/* Don't substitute into an incremented register. */
|| FIND_REG_INC_NOTE (i3, dest)
|| (succ && FIND_REG_INC_NOTE (succ, dest))
+ /* Don't substitute into a non-local goto, this confuses CFG. */
+ || (JUMP_P (i3) && find_reg_note (i3, REG_NON_LOCAL_GOTO, NULL_RTX))
#if 0
/* Don't combine the end of a libcall into anything. */
/* ??? This gives worse code, and appears to be unnecessary, since no
&& (GET_MODE_MASK (GET_MODE (x)) & ~mask) == 0)
return gen_lowpart (mode, x);
- /* If we aren't changing the mode, X is not a SUBREG, and all zero bits in
- MASK are already known to be zero in X, we need not do anything. */
- if (GET_MODE (x) == mode && code != SUBREG && (~mask & nonzero) == 0)
- return x;
-
switch (code)
{
case CLOBBER:
in STORE_FLAG_VALUE and FOO has a single bit that might be nonzero,
which is equal to STORE_FLAG_VALUE. */
if ((mask & ~STORE_FLAG_VALUE) == 0 && XEXP (x, 1) == const0_rtx
+ && GET_MODE (XEXP (x, 0)) == mode
&& exact_log2 (nonzero_bits (XEXP (x, 0), mode)) >= 0
&& (nonzero_bits (XEXP (x, 0), mode)
== (unsigned HOST_WIDE_INT) STORE_FLAG_VALUE))
varop = XEXP (varop, 0);
continue;
}
+
+ /* Check for 'PLUS signbit', which is the canonical form of 'XOR
+ signbit', and attempt to change the PLUS to an XOR and move it to
+ the outer operation as is done above in the AND/IOR/XOR case
+ leg for shift(logical). See details in logical handling above
+ for reasoning in doing so. */
+ if (code == LSHIFTRT
+ && GET_CODE (XEXP (varop, 1)) == CONST_INT
+ && mode_signbit_p (result_mode, XEXP (varop, 1))
+ && (new = simplify_binary_operation (code, result_mode,
+ XEXP (varop, 1),
+ GEN_INT (count))) != 0
+ && GET_CODE (new) == CONST_INT
+ && merge_outer_ops (&outer_op, &outer_const, XOR,
+ INTVAL (new), result_mode, &complement_p))
+ {
+ varop = XEXP (varop, 0);
+ continue;
+ }
+
break;
case MINUS:
An insn containing that will not be recognized. */
static rtx
-gen_lowpart_for_combine (enum machine_mode mode, rtx x)
+gen_lowpart_for_combine (enum machine_mode omode, rtx x)
{
+ enum machine_mode imode = GET_MODE (x);
+ unsigned int osize = GET_MODE_SIZE (omode);
+ unsigned int isize = GET_MODE_SIZE (imode);
rtx result;
- if (GET_MODE (x) == mode)
+ if (omode == imode)
return x;
- /* Return identity if this is a CONST or symbolic
- reference. */
- if (mode == Pmode
+ /* Return identity if this is a CONST or symbolic reference. */
+ if (omode == Pmode
&& (GET_CODE (x) == CONST
|| GET_CODE (x) == SYMBOL_REF
|| GET_CODE (x) == LABEL_REF))
/* We can only support MODE being wider than a word if X is a
constant integer or has a mode the same size. */
-
- if (GET_MODE_SIZE (mode) > UNITS_PER_WORD
- && ! ((GET_MODE (x) == VOIDmode
+ if (GET_MODE_SIZE (omode) > UNITS_PER_WORD
+ && ! ((imode == VOIDmode
&& (GET_CODE (x) == CONST_INT
|| GET_CODE (x) == CONST_DOUBLE))
- || GET_MODE_SIZE (GET_MODE (x)) == GET_MODE_SIZE (mode)))
- return gen_rtx_CLOBBER (GET_MODE (x), const0_rtx);
+ || isize == osize))
+ goto fail;
/* X might be a paradoxical (subreg (mem)). In that case, gen_lowpart
won't know what to do. So we will strip off the SUBREG here and
