL (XEXP (lhs, 1)) < HOST_BITS_PER_WIDE_INT)
1829 coeff0l = ((HOST_WIDE_INT) 1) << INTVAL (XEXP (lhs, 1));
1831 lhs = XEXP (lhs, 0);
1834 if (GET_CODE (rhs) == NEG)
1838 rhs = XEXP (rhs, 0);
1840 else if (GET_CODE (rhs) == MULT
1841 && GET_CODE (XEXP (rhs, 1)) == CONST_INT)
1843 negcoeff1l = -INTVAL (XEXP (rhs, 1));
1844 negcoeff1h = INTVAL (XEXP (rhs, 1)) <= 0 ? 0 : -1;
1845 rhs = XEXP (rhs, 0);
1847 else if (GET_CODE (rhs) == ASHIFT
1848 && GET_CODE (XEXP (rhs, 1)) == CONST_INT
1849 && INTVAL (XEXP (rhs, 1)) >= 0
1850 && INTVAL (XEXP (rhs, 1)) < HOST_BITS_PER_WIDE_INT)
1852 negcoeff1l = -(((HOST_WIDE_INT) 1) << INTVAL (XEXP (rhs, 1)));
1854 rhs = XEXP (rhs, 0);
1857 if (rtx_equal_p (lhs, rhs))
1859 rtx orig = gen_rtx_MINUS (mode, op0, op1);
1861 unsigned HOST_WIDE_INT l;
1864 add_double (coeff0l, coeff0h, negcoeff1l, negcoeff1h, &l, &h);
1865 coeff = immed_double_const (l, h, mode);
1867 tem = simplify_gen_binary (MULT, mode, lhs, coeff);
1868 return rtx_cost (tem, SET) <= rtx_cost (orig, SET)
1873 /* (a - (-b)) -> (a + b). True even for IEEE. */
1874 if (GET_CODE (op1) == NEG)
1875 return simplify_gen_binary (PLUS, mode, op0, XEXP (op1, 0));
1877 /* (-x - c) may be simplified as (-c - x). */
1878 if (GET_CODE (op0) == NEG
1879 && (GET_CODE (op1) == CONST_INT
1880 || GET_CODE (op1) == CONST_DOUBLE))
1882 tem = simplify_unary_operation (NEG, mode, op1, mode);
1884 return simplify_gen_binary (MINUS, mode, tem, XEXP (op0, 0));
1887 /* Don't let a relocatable value get a negative coeff. */
1888 if (GET_CODE (op1) == CONST_INT && GET_MODE (op0) != VOIDmode)
1889 return simplify_gen_binary (PLUS, mode,
1891 neg_const_int (mode, op1));
1893 /* (x - (x & y)) -> (x & ~y) */
1894 if (GET_CODE (op1) == AND)
1896 if (rtx_equal_p (op0, XEXP (op1, 0)))
1898 tem = simplify_gen_unary (NOT, mode, XEXP (op1, 1),
1899 GET_MODE (XEXP (op1, 1)));
1900 return simplify_gen_binary (AND, mode, op0, tem);
1902 if (rtx_equal_p (op0, XEXP (op1, 1)))
1904 tem = simplify_gen_unary (NOT, mode, XEXP (op1, 0),
1905 GET_MODE (XEXP (op1, 0)));
1906 return simplify_gen_binary (AND, mode, op0, tem);
1910 /* If STORE_FLAG_VALUE is 1, (minus 1 (comparison foo bar)) can be done
1911 by reversing the comparison code if valid. */
1912 if (STORE_FLAG_VALUE == 1
1913 && trueop0 == const1_rtx
1914 && COMPARISON_P (op1)
1915 && (reversed = reversed_comparison (op1, mode)))
1918 /* Canonicalize (minus A (mult (neg B) C)) to (plus (mult B C) A). */
1919 if (!HONOR_SIGN_DEPENDENT_ROUNDING (mode)
1920 && GET_CODE (op1) == MULT
1921 && GET_CODE (XEXP (op1, 0)) == NEG)
1925 in1 = XEXP (XEXP (op1, 0), 0);
1926 in2 = XEXP (op1, 1);
1927 return simplify_gen_binary (PLUS, mode,
1928 simplify_gen_binary (MULT, mode,
1933 /* Canonicalize (minus (neg A) (mult B C)) to
1934 (minus (mult (neg B) C) A). */
1935 if (!HONOR_SIGN_DEPENDENT_ROUNDING (mode)
1936 && GET_CODE (op1) == MULT
1937 && GET_CODE (op0) == NEG)
1941 in1 = simplify_gen_unary (NEG, mode, XEXP (op1, 0), mode);
1942 in2 = XEXP (op1, 1);
1943 return simplify_gen_binary (MINUS, mode,
1944 simplify_gen_binary (MULT, mode,
1949 /* If one of the operands is a PLUS or a MINUS, see if we can
1950 simplify this by the associative law. This will, for example,
1951 canonicalize (minus A (plus B C)) to (minus (minus A B) C).
1952 Don't use the associative law for floating point.
1953 The inaccuracy makes it nonassociative,
1954 and subtle programs can break if operations are associated. */
1956 if (INTEGRAL_MODE_P (mode)
1957 && (plus_minus_operand_p (op0)
1958 || plus_minus_operand_p (op1))
1959 && (tem = simplify_plus_minus (code, mode, op0, op1)) != 0)
1964 if (trueop1 == constm1_rtx)
1965 return simplify_gen_unary (NEG, mode, op0, mode);
1967 /* Maybe simplify x * 0 to 0. The reduction is not valid if
1968 x is NaN, since x * 0 is then also NaN. Nor is it valid
1969 when the mode has signed zeros, since multiplying a negative
1970 number by 0 will give -0, not 0. */
1971 if (!HONOR_NANS (mode)
1972 && !HONOR_SIGNED_ZEROS (mode)
1973 && trueop1 == CONST0_RTX (mode)
1974 && ! side_effects_p (op0))
1977 /* In IEEE floating point, x*1 is not equivalent to x for
1979 if (!HONOR_SNANS (mode)
1980 && trueop1 == CONST1_RTX (mode))
1983 /* Convert multiply by constant power of two into shift unless
1984 we are still generating RTL. This test is a kludge. */
1985 if (GET_CODE (trueop1) == CONST_INT
1986 && (val = exact_log2 (INTVAL (trueop1))) >= 0
1987 /* If the mode is larger than the host word size, and the
1988 uppermost bit is set, then this isn't a power of two due
1989 to implicit sign extension. */
1990 && (width <= HOST_BITS_PER_WIDE_INT
1991 || val != HOST_BITS_PER_WIDE_INT - 1))
1992 return simplify_gen_binary (ASHIFT, mode, op0, GEN_INT (val));
1994 /* Likewise for multipliers wider than a word. */
1995 if (GET_CODE (trueop1) == CONST_DOUBLE
1996 && (GET_MODE (trueop1) == VOIDmode
1997 || GET_MODE_CLASS (GET_MODE (trueop1)) == MODE_INT)
1998 && GET_MODE (op0) == mode
1999 && CONST_DOUBLE_LOW (trueop1) == 0
2000 && (val = exact_log2 (CONST_DOUBLE_HIGH (trueop1))) >= 0)
2001 return simplify_gen_binary (ASHIFT, mode, op0,
2002 GEN_INT (val + HOST_BITS_PER_WIDE_INT));
2004 /* x*2 is x+x and x*(-1) is -x */
2005 if (GET_CODE (trueop1) == CONST_DOUBLE
2006 && SCALAR_FLOAT_MODE_P (GET_MODE (trueop1))
2007 && GET_MODE (op0) == mode)
2010 REAL_VALUE_FROM_CONST_DOUBLE (d, trueop1);
2012 if (REAL_VALUES_EQUAL (d, dconst2))
2013 return simplify_gen_binary (PLUS, mode, op0, copy_rtx (op0));
2015 if (!HONOR_SNANS (mode)
2016 && REAL_VALUES_EQUAL (d, dconstm1))
2017 return simplify_gen_unary (NEG, mode, op0, mode);
2020 /* Optimize -x * -x as x * x. */
2021 if (FLOAT_MODE_P (mode)
2022 && GET_CODE (op0) == NEG
2023 && GET_CODE (op1) == NEG
2024 && rtx_equal_p (XEXP (op0, 0), XEXP (op1, 0))
2025 && !side_effects_p (XEXP (op0, 0)))
2026 return simplify_gen_binary (MULT, mode, XEXP (op0, 0), XEXP (op1, 0));
2028 /* Likewise, optimize abs(x) * abs(x) as x * x. */
2029 if (SCALAR_FLOAT_MODE_P (mode)
2030 && GET_CODE (op0) == ABS
2031 && GET_CODE (op1) == ABS
2032 && rtx_equal_p (XEXP (op0, 0), XEXP (op1, 0))
2033 && !side_effects_p (XEXP (op0, 0)))
2034 return simplify_gen_binary (MULT, mode, XEXP (op0, 0), XEXP (op1, 0));
2036 /* Reassociate multiplication, but for floating point MULTs
2037 only when the user specifies unsafe math optimizations. */
2038 if (! FLOAT_MODE_P (mode)
2039 || flag_unsafe_math_optimizations)
2041 tem = simplify_associative_operation (code, mode, op0, op1);
2048 if (trueop1 == const0_rtx)
2050 if (GET_CODE (trueop1) == CONST_INT
2051 && ((INTVAL (trueop1) & GET_MODE_MASK (mode))
2052 == GET_MODE_MASK (mode)))
2054 if (rtx_equal_p (trueop0, trueop1) && ! side_effects_p (op0))
2056 /* A | (~A) -> -1 */
2057 if (((GET_CODE (op0) == NOT && rtx_equal_p (XEXP (op0, 0), op1))
2058 || (GET_CODE (op1) == NOT && rtx_equal_p (XEXP (op1, 0), op0)))
2059 && ! side_effects_p (op0)
2060 && SCALAR_INT_MODE_P (mode))
2063 /* (ior A C) is C if all bits of A that might be nonzero are on in C. */
2064 if (GET_CODE (op1) == CONST_INT
2065 && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
2066 && (nonzero_bits (op0, mode) & ~INTVAL (op1)) == 0)
2069 /* Canonicalize (X & C1) | C2. */
2070 if (GET_CODE (op0) == AND
2071 && GET_CODE (trueop1) == CONST_INT
2072 && GET_CODE (XEXP (op0, 1)) == CONST_INT)
2074 HOST_WIDE_INT mask = GET_MODE_MASK (mode);
2075 HOST_WIDE_INT c1 = INTVAL (XEXP (op0, 1));
2076 HOST_WIDE_INT c2 = INTVAL (trueop1);
2078 /* If (C1&C2) == C1, then (X&C1)|C2 becomes X. */
2080 && !side_effects_p (XEXP (op0, 0)))
2083 /* If (C1|C2) == ~0 then (X&C1)|C2 becomes X|C2. */
2084 if (((c1|c2) & mask) == mask)
2085 return simplify_gen_binary (IOR, mode, XEXP (op0, 0), op1);
2087 /* Minimize the number of bits set in C1, i.e. C1 := C1 & ~C2. */
2088 if (((c1 & ~c2) & mask) != (c1 & mask))
2090 tem = simplify_gen_binary (AND, mode, XEXP (op0, 0),
2091 gen_int_mode (c1 & ~c2, mode));
2092 return simplify_gen_binary (IOR, mode, tem, op1);
2096 /* Convert (A & B) | A to A. */
2097 if (GET_CODE (op0) == AND
2098 && (rtx_equal_p (XEXP (op0, 0), op1)
2099 || rtx_equal_p (XEXP (op0, 1), op1))
2100 && ! side_effects_p (XEXP (op0, 0))
2101 && ! side_effects_p (XEXP (op0, 1)))
2104 /* Convert (ior (ashift A CX) (lshiftrt A CY)) where CX+CY equals the
2105 mode size to (rotate A CX). */
2107 if (GET_CODE (op1) == ASHIFT
2108 || GET_CODE (op1) == SUBREG)
2119 if (GET_CODE (opleft) == ASHIFT && GET_CODE (opright) == LSHIFTRT
2120 && rtx_equal_p (XEXP (opleft, 0), XEXP (opright, 0))
2121 && GET_CODE (XEXP (opleft, 1)) == CONST_INT
2122 && GET_CODE (XEXP (opright, 1)) == CONST_INT
2123 && (INTVAL (XEXP (opleft, 1)) + INTVAL (XEXP (opright, 1))
2124 == GET_MODE_BITSIZE (mode)))
2125 return gen_rtx_ROTATE (mode, XEXP (opright, 0), XEXP (opleft, 1));
2127 /* Same, but for ashift that has been "simplified" to a wider mode
2128 by simplify_shift_const. */
2130 if (GET_CODE (opleft) == SUBREG
2131 && GET_CODE (SUBREG_REG (opleft)) == ASHIFT
2132 && GET_CODE (opright) == LSHIFTRT
2133 && GET_CODE (XEXP (opright, 0)) == SUBREG
2134 && GET_MODE (opleft) == GET_MODE (XEXP (opright, 0))
2135 && SUBREG_BYTE (opleft) == SUBREG_BYTE (XEXP (opright, 0))
2136 && (GET_MODE_SIZE (GET_MODE (opleft))
2137 < GET_MODE_SIZE (GET_MODE (SUBREG_REG (opleft))))
2138 && rtx_equal_p (XEXP (SUBREG_REG (opleft), 0),
2139 SUBREG_REG (XEXP (opright, 0)))
2140 && GET_CODE (XEXP (SUBREG_REG (opleft), 1)) == CONST_INT
2141 && GET_CODE (XEXP (opright, 1)) == CONST_INT
2142 && (INTVAL (XEXP (SUBREG_REG (opleft), 1)) + INTVAL (XEXP (opright, 1))
2143 == GET_MODE_BITSIZE (mode)))
2144 return gen_rtx_ROTATE (mode, XEXP (opright, 0),
2145 XEXP (SUBREG_REG (opleft), 1));
2147 /* If we have (ior (and (X C1) C2)), simplify this by making
2148 C1 as small as possible if C1 actually changes. */
2149 if (GET_CODE (op1) == CONST_INT
2150 && (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
2151 || INTVAL (op1) > 0)
2152 && GET_CODE (op0) == AND
2153 && GET_CODE (XEXP (op0, 1)) == CONST_INT
2154 && GET_CODE (op1) == CONST_INT
2155 && (INTVAL (XEXP (op0, 1)) & INTVAL (op1)) != 0)
2156 return simplify_gen_binary (IOR, mode,
2158 (AND, mode, XEXP (op0, 0),
2159 GEN_INT (INTVAL (XEXP (op0, 1))
2163 /* If OP0 is (ashiftrt (plus ...) C), it might actually be
2164 a (sign_extend (plus ...)). Then check if OP1 is a CONST_INT and
2165 the PLUS does not affect any of the bits in OP1: then we can do
2166 the IOR as a PLUS and we can associate. This is valid if OP1
2167 can be safely shifted left C bits. */
2168 if (GET_CODE (trueop1) == CONST_INT && GET_CODE (op0) == ASHIFTRT
2169 && GET_CODE (XEXP (op0, 0)) == PLUS
2170 && GET_CODE (XEXP (XEXP (op0, 0), 1)) == CONST_INT
2171 && GET_CODE (XEXP (op0, 1)) == CONST_INT
2172 && INTVAL (XEXP (op0, 1)) < HOST_BITS_PER_WIDE_INT)
2174 int count = INTVAL (XEXP (op0, 1));
2175 HOST_WIDE_INT mask = INTVAL (trueop1) << count;
2177 if (mask >> count == INTVAL (trueop1)
2178 && (mask & nonzero_bits (XEXP (op0, 0), mode)) == 0)
2179 return simplify_gen_binary (ASHIFTRT, mode,
2180 plus_constant (XEXP (op0, 0), mask),
2184 tem = simplify_associative_operation (code, mode, op0, op1);
2190 if (trueop1 == const0_rtx)
2192 if (GET_CODE (trueop1) == CONST_INT
2193 && ((INTVAL (trueop1) & GET_MODE_MASK (mode))
2194 == GET_MODE_MASK (mode)))
2195 return simplify_gen_unary (NOT, mode, op0, mode);
2196 if (rtx_equal_p (trueop0, trueop1)
2197 && ! side_effects_p (op0)
2198 && GET_MODE_CLASS (mode) != MODE_CC)
2199 return CONST0_RTX (mode);
2201 /* Canonicalize XOR of the most significant bit to PLUS. */
2202 if ((GET_CODE (op1) == CONST_INT
2203 || GET_CODE (op1) == CONST_DOUBLE)
2204 && mode_signbit_p (mode, op1))
2205 return simplify_gen_binary (PLUS, mode, op0, op1);
2206 /* (xor (plus X C1) C2) is (xor X (C1^C2)) if C1 is signbit. */
2207 if ((GET_CODE (op1) == CONST_INT
2208 || GET_CODE (op1) == CONST_DOUBLE)
2209 && GET_CODE (op0) == PLUS
2210 && (GET_CODE (XEXP (op0, 1)) == CONST_INT
2211 || GET_CODE (XEXP (op0, 1)) == CONST_DOUBLE)
2212 && mode_signbit_p (mode, XEXP (op0, 1)))
2213 return simplify_gen_binary (XOR, mode, XEXP (op0, 0),
2214 simplify_gen_binary (XOR, mode, op1,
2217 /* If we are XORing two things that have no bits in common,
2218 convert them into an IOR. This helps to detect rotation encoded
2219 using those methods and possibly other simplifications. */
2221 if (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
2222 && (nonzero_bits (op0, mode)
2223 & nonzero_bits (op1, mode)) == 0)
2224 return (simplify_gen_binary (IOR, mode, op0, op1));
2226 /* Convert (XOR (NOT x) (NOT y)) to (XOR x y).
