/* Fold a constant sub-tree into a single node for C-compiler
Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
- 1999, 2000, 2001 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
This file is part of GCC.
#include "system.h"
#include "flags.h"
#include "tree.h"
+#include "real.h"
#include "rtl.h"
#include "expr.h"
#include "tm_p.h"
#include "toplev.h"
#include "ggc.h"
#include "hashtab.h"
+#include "langhooks.h"
static void encode PARAMS ((HOST_WIDE_INT *,
unsigned HOST_WIDE_INT,
static void decode PARAMS ((HOST_WIDE_INT *,
unsigned HOST_WIDE_INT *,
HOST_WIDE_INT *));
-#ifndef REAL_ARITHMETIC
-static void exact_real_inverse_1 PARAMS ((PTR));
-#endif
static tree negate_expr PARAMS ((tree));
static tree split_tree PARAMS ((tree, enum tree_code, tree *, tree *,
- int));
+ tree *, int));
static tree associate_trees PARAMS ((tree, tree, enum tree_code, tree));
static tree int_const_binop PARAMS ((enum tree_code, tree, tree, int));
-static void const_binop_1 PARAMS ((PTR));
static tree const_binop PARAMS ((enum tree_code, tree, tree, int));
static hashval_t size_htab_hash PARAMS ((const void *));
static int size_htab_eq PARAMS ((const void *, const void *));
-static void fold_convert_1 PARAMS ((PTR));
static tree fold_convert PARAMS ((tree, tree));
static enum tree_code invert_tree_comparison PARAMS ((enum tree_code));
static enum tree_code swap_tree_comparison PARAMS ((enum tree_code));
enum machine_mode *, int *,
int *, tree *, tree *));
static int all_ones_mask_p PARAMS ((tree, int));
+static tree sign_bit_p PARAMS ((tree, tree));
static int simple_operand_p PARAMS ((tree));
static tree range_binop PARAMS ((enum tree_code, tree, tree, int,
tree, int));
static int multiple_of_p PARAMS ((tree, tree, tree));
static tree constant_boolean_node PARAMS ((int, tree));
static int count_cond PARAMS ((tree, int));
-static tree fold_binary_op_with_conditional_arg
+static tree fold_binary_op_with_conditional_arg
PARAMS ((enum tree_code, tree, tree, tree, int));
-
-#ifndef BRANCH_COST
-#define BRANCH_COST 1
-#endif
+static bool fold_real_zero_addition_p PARAMS ((tree, tree, int));
#if defined(HOST_EBCDIC)
/* bit 8 is significant in EBCDIC */
HOST_WIDE_INT arg1[4];
HOST_WIDE_INT arg2[4];
HOST_WIDE_INT prod[4 * 2];
- register unsigned HOST_WIDE_INT carry;
- register int i, j, k;
+ unsigned HOST_WIDE_INT carry;
+ int i, j, k;
unsigned HOST_WIDE_INT toplow, neglow;
HOST_WIDE_INT tophigh, neghigh;
HOST_WIDE_INT *hv;
int arith;
{
+ unsigned HOST_WIDE_INT signmask;
+
if (count < 0)
{
rshift_double (l1, h1, -count, prec, lv, hv, arith);
| (l1 >> (HOST_BITS_PER_WIDE_INT - count - 1) >> 1));
*lv = l1 << count;
}
+
+ /* Sign extend all bits that are beyond the precision. */
+
+ signmask = -((prec > HOST_BITS_PER_WIDE_INT
+ ? ((unsigned HOST_WIDE_INT) *hv
+ >> (prec - HOST_BITS_PER_WIDE_INT - 1))
+ : (*lv >> (prec - 1))) & 1);
+
+ if (prec >= 2 * HOST_BITS_PER_WIDE_INT)
+ ;
+ else if (prec >= HOST_BITS_PER_WIDE_INT)
+ {
+ *hv &= ~((HOST_WIDE_INT) (-1) << (prec - HOST_BITS_PER_WIDE_INT));
+ *hv |= signmask << (prec - HOST_BITS_PER_WIDE_INT);
+ }
+ else
+ {
+ *hv = signmask;
+ *lv &= ~((unsigned HOST_WIDE_INT) (-1) << prec);
+ *lv |= signmask << prec;
+ }
}
/* Shift the doubleword integer in L1, H1 right by COUNT places
rshift_double (l1, h1, count, prec, lv, hv, arith)
unsigned HOST_WIDE_INT l1;
HOST_WIDE_INT h1, count;
- unsigned int prec ATTRIBUTE_UNUSED;
+ unsigned int prec;
unsigned HOST_WIDE_INT *lv;
HOST_WIDE_INT *hv;
int arith;
{
/* Shifting by the host word size is undefined according to the
ANSI standard, so we must handle this as a special case. */
- *hv = signmask;
- *lv = signmask;
+ *hv = 0;
+ *lv = 0;
}
else if (count >= HOST_BITS_PER_WIDE_INT)
{
- *hv = signmask;
- *lv = ((signmask << (2 * HOST_BITS_PER_WIDE_INT - count - 1) << 1)
- | ((unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT)));
+ *hv = 0;
+ *lv = (unsigned HOST_WIDE_INT) h1 >> (count - HOST_BITS_PER_WIDE_INT);
}
else
{
+ *hv = (unsigned HOST_WIDE_INT) h1 >> count;
*lv = ((l1 >> count)
| ((unsigned HOST_WIDE_INT) h1 << (HOST_BITS_PER_WIDE_INT - count - 1) << 1));
- *hv = ((signmask << (HOST_BITS_PER_WIDE_INT - count))
- | ((unsigned HOST_WIDE_INT) h1 >> count));
+ }
+
+ /* Zero / sign extend all bits that are beyond the precision. */
+
+ if (count >= (HOST_WIDE_INT)prec)
+ {
+ *hv = signmask;
+ *lv = signmask;
+ }
+ else if ((prec - count) >= 2 * HOST_BITS_PER_WIDE_INT)
+ ;
+ else if ((prec - count) >= HOST_BITS_PER_WIDE_INT)
+ {
+ *hv &= ~((HOST_WIDE_INT) (-1) << (prec - count - HOST_BITS_PER_WIDE_INT));
+ *hv |= signmask << (prec - count - HOST_BITS_PER_WIDE_INT);
+ }
+ else
+ {
+ *hv = signmask;
+ *lv &= ~((unsigned HOST_WIDE_INT) (-1) << (prec - count));
+ *lv |= signmask << (prec - count);
}
}
\f
int quo_neg = 0;
HOST_WIDE_INT num[4 + 1]; /* extra element for scaling. */
HOST_WIDE_INT den[4], quo[4];
- register int i, j;
+ int i, j;
unsigned HOST_WIDE_INT work;
unsigned HOST_WIDE_INT carry = 0;
unsigned HOST_WIDE_INT lnum = lnum_orig;
/* If quo_est was high by one, then num[i] went negative and
we need to correct things. */
- if (num[num_hi_sig] < carry)
+ if (num[num_hi_sig] < (HOST_WIDE_INT) carry)
{
quo_est--;
carry = 0; /* add divisor back in */
return overflow;
}
\f
-#ifndef REAL_ARITHMETIC
-/* Effectively truncate a real value to represent the nearest possible value
- in a narrower mode. The result is actually represented in the same data
- type as the argument, but its value is usually different.