if (GET_CODE (x) == SUBREG && MEM_P (SUBREG_REG (x)))
{
x = SUBREG_REG (x);
- if (GET_MODE (x) == mode)
+ if (GET_MODE (x) == omode)
return x;
}
- result = gen_lowpart_common (mode, x);
+ result = gen_lowpart_common (omode, x);
+
#ifdef CANNOT_CHANGE_MODE_CLASS
- if (result != 0
- && GET_CODE (result) == SUBREG
- && REG_P (SUBREG_REG (result))
- && REGNO (SUBREG_REG (result)) >= FIRST_PSEUDO_REGISTER)
- bitmap_set_bit (&subregs_of_mode, REGNO (SUBREG_REG (result))
- * MAX_MACHINE_MODE
- + GET_MODE (result));
+ if (result != 0 && GET_CODE (result) == SUBREG)
+ record_subregs_of_mode (result);
#endif
if (result)
/* Refuse to work on a volatile memory ref or one with a mode-dependent
address. */
if (MEM_VOLATILE_P (x) || mode_dependent_address_p (XEXP (x, 0)))
- return gen_rtx_CLOBBER (GET_MODE (x), const0_rtx);
+ goto fail;
/* If we want to refer to something bigger than the original memref,
generate a paradoxical subreg instead. That will force a reload
of the original memref X. */
- if (GET_MODE_SIZE (GET_MODE (x)) < GET_MODE_SIZE (mode))
- return gen_rtx_SUBREG (mode, x, 0);
+ if (isize < osize)
+ return gen_rtx_SUBREG (omode, x, 0);
if (WORDS_BIG_ENDIAN)
- offset = (MAX (GET_MODE_SIZE (GET_MODE (x)), UNITS_PER_WORD)
- - MAX (GET_MODE_SIZE (mode), UNITS_PER_WORD));
+ offset = MAX (isize, UNITS_PER_WORD) - MAX (osize, UNITS_PER_WORD);
+ /* Adjust the address so that the address-after-the-data is unchanged. */
if (BYTES_BIG_ENDIAN)
- {
- /* Adjust the address so that the address-after-the-data is
- unchanged. */
- offset -= (MIN (UNITS_PER_WORD, GET_MODE_SIZE (mode))
- - MIN (UNITS_PER_WORD, GET_MODE_SIZE (GET_MODE (x))));
- }
+ offset -= MIN (UNITS_PER_WORD, osize) - MIN (UNITS_PER_WORD, isize);
- return adjust_address_nv (x, mode, offset);
+ return adjust_address_nv (x, omode, offset);
}
/* If X is a comparison operator, rewrite it in a new mode. This
probably won't match, but may allow further simplifications. */
else if (COMPARISON_P (x))
- return gen_rtx_fmt_ee (GET_CODE (x), mode, XEXP (x, 0), XEXP (x, 1));
+ return gen_rtx_fmt_ee (GET_CODE (x), omode, XEXP (x, 0), XEXP (x, 1));
/* If we couldn't simplify X any other way, just enclose it in a
SUBREG. Normally, this SUBREG won't match, but some patterns may
{
int offset = 0;
rtx res;
- enum machine_mode sub_mode = GET_MODE (x);
- offset = subreg_lowpart_offset (mode, sub_mode);
- if (sub_mode == VOIDmode)
+ offset = subreg_lowpart_offset (omode, imode);
+ if (imode == VOIDmode)
{
- sub_mode = int_mode_for_mode (mode);
- x = gen_lowpart_common (sub_mode, x);
- if (x == 0)
- return gen_rtx_CLOBBER (VOIDmode, const0_rtx);
+ imode = int_mode_for_mode (omode);
+ x = gen_lowpart_common (imode, x);
+ if (x == NULL)
+ goto fail;
}
- res = simplify_gen_subreg (mode, x, sub_mode, offset);
+ res = simplify_gen_subreg (omode, x, imode, offset);
if (res)
return res;
- return gen_rtx_CLOBBER (GET_MODE (x), const0_rtx);
}
+
+ fail:
+ return gen_rtx_CLOBBER (imode, const0_rtx);
}
\f
/* These routines make binary and unary operations by first seeing if they
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