2227 Also convert (XOR (NOT x) y) to (NOT (XOR x y)), similarly for
2230 int num_negated = 0;
2232 if (GET_CODE (op0) == NOT)
2233 num_negated++, op0 = XEXP (op0, 0);
2234 if (GET_CODE (op1) == NOT)
2235 num_negated++, op1 = XEXP (op1, 0);
2237 if (num_negated == 2)
2238 return simplify_gen_binary (XOR, mode, op0, op1);
2239 else if (num_negated == 1)
2240 return simplify_gen_unary (NOT, mode,
2241 simplify_gen_binary (XOR, mode, op0, op1),
2245 /* Convert (xor (and A B) B) to (and (not A) B). The latter may
2246 correspond to a machine insn or result in further simplifications
2247 if B is a constant. */
2249 if (GET_CODE (op0) == AND
2250 && rtx_equal_p (XEXP (op0, 1), op1)
2251 && ! side_effects_p (op1))
2252 return simplify_gen_binary (AND, mode,
2253 simplify_gen_unary (NOT, mode,
2254 XEXP (op0, 0), mode),
2257 else if (GET_CODE (op0) == AND
2258 && rtx_equal_p (XEXP (op0, 0), op1)
2259 && ! side_effects_p (op1))
2260 return simplify_gen_binary (AND, mode,
2261 simplify_gen_unary (NOT, mode,
2262 XEXP (op0, 1), mode),
2265 /* (xor (comparison foo bar) (const_int 1)) can become the reversed
2266 comparison if STORE_FLAG_VALUE is 1. */
2267 if (STORE_FLAG_VALUE == 1
2268 && trueop1 == const1_rtx
2269 && COMPARISON_P (op0)
2270 && (reversed = reversed_comparison (op0, mode)))
2273 /* (lshiftrt foo C) where C is the number of bits in FOO minus 1
2274 is (lt foo (const_int 0)), so we can perform the above
2275 simplification if STORE_FLAG_VALUE is 1. */
2277 if (STORE_FLAG_VALUE == 1
2278 && trueop1 == const1_rtx
2279 && GET_CODE (op0) == LSHIFTRT
2280 && GET_CODE (XEXP (op0, 1)) == CONST_INT
2281 && INTVAL (XEXP (op0, 1)) == GET_MODE_BITSIZE (mode) - 1)
2282 return gen_rtx_GE (mode, XEXP (op0, 0), const0_rtx);
2284 /* (xor (comparison foo bar) (const_int sign-bit))
2285 when STORE_FLAG_VALUE is the sign bit. */
2286 if (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
2287 && ((STORE_FLAG_VALUE & GET_MODE_MASK (mode))
2288 == (unsigned HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (mode) - 1))
2289 && trueop1 == const_true_rtx
2290 && COMPARISON_P (op0)
2291 && (reversed = reversed_comparison (op0, mode)))
2294 tem = simplify_associative_operation (code, mode, op0, op1);
2300 if (trueop1 == CONST0_RTX (mode) && ! side_effects_p (op0))
2302 /* If we are turning off bits already known off in OP0, we need
2304 if (GET_CODE (trueop1) == CONST_INT
2305 && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
2306 && (nonzero_bits (trueop0, mode) & ~INTVAL (trueop1)) == 0)
2308 if (rtx_equal_p (trueop0, trueop1) && ! side_effects_p (op0)
2309 && GET_MODE_CLASS (mode) != MODE_CC)
2312 if (((GET_CODE (op0) == NOT && rtx_equal_p (XEXP (op0, 0), op1))
2313 || (GET_CODE (op1) == NOT && rtx_equal_p (XEXP (op1, 0), op0)))
2314 && ! side_effects_p (op0)
2315 && GET_MODE_CLASS (mode) != MODE_CC)
2316 return CONST0_RTX (mode);
2318 /* Transform (and (extend X) C) into (zero_extend (and X C)) if
2319 there are no nonzero bits of C outside of X's mode. */
2320 if ((GET_CODE (op0) == SIGN_EXTEND
2321 || GET_CODE (op0) == ZERO_EXTEND)
2322 && GET_CODE (trueop1) == CONST_INT
2323 && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
2324 && (~GET_MODE_MASK (GET_MODE (XEXP (op0, 0)))
2325 & INTVAL (trueop1)) == 0)
2327 enum machine_mode imode = GET_MODE (XEXP (op0, 0));
2328 tem = simplify_gen_binary (AND, imode, XEXP (op0, 0),
2329 gen_int_mode (INTVAL (trueop1),
2331 return simplify_gen_unary (ZERO_EXTEND, mode, tem, imode);
2334 /* Canonicalize (A | C1) & C2 as (A & C2) | (C1 & C2). */
2335 if (GET_CODE (op0) == IOR
2336 && GET_CODE (trueop1) == CONST_INT
2337 && GET_CODE (XEXP (op0, 1)) == CONST_INT)
2339 HOST_WIDE_INT tmp = INTVAL (trueop1) & INTVAL (XEXP (op0, 1));
2340 return simplify_gen_binary (IOR, mode,
2341 simplify_gen_binary (AND, mode,
2342 XEXP (op0, 0), op1),
2343 gen_int_mode (tmp, mode));
2346 /* Convert (A ^ B) & A to A & (~B) since the latter is often a single
2347 insn (and may simplify more). */
2348 if (GET_CODE (op0) == XOR
2349 && rtx_equal_p (XEXP (op0, 0), op1)
2350 && ! side_effects_p (op1))
2351 return simplify_gen_binary (AND, mode,
2352 simplify_gen_unary (NOT, mode,
2353 XEXP (op0, 1), mode),
2356 if (GET_CODE (op0) == XOR
2357 && rtx_equal_p (XEXP (op0, 1), op1)
2358 && ! side_effects_p (op1))
2359 return simplify_gen_binary (AND, mode,
2360 simplify_gen_unary (NOT, mode,
2361 XEXP (op0, 0), mode),
2364 /* Similarly for (~(A ^ B)) & A. */
2365 if (GET_CODE (op0) == NOT
2366 && GET_CODE (XEXP (op0, 0)) == XOR
2367 && rtx_equal_p (XEXP (XEXP (op0, 0), 0), op1)
2368 && ! side_effects_p (op1))
2369 return simplify_gen_binary (AND, mode, XEXP (XEXP (op0, 0), 1), op1);
2371 if (GET_CODE (op0) == NOT
2372 && GET_CODE (XEXP (op0, 0)) == XOR
2373 && rtx_equal_p (XEXP (XEXP (op0, 0), 1), op1)
2374 && ! side_effects_p (op1))
2375 return simplify_gen_binary (AND, mode, XEXP (XEXP (op0, 0), 0), op1);
2377 /* Convert (A | B) & A to A. */
2378 if (GET_CODE (op0) == IOR
2379 && (rtx_equal_p (XEXP (op0, 0), op1)
2380 || rtx_equal_p (XEXP (op0, 1), op1))
2381 && ! side_effects_p (XEXP (op0, 0))
2382 && ! side_effects_p (XEXP (op0, 1)))
2385 /* For constants M and N, if M == (1LL << cst) - 1 && (N & M) == M,
2386 ((A & N) + B) & M -> (A + B) & M
2387 Similarly if (N & M) == 0,
2388 ((A | N) + B) & M -> (A + B) & M
2389 and for - instead of + and/or ^ instead of |. */
2390 if (GET_CODE (trueop1) == CONST_INT
2391 && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
2392 && ~INTVAL (trueop1)
2393 && (INTVAL (trueop1) & (INTVAL (trueop1) + 1)) == 0
2394 && (GET_CODE (op0) == PLUS || GET_CODE (op0) == MINUS))
2399 pmop[0] = XEXP (op0, 0);
2400 pmop[1] = XEXP (op0, 1);
2402 for (which = 0; which < 2; which++)
2405 switch (GET_CODE (tem))
2408 if (GET_CODE (XEXP (tem, 1)) == CONST_INT
2409 && (INTVAL (XEXP (tem, 1)) & INTVAL (trueop1))
2410 == INTVAL (trueop1))
2411 pmop[which] = XEXP (tem, 0);
2415 if (GET_CODE (XEXP (tem, 1)) == CONST_INT
2416 && (INTVAL (XEXP (tem, 1)) & INTVAL (trueop1)) == 0)
2417 pmop[which] = XEXP (tem, 0);
2424 if (pmop[0] != XEXP (op0, 0) || pmop[1] != XEXP (op0, 1))
2426 tem = simplify_gen_binary (GET_CODE (op0), mode,
2428 return simplify_gen_binary (code, mode, tem, op1);
2431 tem = simplify_associative_operation (code, mode, op0, op1);
2437 /* 0/x is 0 (or x&0 if x has side-effects). */
2438 if (trueop0 == CONST0_RTX (mode))
2440 if (side_effects_p (op1))
2441 return simplify_gen_binary (AND, mode, op1, trueop0);
2445 if (trueop1 == CONST1_RTX (mode))
2446 return rtl_hooks.gen_lowpart_no_emit (mode, op0);
2447 /* Convert divide by power of two into shift. */
2448 if (GET_CODE (trueop1) == CONST_INT
2449 && (val = exact_log2 (INTVAL (trueop1))) > 0)
2450 return simplify_gen_binary (LSHIFTRT, mode, op0, GEN_INT (val));
2454 /* Handle floating point and integers separately. */
2455 if (SCALAR_FLOAT_MODE_P (mode))
2457 /* Maybe change 0.0 / x to 0.0. This transformation isn't
2458 safe for modes with NaNs, since 0.0 / 0.0 will then be
2459 NaN rather than 0.0. Nor is it safe for modes with signed
2460 zeros, since dividing 0 by a negative number gives -0.0 */
2461 if (trueop0 == CONST0_RTX (mode)
2462 && !HONOR_NANS (mode)
2463 && !HONOR_SIGNED_ZEROS (mode)
2464 && ! side_effects_p (op1))
2467 if (trueop1 == CONST1_RTX (mode)
2468 && !HONOR_SNANS (mode))
2471 if (GET_CODE (trueop1) == CONST_DOUBLE
2472 && trueop1 != CONST0_RTX (mode))
2475 REAL_VALUE_FROM_CONST_DOUBLE (d, trueop1);
2478 if (REAL_VALUES_EQUAL (d, dconstm1)
2479 && !HONOR_SNANS (mode))
2480 return simplify_gen_unary (NEG, mode, op0, mode);
2482 /* Change FP division by a constant into multiplication.