-
- A trap may occur during the FP operations and it is the responsibility
- of the calling function to have a handler established. */
-
-REAL_VALUE_TYPE
-real_value_truncate (mode, arg)
- enum machine_mode mode;
- REAL_VALUE_TYPE arg;
-{
- return REAL_VALUE_TRUNCATE (mode, arg);
-}
-
-#if TARGET_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
-
-/* Check for infinity in an IEEE double precision number. */
-
-int
-target_isinf (x)
- REAL_VALUE_TYPE x;
-{
- /* The IEEE 64-bit double format. */
- union {
- REAL_VALUE_TYPE d;
- struct {
- unsigned sign : 1;
- unsigned exponent : 11;
- unsigned mantissa1 : 20;
- unsigned mantissa2 : 32;
- } little_endian;
- struct {
- unsigned mantissa2 : 32;
- unsigned mantissa1 : 20;
- unsigned exponent : 11;
- unsigned sign : 1;
- } big_endian;
- } u;
-
- u.d = dconstm1;
- if (u.big_endian.sign == 1)
- {
- u.d = x;
- return (u.big_endian.exponent == 2047
- && u.big_endian.mantissa1 == 0
- && u.big_endian.mantissa2 == 0);
- }
- else
- {
- u.d = x;
- return (u.little_endian.exponent == 2047
- && u.little_endian.mantissa1 == 0
- && u.little_endian.mantissa2 == 0);
- }
-}
-
-/* Check whether an IEEE double precision number is a NaN. */
-
-int
-target_isnan (x)
- REAL_VALUE_TYPE x;
-{
- /* The IEEE 64-bit double format. */
- union {
- REAL_VALUE_TYPE d;
- struct {
- unsigned sign : 1;
- unsigned exponent : 11;
- unsigned mantissa1 : 20;
- unsigned mantissa2 : 32;
- } little_endian;
- struct {
- unsigned mantissa2 : 32;
- unsigned mantissa1 : 20;
- unsigned exponent : 11;
- unsigned sign : 1;
- } big_endian;
- } u;
-
- u.d = dconstm1;
- if (u.big_endian.sign == 1)
- {
- u.d = x;
- return (u.big_endian.exponent == 2047
- && (u.big_endian.mantissa1 != 0
- || u.big_endian.mantissa2 != 0));
- }
- else
- {
- u.d = x;
- return (u.little_endian.exponent == 2047
- && (u.little_endian.mantissa1 != 0
- || u.little_endian.mantissa2 != 0));
- }
-}
-
-/* Check for a negative IEEE double precision number. */
-
-int
-target_negative (x)
- REAL_VALUE_TYPE x;
-{
- /* The IEEE 64-bit double format. */
- union {
- REAL_VALUE_TYPE d;
- struct {
- unsigned sign : 1;
- unsigned exponent : 11;
- unsigned mantissa1 : 20;
- unsigned mantissa2 : 32;
- } little_endian;
- struct {
- unsigned mantissa2 : 32;
- unsigned mantissa1 : 20;
- unsigned exponent : 11;
- unsigned sign : 1;
- } big_endian;
- } u;
-
- u.d = dconstm1;
- if (u.big_endian.sign == 1)
- {
- u.d = x;
- return u.big_endian.sign;
- }
- else
- {
- u.d = x;
- return u.little_endian.sign;
- }
-}
-#else /* Target not IEEE */
-
-/* Let's assume other float formats don't have infinity.
- (This can be overridden by redefining REAL_VALUE_ISINF.) */
-
-int
-target_isinf (x)
- REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
-{
- return 0;
-}
-
-/* Let's assume other float formats don't have NaNs.
- (This can be overridden by redefining REAL_VALUE_ISNAN.) */
-
-int
-target_isnan (x)
- REAL_VALUE_TYPE x ATTRIBUTE_UNUSED;
-{
- return 0;
-}
-
-/* Let's assume other float formats don't have minus zero.
- (This can be overridden by redefining REAL_VALUE_NEGATIVE.) */
-
-int
-target_negative (x)
- REAL_VALUE_TYPE x;
-{
- return x < 0;
-}
-#endif /* Target not IEEE */
-
-/* Try to change R into its exact multiplicative inverse in machine mode
- MODE. Return nonzero function value if successful. */
-struct exact_real_inverse_args
-{
- REAL_VALUE_TYPE *r;
- enum machine_mode mode;
- int success;
-};
-
-static void
-exact_real_inverse_1 (p)
- PTR p;
-{
- struct exact_real_inverse_args *args =
- (struct exact_real_inverse_args *) p;
-
- enum machine_mode mode = args->mode;
- REAL_VALUE_TYPE *r = args->r;
-
- union
- {
- double d;
- unsigned short i[4];
- }
- x, t, y;
-#ifdef CHECK_FLOAT_VALUE
- int i;
-#endif
-
- /* Set array index to the less significant bits in the unions, depending
- on the endian-ness of the host doubles. */
-#if HOST_FLOAT_FORMAT == VAX_FLOAT_FORMAT \
- || HOST_FLOAT_FORMAT == IBM_FLOAT_FORMAT
-# define K 2
-#else
-# define K (2 * HOST_FLOAT_WORDS_BIG_ENDIAN)
-#endif
-
- /* Domain check the argument. */
- x.d = *r;
- if (x.d == 0.0)
- goto fail;
-
-#ifdef REAL_INFINITY
- if (REAL_VALUE_ISINF (x.d) || REAL_VALUE_ISNAN (x.d))
- goto fail;
-#endif
-
- /* Compute the reciprocal and check for numerical exactness.
- It is unnecessary to check all the significand bits to determine
- whether X is a power of 2. If X is not, then it is impossible for
- the bottom half significand of both X and 1/X to be all zero bits.
- Hence we ignore the data structure of the top half and examine only
- the low order bits of the two significands. */
- t.d = 1.0 / x.d;
- if (x.i[K] != 0 || x.i[K + 1] != 0 || t.i[K] != 0 || t.i[K + 1] != 0)
- goto fail;
-
- /* Truncate to the required mode and range-check the result. */
- y.d = REAL_VALUE_TRUNCATE (mode, t.d);
-#ifdef CHECK_FLOAT_VALUE
- i = 0;
- if (CHECK_FLOAT_VALUE (mode, y.d, i))
- goto fail;
-#endif
-
- /* Fail if truncation changed the value. */
- if (y.d != t.d || y.d == 0.0)
- goto fail;
-
-#ifdef REAL_INFINITY
- if (REAL_VALUE_ISINF (y.d) || REAL_VALUE_ISNAN (y.d))
- goto fail;
-#endif
-
- /* Output the reciprocal and return success flag. */
- *r = y.d;
- args->success = 1;
- return;
-
- fail:
- args->success = 0;
- return;
-
-#undef K
-}
-
-
-int
-exact_real_inverse (mode, r)
- enum machine_mode mode;
- REAL_VALUE_TYPE *r;
-{
- struct exact_real_inverse_args args;
-
- /* Disable if insufficient information on the data structure. */
-#if HOST_FLOAT_FORMAT == UNKNOWN_FLOAT_FORMAT
- return 0;
-#endif
-
- /* Usually disable if bounds checks are not reliable. */
- if ((HOST_FLOAT_FORMAT != TARGET_FLOAT_FORMAT) && !flag_pretend_float)
- return 0;
-
- args.mode = mode;
- args.r = r;
-
- if (do_float_handler (exact_real_inverse_1, (PTR) &args))
- return args.success;
- return 0;
-}
-
-/* Convert C99 hexadecimal floating point string constant S. Return
- real value type in mode MODE. This function uses the host computer's
- floating point arithmetic when there is no REAL_ARITHMETIC. */
-
-REAL_VALUE_TYPE
-real_hex_to_f (s, mode)
- const char *s;
- enum machine_mode mode;
-{
- REAL_VALUE_TYPE ip;
- const char *p = s;
- unsigned HOST_WIDE_INT low, high;
- int shcount, nrmcount, k;
- int sign, expsign, isfloat;
- int lost = 0;/* Nonzero low order bits shifted out and discarded. */
- int frexpon = 0; /* Bits after the decimal point. */
- int expon = 0; /* Value of exponent. */
- int decpt = 0; /* How many decimal points. */
- int gotp = 0; /* How many P's. */
- char c;
-
- isfloat = 0;
- expsign = 1;
- ip = 0.0;
-
- while (*p == ' ' || *p == '\t')
- ++p;
-
- /* Sign, if any, comes first. */
- sign = 1;
- if (*p == '-')
- {
- sign = -1;
- ++p;
- }
-
- /* The string is supposed to start with 0x or 0X . */
- if (*p == '0')
- {
- ++p;
- if (*p == 'x' || *p == 'X')
- ++p;
- else
- abort ();
- }
- else
- abort ();
-
- while (*p == '0')
- ++p;
-
- high = 0;
- low = 0;
- shcount = 0;
- while ((c = *p) != '\0')
- {
- if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'F')
- || (c >= 'a' && c <= 'f'))
- {
- k = c & CHARMASK;
- if (k >= 'a' && k <= 'f')
- k = k - 'a' + 10;
- else if (k >= 'A')
- k = k - 'A' + 10;
- else
- k = k - '0';
-
- if ((high & 0xf0000000) == 0)
- {
- high = (high << 4) + ((low >> 28) & 15);
- low = (low << 4) + k;
- shcount += 4;
- if (decpt)
- frexpon += 4;
- }
- else
- {
- /* Record nonzero lost bits. */
- lost |= k;
- if (! decpt)
- frexpon -= 4;
- }
- ++p;
- }
- else if (c == '.')
- {
- ++decpt;
- ++p;
- }
-
- else if (c == 'p' || c == 'P')
- {
- ++gotp;
- ++p;
- /* Sign of exponent. */
- if (*p == '-')
- {
- expsign = -1;
- ++p;
- }
-
- /* Value of exponent.
- The exponent field is a decimal integer. */
- while (ISDIGIT (*p))
- {
- k = (*p++ & CHARMASK) - '0';
- expon = 10 * expon + k;
- }
-
- expon *= expsign;
- /* F suffix is ambiguous in the significand part
- so it must appear after the decimal exponent field. */
- if (*p == 'f' || *p == 'F')
- {
- isfloat = 1;
- ++p;
- break;
- }
- }
-
- else if (c == 'l' || c == 'L')
- {
- ++p;
- break;
- }
- else
- break;
- }
-
- /* Abort if last character read was not legitimate. */
- c = *p;
- if ((c != '\0' && c != ' ' && c != '\n' && c != '\r') || (decpt > 1))
- abort ();
-
- /* There must be either one decimal point or one p. */
- if (decpt == 0 && gotp == 0)
- abort ();
-
- shcount -= 4;
- if (high == 0 && low == 0)
- return dconst0;
-
- /* Normalize. */
- nrmcount = 0;
- if (high == 0)
- {
- high = low;
- low = 0;
- nrmcount += 32;
- }
-
- /* Leave a high guard bit for carry-out. */
- if ((high & 0x80000000) != 0)
- {
- lost |= low & 1;
- low = (low >> 1) | (high << 31);
- high = high >> 1;
- nrmcount -= 1;
- }
-
- if ((high & 0xffff8000) == 0)
- {
- high = (high << 16) + ((low >> 16) & 0xffff);
- low = low << 16;
- nrmcount += 16;
- }
-
- while ((high & 0xc0000000) == 0)
- {
- high = (high << 1) + ((low >> 31) & 1);
- low = low << 1;
- nrmcount += 1;
- }
-
- if (isfloat || GET_MODE_SIZE (mode) == UNITS_PER_WORD)
- {
- /* Keep 24 bits precision, bits 0x7fffff80.
- Rounding bit is 0x40. */
- lost = lost | low | (high & 0x3f);
- low = 0;
- if (high & 0x40)
- {
- if ((high & 0x80) || lost)
- high += 0x40;
- }
- high &= 0xffffff80;
- }
- else
- {
- /* We need real.c to do long double formats, so here default
- to double precision. */
-#if HOST_FLOAT_FORMAT == IEEE_FLOAT_FORMAT
- /* IEEE double.
- Keep 53 bits precision, bits 0x7fffffff fffffc00.
- Rounding bit is low word 0x200. */
- lost = lost | (low & 0x1ff);
- if (low & 0x200)
- {
- if ((low & 0x400) || lost)
- {
- low = (low + 0x200) & 0xfffffc00;
- if (low == 0)
- high += 1;
- }
- }
- low &= 0xfffffc00;
-#else
- /* Assume it's a VAX with 56-bit significand,
- bits 0x7fffffff ffffff80. */
- lost = lost | (low & 0x7f);
- if (low & 0x40)
- {
- if ((low & 0x80) || lost)
- {
- low = (low + 0x40) & 0xffffff80;
- if (low == 0)
- high += 1;
- }
- }
- low &= 0xffffff80;
-#endif
- }
-
- ip = (double) high;
- ip = REAL_VALUE_LDEXP (ip, 32) + (double) low;
- /* Apply shifts and exponent value as power of 2. */
- ip = REAL_VALUE_LDEXP (ip, expon - (nrmcount + frexpon));
-
- if (sign < 0)
- ip = -ip;
- return ip;
-}
-
-#endif /* no REAL_ARITHMETIC */
-\f
/* Given T, an expression, return the negation of T. Allow for T to be
null, in which case return null. */
break;
}
- return convert (type, build1 (NEGATE_EXPR, TREE_TYPE (t), t));
+ return convert (type, fold (build1 (NEGATE_EXPR, TREE_TYPE (t), t)));
}
\f
/* Split a tree IN into a constant, literal and variable parts that could be
combined with CODE to make IN. "constant" means an expression with
TREE_CONSTANT but that isn't an actual constant. CODE must be a
commutative arithmetic operation. Store the constant part into *CONP,
- the literal in &LITP and return the variable part. If a part isn't
+ the literal in *LITP and return the variable part. If a part isn't
present, set it to null. If the tree does not decompose in this way,
return the entire tree as the variable part and the other parts as null.
If CODE is PLUS_EXPR we also split trees that use MINUS_EXPR. In that
- case, we negate an operand that was subtracted. If NEGATE_P is true, we
- are negating all of IN.
+ case, we negate an operand that was subtracted. Except if it is a
+ literal for which we use *MINUS_LITP instead.
+
+ If NEGATE_P is true, we are negating all of IN, again except a literal
+ for which we use *MINUS_LITP instead.