2483 Only do this with -freciprocal-math. */
2484 if (flag_reciprocal_math
2485 && !REAL_VALUES_EQUAL (d, dconst0))
2487 REAL_ARITHMETIC (d, RDIV_EXPR, dconst1, d);
2488 tem = CONST_DOUBLE_FROM_REAL_VALUE (d, mode);
2489 return simplify_gen_binary (MULT, mode, op0, tem);
2495 /* 0/x is 0 (or x&0 if x has side-effects). */
2496 if (trueop0 == CONST0_RTX (mode))
2498 if (side_effects_p (op1))
2499 return simplify_gen_binary (AND, mode, op1, trueop0);
2503 if (trueop1 == CONST1_RTX (mode))
2504 return rtl_hooks.gen_lowpart_no_emit (mode, op0);
2506 if (trueop1 == constm1_rtx)
2508 rtx x = rtl_hooks.gen_lowpart_no_emit (mode, op0);
2509 return simplify_gen_unary (NEG, mode, x, mode);
2515 /* 0%x is 0 (or x&0 if x has side-effects). */
2516 if (trueop0 == CONST0_RTX (mode))
2518 if (side_effects_p (op1))
2519 return simplify_gen_binary (AND, mode, op1, trueop0);
2522 /* x%1 is 0 (of x&0 if x has side-effects). */
2523 if (trueop1 == CONST1_RTX (mode))
2525 if (side_effects_p (op0))
2526 return simplify_gen_binary (AND, mode, op0, CONST0_RTX (mode));
2527 return CONST0_RTX (mode);
2529 /* Implement modulus by power of two as AND. */
2530 if (GET_CODE (trueop1) == CONST_INT
2531 && exact_log2 (INTVAL (trueop1)) > 0)
2532 return simplify_gen_binary (AND, mode, op0,
2533 GEN_INT (INTVAL (op1) - 1));
2537 /* 0%x is 0 (or x&0 if x has side-effects). */
2538 if (trueop0 == CONST0_RTX (mode))
2540 if (side_effects_p (op1))
2541 return simplify_gen_binary (AND, mode, op1, trueop0);
2544 /* x%1 and x%-1 is 0 (or x&0 if x has side-effects). */
2545 if (trueop1 == CONST1_RTX (mode) || trueop1 == constm1_rtx)
2547 if (side_effects_p (op0))
2548 return simplify_gen_binary (AND, mode, op0, CONST0_RTX (mode));
2549 return CONST0_RTX (mode);
2556 if (trueop1 == CONST0_RTX (mode))
2558 if (trueop0 == CONST0_RTX (mode) && ! side_effects_p (op1))
2560 /* Rotating ~0 always results in ~0. */
2561 if (GET_CODE (trueop0) == CONST_INT && width <= HOST_BITS_PER_WIDE_INT
2562 && (unsigned HOST_WIDE_INT) INTVAL (trueop0) == GET_MODE_MASK (mode)
2563 && ! side_effects_p (op1))
2570 if (trueop1 == CONST0_RTX (mode))
2572 if (trueop0 == CONST0_RTX (mode) && ! side_effects_p (op1))
2577 if (trueop1 == CONST0_RTX (mode))
2579 if (trueop0 == CONST0_RTX (mode) && ! side_effects_p (op1))
2581 /* Optimize (lshiftrt (clz X) C) as (eq X 0). */
2582 if (GET_CODE (op0) == CLZ
2583 && GET_CODE (trueop1) == CONST_INT
2584 && STORE_FLAG_VALUE == 1
2585 && INTVAL (trueop1) < (HOST_WIDE_INT)width)
2587 enum machine_mode imode = GET_MODE (XEXP (op0, 0));
2588 unsigned HOST_WIDE_INT zero_val = 0;
2590 if (CLZ_DEFINED_VALUE_AT_ZERO (imode, zero_val)
2591 && zero_val == GET_MODE_BITSIZE (imode)
2592 && INTVAL (trueop1) == exact_log2 (zero_val))
2593 return simplify_gen_relational (EQ, mode, imode,
2594 XEXP (op0, 0), const0_rtx);
2599 if (width <= HOST_BITS_PER_WIDE_INT
2600 && GET_CODE (trueop1) == CONST_INT
2601 && INTVAL (trueop1) == (HOST_WIDE_INT) 1 << (width -1)
2602 && ! side_effects_p (op0))
2604 if (rtx_equal_p (trueop0, trueop1) && ! side_effects_p (op0))
2606 tem = simplify_associative_operation (code, mode, op0, op1);
2612 if (width <= HOST_BITS_PER_WIDE_INT
2613 && GET_CODE (trueop1) == CONST_INT
2614 && ((unsigned HOST_WIDE_INT) INTVAL (trueop1)
2615 == (unsigned HOST_WIDE_INT) GET_MODE_MASK (mode) >> 1)
2616 && ! side_effects_p (op0))
2618 if (rtx_equal_p (trueop0, trueop1) && ! side_effects_p (op0))
2620 tem = simplify_associative_operation (code, mode, op0, op1);
2626 if (trueop1 == CONST0_RTX (mode) && ! side_effects_p (op0))
2628 if (rtx_equal_p (trueop0, trueop1) && ! side_effects_p (op0))
2630 tem = simplify_associative_operation (code, mode, op0, op1);
2636 if (trueop1 == constm1_rtx && ! side_effects_p (op0))
2638 if (rtx_equal_p (trueop0, trueop1) && ! side_effects_p (op0))
2640 tem = simplify_associative_operation (code, mode, op0, op1);
2653 /* ??? There are simplifications that can be done. */
2657 if (!VECTOR_MODE_P (mode))
2659 gcc_assert (VECTOR_MODE_P (GET_MODE (trueop0)));
2660 gcc_assert (mode == GET_MODE_INNER (GET_MODE (trueop0)));
2661 gcc_assert (GET_CODE (trueop1) == PARALLEL);
2662 gcc_assert (XVECLEN (trueop1, 0) == 1);
2663 gcc_assert (GET_CODE (XVECEXP (trueop1, 0, 0)) == CONST_INT);
2665 if (GET_CODE (trueop0) == CONST_VECTOR)
2666 return CONST_VECTOR_ELT (trueop0, INTVAL (XVECEXP
2669 /* Extract a scalar element from a nested VEC_SELECT expression
2670 (with optional nested VEC_CONCAT expression). Some targets
2671 (i386) extract scalar element from a vector using chain of
2672 nested VEC_SELECT expressions. When input operand is a memory
2673 operand, this operation can be simplified to a simple scalar
2674 load from an offseted memory address. */
2675 if (GET_CODE (trueop0) == VEC_SELECT)
2677 rtx op0 = XEXP (trueop0, 0);
2678 rtx op1 = XEXP (trueop0, 1);
2680 enum machine_mode opmode = GET_MODE (op0);
2681 int elt_size = GET_MODE_SIZE (GET_MODE_INNER (opmode));
2682 int n_elts = GET_MODE_SIZE (opmode) / elt_size;
2684 int i = INTVAL (XVECEXP (trueop1, 0, 0));
2690 gcc_assert (GET_CODE (op1) == PARALLEL);
2691 gcc_assert (i < n_elts);
2693 /* Select element, pointed by nested selector. */
2694 elem = INTVAL (XVECEXP (op1, 0, i));
2696 /* Handle the case when nested VEC_SELECT wraps VEC_CONCAT. */
2697 if (GET_CODE (op0) == VEC_CONCAT)
2699 rtx op00 = XEXP (op0, 0);
2700 rtx op01 = XEXP (op0, 1);
2702 enum machine_mode mode00, mode01;
2703 int n_elts00, n_elts01;
2705 mode00 = GET_MODE (op00);
2706 mode01 = GET_MODE (op01);
2708 /* Find out number of elements of each operand. */
2709 if (VECTOR_MODE_P (mode00))
2711 elt_size = GET_MODE_SIZE (GET_MODE_INNER (mode00));
2712 n_elts00 = GET_MODE_SIZE (mode00) / elt_size;
2717 if (VECTOR_MODE_P (mode01))
2719 elt_size = GET_MODE_SIZE (GET_MODE_INNER (mode01));
2720 n_elts01 = GET_MODE_SIZE (mode01) / elt_size;
2725 gcc_assert (n_elts == n_elts00 + n_elts01);
2727 /* Select correct operand of VEC_CONCAT
2728 and adjust selector. */
2729 if (elem < n_elts01)
2740 vec = rtvec_alloc (1);
2741 RTVEC_ELT (vec, 0) = GEN_INT (elem);
2743 tmp = gen_rtx_fmt_ee (code, mode,
2744 tmp_op, gen_rtx_PARALLEL (VOIDmode, vec));
2750 gcc_assert (VECTOR_MODE_P (GET_MODE (trueop0)));
2751 gcc_assert (GET_MODE_INNER (mode)
2752 == GET_MODE_INNER (GET_MODE (trueop0)));
2753 gcc_assert (GET_CODE (trueop1) == PARALLEL);
2755 if (GET_CODE (trueop0) == CONST_VECTOR)
2757 int elt_size = GET_MODE_SIZE (GET_MODE_INNER (mode));
2758 unsigned n_elts = (GET_MODE_SIZE (mode) / elt_size);
2759 rtvec v = rtvec_alloc (n_elts);
2762 gcc_assert (XVECLEN (trueop1, 0) == (int) n_elts);
2763 for (i = 0; i < n_elts; i++)
2765 rtx x = XVECEXP (trueop1, 0, i);
2767 gcc_assert (GET_CODE (x) == CONST_INT);
2768 RTVEC_ELT (v, i) = CONST_VECTOR_ELT (trueop0,
2772 return gen_rtx_CONST_VECTOR (mode, v);
2776 if (XVECLEN (trueop1, 0) == 1
2777 && GET_CODE (XVECEXP (trueop1, 0, 0)) == CONST_INT
2778 && GET_CODE (trueop0) == VEC_CONCAT)
2781 int offset = INTVAL (XVECEXP (trueop1, 0, 0)) * GET_MODE_SIZE (mode);
2783 /* Try to find the element in the VEC_CONCAT. */
2784 while (GET_MODE (vec) != mode
2785 && GET_CODE (vec) == VEC_CONCAT)
2787 HOST_WIDE_INT vec_size = GET_MODE_SIZE (GET_MODE (XEXP (vec, 0)));
2788 if (offset < vec_size)
2789 vec = XEXP (vec, 0);
2793 vec = XEXP (vec, 1);
2795 vec = avoid_constant_pool_reference (vec);
2798 if (GET_MODE (vec) == mode)
2805 enum machine_mode op0_mode = (GET_MODE (trueop0) != VOIDmode
2806 ? GET_MODE (trueop0)
2807 : GET_MODE_INNER (mode));
2808 enum machine_mode op1_mode = (GET_MODE (trueop1) != VOIDmode
2809 ? GET_MODE (trueop1)
2810 : GET_MODE_INNER (mode));
2812 gcc_assert (VECTOR_MODE_P (mode));
2813 gcc_assert (GET_MODE_SIZE (op0_mode) + GET_MODE_SIZE (op1_mode)
2814 == GET_MODE_SIZE (mode));
2816 if (VECTOR_MODE_P (op0_mode))
2817 gcc_assert (GET_MODE_INNER (mode)
2818 == GET_MODE_INNER (op0_mode));
2820 gcc_assert (GET_MODE_INNER (mode) == op0_mode);
2822 if (VECTOR_MODE_P (op1_mode))
2823 gcc_assert (GET_MODE_INNER (mode)
2824 == GET_MODE_INNER (op1_mode));
2826 gcc_assert (GET_MODE_INNER (mode) == op1_mode);
2828 if ((GET_CODE (trueop0) == CONST_VECTOR
2829 || GET_CODE (trueop0) == CONST_INT
2830 || GET_CODE (trueop0) == CONST_DOUBLE)
2831 && (GET_CODE (trueop1) == CONST_VECTOR
2832 || GET_CODE (trueop1) == CONST_INT
2833 || GET_CODE (trueop1) == CONST_DOUBLE))
2835 int elt_size = GET_MODE_SIZE (GET_MODE_INNER (mode));
2836 unsigned n_elts = (GET_MODE_SIZE (mode) / elt_size);
2837 rtvec v = rtvec_alloc (n_elts);
2839 unsigned in_n_elts = 1;
2841 if (VECTOR_MODE_P (op0_mode))
2842 in_n_elts = (GET_MODE_SIZE (op0_mode) / elt_size);
2843 for (i = 0; i < n_elts; i++)
2847 if (!VECTOR_MODE_P (op0_mode))
2848 RTVEC_ELT (v, i) = trueop0;
2850 RTVEC_ELT (v, i) = CONST_VECTOR_ELT (trueop0, i);
2854 if (!VECTOR_MODE_P (op1_mode))
2855 RTVEC_ELT (v, i) = trueop1;
2857 RTVEC_ELT (v, i) = CONST_VECTOR_ELT (trueop1,
2862 return gen_rtx_CONST_VECTOR (mode, v);
2875 simplify_const_binary_operation (enum rtx_code code, enum machine_mode mode,
2878 HOST_WIDE_INT arg0, arg1, arg0s, arg1s;
2880 unsigned int width = GET_MODE_BITSIZE (mode);
2882 if (VECTOR_MODE_P (mode)
2883 && code != VEC_CONCAT
2884 && GET_CODE (op0) == CONST_VECTOR
2885 && GET_CODE (op1) == CONST_VECTOR)
2887 unsigned n_elts = GET_MODE_NUNITS (mode);
2888 enum machine_mode op0mode = GET_MODE (op0);
2889 unsigned op0_n_elts = GET_MODE_NUNITS (op0mode);
2890 enum machine_mode op1mode = GET_MODE (op1);
2891 unsigned op1_n_elts = GET_MODE_NUNITS (op1mode);
2892 rtvec v = rtvec_alloc (n_elts);
2895 gcc_assert (op0_n_elts == n_elts);
2896 gcc_assert (op1_n_elts == n_elts);
2897 for (i = 0; i < n_elts; i++)
2899 rtx x = simplify_binary_operation (code, GET_MODE_INNER (mode),
2900 CONST_VECTOR_ELT (op0, i),
2901 CONST_VECTOR_ELT (op1, i));
2904 RTVEC_ELT (v, i) = x;
2907 return gen_rtx_CONST_VECTOR (mode, v);
2910 if (VECTOR_MODE_P (mode)
2911 && code == VEC_CONCAT
2912 && CONSTANT_P (op0) && CONSTANT_P (op1))
2914 unsigned n_elts = GET_MODE_NUNITS (mode);
2915 rtvec v = rtvec_alloc (n_elts);
2917 gcc_assert (n_elts >= 2);
2920 gcc_assert (GET_CODE (op0) != CONST_VECTOR);
2921 gcc_assert (GET_CODE (op1) != CONST_VECTOR);
2923 RTVEC_ELT (v, 0) = op0;
2924 RTVEC_ELT (v, 1) = op1;
2928 unsigned op0_n_elts = GET_MODE_NUNITS (GET_MODE (op0));
2929 unsigned op1_n_elts = GET_MODE_NUNITS (GET_MODE (op1));
2932 gcc_assert (GET_CODE (op0) == CONST_VECTOR);
2933 gcc_assert (GET_CODE (op1) == CONST_VECTOR);
2934 gcc_assert (op0_n_elts + op1_n_elts == n_elts);
2936 for (i = 0; i < op0_n_elts; ++i)
2937 RTVEC_ELT (v, i) = XVECEXP (op0, 0, i);
2938 for (i = 0; i < op1_n_elts; ++i)
2939 RTVEC_ELT (v, op0_n_elts+i) = XVECEXP (op1, 0, i);
2942 return gen_rtx_CONST_VECTOR (mode, v);
2945 if (SCALAR_FLOAT_MODE_P (mode)
2946 && GET_CODE (op0) == CONST_DOUBLE
2947 && GET_CODE (op1) == CONST_DOUBLE
2948 && mode == GET_MODE (op0) && mode == GET_MODE (op1))
2959 real_to_target (tmp0, CONST_DOUBLE_REAL_VALUE (op0),
2961 real_to_target (tmp1, CONST_DOUBLE_REAL_VALUE (op1),
2963 for (i = 0; i < 4; i++)
2980 real_from_target (&r, tmp0, mode);
2981 return CONST_DOUBLE_FROM_REAL_VALUE (r, mode);
2985 REAL_VALUE_TYPE f0, f1, value, result;
2988 REAL_VALUE_FROM_CONST_DOUBLE (f0, op0);
2989 REAL_VALUE_FROM_CONST_DOUBLE (f1, op1);
2990 real_convert (&f0, mode, &f0);
2991 real_convert (&f1, mode, &f1);
2993 if (HONOR_SNANS (mode)
2994 && (REAL_VALUE_ISNAN (f0) || REAL_VALUE_ISNAN (f1)))
2998 && REAL_VALUES_EQUAL (f1, dconst0)
2999 && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode)))
3002 if (MODE_HAS_INFINITIES (mode) && HONOR_NANS (mode)
3003 && flag_trapping_math
3004 && REAL_VALUE_ISINF (f0) && REAL_VALUE_ISINF (f1))
3006 int s0 = REAL_VALUE_NEGATIVE (f0);
3007 int s1 = REAL_VALUE_NEGATIVE (f1);
3012 /* Inf + -Inf = NaN plus exception. */
3017 /* Inf - Inf = NaN plus exception. */
3022 /* Inf / Inf = NaN plus exception. */
3029 if (code == MULT && MODE_HAS_INFINITIES (mode) && HONOR_NANS (mode)
3030 && flag_trapping_math
3031 && ((REAL_VALUE_ISINF (f0) && REAL_VALUES_EQUAL (f1, dconst0))
3032 || (REAL_VALUE_ISINF (f1)
3033 && REAL_VALUES_EQUAL (f0, dconst0))))
3034 /* Inf * 0 = NaN plus exception. */
3037 inexact = real_arithmetic (&value, rtx_to_tree_code (code),
3039 real_convert (&result, mode, &value);
3041 /* Don't constant fold this floating point operation if
3042 the result has overflowed and flag_trapping_math. */
3044 if (flag_trapping_math
3045 && MODE_HAS_INFINITIES (mode)
3046 && REAL_VALUE_ISINF (result)
3047 && !REAL_VALUE_ISINF (f0)
3048 && !REAL_VALUE_ISINF (f1))
3049 /* Overflow plus exception. */
3052 /* Don't constant fold this floating point operation if the
3053 result may dependent upon the run-time rounding mode and
3054 flag_rounding_math is set, or if GCC's software emulation
3055 is unable to accurately represent the result. */
3057 if ((flag_rounding_math
3058 || (REAL_MODE_FORMAT_COMPOSITE_P (mode)
3059 && !flag_unsafe_math_optimizations))
3060 && (inexact || !real_identical (&result, &value)))
3063 return CONST_DOUBLE_FROM_REAL_VALUE (result, mode);
3067 /* We can fold some multi-word operations. */
3068 if (GET_MODE_CLASS (mode) == MODE_INT
3069 && width == HOST_BITS_PER_WIDE_INT * 2
3070 && (GET_CODE (op0) == CONST_DOUBLE || GET_CODE (op0) == CONST_INT)
3071 && (GET_CODE (op1) == CONST_DOUBLE || GET_CODE (op1) == CONST_INT))
3073 unsigned HOST_WIDE_INT l1, l2, lv, lt;
3074 HOST_WIDE_INT h1, h2, hv, ht;
3076 if (GET_CODE (op0) == CONST_DOUBLE)
3077 l1 = CONST_DOUBLE_LOW (op0), h1 = CONST_DOUBLE_HIGH (op0);
3079 l1 = INTVAL (op0), h1 = HWI_SIGN_EXTEND (l1);
3081 if (GET_CODE (op1) == CONST_DOUBLE)
3082 l2 = CONST_DOUBLE_LOW (op1), h2 = CONST_DOUBLE_HIGH (op1);
3084 l2 = INTVAL (op1), h2 = HWI_SIGN_EXTEND (l2);
3089 /* A - B == A + (-B). */
3090 neg_double (l2, h2, &lv, &hv);
3093 /* Fall through.... */
3096 add_double (l1, h1, l2, h2, &lv, &hv);
3100 mul_double (l1, h1, l2, h2, &lv, &hv);
3104 if (div_and_round_double (TRUNC_DIV_EXPR, 0, l1, h1, l2, h2,
3105 &lv, &hv, <, &ht))
3110 if (div_and_round_double (TRUNC_DIV_EXPR, 0, l1, h1, l2, h2,
3111 <, &ht, &lv, &hv))
3116 if (div_and_round_double (TRUNC_DIV_EXPR, 1, l1, h1, l2, h2,
3117 &lv, &hv, <, &ht))
3122 if (div_and_round_double (TRUNC_DIV_EXPR, 1, l1, h1, l2, h2,
3123 <, &ht, &lv, &hv))
3128 lv = l1 & l2, hv = h1 & h2;
3132 lv = l1 | l2, hv = h1 | h2;
3136 lv = l1 ^ l2, hv = h1 ^ h2;
3142 && ((unsigned HOST_WIDE_INT) l1
3143 < (unsigned HOST_WIDE_INT) l2)))
3152 && ((unsigned HOST_WIDE_INT) l1
3153 > (unsigned HOST_WIDE_INT) l2)))
3160 if ((unsigned HOST_WIDE_INT) h1 < (unsigned HOST_WIDE_INT) h2
3162 && ((unsigned HOST_WIDE_INT) l1
3163 < (unsigned HOST_WIDE_INT) l2)))
3170 if ((unsigned HOST_WIDE_INT) h1 > (unsigned HOST_WIDE_INT) h2
3172 && ((unsigned HOST_WIDE_INT) l1
3173 > (unsigned HOST_WIDE_INT) l2)))
3179 case LSHIFTRT: case ASHIFTRT:
3181 case ROTATE: case ROTATERT:
3182 if (SHIFT_COUNT_TRUNCATED)
3183 l2 &= (GET_MODE_BITSIZE (mode) - 1), h2 = 0;
3185 if (h2 != 0 || l2 >= GET_MODE_BITSIZE (mode))
3188 if (code == LSHIFTRT || code == ASHIFTRT)
3189 rshift_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv,
3191 else if (code == ASHIFT)
3192 lshift_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv, 1);
3193 else if (code == ROTATE)
3194 lrotate_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv);
3195 else /* code == ROTATERT */
3196 rrotate_double (l1, h1, l2, GET_MODE_BITSIZE (mode), &lv, &hv);
3203 return immed_double_const (lv, hv, mode);
3206 if (GET_CODE (op0) == CONST_INT && GET_CODE (op1) == CONST_INT
3207 && width <= HOST_BITS_PER_WIDE_INT && width != 0)
3209 /* Get the integer argument values in two forms:
3210 zero-extended in ARG0, ARG1 and sign-extended in ARG0S, ARG1S. */
3212 arg0 = INTVAL (op0);
3213 arg1 = INTVAL (op1);
3215 if (width < HOST_BITS_PER_WIDE_INT)
3217 arg0 &= ((HOST_WIDE_INT) 1 << width) - 1;
3218 arg1 &= ((HOST_WIDE_INT) 1 << width) - 1;
3221 if (arg0s & ((HOST_WIDE_INT) 1 << (width - 1)))
3222 arg0s |= ((HOST_WIDE_INT) (-1) << width);
3225 if (arg1s & ((HOST_WIDE_INT) 1 << (width - 1)))
3226 arg1s |= ((HOST_WIDE_INT) (-1) << width);
3234 /* Compute the value of the arithmetic. */
3239 val = arg0s + arg1s;
3243 val = arg0s - arg1s;
3247 val = arg0s * arg1s;
3252 || (arg0s == (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1)
3255 val = arg0s / arg1s;
3260 || (arg0s == (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1)
3263 val = arg0s % arg1s;
3268 || (arg0s == (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1)
3271 val = (unsigned HOST_WIDE_INT) arg0 / arg1;
3276 || (arg0s == (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT - 1)
3279 val = (unsigned HOST_WIDE_INT) arg0 % arg1;
3297 /* Truncate the shift if SHIFT_COUNT_TRUNCATED, otherwise make sure
3298 the value is in range. We can't return any old value for
3299 out-of-range arguments because either the middle-end (via
3300 shift_truncation_mask) or the back-end might be relying on
3301 target-specific knowledge. Nor can we rely on
3302 shift_truncation_mask, since the shift might not be part of an
3303 ashlM3, lshrM3 or ashrM3 instruction. */
3304 if (SHIFT_COUNT_TRUNCATED)
3305 arg1 = (unsigned HOST_WIDE_INT) arg1 % width;
3306 else if (arg1 < 0 || arg1 >= GET_MODE_BITSIZE (mode))
3309 val = (code == ASHIFT
3310 ? ((unsigned HOST_WIDE_INT) arg0) << arg1
3311 : ((unsigned HOST_WIDE_INT) arg0) >> arg1);
3313 /* Sign-extend the result for arithmetic right shifts. */
3314 if (code == ASHIFTRT && arg0s < 0 && arg1 > 0)
3315 val |= ((HOST_WIDE_INT) -1) << (width - arg1);
3323 val = ((((unsigned HOST_WIDE_INT) arg0) << (width - arg1))
3324 | (((unsigned HOST_WIDE_INT) arg0) >> arg1));
3332 val = ((((unsigned HOST_WIDE_INT) arg0) << arg1)
3333 | (((unsigned HOST_WIDE_INT) arg0) >> (width - arg1)));
3337 /* Do nothing here. */
3341 val = arg0s <= arg1s ? arg0s : arg1s;
3345 val = ((unsigned HOST_WIDE_INT) arg0
3346 <= (unsigned HOST_WIDE_INT) arg1 ? arg0 : arg1);
3350 val = arg0s > arg1s ? arg0s : arg1s;
3354 val = ((unsigned HOST_WIDE_INT) arg0
3355 > (unsigned HOST_WIDE_INT) arg1 ? arg0 : arg1);
3368 /* ??? There are simplifications that can be done. */
3375 return gen_int_mode (val, mode);
3383 /* Simplify a PLUS or MINUS, at least one of whose operands may be another
3386 Rather than test for specific case, we do this by a brute-force method
3387 and do all possible simplifications until no more changes occur. Then
3388 we rebuild the operation. */
3390 struct simplify_plus_minus_op_data
3397 simplify_plus_minus_op_data_cmp (rtx x, rtx y)
3401 result = (commutative_operand_precedence (y)
3402 - commutative_operand_precedence (x));
3406 /* Group together equal REGs to do more simplification. */
3407 if (REG_P (x) && REG_P (y))
3408 return REGNO (x) > REGNO (y);
3414 simplify_plus_minus (enum rtx_code code, enum machine_mode mode, rtx op0,
3417 struct simplify_plus_minus_op_data ops[8];
3419 int n_ops = 2, input_ops = 2;
3420 int changed, n_constants = 0, canonicalized = 0;
3423 memset (ops, 0, sizeof ops);
3425 /* Set up the two operands and then expand them until nothing has been
3426 changed. If we run out of room in our array, give up; this should
3427 almost never happen. */
3432 ops[1].neg = (code == MINUS);
3438 for (i = 0; i < n_ops; i++)
3440 rtx this_op = ops[i].op;
3441 int this_neg = ops[i].neg;
3442 enum rtx_code this_code = GET_CODE (this_op);
3451 ops[n_ops].op = XEXP (this_op, 1);
3452 ops[n_ops].neg = (this_code == MINUS) ^ this_neg;
3455 ops[i].op = XEXP (this_op, 0);
3458 canonicalized |= this_neg;
3462 ops[i].op = XEXP (this_op, 0);
3463 ops[i].neg = ! this_neg;
3470 && GET_CODE (XEXP (this_op, 0)) == PLUS
3471 && CONSTANT_P (XEXP (XEXP (this_op, 0), 0))
3472 && CONSTANT_P (XEXP (XEXP (this_op, 0), 1)))
3474 ops[i].op = XEXP (XEXP (this_op, 0), 0);
3475 ops[n_ops].op = XEXP (XEXP (this_op, 0), 1);
3476 ops[n_ops].neg = this_neg;
3484 /* ~a -> (-a - 1) */
3487 ops[n_ops].op = constm1_rtx;
3488 ops[n_ops++].neg = this_neg;
3489 ops[i].op = XEXP (this_op, 0);
3490 ops[i].neg = !this_neg;
3500 ops[i].op = neg_const_int (mode, this_op);
3514 if (n_constants > 1)
3517 gcc_assert (n_ops >= 2);
3519 /* If we only have two operands, we can avoid the loops. */
3522 enum rtx_code code = ops[0].neg || ops[1].neg ? MINUS : PLUS;
3525 /* Get the two operands. Be careful with the order, especially for
3526 the cases where code == MINUS. */
3527 if (ops[0].neg && ops[1].neg)
3529 lhs = gen_rtx_NEG (mode, ops[0].op);
3532 else if (ops[0].neg)
3543 return simplify_const_binary_operation (code, mode, lhs, rhs);
3546 /* Now simplify each pair of operands until nothing changes. */
3549 /* Insertion sort is good enough for an eight-element array. */
3550 for (i = 1; i < n_ops; i++)
3552 struct simplify_plus_minus_op_data save;
3554 if (!simplify_plus_minus_op_data_cmp (ops[j].op, ops[i].op))
3560 ops[j + 1] = ops[j];
3561 while (j-- && simplify_plus_minus_op_data_cmp (ops[j].op, save.op));
3565 /* This is only useful the first time through. */
3570 for (i = n_ops - 1; i > 0; i--)
3571 for (j = i - 1; j >= 0; j--)
3573 rtx lhs = ops[j].op, rhs = ops[i].op;
3574 int lneg = ops[j].neg, rneg = ops[i].neg;
3576 if (lhs != 0 && rhs != 0)
3578 enum rtx_code ncode = PLUS;
3584 tem = lhs, lhs = rhs, rhs = tem;
3586 else if (swap_commutative_operands_p (lhs, rhs))
3587 tem = lhs, lhs = rhs, rhs = tem;
3589 if ((GET_CODE (lhs) == CONST || GET_CODE (lhs) == CONST_INT)
3590 && (GET_CODE (rhs) == CONST || GET_CODE (rhs) == CONST_INT))
3592 rtx tem_lhs, tem_rhs;
3594 tem_lhs = GET_CODE (lhs) == CONST ? XEXP (lhs, 0) : lhs;
3595 tem_rhs = GET_CODE (rhs) == CONST ? XEXP (rhs, 0) : rhs;
3596 tem = simplify_binary_operation (ncode, mode, tem_lhs, tem_rhs);
3598 if (tem && !CONSTANT_P (tem))
3599 tem = gen_rtx_CONST (GET_MODE (tem), tem);
3602 tem = simplify_binary_operation (ncode, mode, lhs, rhs);
3604 /* Reject "simplifications" that just wrap the two
3605 arguments in a CONST. Failure to do so can result
3606 in infinite recursion with simplify_binary_operation
3607 when it calls us to simplify CONST operations. */
3609 && ! (GET_CODE (tem) == CONST
3610 && GET_CODE (XEXP (tem, 0)) == ncode
3611 && XEXP (XEXP (tem, 0), 0) == lhs
3612 && XEXP (XEXP (tem, 0), 1) == rhs))
3615 if (GET_CODE (tem) == NEG)
3616 tem = XEXP (tem, 0), lneg = !lneg;
3617 if (GET_CODE (tem) == CONST_INT && lneg)
3618 tem = neg_const_int (mode, tem), lneg = 0;
3622 ops[j].op = NULL_RTX;
3628 /* Pack all the operands to the lower-numbered entries. */
3629 for (i = 0, j = 0; j < n_ops; j++)
3639 /* Create (minus -C X) instead of (neg (const (plus X C))). */
3641 && GET_CODE (ops[1].op) == CONST_INT
3642 && CONSTANT_P (ops[0].op)
3644 return gen_rtx_fmt_ee (MINUS, mode, ops[1].op, ops[0].op);
3646 /* We suppressed creation of trivial CONST expressions in the
3647 combination loop to avoid recursion. Create one manually now.