If IN is itself a literal or constant, return it as appropriate.
same type as IN, but they will have the same signedness and mode. */
static tree
-split_tree (in, code, conp, litp, negate_p)
+split_tree (in, code, conp, litp, minus_litp, negate_p)
tree in;
enum tree_code code;
- tree *conp, *litp;
+ tree *conp, *litp, *minus_litp;
int negate_p;
{
tree var = 0;
*conp = 0;
*litp = 0;
+ *minus_litp = 0;
/* Strip any conversions that don't change the machine mode or signedness. */
STRIP_SIGN_NOPS (in);
var = op1, neg_var_p = neg1_p;
/* Now do any needed negations. */
- if (neg_litp_p) *litp = negate_expr (*litp);
- if (neg_conp_p) *conp = negate_expr (*conp);
- if (neg_var_p) var = negate_expr (var);
+ if (neg_litp_p)
+ *minus_litp = *litp, *litp = 0;
+ if (neg_conp_p)
+ *conp = negate_expr (*conp);
+ if (neg_var_p)
+ var = negate_expr (var);
}
else if (TREE_CONSTANT (in))
*conp = in;
if (negate_p)
{
- var = negate_expr (var);
+ if (*litp)
+ *minus_litp = *litp, *litp = 0;
+ else if (*minus_litp)
+ *litp = *minus_litp, *minus_litp = 0;
*conp = negate_expr (*conp);
- *litp = negate_expr (*litp);
+ var = negate_expr (var);
}
return var;
/* Re-associate trees split by the above function. T1 and T2 are either
expressions to associate or null. Return the new expression, if any. If
- we build an operation, do it in TYPE and with CODE, except if CODE is a
- MINUS_EXPR, in which case we use PLUS_EXPR since split_tree will already
- have taken care of the negations. */
+ we build an operation, do it in TYPE and with CODE. */
static tree
associate_trees (t1, t2, code, type)
else if (t2 == 0)
return t1;
- if (code == MINUS_EXPR)
- code = PLUS_EXPR;
-
/* If either input is CODE, a PLUS_EXPR, or a MINUS_EXPR, don't
try to fold this since we will have infinite recursion. But do
deal with any NEGATE_EXPRs. */
static tree
int_const_binop (code, arg1, arg2, notrunc)
enum tree_code code;
- register tree arg1, arg2;
+ tree arg1, arg2;
int notrunc;
{
unsigned HOST_WIDE_INT int1l, int2l;
HOST_WIDE_INT hi;
unsigned HOST_WIDE_INT garbagel;
HOST_WIDE_INT garbageh;
- register tree t;
+ tree t;
tree type = TREE_TYPE (arg1);
int uns = TREE_UNSIGNED (type);
int is_sizetype
return t;
}
-/* Define input and output argument for const_binop_1. */
-struct cb_args
-{
- enum tree_code code; /* Input: tree code for operation. */
- tree type; /* Input: tree type for operation. */
- REAL_VALUE_TYPE d1, d2; /* Input: floating point operands. */
- tree t; /* Output: constant for result. */
-};
-
-/* Do the real arithmetic for const_binop while protected by a
- float overflow handler. */
-
-static void
-const_binop_1 (data)
- PTR data;
-{
- struct cb_args *args = (struct cb_args *) data;
- REAL_VALUE_TYPE value;
-
-#ifdef REAL_ARITHMETIC
- REAL_ARITHMETIC (value, args->code, args->d1, args->d2);
-#else
- switch (args->code)
- {
- case PLUS_EXPR:
- value = args->d1 + args->d2;
- break;
-
- case MINUS_EXPR:
- value = args->d1 - args->d2;
- break;
-
- case MULT_EXPR:
- value = args->d1 * args->d2;
- break;
-
- case RDIV_EXPR:
-#ifndef REAL_INFINITY
- if (args->d2 == 0)
- abort ();
-#endif
-
- value = args->d1 / args->d2;
- break;
-
- case MIN_EXPR:
- value = MIN (args->d1, args->d2);
- break;
-
- case MAX_EXPR:
- value = MAX (args->d1, args->d2);
- break;
-
- default:
- abort ();
- }
-#endif /* no REAL_ARITHMETIC */
-
- args->t
- = build_real (args->type,
- real_value_truncate (TYPE_MODE (args->type), value));
-}
-
/* Combine two constants ARG1 and ARG2 under operation CODE to produce a new
constant. We assume ARG1 and ARG2 have the same data type, or at least
are the same kind of constant and the same machine mode.
static tree
const_binop (code, arg1, arg2, notrunc)
enum tree_code code;
- register tree arg1, arg2;
+ tree arg1, arg2;
int notrunc;
{
STRIP_NOPS (arg1);
if (TREE_CODE (arg1) == INTEGER_CST)
return int_const_binop (code, arg1, arg2, notrunc);
-#if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
if (TREE_CODE (arg1) == REAL_CST)
{
REAL_VALUE_TYPE d1;
REAL_VALUE_TYPE d2;
- int overflow = 0;
+ REAL_VALUE_TYPE value;
tree t;
- struct cb_args args;
d1 = TREE_REAL_CST (arg1);
d2 = TREE_REAL_CST (arg2);
else if (REAL_VALUE_ISNAN (d2))
return arg2;
- /* Setup input for const_binop_1() */
- args.type = TREE_TYPE (arg1);
- args.d1 = d1;
- args.d2 = d2;
- args.code = code;
+ REAL_ARITHMETIC (value, code, d1, d2);
- if (do_float_handler (const_binop_1, (PTR) &args))
- /* Receive output from const_binop_1. */
- t = args.t;
- else
- {
- /* We got an exception from const_binop_1. */
- t = copy_node (arg1);
- overflow = 1;
- }
+ t = build_real (TREE_TYPE (arg1),
+ real_value_truncate (TYPE_MODE (TREE_TYPE (arg1)),
+ value));
TREE_OVERFLOW (t)
- = (force_fit_type (t, overflow)
+ = (force_fit_type (t, 0)
| TREE_OVERFLOW (arg1) | TREE_OVERFLOW (arg2));
TREE_CONSTANT_OVERFLOW (t)
= TREE_OVERFLOW (t)
| TREE_CONSTANT_OVERFLOW (arg2);
return t;
}
-#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
if (TREE_CODE (arg1) == COMPLEX_CST)
{
- register tree type = TREE_TYPE (arg1);
- register tree r1 = TREE_REALPART (arg1);
- register tree i1 = TREE_IMAGPART (arg1);
- register tree r2 = TREE_REALPART (arg2);
- register tree i2 = TREE_IMAGPART (arg2);
- register tree t;
+ tree type = TREE_TYPE (arg1);
+ tree r1 = TREE_REALPART (arg1);
+ tree i1 = TREE_IMAGPART (arg1);
+ tree r2 = TREE_REALPART (arg2);
+ tree i2 = TREE_IMAGPART (arg2);
+ tree t;
switch (code)
{
case RDIV_EXPR:
{
- register tree magsquared
+ tree magsquared
= const_binop (PLUS_EXPR,
const_binop (MULT_EXPR, r2, r2, notrunc),
const_binop (MULT_EXPR, i2, i2, notrunc),
/* Likewise, but the desired type is specified explicitly. */
+static GTY (()) tree new_const;
+static GTY ((if_marked ("ggc_marked_p"), param_is (union tree_node)))
+ htab_t size_htab;
+
tree
size_int_type_wide (number, type)
HOST_WIDE_INT number;
tree type;
{
- static htab_t size_htab = 0;
- static tree new_const = 0;
PTR *slot;
if (size_htab == 0)
{
size_htab = htab_create (1024, size_htab_hash, size_htab_eq, NULL);
- ggc_add_deletable_htab (size_htab, NULL, NULL);
new_const = make_node (INTEGER_CST);
- ggc_add_tree_root (&new_const, 1);
}
/* Adjust NEW_CONST to be the constant we want. If it's already in the
convert (ctype, size_binop (MINUS_EXPR, arg1, arg0)));
}
\f
-/* This structure is used to communicate arguments to fold_convert_1. */
-struct fc_args
-{
- tree arg1; /* Input: value to convert. */
- tree type; /* Input: type to convert value to. */
- tree t; /* Ouput: result of conversion. */
-};
-
-/* Function to convert floating-point constants, protected by floating
- point exception handler. */
-
-static void
-fold_convert_1 (data)
- PTR data;
-{
- struct fc_args *args = (struct fc_args *) data;
-
- args->t = build_real (args->type,
- real_value_truncate (TYPE_MODE (args->type),
- TREE_REAL_CST (args->arg1)));
-}
/* Given T, a tree representing type conversion of ARG1, a constant,
return a constant tree representing the result of conversion. */
static tree
fold_convert (t, arg1)
- register tree t;
- register tree arg1;
+ tree t;
+ tree arg1;
{
- register tree type = TREE_TYPE (t);
+ tree type = TREE_TYPE (t);
int overflow = 0;
if (POINTER_TYPE_P (type) || INTEGRAL_TYPE_P (type))
TREE_CONSTANT_OVERFLOW (t)
= TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
}
-#if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
else if (TREE_CODE (arg1) == REAL_CST)
{
/* Don't initialize these, use assignments.