3648 The combination loop should have ensured that there is exactly
3649 one CONST_INT, and the sort will have ensured that it is last
3650 in the array and that any other constant will be next-to-last. */
3653 && GET_CODE (ops[n_ops - 1].op) == CONST_INT
3654 && CONSTANT_P (ops[n_ops - 2].op))
3656 rtx value = ops[n_ops - 1].op;
3657 if (ops[n_ops - 1].neg ^ ops[n_ops - 2].neg)
3658 value = neg_const_int (mode, value);
3659 ops[n_ops - 2].op = plus_constant (ops[n_ops - 2].op, INTVAL (value));
3663 /* Put a non-negated operand first, if possible. */
3665 for (i = 0; i < n_ops && ops[i].neg; i++)
3668 ops[0].op = gen_rtx_NEG (mode, ops[0].op);
3677 /* Now make the result by performing the requested operations. */
3679 for (i = 1; i < n_ops; i++)
3680 result = gen_rtx_fmt_ee (ops[i].neg ? MINUS : PLUS,
3681 mode, result, ops[i].op);
3686 /* Check whether an operand is suitable for calling simplify_plus_minus. */
3688 plus_minus_operand_p (const_rtx x)
3690 return GET_CODE (x) == PLUS
3691 || GET_CODE (x) == MINUS
3692 || (GET_CODE (x) == CONST
3693 && GET_CODE (XEXP (x, 0)) == PLUS
3694 && CONSTANT_P (XEXP (XEXP (x, 0), 0))
3695 && CONSTANT_P (XEXP (XEXP (x, 0), 1)));
3698 /* Like simplify_binary_operation except used for relational operators.
3699 MODE is the mode of the result. If MODE is VOIDmode, both operands must
3700 not also be VOIDmode.
3702 CMP_MODE specifies in which mode the comparison is done in, so it is
3703 the mode of the operands. If CMP_MODE is VOIDmode, it is taken from
3704 the operands or, if both are VOIDmode, the operands are compared in
3705 "infinite precision". */
3707 simplify_relational_operation (enum rtx_code code, enum machine_mode mode,
3708 enum machine_mode cmp_mode, rtx op0, rtx op1)
3710 rtx tem, trueop0, trueop1;
3712 if (cmp_mode == VOIDmode)
3713 cmp_mode = GET_MODE (op0);
3714 if (cmp_mode == VOIDmode)
3715 cmp_mode = GET_MODE (op1);
3717 tem = simplify_const_relational_operation (code, cmp_mode, op0, op1);
3720 if (SCALAR_FLOAT_MODE_P (mode))
3722 if (tem == const0_rtx)
3723 return CONST0_RTX (mode);
3724 #ifdef FLOAT_STORE_FLAG_VALUE
3726 REAL_VALUE_TYPE val;
3727 val = FLOAT_STORE_FLAG_VALUE (mode);
3728 return CONST_DOUBLE_FROM_REAL_VALUE (val, mode);
3734 if (VECTOR_MODE_P (mode))
3736 if (tem == const0_rtx)
3737 return CONST0_RTX (mode);
3738 #ifdef VECTOR_STORE_FLAG_VALUE
3743 rtx val = VECTOR_STORE_FLAG_VALUE (mode);
3744 if (val == NULL_RTX)
3746 if (val == const1_rtx)
3747 return CONST1_RTX (mode);
3749 units = GET_MODE_NUNITS (mode);
3750 v = rtvec_alloc (units);
3751 for (i = 0; i < units; i++)
3752 RTVEC_ELT (v, i) = val;
3753 return gen_rtx_raw_CONST_VECTOR (mode, v);
3763 /* For the following tests, ensure const0_rtx is op1. */
3764 if (swap_commutative_operands_p (op0, op1)
3765 || (op0 == const0_rtx && op1 != const0_rtx))
3766 tem = op0, op0 = op1, op1 = tem, code = swap_condition (code);
3768 /* If op0 is a compare, extract the comparison arguments from it. */
3769 if (GET_CODE (op0) == COMPARE && op1 == const0_rtx)
3770 return simplify_relational_operation (code, mode, VOIDmode,
3771 XEXP (op0, 0), XEXP (op0, 1));
3773 if (GET_MODE_CLASS (cmp_mode) == MODE_CC
3777 trueop0 = avoid_constant_pool_reference (op0);
3778 trueop1 = avoid_constant_pool_reference (op1);
3779 return simplify_relational_operation_1 (code, mode, cmp_mode,
3783 /* This part of simplify_relational_operation is only used when CMP_MODE
3784 is not in class MODE_CC (i.e. it is a real comparison).
3786 MODE is the mode of the result, while CMP_MODE specifies in which
3787 mode the comparison is done in, so it is the mode of the operands. */
3790 simplify_relational_operation_1 (enum rtx_code code, enum machine_mode mode,
3791 enum machine_mode cmp_mode, rtx op0, rtx op1)
3793 enum rtx_code op0code = GET_CODE (op0);
3795 if (op1 == const0_rtx && COMPARISON_P (op0))
3797 /* If op0 is a comparison, extract the comparison arguments
3801 if (GET_MODE (op0) == mode)
3802 return simplify_rtx (op0);
3804 return simplify_gen_relational (GET_CODE (op0), mode, VOIDmode,
3805 XEXP (op0, 0), XEXP (op0, 1));
3807 else if (code == EQ)
3809 enum rtx_code new_code = reversed_comparison_code (op0, NULL_RTX);
3810 if (new_code != UNKNOWN)
3811 return simplify_gen_relational (new_code, mode, VOIDmode,
3812 XEXP (op0, 0), XEXP (op0, 1));
3816 /* Canonicalize (LTU/GEU (PLUS a b) b) as (LTU/GEU (PLUS a b) a). */
3817 if ((code == LTU || code == GEU)
3818 && GET_CODE (op0) == PLUS
3819 && rtx_equal_p (op1, XEXP (op0, 1))
3820 /* Don't recurse "infinitely" for (LTU/GEU (PLUS b b) b). */
3821 && !rtx_equal_p (op1, XEXP (op0, 0)))
3822 return simplify_gen_relational (code, mode, cmp_mode, op0, XEXP (op0, 0));
3824 if (op1 == const0_rtx)
3826 /* Canonicalize (GTU x 0) as (NE x 0). */
3828 return simplify_gen_relational (NE, mode, cmp_mode, op0, op1);
3829 /* Canonicalize (LEU x 0) as (EQ x 0). */
3831 return simplify_gen_relational (EQ, mode, cmp_mode, op0, op1);
3833 else if (op1 == const1_rtx)
3838 /* Canonicalize (GE x 1) as (GT x 0). */
3839 return simplify_gen_relational (GT, mode, cmp_mode,
3842 /* Canonicalize (GEU x 1) as (NE x 0). */
3843 return simplify_gen_relational (NE, mode, cmp_mode,
3846 /* Canonicalize (LT x 1) as (LE x 0). */
3847 return simplify_gen_relational (LE, mode, cmp_mode,
3850 /* Canonicalize (LTU x 1) as (EQ x 0). */
3851 return simplify_gen_relational (EQ, mode, cmp_mode,
3857 else if (op1 == constm1_rtx)
3859 /* Canonicalize (LE x -1) as (LT x 0). */
3861 return simplify_gen_relational (LT, mode, cmp_mode, op0, const0_rtx);
3862 /* Canonicalize (GT x -1) as (GE x 0). */
3864 return simplify_gen_relational (GE, mode, cmp_mode, op0, const0_rtx);
3867 /* (eq/ne (plus x cst1) cst2) simplifies to (eq/ne x (cst2 - cst1)) */
3868 if ((code == EQ || code == NE)
3869 && (op0code == PLUS || op0code == MINUS)
3871 && CONSTANT_P (XEXP (op0, 1))
3872 && (INTEGRAL_MODE_P (cmp_mode) || flag_unsafe_math_optimizations))
3874 rtx x = XEXP (op0, 0);
3875 rtx c = XEXP (op0, 1);
3877 c = simplify_gen_binary (op0code == PLUS ? MINUS : PLUS,
3879 return simplify_gen_relational (code, mode, cmp_mode, x, c);
3882 /* (ne:SI (zero_extract:SI FOO (const_int 1) BAR) (const_int 0))) is
3883 the same as (zero_extract:SI FOO (const_int 1) BAR). */
3885 && op1 == const0_rtx
3886 && GET_MODE_CLASS (mode) == MODE_INT
3887 && cmp_mode != VOIDmode
3888 /* ??? Work-around BImode bugs in the ia64 backend. */
3890 && cmp_mode != BImode
3891 && nonzero_bits (op0, cmp_mode) == 1
3892 && STORE_FLAG_VALUE == 1)
3893 return GET_MODE_SIZE (mode) > GET_MODE_SIZE (cmp_mode)
3894 ? simplify_gen_unary (ZERO_EXTEND, mode, op0, cmp_mode)
3895 : lowpart_subreg (mode, op0, cmp_mode);
3897 /* (eq/ne (xor x y) 0) simplifies to (eq/ne x y). */
3898 if ((code == EQ || code == NE)
3899 && op1 == const0_rtx
3901 return simplify_gen_relational (code, mode, cmp_mode,
3902 XEXP (op0, 0), XEXP (op0, 1));
3904 /* (eq/ne (xor x y) x) simplifies to (eq/ne y 0). */
3905 if ((code == EQ || code == NE)
3907 && rtx_equal_p (XEXP (op0, 0), op1)
3908 && !side_effects_p (XEXP (op0, 0)))
3909 return simplify_gen_relational (code, mode, cmp_mode,
3910 XEXP (op0, 1), const0_rtx);
3912 /* Likewise (eq/ne (xor x y) y) simplifies to (eq/ne x 0). */
3913 if ((code == EQ || code == NE)
3915 && rtx_equal_p (XEXP (op0, 1), op1)
3916 && !side_effects_p (XEXP (op0, 1)))
3917 return simplify_gen_relational (code, mode, cmp_mode,
3918 XEXP (op0, 0), const0_rtx);
3920 /* (eq/ne (xor x C1) C2) simplifies to (eq/ne x (C1^C2)). */
3921 if ((code == EQ || code == NE)
3923 && (GET_CODE (op1) == CONST_INT
3924 || GET_CODE (op1) == CONST_DOUBLE)
3925 && (GET_CODE (XEXP (op0, 1)) == CONST_INT
3926 || GET_CODE (XEXP (op0, 1)) == CONST_DOUBLE))
3927 return simplify_gen_relational (code, mode, cmp_mode, XEXP (op0, 0),
3928 simplify_gen_binary (XOR, cmp_mode,
3929 XEXP (op0, 1), op1));
3931 if (op0code == POPCOUNT && op1 == const0_rtx)
3937 /* (eq (popcount x) (const_int 0)) -> (eq x (const_int 0)). */
3938 return simplify_gen_relational (EQ, mode, GET_MODE (XEXP (op0, 0)),
3939 XEXP (op0, 0), const0_rtx);
3944 /* (ne (popcount x) (const_int 0)) -> (ne x (const_int 0)). */
3945 return simplify_gen_relational (NE, mode, GET_MODE (XEXP (op0, 0)),
3946 XEXP (op0, 0), const0_rtx);
3965 /* Convert the known results for EQ, LT, GT, LTU, GTU contained in
3966 KNOWN_RESULT to a CONST_INT, based on the requested comparison CODE
3967 For KNOWN_RESULT to make sense it should be either CR_EQ, or the
3968 logical OR of one of (CR_LT, CR_GT) and one of (CR_LTU, CR_GTU).
3969 For floating-point comparisons, assume that the operands were ordered. */
3972 comparison_result (enum rtx_code code, int known_results)
3974 /* If we reach here, EQUAL, OP0LT, OP0LTU, OP1LT, and OP1LTU are set
3980 return (known_results & CR_EQ) ? const_true_rtx : const0_rtx;
3983 return (known_results & CR_EQ) ? const0_rtx : const_true_rtx;
3987 return (known_results & CR_LT) ? const_true_rtx : const0_rtx;
3990 return (known_results & CR_LT) ? const0_rtx : const_true_rtx;
3994 return (known_results & CR_GT) ? const_true_rtx : const0_rtx;
3997 return (known_results & CR_GT) ? const0_rtx : const_true_rtx;
4000 return (known_results & CR_LTU) ? const_true_rtx : const0_rtx;
4002 return (known_results & CR_LTU) ? const0_rtx : const_true_rtx;
4005 return (known_results & CR_GTU) ? const_true_rtx : const0_rtx;
4007 return (known_results & CR_GTU) ? const0_rtx : const_true_rtx;
4010 return const_true_rtx;
4018 /* Check if the given comparison (done in the given MODE) is actually a
4019 tautology or a contradiction.
4020 If no simplification is possible, this function returns zero.
4021 Otherwise, it returns either const_true_rtx or const0_rtx. */
4024 simplify_const_relational_operation (enum rtx_code code,
4025 enum machine_mode mode,
4032 gcc_assert (mode != VOIDmode
4033 || (GET_MODE (op0) == VOIDmode
4034 && GET_MODE (op1) == VOIDmode));
4036 /* If op0 is a compare, extract the comparison arguments from it. */
4037 if (GET_CODE (op0) == COMPARE && op1 == const0_rtx)
4039 op1 = XEXP (op0, 1);
4040 op0 = XEXP (op0, 0);
4042 if (GET_MODE (op0) != VOIDmode)
4043 mode = GET_MODE (op0);
4044 else if (GET_MODE (op1) != VOIDmode)
4045 mode = GET_MODE (op1);
4050 /* We can't simplify MODE_CC values since we don't know what the
4051 actual comparison is. */
4052 if (GET_MODE_CLASS (GET_MODE (op0)) == MODE_CC || CC0_P (op0))
4055 /* Make sure the constant is second. */
4056 if (swap_commutative_operands_p (op0, op1))
4058 tem = op0, op0 = op1, op1 = tem;
4059 code = swap_condition (code);
4062 trueop0 = avoid_constant_pool_reference (op0);
4063 trueop1 = avoid_constant_pool_reference (op1);
4065 /* For integer comparisons of A and B maybe we can simplify A - B and can
4066 then simplify a comparison of that with zero. If A and B are both either
4067 a register or a CONST_INT, this can't help; testing for these cases will
4068 prevent infinite recursion here and speed things up.
4070 We can only do this for EQ and NE comparisons as otherwise we may
4071 lose or introduce overflow which we cannot disregard as undefined as
4072 we do not know the signedness of the operation on either the left or
4073 the right hand side of the comparison. */
4075 if (INTEGRAL_MODE_P (mode) && trueop1 != const0_rtx
4076 && (code == EQ || code == NE)
4077 && ! ((REG_P (op0) || GET_CODE (trueop0) == CONST_INT)
4078 && (REG_P (op1) || GET_CODE (trueop1) == CONST_INT))
4079 && 0 != (tem = simplify_binary_operation (MINUS, mode, op0, op1))
4080 /* We cannot do this if tem is a nonzero address. */
4081 && ! nonzero_address_p (tem))
4082 return simplify_const_relational_operation (signed_condition (code),
4083 mode, tem, const0_rtx);
4085 if (! HONOR_NANS (mode) && code == ORDERED)
4086 return const_true_rtx;
4088 if (! HONOR_NANS (mode) && code == UNORDERED)
4091 /* For modes without NaNs, if the two operands are equal, we know the
4092 result except if they have side-effects. Even with NaNs we know
4093 the result of unordered comparisons and, if signaling NaNs are
4094 irrelevant, also the result of LT/GT/LTGT. */
4095 if ((! HONOR_NANS (GET_MODE (trueop0))
4096 || code == UNEQ || code == UNLE || code == UNGE
4097 || ((code == LT || code == GT || code == LTGT)
4098 && ! HONOR_SNANS (GET_MODE (trueop0))))
4099 && rtx_equal_p (trueop0, trueop1)
4100 && ! side_effects_p (trueop0))
4101 return comparison_result (code, CR_EQ);
4103 /* If the operands are floating-point constants, see if we can fold
4105 if (GET_CODE (trueop0) == CONST_DOUBLE
4106 && GET_CODE (trueop1) == CONST_DOUBLE
4107 && SCALAR_FLOAT_MODE_P (GET_MODE (trueop0)))
4109 REAL_VALUE_TYPE d0, d1;
4111 REAL_VALUE_FROM_CONST_DOUBLE (d0, trueop0);
4112 REAL_VALUE_FROM_CONST_DOUBLE (d1, trueop1);
4114 /* Comparisons are unordered iff at least one of the values is NaN. */
4115 if (REAL_VALUE_ISNAN (d0) || REAL_VALUE_ISNAN (d1))
4125 return const_true_rtx;
4138 return comparison_result (code,
4139 (REAL_VALUES_EQUAL (d0, d1) ? CR_EQ :
4140 REAL_VALUES_LESS (d0, d1) ? CR_LT : CR_GT));
4143 /* Otherwise, see if the operands are both integers. */
4144 if ((GET_MODE_CLASS (mode) == MODE_INT || mode == VOIDmode)
4145 && (GET_CODE (trueop0) == CONST_DOUBLE
4146 || GET_CODE (trueop0) == CONST_INT)
4147 && (GET_CODE (trueop1) == CONST_DOUBLE
4148 || GET_CODE (trueop1) == CONST_INT))
4150 int width = GET_MODE_BITSIZE (mode);
4151 HOST_WIDE_INT l0s, h0s, l1s, h1s;
4152 unsigned HOST_WIDE_INT l0u, h0u, l1u, h1u;
4154 /* Get the two words comprising each integer constant. */
4155 if (GET_CODE (trueop0) == CONST_DOUBLE)
4157 l0u = l0s = CONST_DOUBLE_LOW (trueop0);
4158 h0u = h0s = CONST_DOUBLE_HIGH (trueop0);
4162 l0u = l0s = INTVAL (trueop0);
4163 h0u = h0s = HWI_SIGN_EXTEND (l0s);
4166 if (GET_CODE (trueop1) == CONST_DOUBLE)
4168 l1u = l1s = CONST_DOUBLE_LOW (trueop1);
4169 h1u = h1s = CONST_DOUBLE_HIGH (trueop1);
4173 l1u = l1s = INTVAL (trueop1);
4174 h1u = h1s = HWI_SIGN_EXTEND (l1s);
4177 /* If WIDTH is nonzero and smaller than HOST_BITS_PER_WIDE_INT,
4178 we have to sign or zero-extend the values. */
4179 if (width != 0 && width < HOST_BITS_PER_WIDE_INT)
4181 l0u &= ((HOST_WIDE_INT) 1 << width) - 1;
4182 l1u &= ((HOST_WIDE_INT) 1 << width) - 1;
4184 if (l0s & ((HOST_WIDE_INT) 1 << (width - 1)))
4185 l0s |= ((HOST_WIDE_INT) (-1) << width);
4187 if (l1s & ((HOST_WIDE_INT) 1 << (width - 1)))
4188 l1s |= ((HOST_WIDE_INT) (-1) << width);
4190 if (width != 0 && width <= HOST_BITS_PER_WIDE_INT)
4191 h0u = h1u = 0, h0s = HWI_SIGN_EXTEND (l0s), h1s = HWI_SIGN_EXTEND (l1s);
4193 if (h0u == h1u && l0u == l1u)
4194 return comparison_result (code, CR_EQ);
4198 cr = (h0s < h1s || (h0s == h1s && l0u < l1u)) ? CR_LT : CR_GT;
4199 cr |= (h0u < h1u || (h0u == h1u && l0u < l1u)) ? CR_LTU : CR_GTU;
4200 return comparison_result (code, cr);
4204 /* Optimize comparisons with upper and lower bounds. */
4205 if (SCALAR_INT_MODE_P (mode)
4206 && GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
4207 && GET_CODE (trueop1) == CONST_INT)
4210 unsigned HOST_WIDE_INT nonzero = nonzero_bits (trueop0, mode);
4211 HOST_WIDE_INT val = INTVAL (trueop1);
4212 HOST_WIDE_INT mmin, mmax;
4222 /* Get a reduced range if the sign bit is zero. */
4223 if (nonzero <= (GET_MODE_MASK (mode) >> 1))
4230 rtx mmin_rtx, mmax_rtx;
4231 unsigned int sign_copies = num_sign_bit_copies (trueop0, mode);
4232 get_mode_bounds (mode, sign, mode, &mmin_rtx, &mmax_rtx);
4234 /* Since unsigned mmin will never be interpreted as negative, use
4235 INTVAL (and an arithmetic right shift). */
4236 mmin = INTVAL (mmin_rtx) >> (sign_copies - 1);
4237 /* Since signed mmax will always be positive, use UINTVAL (and
4238 a logical right shift). */
4239 mmax = UINTVAL (mmax_rtx) >> (sign_copies - 1);
4244 /* x >= y is always true for y <= mmin, always false for y > mmax. */
4246 if ((unsigned HOST_WIDE_INT) val <= (unsigned HOST_WIDE_INT) mmin)
4247 return const_true_rtx;
4248 if ((unsigned HOST_WIDE_INT) val > (unsigned HOST_WIDE_INT) mmax)
4253 return const_true_rtx;
4258 /* x <= y is always true for y >= mmax, always false for y < mmin. */
4260 if ((unsigned HOST_WIDE_INT) val >= (unsigned HOST_WIDE_INT) mmax)
4261 return const_true_rtx;
4262 if ((unsigned HOST_WIDE_INT) val < (unsigned HOST_WIDE_INT) mmin)
4267 return const_true_rtx;
4273 /* x == y is always false for y out of range. */
4274 if (val < mmin || val > mmax)
4278 /* x > y is always false for y >= mmax, always true for y < mmin. */
4280 if ((unsigned HOST_WIDE_INT) val >= (unsigned HOST_WIDE_INT) mmax)
4282 if ((unsigned HOST_WIDE_INT) val < (unsigned HOST_WIDE_INT) mmin)
4283 return const_true_rtx;
4289 return const_true_rtx;
4292 /* x < y is always false for y <= mmin, always true for y > mmax. */
4294 if ((unsigned HOST_WIDE_INT) val <= (unsigned HOST_WIDE_INT) mmin)
4296 if ((unsigned HOST_WIDE_INT) val > (unsigned HOST_WIDE_INT) mmax)
4297 return const_true_rtx;
4303 return const_true_rtx;
4307 /* x != y is always true for y out of range. */
4308 if (val < mmin || val > mmax)
4309 return const_true_rtx;
4317 /* Optimize integer comparisons with zero. */
4318 if (trueop1 == const0_rtx)
4320 /* Some addresses are known to be nonzero. We don't know
4321 their sign, but equality comparisons are known. */
4322 if (nonzero_address_p (trueop0))
4324 if (code == EQ || code == LEU)
4326 if (code == NE || code == GTU)
4327 return const_true_rtx;
4330 /* See if the first operand is an IOR with a constant. If so, we
4331 may be able to determine the result of this comparison. */
4332 if (GET_CODE (op0) == IOR)
4334 rtx inner_const = avoid_constant_pool_reference (XEXP (op0, 1));
4335 if (GET_CODE (inner_const) == CONST_INT && inner_const != const0_rtx)
4337 int sign_bitnum = GET_MODE_BITSIZE (mode) - 1;
4338 int has_sign = (HOST_BITS_PER_WIDE_INT >= sign_bitnum
4339 && (INTVAL (inner_const)
4340 & ((HOST_WIDE_INT) 1 << sign_bitnum)));
4349 return const_true_rtx;
4353 return const_true_rtx;
4367 /* Optimize comparison of ABS with zero. */
4368 if (trueop1 == CONST0_RTX (mode)
4369 && (GET_CODE (trueop0) == ABS
4370 || (GET_CODE (trueop0) == FLOAT_EXTEND
4371 && GET_CODE (XEXP (trueop0, 0)) == ABS)))
4376 /* Optimize abs(x) < 0.0. */
4377 if (!HONOR_SNANS (mode)
4378 && (!INTEGRAL_MODE_P (mode)
4379 || (!flag_wrapv && !flag_trapv && flag_strict_overflow)))
4381 if (INTEGRAL_MODE_P (mode)
4382 && (issue_strict_overflow_warning
4383 (WARN_STRICT_OVERFLOW_CONDITIONAL)))
4384 warning (OPT_Wstrict_overflow,
4385 ("assuming signed overflow does not occur when "
4386 "assuming abs (x) < 0 is false"));
4392 /* Optimize abs(x) >= 0.0. */
4393 if (!HONOR_NANS (mode)
4394 && (!INTEGRAL_MODE_P (mode)
4395 || (!flag_wrapv && !flag_trapv && flag_strict_overflow)))
4397 if (INTEGRAL_MODE_P (mode)
4398 && (issue_strict_overflow_warning
4399 (WARN_STRICT_OVERFLOW_CONDITIONAL)))
4400 warning (OPT_Wstrict_overflow,
4401 ("assuming signed overflow does not occur when "
4402 "assuming abs (x) >= 0 is true"));
4403 return const_true_rtx;
4408 /* Optimize ! (abs(x) < 0.0). */
4409 return const_true_rtx;
4419 /* Simplify CODE, an operation with result mode MODE and three operands,
4420 OP0, OP1, and OP2. OP0_MODE was the mode of OP0 before it became
4421 a constant. Return 0 if no simplifications is possible. */
4424 simplify_ternary_operation (enum rtx_code code, enum machine_mode mode,
4425 enum machine_mode op0_mode, rtx op0, rtx op1,
4428 unsigned int width = GET_MODE_BITSIZE (mode);
4430 /* VOIDmode means "infinite" precision. */
4432 width = HOST_BITS_PER_WIDE_INT;
4438 if (GET_CODE (op0) == CONST_INT
4439 && GET_CODE (op1) == CONST_INT
4440 && GET_CODE (op2) == CONST_INT
4441 && ((unsigned) INTVAL (op1) + (unsigned) INTVAL (op2) <= width)
4442 && width <= (unsigned) HOST_BITS_PER_WIDE_INT)
4444 /* Extracting a bit-field from a constant */
4445 HOST_WIDE_INT val = INTVAL (op0);
4447 if (BITS_BIG_ENDIAN)
4448 val >>= (GET_MODE_BITSIZE (op0_mode)
4449 - INTVAL (op2) - INTVAL (op1));
4451 val >>= INTVAL (op2);
4453 if (HOST_BITS_PER_WIDE_INT != INTVAL (op1))
4455 /* First zero-extend. */
4456 val &= ((HOST_WIDE_INT) 1 << INTVAL (op1)) - 1;
4457 /* If desired, propagate sign bit. */
4458 if (code == SIGN_EXTRACT
4459 && (val & ((HOST_WIDE_INT) 1 << (INTVAL (op1) - 1))))
4460 val |= ~ (((HOST_WIDE_INT) 1 << INTVAL (op1)) - 1);
4463 /* Clear the bits that don't belong in our mode,
4464 unless they and our sign bit are all one.