/* See if X will be in range after truncation towards 0.
To compensate for truncation, move the bounds away from 0,
but reject if X exactly equals the adjusted bounds. */
-#ifdef REAL_ARITHMETIC
REAL_ARITHMETIC (l, MINUS_EXPR, l, dconst1);
if (!no_upper_bound)
REAL_ARITHMETIC (u, PLUS_EXPR, u, dconst1);
-#else
- l--;
- if (!no_upper_bound)
- u++;
-#endif
/* If X is a NaN, use zero instead and show we have an overflow.
Otherwise, range check. */
if (REAL_VALUE_ISNAN (x))
&& REAL_VALUES_LESS (x, u)))
overflow = 1;
-#ifndef REAL_ARITHMETIC
- {
- HOST_WIDE_INT low, high;
- HOST_WIDE_INT half_word
- = (HOST_WIDE_INT) 1 << (HOST_BITS_PER_WIDE_INT / 2);
-
- if (x < 0)
- x = -x;
-
- high = (HOST_WIDE_INT) (x / half_word / half_word);
- x -= (REAL_VALUE_TYPE) high * half_word * half_word;
- if (x >= (REAL_VALUE_TYPE) half_word * half_word / 2)
- {
- low = x - (REAL_VALUE_TYPE) half_word * half_word / 2;
- low |= (HOST_WIDE_INT) -1 << (HOST_BITS_PER_WIDE_INT - 1);
- }
- else
- low = (HOST_WIDE_INT) x;
- if (TREE_REAL_CST (arg1) < 0)
- neg_double (low, high, &low, &high);
- t = build_int_2 (low, high);
- }
-#else
{
HOST_WIDE_INT low, high;
REAL_VALUE_TO_INT (&low, &high, x);
t = build_int_2 (low, high);
}
-#endif
TREE_TYPE (t) = type;
TREE_OVERFLOW (t)
= TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
TREE_CONSTANT_OVERFLOW (t)
= TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
}
-#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
TREE_TYPE (t) = type;
}
else if (TREE_CODE (type) == REAL_TYPE)
{
-#if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
if (TREE_CODE (arg1) == INTEGER_CST)
return build_real_from_int_cst (type, arg1);
-#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
if (TREE_CODE (arg1) == REAL_CST)
{
- struct fc_args args;
-
if (REAL_VALUE_ISNAN (TREE_REAL_CST (arg1)))
{
t = arg1;
return t;
}
- /* Setup input for fold_convert_1() */
- args.arg1 = arg1;
- args.type = type;
-
- if (do_float_handler (fold_convert_1, (PTR) &args))
- {
- /* Receive output from fold_convert_1() */
- t = args.t;
- }
- else
- {
- /* We got an exception from fold_convert_1() */
- overflow = 1;
- t = copy_node (arg1);
- }
+ t = build_real (type,
+ real_value_truncate (TYPE_MODE (type),
+ TREE_REAL_CST (arg1)));
TREE_OVERFLOW (t)
- = TREE_OVERFLOW (arg1) | force_fit_type (t, overflow);
+ = TREE_OVERFLOW (arg1) | force_fit_type (t, 0);
TREE_CONSTANT_OVERFLOW (t)
= TREE_OVERFLOW (t) | TREE_CONSTANT_OVERFLOW (arg1);
return t;
&& REAL_VALUES_IDENTICAL (TREE_REAL_CST (arg0),
TREE_REAL_CST (arg1)));
+ case VECTOR_CST:
+ {
+ tree v1, v2;
+
+ if (TREE_CONSTANT_OVERFLOW (arg0)
+ || TREE_CONSTANT_OVERFLOW (arg1))
+ return 0;
+
+ v1 = TREE_VECTOR_CST_ELTS (arg0);
+ v2 = TREE_VECTOR_CST_ELTS (arg1);
+ while (v1 && v2)
+ {
+ if (!operand_equal_p (v1, v2, only_const))
+ return 0;
+ v1 = TREE_CHAIN (v1);
+ v2 = TREE_CHAIN (v2);
+ }
+
+ return 1;
+ }
+
case COMPLEX_CST:
return (operand_equal_p (TREE_REALPART (arg0), TREE_REALPART (arg1),
only_const)
/* Make sure shorter operand is extended the right way
to match the longer operand. */
- primarg1 = convert (signed_or_unsigned_type (unsignedp1,
- TREE_TYPE (primarg1)),
- primarg1);
+ primarg1 = convert ((*lang_hooks.types.signed_or_unsigned_type)
+ (unsignedp1, TREE_TYPE (primarg1)), primarg1);
if (operand_equal_p (arg0, convert (type, primarg1), 0))
return 1;
{
if (FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg, 0)))
&& !flag_unsafe_math_optimizations
- && code != NE_EXPR
+ && code != NE_EXPR
&& code != EQ_EXPR)
return build1 (TRUTH_NOT_EXPR, type, arg);
else
enum machine_mode lmode, rmode, nmode;
int lunsignedp, runsignedp;
int lvolatilep = 0, rvolatilep = 0;
- unsigned int alignment;
tree linner, rinner = NULL_TREE;
tree mask;
tree offset;
do anything if the inner expression is a PLACEHOLDER_EXPR since we
then will no longer be able to replace it. */
linner = get_inner_reference (lhs, &lbitsize, &lbitpos, &offset, &lmode,
- &lunsignedp, &lvolatilep, &alignment);
+ &lunsignedp, &lvolatilep);
if (linner == lhs || lbitsize == GET_MODE_BITSIZE (lmode) || lbitsize < 0
|| offset != 0 || TREE_CODE (linner) == PLACEHOLDER_EXPR)
return 0;
/* If this is not a constant, we can only do something if bit positions,
sizes, and signedness are the same. */
rinner = get_inner_reference (rhs, &rbitsize, &rbitpos, &offset, &rmode,
- &runsignedp, &rvolatilep, &alignment);
+ &runsignedp, &rvolatilep);
if (rinner == rhs || lbitpos != rbitpos || lbitsize != rbitsize
|| lunsignedp != runsignedp || offset != 0
/* Set signed and unsigned types of the precision of this mode for the
shifts below. */
- signed_type = type_for_mode (nmode, 0);
- unsigned_type = type_for_mode (nmode, 1);
+ signed_type = (*lang_hooks.types.type_for_mode) (nmode, 0);
+ unsigned_type = (*lang_hooks.types.type_for_mode) (nmode, 1);
/* Compute the bit position and size for the new reference and our offset
within it. If the new reference is the same size as the original, we
convert (unsigned_type, rhs),
size_int (lbitsize), 0)))
{
- warning ("comparison is always %d due to width of bitfield",
+ warning ("comparison is always %d due to width of bit-field",
code == NE_EXPR);
return convert (compare_type,
(code == NE_EXPR
size_int (lbitsize - 1), 0);
if (! integer_zerop (tem) && ! integer_all_onesp (tem))
{
- warning ("comparison is always %d due to width of bitfield",
+ warning ("comparison is always %d due to width of bit-field",
code == NE_EXPR);
return convert (compare_type,
(code == NE_EXPR
tree mask, inner, offset;
tree unsigned_type;
unsigned int precision;
- unsigned int alignment;
/* All the optimizations using this function assume integer fields.
There are problems with FP fields since the type_for_size call
}
inner = get_inner_reference (exp, pbitsize, pbitpos, &offset, pmode,
- punsignedp, pvolatilep, &alignment);
+ punsignedp, pvolatilep);
if ((inner == exp && and_mask == 0)
|| *pbitsize < 0 || offset != 0
|| TREE_CODE (inner) == PLACEHOLDER_EXPR)
return 0;
/* Compute the mask to access the bitfield. */
- unsigned_type = type_for_size (*pbitsize, 1);
+ unsigned_type = (*lang_hooks.types.type_for_size) (*pbitsize, 1);
precision = TYPE_PRECISION (unsigned_type);
mask = build_int_2 (~0, ~0);
tree tmask;
tmask = build_int_2 (~0, ~0);
- TREE_TYPE (tmask) = signed_type (type);
+ TREE_TYPE (tmask) = (*lang_hooks.types.signed_type) (type);
force_fit_type (tmask, 0);
return
tree_int_cst_equal (mask,
size_int (precision - size), 0));
}
+/* Subroutine for fold: determine if VAL is the INTEGER_CONST that
+ represents the sign bit of EXP's type. If EXP represents a sign
+ or zero extension, also test VAL against the unextended type.
+ The return value is the (sub)expression whose sign bit is VAL,
+ or NULL_TREE otherwise. */
+
+static tree
+sign_bit_p (exp, val)
+ tree exp;
+ tree val;
+{
+ unsigned HOST_WIDE_INT lo;
+ HOST_WIDE_INT hi;
+ int width;
+ tree t;
+
+ /* Tree EXP must have a integral type. */
+ t = TREE_TYPE (exp);
+ if (! INTEGRAL_TYPE_P (t))
+ return NULL_TREE;
+
+ /* Tree VAL must be an integer constant. */
+ if (TREE_CODE (val) != INTEGER_CST
+ || TREE_CONSTANT_OVERFLOW (val))
+ return NULL_TREE;
+
+ width = TYPE_PRECISION (t);
+ if (width > HOST_BITS_PER_WIDE_INT)
+ {
+ hi = (unsigned HOST_WIDE_INT) 1 << (width - HOST_BITS_PER_WIDE_INT - 1);
+ lo = 0;
+ }
+ else
+ {
+ hi = 0;
+ lo = (unsigned HOST_WIDE_INT) 1 << (width - 1);
+ }
+
+ if (TREE_INT_CST_HIGH (val) == hi && TREE_INT_CST_LOW (val) == lo)
+ return exp;
+
+ /* Handle extension from a narrower type. */
+ if (TREE_CODE (exp) == NOP_EXPR
+ && TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp, 0))) < width)
+ return sign_bit_p (TREE_OPERAND (exp, 0), val);
+
+ return NULL_TREE;
+}
+
/* Subroutine for fold_truthop: determine if an operand is simple enough
to be evaluated unconditionally. */
be interpreted as positive. */
if (TREE_UNSIGNED (type) && ! TREE_UNSIGNED (TREE_TYPE (exp)))
{
- tree equiv_type = type_for_mode (TYPE_MODE (type), 1);
+ tree equiv_type = (*lang_hooks.types.type_for_mode)
+ (TYPE_MODE (type), 1);
tree high_positive;
/* A range without an upper bound is, naturally, unbounded.
tree low, high;
{
tree etype = TREE_TYPE (exp);
- tree utype, value;
+ tree value;
if (! in_p
&& (0 != (value = build_range_check (type, exp, 1, low, high))))
return invert_truthvalue (value);
- else if (low == 0 && high == 0)
+ if (low == 0 && high == 0)
return convert (type, integer_one_node);
- else if (low == 0)
+ if (low == 0)
return fold (build (LE_EXPR, type, exp, high));
- else if (high == 0)
+ if (high == 0)
return fold (build (GE_EXPR, type, exp, low));
- else if (operand_equal_p (low, high, 0))
+ if (operand_equal_p (low, high, 0))
return fold (build (EQ_EXPR, type, exp, low));
- else if (TREE_UNSIGNED (etype) && integer_zerop (low))
- return build_range_check (type, exp, 1, 0, high);
+ if (integer_zerop (low))
+ {
+ if (! TREE_UNSIGNED (etype))
+ {
+ etype = (*lang_hooks.types.unsigned_type) (etype);
+ high = convert (etype, high);
+ exp = convert (etype, exp);
+ }
+ return build_range_check (type, exp, 1, 0, high);
+ }
- else if (integer_zerop (low))
+ /* Optimize (c>=1) && (c<=127) into (signed char)c > 0. */
+ if (integer_onep (low) && TREE_CODE (high) == INTEGER_CST)
{
- utype = unsigned_type (etype);
- return build_range_check (type, convert (utype, exp), 1, 0,
- convert (utype, high));
+ unsigned HOST_WIDE_INT lo;
+ HOST_WIDE_INT hi;
+ int prec;
+
+ prec = TYPE_PRECISION (etype);
+ if (prec <= HOST_BITS_PER_WIDE_INT)
+ {
+ hi = 0;
+ lo = ((unsigned HOST_WIDE_INT) 1 << (prec - 1)) - 1;
+ }
+ else
+ {
+ hi = ((HOST_WIDE_INT) 1 << (prec - HOST_BITS_PER_WIDE_INT - 1)) - 1;
+ lo = (unsigned HOST_WIDE_INT) -1;
+ }
+
+ if (TREE_INT_CST_HIGH (high) == hi && TREE_INT_CST_LOW (high) == lo)
+ {
+ if (TREE_UNSIGNED (etype))
+ {
+ etype = (*lang_hooks.types.signed_type) (etype);
+ exp = convert (etype, exp);
+ }
+ return fold (build (GT_EXPR, type, exp,
+ convert (etype, integer_zero_node)));
+ }
}
- else if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
- && ! TREE_OVERFLOW (value))
+ if (0 != (value = const_binop (MINUS_EXPR, high, low, 0))
+ && ! TREE_OVERFLOW (value))
return build_range_check (type,
fold (build (MINUS_EXPR, etype, exp, low)),
1, convert (etype, integer_zero_node), value);
- else
- return 0;
+
+ return 0;
}
\f
/* Given two ranges, see if we can merge them into one. Return 1 if we
TREE_TYPE (exp), TREE_OPERAND (exp, 0),
TREE_OPERAND (exp, 1));
- else if (global_bindings_p () == 0
+ else if ((*lang_hooks.decls.global_bindings_p) () == 0
&& ! contains_placeholder_p (lhs))
{
tree common = save_expr (lhs);
zero or one, and the conversion to a signed type can never overflow.