4465 So we get either a reasonable negative value or a reasonable
4466 unsigned value for this mode. */
4467 if (width < HOST_BITS_PER_WIDE_INT
4468 && ((val & ((HOST_WIDE_INT) (-1) << (width - 1)))
4469 != ((HOST_WIDE_INT) (-1) << (width - 1))))
4470 val &= ((HOST_WIDE_INT) 1 << width) - 1;
4472 return gen_int_mode (val, mode);
4477 if (GET_CODE (op0) == CONST_INT)
4478 return op0 != const0_rtx ? op1 : op2;
4480 /* Convert c ? a : a into "a". */
4481 if (rtx_equal_p (op1, op2) && ! side_effects_p (op0))
4484 /* Convert a != b ? a : b into "a". */
4485 if (GET_CODE (op0) == NE
4486 && ! side_effects_p (op0)
4487 && ! HONOR_NANS (mode)
4488 && ! HONOR_SIGNED_ZEROS (mode)
4489 && ((rtx_equal_p (XEXP (op0, 0), op1)
4490 && rtx_equal_p (XEXP (op0, 1), op2))
4491 || (rtx_equal_p (XEXP (op0, 0), op2)
4492 && rtx_equal_p (XEXP (op0, 1), op1))))
4495 /* Convert a == b ? a : b into "b". */
4496 if (GET_CODE (op0) == EQ
4497 && ! side_effects_p (op0)
4498 && ! HONOR_NANS (mode)
4499 && ! HONOR_SIGNED_ZEROS (mode)
4500 && ((rtx_equal_p (XEXP (op0, 0), op1)
4501 && rtx_equal_p (XEXP (op0, 1), op2))
4502 || (rtx_equal_p (XEXP (op0, 0), op2)
4503 && rtx_equal_p (XEXP (op0, 1), op1))))
4506 if (COMPARISON_P (op0) && ! side_effects_p (op0))
4508 enum machine_mode cmp_mode = (GET_MODE (XEXP (op0, 0)) == VOIDmode
4509 ? GET_MODE (XEXP (op0, 1))
4510 : GET_MODE (XEXP (op0, 0)));
4513 /* Look for happy constants in op1 and op2. */
4514 if (GET_CODE (op1) == CONST_INT && GET_CODE (op2) == CONST_INT)
4516 HOST_WIDE_INT t = INTVAL (op1);
4517 HOST_WIDE_INT f = INTVAL (op2);
4519 if (t == STORE_FLAG_VALUE && f == 0)
4520 code = GET_CODE (op0);
4521 else if (t == 0 && f == STORE_FLAG_VALUE)
4524 tmp = reversed_comparison_code (op0, NULL_RTX);
4532 return simplify_gen_relational (code, mode, cmp_mode,
4533 XEXP (op0, 0), XEXP (op0, 1));
4536 if (cmp_mode == VOIDmode)
4537 cmp_mode = op0_mode;
4538 temp = simplify_relational_operation (GET_CODE (op0), op0_mode,
4539 cmp_mode, XEXP (op0, 0),
4542 /* See if any simplifications were possible. */
4545 if (GET_CODE (temp) == CONST_INT)
4546 return temp == const0_rtx ? op2 : op1;
4548 return gen_rtx_IF_THEN_ELSE (mode, temp, op1, op2);
4554 gcc_assert (GET_MODE (op0) == mode);
4555 gcc_assert (GET_MODE (op1) == mode);
4556 gcc_assert (VECTOR_MODE_P (mode));
4557 op2 = avoid_constant_pool_reference (op2);
4558 if (GET_CODE (op2) == CONST_INT)
4560 int elt_size = GET_MODE_SIZE (GET_MODE_INNER (mode));
4561 unsigned n_elts = (GET_MODE_SIZE (mode) / elt_size);
4562 int mask = (1 << n_elts) - 1;
4564 if (!(INTVAL (op2) & mask))
4566 if ((INTVAL (op2) & mask) == mask)
4569 op0 = avoid_constant_pool_reference (op0);
4570 op1 = avoid_constant_pool_reference (op1);
4571 if (GET_CODE (op0) == CONST_VECTOR
4572 && GET_CODE (op1) == CONST_VECTOR)
4574 rtvec v = rtvec_alloc (n_elts);
4577 for (i = 0; i < n_elts; i++)
4578 RTVEC_ELT (v, i) = (INTVAL (op2) & (1 << i)
4579 ? CONST_VECTOR_ELT (op0, i)
4580 : CONST_VECTOR_ELT (op1, i));
4581 return gen_rtx_CONST_VECTOR (mode, v);
4593 /* Evaluate a SUBREG of a CONST_INT or CONST_DOUBLE or CONST_FIXED
4595 returning another CONST_INT or CONST_DOUBLE or CONST_FIXED or CONST_VECTOR.
4597 Works by unpacking OP into a collection of 8-bit values
4598 represented as a little-endian array of 'unsigned char', selecting by BYTE,
4599 and then repacking them again for OUTERMODE. */
4602 simplify_immed_subreg (enum machine_mode outermode, rtx op,
4603 enum machine_mode innermode, unsigned int byte)
4605 /* We support up to 512-bit values (for V8DFmode). */
4609 value_mask = (1 << value_bit) - 1
4611 unsigned char value[max_bitsize / value_bit];
4620 rtvec result_v = NULL;
4621 enum mode_class outer_class;
4622 enum machine_mode outer_submode;
4624 /* Some ports misuse CCmode. */
4625 if (GET_MODE_CLASS (outermode) == MODE_CC && GET_CODE (op) == CONST_INT)
4628 /* We have no way to represent a complex constant at the rtl level. */
4629 if (COMPLEX_MODE_P (outermode))
4632 /* Unpack the value. */
4634 if (GET_CODE (op) == CONST_VECTOR)
4636 num_elem = CONST_VECTOR_NUNITS (op);
4637 elems = &CONST_VECTOR_ELT (op, 0);
4638 elem_bitsize = GET_MODE_BITSIZE (GET_MODE_INNER (innermode));
4644 elem_bitsize = max_bitsize;
4646 /* If this asserts, it is too complicated; reducing value_bit may help. */
4647 gcc_assert (BITS_PER_UNIT % value_bit == 0);
4648 /* I don't know how to handle endianness of sub-units. */
4649 gcc_assert (elem_bitsize % BITS_PER_UNIT == 0);
4651 for (elem = 0; elem < num_elem; elem++)
4654 rtx el = elems[elem];
4656 /* Vectors are kept in target memory order. (This is probably
4659 unsigned byte = (elem * elem_bitsize) / BITS_PER_UNIT;
4660 unsigned ibyte = (((num_elem - 1 - elem) * elem_bitsize)
4662 unsigned word_byte = WORDS_BIG_ENDIAN ? ibyte : byte;
4663 unsigned subword_byte = BYTES_BIG_ENDIAN ? ibyte : byte;
4664 unsigned bytele = (subword_byte % UNITS_PER_WORD
4665 + (word_byte / UNITS_PER_WORD) * UNITS_PER_WORD);
4666 vp = value + (bytele * BITS_PER_UNIT) / value_bit;
4669 switch (GET_CODE (el))
4673 i < HOST_BITS_PER_WIDE_INT && i < elem_bitsize;
4675 *vp++ = INTVAL (el) >> i;
4676 /* CONST_INTs are always logically sign-extended. */
4677 for (; i < elem_bitsize; i += value_bit)
4678 *vp++ = INTVAL (el) < 0 ? -1 : 0;
4682 if (GET_MODE (el) == VOIDmode)
4684 /* If this triggers, someone should have generated a
4685 CONST_INT instead. */
4686 gcc_assert (elem_bitsize > HOST_BITS_PER_WIDE_INT);
4688 for (i = 0; i < HOST_BITS_PER_WIDE_INT; i += value_bit)
4689 *vp++ = CONST_DOUBLE_LOW (el) >> i;
4690 while (i < HOST_BITS_PER_WIDE_INT * 2 && i < elem_bitsize)
4693 = CONST_DOUBLE_HIGH (el) >> (i - HOST_BITS_PER_WIDE_INT);
4696 /* It shouldn't matter what's done here, so fill it with
4698 for (; i < elem_bitsize; i += value_bit)
4703 long tmp[max_bitsize / 32];
4704 int bitsize = GET_MODE_BITSIZE (GET_MODE (el));
4706 gcc_assert (SCALAR_FLOAT_MODE_P (GET_MODE (el)));
4707 gcc_assert (bitsize <= elem_bitsize);
4708 gcc_assert (bitsize % value_bit == 0);
4710 real_to_target (tmp, CONST_DOUBLE_REAL_VALUE (el),
4713 /* real_to_target produces its result in words affected by
4714 FLOAT_WORDS_BIG_ENDIAN. However, we ignore this,
4715 and use WORDS_BIG_ENDIAN instead; see the documentation
4716 of SUBREG in rtl.texi. */
4717 for (i = 0; i < bitsize; i += value_bit)
4720 if (WORDS_BIG_ENDIAN)
4721 ibase = bitsize - 1 - i;
4724 *vp++ = tmp[ibase / 32] >> i % 32;
4727 /* It shouldn't matter what's done here, so fill it with
4729 for (; i < elem_bitsize; i += value_bit)
4735 if (elem_bitsize <= HOST_BITS_PER_WIDE_INT)
4737 for (i = 0; i < elem_bitsize; i += value_bit)
4738 *vp++ = CONST_FIXED_VALUE_LOW (el) >> i;
4742 for (i = 0; i < HOST_BITS_PER_WIDE_INT; i += value_bit)
4743 *vp++ = CONST_FIXED_VALUE_LOW (el) >> i;
4744 for (; i < 2 * HOST_BITS_PER_WIDE_INT && i < elem_bitsize;
4746 *vp++ = CONST_FIXED_VALUE_HIGH (el)
4747 >> (i - HOST_BITS_PER_WIDE_INT);
4748 for (; i < elem_bitsize; i += value_bit)
4758 /* Now, pick the right byte to start with. */
4759 /* Renumber BYTE so that the least-significant byte is byte 0. A special
4760 case is paradoxical SUBREGs, which shouldn't be adjusted since they
4761 will already have offset 0. */
4762 if (GET_MODE_SIZE (innermode) >= GET_MODE_SIZE (outermode))
4764 unsigned ibyte = (GET_MODE_SIZE (innermode) - GET_MODE_SIZE (outermode)
4766 unsigned word_byte = WORDS_BIG_ENDIAN ? ibyte : byte;
4767 unsigned subword_byte = BYTES_BIG_ENDIAN ? ibyte : byte;
4768 byte = (subword_byte % UNITS_PER_WORD
4769 + (word_byte / UNITS_PER_WORD) * UNITS_PER_WORD);
4772 /* BYTE should still be inside OP. (Note that BYTE is unsigned,
4773 so if it's become negative it will instead be very large.) */
4774 gcc_assert (byte < GET_MODE_SIZE (innermode));
4776 /* Convert from bytes to chunks of size value_bit. */
4777 value_start = byte * (BITS_PER_UNIT / value_bit);
4779 /* Re-pack the value. */
4781 if (VECTOR_MODE_P (outermode))
4783 num_elem = GET_MODE_NUNITS (outermode);
4784 result_v = rtvec_alloc (num_elem);
4785 elems = &RTVEC_ELT (result_v, 0);
4786 outer_submode = GET_MODE_INNER (outermode);
4792 outer_submode = outermode;
4795 outer_class = GET_MODE_CLASS (outer_submode);
4796 elem_bitsize = GET_MODE_BITSIZE (outer_submode);
4798 gcc_assert (elem_bitsize % value_bit == 0);
4799 gcc_assert (elem_bitsize + value_start * value_bit <= max_bitsize);
4801 for (elem = 0; elem < num_elem; elem++)
4805 /* Vectors are stored in target memory order. (This is probably
4808 unsigned byte = (elem * elem_bitsize) / BITS_PER_UNIT;
4809 unsigned ibyte = (((num_elem - 1 - elem) * elem_bitsize)
4811 unsigned word_byte = WORDS_BIG_ENDIAN ? ibyte : byte;
4812 unsigned subword_byte = BYTES_BIG_ENDIAN ? ibyte : byte;
4813 unsigned bytele = (subword_byte % UNITS_PER_WORD
4814 + (word_byte / UNITS_PER_WORD) * UNITS_PER_WORD);
4815 vp = value + value_start + (bytele * BITS_PER_UNIT) / value_bit;
4818 switch (outer_class)
4821 case MODE_PARTIAL_INT:
4823 unsigned HOST_WIDE_INT hi = 0, lo = 0;
4826 i < HOST_BITS_PER_WIDE_INT && i < elem_bitsize;
4828 lo |= (HOST_WIDE_INT)(*vp++ & value_mask) << i;
4829 for (; i < elem_bitsize; i += value_bit)
4830 hi |= ((HOST_WIDE_INT)(*vp++ & value_mask)
4831 << (i - HOST_BITS_PER_WIDE_INT));
4833 /* immed_double_const doesn't call trunc_int_for_mode. I don't
4835 if (elem_bitsize <= HOST_BITS_PER_WIDE_INT)
4836 elems[elem] = gen_int_mode (lo, outer_submode);
4837 else if (elem_bitsize <= 2 * HOST_BITS_PER_WIDE_INT)
4838 elems[elem] = immed_double_const (lo, hi, outer_submode);
4845 case MODE_DECIMAL_FLOAT:
4848 long tmp[max_bitsize / 32];
4850 /* real_from_target wants its input in words affected by
4851 FLOAT_WORDS_BIG_ENDIAN. However, we ignore this,
4852 and use WORDS_BIG_ENDIAN instead; see the documentation
4853 of SUBREG in rtl.texi. */
4854 for (i = 0; i < max_bitsize / 32; i++)
4856 for (i = 0; i < elem_bitsize; i += value_bit)
4859 if (WORDS_BIG_ENDIAN)
4860 ibase = elem_bitsize - 1 - i;
4863 tmp[ibase / 32] |= (*vp++ & value_mask) << i % 32;
4866 real_from_target (&r, tmp, outer_submode);
4867 elems[elem] = CONST_DOUBLE_FROM_REAL_VALUE (r, outer_submode);
4879 f.mode = outer_submode;
4882 i < HOST_BITS_PER_WIDE_INT && i < elem_bitsize;
4884 f.data.low |= (HOST_WIDE_INT)(*vp++ & value_mask) << i;
4885 for (; i < elem_bitsize; i += value_bit)
4886 f.data.high |= ((HOST_WIDE_INT)(*vp++ & value_mask)
4887 << (i - HOST_BITS_PER_WIDE_INT));
4889 elems[elem] = CONST_FIXED_FROM_FIXED_VALUE (f, outer_submode);
4897 if (VECTOR_MODE_P (outermode))
4898 return gen_rtx_CONST_VECTOR (outermode, result_v);
4903 /* Simplify SUBREG:OUTERMODE(OP:INNERMODE, BYTE)
4904 Return 0 if no simplifications are possible. */
4906 simplify_subreg (enum machine_mode outermode, rtx op,
4907 enum machine_mode innermode, unsigned int byte)
4909 /* Little bit of sanity checking. */
4910 gcc_assert (innermode != VOIDmode);
4911 gcc_assert (outermode != VOIDmode);
4912 gcc_assert (innermode != BLKmode);
4913 gcc_assert (outermode != BLKmode);
4915 gcc_assert (GET_MODE (op) == innermode
4916 || GET_MODE (op) == VOIDmode);
4918 gcc_assert ((byte % GET_MODE_SIZE (outermode)) == 0);
4919 gcc_assert (byte < GET_MODE_SIZE (innermode));
4921 if (outermode == innermode && !byte)
4924 if (GET_CODE (op) == CONST_INT
4925 || GET_CODE (op) == CONST_DOUBLE
4926 || GET_CODE (op) == CONST_FIXED
4927 || GET_CODE (op) == CONST_VECTOR)
4928 return simplify_immed_subreg (outermode, op, innermode, byte);
4930 /* Changing mode twice with SUBREG => just change it once,
4931 or not at all if changing back op starting mode. */
4932 if (GET_CODE (op) == SUBREG)
4934 enum machine_mode innermostmode = GET_MODE (SUBREG_REG (op));
4935 int final_offset = byte + SUBREG_BYTE (op);
4938 if (outermode == innermostmode
4939 && byte == 0 && SUBREG_BYTE (op) == 0)
4940 return SUBREG_REG (op);
4942 /* The SUBREG_BYTE represents offset, as if the value were stored
4943 in memory. Irritating exception is paradoxical subreg, where
4944 we define SUBREG_BYTE to be 0. On big endian machines, this
4945 value should be negative. For a moment, undo this exception. */
4946 if (byte == 0 && GET_MODE_SIZE (innermode) < GET_MODE_SIZE (outermode))
4948 int difference = (GET_MODE_SIZE (innermode) - GET_MODE_SIZE (outermode));
4949 if (WORDS_BIG_ENDIAN)
4950 final_offset += (difference / UNITS_PER_WORD) * UNITS_PER_WORD;
4951 if (BYTES_BIG_ENDIAN)
4952 final_offset += difference % UNITS_PER_WORD;
4954 if (SUBREG_BYTE (op) == 0
4955 && GET_MODE_SIZE (innermostmode) < GET_MODE_SIZE (innermode))
4957 int difference = (GET_MODE_SIZE (innermostmode) - GET_MODE_SIZE (innermode));
4958 if (WORDS_BIG_ENDIAN)
4959 final_offset += (difference / UNITS_PER_WORD) * UNITS_PER_WORD;
4960 if (BYTES_BIG_ENDIAN)
4961 final_offset += difference % UNITS_PER_WORD;
4964 /* See whether resulting subreg will be paradoxical. */
4965 if (GET_MODE_SIZE (innermostmode) > GET_MODE_SIZE (outermode))
4967 /* In nonparadoxical subregs we can't handle negative offsets. */
4968 if (final_offset < 0)
4970 /* Bail out in case resulting subreg would be incorrect. */
4971 if (final_offset % GET_MODE_SIZE (outermode)
4972 || (unsigned) final_offset >= GET_MODE_SIZE (innermostmode))
4978 int difference = (GET_MODE_SIZE (innermostmode) - GET_MODE_SIZE (outermode));
4980 /* In paradoxical subreg, see if we are still looking on lower part.