We could get an overflow if this conversion is done anywhere else. */
if (TREE_UNSIGNED (type))
- temp = convert (signed_type (type), temp);
+ temp = convert ((*lang_hooks.types.signed_type) (type), temp);
temp = const_binop (LSHIFT_EXPR, temp, size_int (modesize - 1), 0);
temp = const_binop (RSHIFT_EXPR, temp, size_int (modesize - p - 1), 0);
&& ! FLOAT_TYPE_P (TREE_TYPE (rl_arg))
&& simple_operand_p (rl_arg)
&& simple_operand_p (rr_arg))
- return build (code, truth_type, lhs, rhs);
+ {
+ /* Convert (a != 0) || (b != 0) into (a | b) != 0. */
+ if (code == TRUTH_OR_EXPR
+ && lcode == NE_EXPR && integer_zerop (lr_arg)
+ && rcode == NE_EXPR && integer_zerop (rr_arg)
+ && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
+ return build (NE_EXPR, truth_type,
+ build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
+ ll_arg, rl_arg),
+ integer_zero_node);
+
+ /* Convert (a == 0) && (b == 0) into (a | b) == 0. */
+ if (code == TRUTH_AND_EXPR
+ && lcode == EQ_EXPR && integer_zerop (lr_arg)
+ && rcode == EQ_EXPR && integer_zerop (rr_arg)
+ && TREE_TYPE (ll_arg) == TREE_TYPE (rl_arg))
+ return build (EQ_EXPR, truth_type,
+ build (BIT_IOR_EXPR, TREE_TYPE (ll_arg),
+ ll_arg, rl_arg),
+ integer_zero_node);
+
+ return build (code, truth_type, lhs, rhs);
+ }
/* See if the comparisons can be merged. Then get all the parameters for
each side. */
lnbitsize = GET_MODE_BITSIZE (lnmode);
lnbitpos = first_bit & ~ (lnbitsize - 1);
- lntype = type_for_size (lnbitsize, 1);
+ lntype = (*lang_hooks.types.type_for_size) (lnbitsize, 1);
xll_bitpos = ll_bitpos - lnbitpos, xrl_bitpos = rl_bitpos - lnbitpos;
if (BYTES_BIG_ENDIAN)
rnbitsize = GET_MODE_BITSIZE (rnmode);
rnbitpos = first_bit & ~ (rnbitsize - 1);
- rntype = type_for_size (rnbitsize, 1);
+ rntype = (*lang_hooks.types.type_for_size) (rnbitsize, 1);
xlr_bitpos = lr_bitpos - rnbitpos, xrr_bitpos = rr_bitpos - rnbitpos;
if (BYTES_BIG_ENDIAN)
other operations already in T. WIDE_TYPE, if non-null, is a type that
should be used for the computation if wider than our type.
- For example, if we are dividing (X * 8) + (Y + 16) by 4, we can return
- (X * 2) + (Y + 4). We must, however, be assured that either the original
+ For example, if we are dividing (X * 8) + (Y * 16) by 4, we can return
+ (X * 2) + (Y * 4). We must, however, be assured that either the original
expression would not overflow or that overflow is undefined for the type
in the language in question.
&& ! (TREE_CODE (TREE_TYPE (op0)) == INTEGER_TYPE
&& TYPE_IS_SIZETYPE (TREE_TYPE (op0)))
&& (GET_MODE_SIZE (TYPE_MODE (ctype))
- > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
+ > GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (op0)))))
break;
/* Pass the constant down and see if we can make a simplification. If
of our constant, do the operation and verify it doesn't overflow. */
if (code == MULT_EXPR
|| integer_zerop (const_binop (TRUNC_MOD_EXPR, op1, c, 0)))
- {
- op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
- if (op1 == 0 || TREE_OVERFLOW (op1))
- break;
- }
+ {
+ op1 = const_binop (code, convert (ctype, op1), convert (ctype, c), 0);
+ if (op1 == 0 || TREE_OVERFLOW (op1))
+ break;
+ }
else
- break;
+ break;
/* If we have an unsigned type is not a sizetype, we cannot widen
the operation since it will change the result if the original
multiple of the other, in which case we replace this with either an
operation or CODE or TCODE.
- If we have an unsigned type that is not a sizetype, we canot do
+ If we have an unsigned type that is not a sizetype, we cannot do
this since it will change the result if the original computation
overflowed. */
if ((! TREE_UNSIGNED (ctype)
if (type == integer_type_node)
return value ? integer_one_node : integer_zero_node;
else if (TREE_CODE (type) == BOOLEAN_TYPE)
- return truthvalue_conversion (value ? integer_one_node :
- integer_zero_node);
+ return (*lang_hooks.truthvalue_conversion) (value ? integer_one_node :
+ integer_zero_node);
else
{
tree t = build_int_2 (value, 0);
return MIN (lim, 1 + ctrue + cfalse);
}
-/* Transform `a + (b ? x : y)' into `x ? (a + b) : (a + y)'.
+/* Transform `a + (b ? x : y)' into `b ? (a + x) : (a + y)'.
Transform, `a + (x < y)' into `(x < y) ? (a + 1) : (a + 0)'. Here
CODE corresponds to the `+', COND to the `(b ? x : y)' or `(x < y)'
expression, and ARG to `a'. If COND_FIRST_P is non-zero, then the
side of the expression to be executed if the condition is true
will be pointed to by TRUE_LHS. Similarly, the right-hand side
of the expression to be executed if the condition is true will be
- pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analagous --
+ pointed to by TRUE_RHS. FALSE_LHS and FALSE_RHS are analogous --
but apply to the expression to be executed if the conditional is
false. */
tree *true_lhs;
true_value = convert (testtype, integer_one_node);
false_value = convert (testtype, integer_zero_node);
}
-
+
/* If ARG is complex we want to make sure we only evaluate
it once. Though this is only required if it is volatile, it
might be more efficient even if it is not. However, if we
primarily to see if we do end up with constant and this
SAVE_EXPR interferes with later optimizations, suppressing
it when we can is important.