4981 If so, our SUBREG_BYTE will be 0. */
4982 if (WORDS_BIG_ENDIAN)
4983 offset += (difference / UNITS_PER_WORD) * UNITS_PER_WORD;
4984 if (BYTES_BIG_ENDIAN)
4985 offset += difference % UNITS_PER_WORD;
4986 if (offset == final_offset)
4992 /* Recurse for further possible simplifications. */
4993 newx = simplify_subreg (outermode, SUBREG_REG (op), innermostmode,
4997 if (validate_subreg (outermode, innermostmode,
4998 SUBREG_REG (op), final_offset))
4999 return gen_rtx_SUBREG (outermode, SUBREG_REG (op), final_offset);
5003 /* Merge implicit and explicit truncations. */
5005 if (GET_CODE (op) == TRUNCATE
5006 && GET_MODE_SIZE (outermode) < GET_MODE_SIZE (innermode)
5007 && subreg_lowpart_offset (outermode, innermode) == byte)
5008 return simplify_gen_unary (TRUNCATE, outermode, XEXP (op, 0),
5009 GET_MODE (XEXP (op, 0)));
5011 /* SUBREG of a hard register => just change the register number
5012 and/or mode. If the hard register is not valid in that mode,
5013 suppress this simplification. If the hard register is the stack,
5014 frame, or argument pointer, leave this as a SUBREG. */
5017 && REGNO (op) < FIRST_PSEUDO_REGISTER
5018 #ifdef CANNOT_CHANGE_MODE_CLASS
5019 && ! (REG_CANNOT_CHANGE_MODE_P (REGNO (op), innermode, outermode)
5020 && GET_MODE_CLASS (innermode) != MODE_COMPLEX_INT
5021 && GET_MODE_CLASS (innermode) != MODE_COMPLEX_FLOAT)
5023 && ((reload_completed && !frame_pointer_needed)
5024 || (REGNO (op) != FRAME_POINTER_REGNUM
5025 #if HARD_FRAME_POINTER_REGNUM != FRAME_POINTER_REGNUM
5026 && REGNO (op) != HARD_FRAME_POINTER_REGNUM
5029 #if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
5030 && REGNO (op) != ARG_POINTER_REGNUM
5032 && REGNO (op) != STACK_POINTER_REGNUM
5033 && subreg_offset_representable_p (REGNO (op), innermode,
5036 unsigned int regno = REGNO (op);
5037 unsigned int final_regno
5038 = regno + subreg_regno_offset (regno, innermode, byte, outermode);
5040 /* ??? We do allow it if the current REG is not valid for
5041 its mode. This is a kludge to work around how float/complex
5042 arguments are passed on 32-bit SPARC and should be fixed. */
5043 if (HARD_REGNO_MODE_OK (final_regno, outermode)
5044 || ! HARD_REGNO_MODE_OK (regno, innermode))
5047 int final_offset = byte;
5049 /* Adjust offset for paradoxical subregs. */
5051 && GET_MODE_SIZE (innermode) < GET_MODE_SIZE (outermode))
5053 int difference = (GET_MODE_SIZE (innermode)
5054 - GET_MODE_SIZE (outermode));
5055 if (WORDS_BIG_ENDIAN)
5056 final_offset += (difference / UNITS_PER_WORD) * UNITS_PER_WORD;
5057 if (BYTES_BIG_ENDIAN)
5058 final_offset += difference % UNITS_PER_WORD;
5061 x = gen_rtx_REG_offset (op, outermode, final_regno, final_offset);
5063 /* Propagate original regno. We don't have any way to specify
5064 the offset inside original regno, so do so only for lowpart.
5065 The information is used only by alias analysis that can not
5066 grog partial register anyway. */
5068 if (subreg_lowpart_offset (outermode, innermode) == byte)
5069 ORIGINAL_REGNO (x) = ORIGINAL_REGNO (op);
5074 /* If we have a SUBREG of a register that we are replacing and we are
5075 replacing it with a MEM, make a new MEM and try replacing the
5076 SUBREG with it. Don't do this if the MEM has a mode-dependent address
5077 or if we would be widening it. */
5080 && ! mode_dependent_address_p (XEXP (op, 0))
5081 /* Allow splitting of volatile memory references in case we don't
5082 have instruction to move the whole thing. */
5083 && (! MEM_VOLATILE_P (op)
5084 || ! have_insn_for (SET, innermode))
5085 && GET_MODE_SIZE (outermode) <= GET_MODE_SIZE (GET_MODE (op)))
5086 return adjust_address_nv (op, outermode, byte);
5088 /* Handle complex values represented as CONCAT
5089 of real and imaginary part. */
5090 if (GET_CODE (op) == CONCAT)
5092 unsigned int part_size, final_offset;
5095 part_size = GET_MODE_UNIT_SIZE (GET_MODE (XEXP (op, 0)));
5096 if (byte < part_size)
5098 part = XEXP (op, 0);
5099 final_offset = byte;
5103 part = XEXP (op, 1);
5104 final_offset = byte - part_size;
5107 if (final_offset + GET_MODE_SIZE (outermode) > part_size)
5110 res = simplify_subreg (outermode, part, GET_MODE (part), final_offset);
5113 if (validate_subreg (outermode, GET_MODE (part), part, final_offset))
5114 return gen_rtx_SUBREG (outermode, part, final_offset);
5118 /* Optimize SUBREG truncations of zero and sign extended values. */
5119 if ((GET_CODE (op) == ZERO_EXTEND
5120 || GET_CODE (op) == SIGN_EXTEND)
5121 && GET_MODE_BITSIZE (outermode) < GET_MODE_BITSIZE (innermode))
5123 unsigned int bitpos = subreg_lsb_1 (outermode, innermode, byte);
5125 /* If we're requesting the lowpart of a zero or sign extension,
5126 there are three possibilities. If the outermode is the same
5127 as the origmode, we can omit both the extension and the subreg.
5128 If the outermode is not larger than the origmode, we can apply
5129 the truncation without the extension. Finally, if the outermode
5130 is larger than the origmode, but both are integer modes, we
5131 can just extend to the appropriate mode. */
5134 enum machine_mode origmode = GET_MODE (XEXP (op, 0));
5135 if (outermode == origmode)
5136 return XEXP (op, 0);
5137 if (GET_MODE_BITSIZE (outermode) <= GET_MODE_BITSIZE (origmode))
5138 return simplify_gen_subreg (outermode, XEXP (op, 0), origmode,
5139 subreg_lowpart_offset (outermode,
5141 if (SCALAR_INT_MODE_P (outermode))
5142 return simplify_gen_unary (GET_CODE (op), outermode,
5143 XEXP (op, 0), origmode);
5146 /* A SUBREG resulting from a zero extension may fold to zero if
5147 it extracts higher bits that the ZERO_EXTEND's source bits. */
5148 if (GET_CODE (op) == ZERO_EXTEND
5149 && bitpos >= GET_MODE_BITSIZE (GET_MODE (XEXP (op, 0))))
5150 return CONST0_RTX (outermode);
5153 /* Simplify (subreg:QI (lshiftrt:SI (sign_extend:SI (x:QI)) C), 0) into
5154 to (ashiftrt:QI (x:QI) C), where C is a suitable small constant and
5155 the outer subreg is effectively a truncation to the original mode. */
5156 if ((GET_CODE (op) == LSHIFTRT
5157 || GET_CODE (op) == ASHIFTRT)
5158 && SCALAR_INT_MODE_P (outermode)
5159 /* Ensure that OUTERMODE is at least twice as wide as the INNERMODE
5160 to avoid the possibility that an outer LSHIFTRT shifts by more
5161 than the sign extension's sign_bit_copies and introduces zeros
5162 into the high bits of the result. */
5163 && (2 * GET_MODE_BITSIZE (outermode)) <= GET_MODE_BITSIZE (innermode)
5164 && GET_CODE (XEXP (op, 1)) == CONST_INT
5165 && GET_CODE (XEXP (op, 0)) == SIGN_EXTEND
5166 && GET_MODE (XEXP (XEXP (op, 0), 0)) == outermode
5167 && INTVAL (XEXP (op, 1)) < GET_MODE_BITSIZE (outermode)
5168 && subreg_lsb_1 (outermode, innermode, byte) == 0)
5169 return simplify_gen_binary (ASHIFTRT, outermode,
5170 XEXP (XEXP (op, 0), 0), XEXP (op, 1));
5172 /* Likewise (subreg:QI (lshiftrt:SI (zero_extend:SI (x:QI)) C), 0) into
5173 to (lshiftrt:QI (x:QI) C), where C is a suitable small constant and
5174 the outer subreg is effectively a truncation to the original mode. */
5175 if ((GET_CODE (op) == LSHIFTRT
5176 || GET_CODE (op) == ASHIFTRT)
5177 && SCALAR_INT_MODE_P (outermode)
5178 && GET_MODE_BITSIZE (outermode) < GET_MODE_BITSIZE (innermode)
5179 && GET_CODE (XEXP (op, 1)) == CONST_INT
5180 && GET_CODE (XEXP (op, 0)) == ZERO_EXTEND
5181 && GET_MODE (XEXP (XEXP (op, 0), 0)) == outermode
5182 && INTVAL (XEXP (op, 1)) < GET_MODE_BITSIZE (outermode)
5183 && subreg_lsb_1 (outermode, innermode, byte) == 0)
5184 return simplify_gen_binary (LSHIFTRT, outermode,
5185 XEXP (XEXP (op, 0), 0), XEXP (op, 1));
5187 /* Likewise (subreg:QI (ashift:SI (zero_extend:SI (x:QI)) C), 0) into
5188 to (ashift:QI (x:QI) C), where C is a suitable small constant and
5189 the outer subreg is effectively a truncation to the original mode. */
5190 if (GET_CODE (op) == ASHIFT
5191 && SCALAR_INT_MODE_P (outermode)
5192 && GET_MODE_BITSIZE (outermode) < GET_MODE_BITSIZE (innermode)
5193 && GET_CODE (XEXP (op, 1)) == CONST_INT
5194 && (GET_CODE (XEXP (op, 0)) == ZERO_EXTEND
5195 || GET_CODE (XEXP (op, 0)) == SIGN_EXTEND)
5196 && GET_MODE (XEXP (XEXP (op, 0), 0)) == outermode
5197 && INTVAL (XEXP (op, 1)) < GET_MODE_BITSIZE (outermode)
5198 && subreg_lsb_1 (outermode, innermode, byte) == 0)
5199 return simplify_gen_binary (ASHIFT, outermode,
5200 XEXP (XEXP (op, 0), 0), XEXP (op, 1));
5205 /* Make a SUBREG operation or equivalent if it folds. */
5208 simplify_gen_subreg (enum machine_mode outermode, rtx op,
5209 enum machine_mode innermode, unsigned int byte)
5213 newx = simplify_subreg (outermode, op, innermode, byte);
5217 if (GET_CODE (op) == SUBREG
5218 || GET_CODE (op) == CONCAT
5219 || GET_MODE (op) == VOIDmode)
5222 if (validate_subreg (outermode, innermode, op, byte))
5223 return gen_rtx_SUBREG (outermode, op, byte);
5228 /* Simplify X, an rtx expression.
5230 Return the simplified expression or NULL if no simplifications
5233 This is the preferred entry point into the simplification routines;
5234 however, we still allow passes to call the more specific routines.
5236 Right now GCC has three (yes, three) major bodies of RTL simplification
5237 code that need to be unified.
5239 1. fold_rtx in cse.c. This code uses various CSE specific
5240 information to aid in RTL simplification.
5242 2. simplify_rtx in combine.c. Similar to fold_rtx, except that
5243 it uses combine specific information to aid in RTL
5246 3. The routines in this file.
5249 Long term we want to only have one body of simplification code; to
5250 get to that state I recommend the following steps:
5252 1. Pour over fold_rtx & simplify_rtx and move any simplifications
5253 which are not pass dependent state into these routines.
5255 2. As code is moved by #1, change fold_rtx & simplify_rtx to
5256 use this routine whenever possible.
5258 3. Allow for pass dependent state to be provided to these
5259 routines and add simplifications based on the pass dependent
5260 state. Remove code from cse.c & combine.c that becomes
5263 It will take time, but ultimately the compiler will be easier to
5264 maintain and improve. It's totally silly that when we add a
5265 simplification that it needs to be added to 4 places (3 for RTL
5266 simplification and 1 for tree simplification. */
5269 simplify_rtx (const_rtx x)
5271 const enum rtx_code code = GET_CODE (x);
5272 const enum machine_mode mode = GET_MODE (x);
5274 switch (GET_RTX_CLASS (code))
5277 return simplify_unary_operation (code, mode,
5278 XEXP (x, 0), GET_MODE (XEXP (x, 0)));
5279 case RTX_COMM_ARITH:
5280 if (swap_commutative_operands_p (XEXP (x, 0), XEXP (x, 1)))
5281 return simplify_gen_binary (code, mode, XEXP (x, 1), XEXP (x, 0));
5283 /* Fall through.... */
5286 return simplify_binary_operation (code, mode, XEXP (x, 0), XEXP (x, 1));
5289 case RTX_BITFIELD_OPS:
5290 return simplify_ternary_operation (code, mode, GET_MODE (XEXP (x, 0)),
5291 XEXP (x, 0), XEXP (x, 1),
5295 case RTX_COMM_COMPARE:
5296 return simplify_relational_operation (code, mode,
5297 ((GET_MODE (XEXP (x, 0))
5299 ? GET_MODE (XEXP (x, 0))
5300 : GET_MODE (XEXP (x, 1))),
5306 return simplify_subreg (mode, SUBREG_REG (x),
5307 GET_MODE (SUBREG_REG (x)),
5314 /* Convert (lo_sum (high FOO) FOO) to FOO. */
5315 if (GET_CODE (XEXP (x, 0)) == HIGH
5316 && rtx_equal_p (XEXP (XEXP (x, 0), 0), XEXP (x, 1)))