-
+
If we are not in a function, we can't make a SAVE_EXPR, so don't
try to do so. Don't try to see if the result is a constant
if an arm is a COND_EXPR since we get exponential behavior
in that case. */
-
+
if (TREE_CODE (arg) != SAVE_EXPR && ! TREE_CONSTANT (arg)
- && global_bindings_p () == 0
+ && (*lang_hooks.decls.global_bindings_p) () == 0
&& ((TREE_CODE (arg) != VAR_DECL
&& TREE_CODE (arg) != PARM_DECL)
|| TREE_SIDE_EFFECTS (arg)))
{
if (TREE_CODE (true_value) != COND_EXPR)
lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
-
+
if (TREE_CODE (false_value) != COND_EXPR)
rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
-
+
if ((lhs == 0 || ! TREE_CONSTANT (lhs))
&& (rhs == 0 || !TREE_CONSTANT (rhs)))
arg = save_expr (arg), lhs = rhs = 0;
}
-
+
if (lhs == 0)
lhs = fold (build (lhs_code, lhs_type, *true_lhs, *true_rhs));
if (rhs == 0)
rhs = fold (build (rhs_code, rhs_type, *false_lhs, *false_rhs));
-
+
test = fold (build (COND_EXPR, type, test, lhs, rhs));
-
+
if (TREE_CODE (arg) == SAVE_EXPR)
return build (COMPOUND_EXPR, type,
convert (void_type_node, arg),
}
\f
+/* Subroutine of fold() that checks for the addition of +/- 0.0.
+
+ If !NEGATE, return true if ADDEND is +/-0.0 and, for all X of type
+ TYPE, X + ADDEND is the same as X. If NEGATE, return true if X -
+ ADDEND is the same as X.
+
+ X + 0 and X - 0 both give X when X is NaN, infinite, or non-zero
+ and finite. The problematic cases are when X is zero, and its mode
+ has signed zeros. In the case of rounding towards -infinity,
+ X - 0 is not the same as X because 0 - 0 is -0. In other rounding
+ modes, X + 0 is not the same as X because -0 + 0 is 0. */
+
+static bool
+fold_real_zero_addition_p (type, addend, negate)
+ tree type, addend;
+ int negate;
+{
+ if (!real_zerop (addend))
+ return false;
+
+ /* Allow the fold if zeros aren't signed, or their sign isn't important. */
+ if (!HONOR_SIGNED_ZEROS (TYPE_MODE (type)))
+ return true;
+
+ /* Treat x + -0 as x - 0 and x - -0 as x + 0. */
+ if (TREE_CODE (addend) == REAL_CST
+ && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (addend)))
+ negate = !negate;
+
+ /* The mode has signed zeros, and we have to honor their sign.
+ In this situation, there is only one case we can return true for.
+ X - 0 is the same as X unless rounding towards -infinity is
+ supported. */
+ return negate && !HONOR_SIGN_DEPENDENT_ROUNDING (TYPE_MODE (type));
+}
+
+
/* Perform constant folding and related simplification of EXPR.
The related simplifications include x*1 => x, x*0 => 0, etc.,
and application of the associative law.
fold (expr)
tree expr;
{
- register tree t = expr;
+ tree t = expr;
tree t1 = NULL_TREE;
tree tem;
tree type = TREE_TYPE (expr);
- register tree arg0 = NULL_TREE, arg1 = NULL_TREE;
- register enum tree_code code = TREE_CODE (t);
- register int kind = TREE_CODE_CLASS (code);
+ tree arg0 = NULL_TREE, arg1 = NULL_TREE;
+ enum tree_code code = TREE_CODE (t);
+ int kind = TREE_CODE_CLASS (code);
int invert;
/* WINS will be nonzero when the switch is done
if all operands are constant. */
subop = arg0;
if (subop != 0 && TREE_CODE (subop) != INTEGER_CST
-#if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
&& TREE_CODE (subop) != REAL_CST
-#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
)
/* Note that TREE_CONSTANT isn't enough:
static var addresses are constant but we can't
}
else if (IS_EXPR_CODE_CLASS (kind) || kind == 'r')
{
- register int len = first_rtl_op (code);
- register int i;
+ int len = first_rtl_op (code);
+ int i;
for (i = 0; i < len; i++)
{
tree op = TREE_OPERAND (t, i);
subop = op;
if (TREE_CODE (subop) != INTEGER_CST
-#if ! defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
- && TREE_CODE (subop) != REAL_CST
-#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
- )
+ && TREE_CODE (subop) != REAL_CST)
/* Note that TREE_CONSTANT isn't enough:
static var addresses are constant but we can't
do arithmetic on them. */
&& (TREE_CODE (arg0) != COND_EXPR
|| count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
&& (! TREE_SIDE_EFFECTS (arg0)
- || (global_bindings_p () == 0
+ || ((*lang_hooks.decls.global_bindings_p) () == 0
&& ! contains_placeholder_p (arg0))))
- return
+ return
fold_binary_op_with_conditional_arg (code, type, arg1, arg0,
/*cond_first_p=*/0);
else if (TREE_CODE (arg0) == COMPOUND_EXPR)
&& (TREE_CODE (arg1) != COND_EXPR
|| count_cond (arg0, 25) + count_cond (arg1, 25) <= 25)
&& (! TREE_SIDE_EFFECTS (arg1)
- || (global_bindings_p () == 0
+ || ((*lang_hooks.decls.global_bindings_p) () == 0
&& ! contains_placeholder_p (arg1))))
- return
+ return
fold_binary_op_with_conditional_arg (code, type, arg0, arg1,
/*cond_first_p=*/1);
}
{
case INTEGER_CST:
case REAL_CST:
+ case VECTOR_CST:
case STRING_CST:
case COMPLEX_CST:
case CONSTRUCTOR:
TREE_USED (t) = 1;
return t;
}
+
+ /* Convert (T)(x & c) into (T)x & (T)c, if c is an integer
+ constants (if x has signed type, the sign bit cannot be set
+ in c). This folds extension into the BIT_AND_EXPR. */
+ if (INTEGRAL_TYPE_P (TREE_TYPE (t))
+ && TREE_CODE (TREE_TYPE (t)) != BOOLEAN_TYPE
+ && TREE_CODE (TREE_OPERAND (t, 0)) == BIT_AND_EXPR
+ && TREE_CODE (TREE_OPERAND (TREE_OPERAND (t, 0), 1)) == INTEGER_CST)
+ {
+ tree and = TREE_OPERAND (t, 0);
+ tree and0 = TREE_OPERAND (and, 0), and1 = TREE_OPERAND (and, 1);
+ int change = 0;
+
+ if (TREE_UNSIGNED (TREE_TYPE (and))
+ || (TYPE_PRECISION (TREE_TYPE (t))
+ <= TYPE_PRECISION (TREE_TYPE (and))))
+ change = 1;
+ else if (TYPE_PRECISION (TREE_TYPE (and1))
+ <= HOST_BITS_PER_WIDE_INT
+ && host_integerp (and1, 1))
+ {
+ unsigned HOST_WIDE_INT cst;
+
+ cst = tree_low_cst (and1, 1);
+ cst &= (HOST_WIDE_INT) -1
+ << (TYPE_PRECISION (TREE_TYPE (and1)) - 1);
+ change = (cst == 0);
+#ifdef LOAD_EXTEND_OP
+ if (change
+ && (LOAD_EXTEND_OP (TYPE_MODE (TREE_TYPE (and0)))
+ == ZERO_EXTEND))
+ {
+ tree uns = (*lang_hooks.types.unsigned_type) (TREE_TYPE (and0));
+ and0 = convert (uns, and0);
+ and1 = convert (uns, and1);
+ }
+#endif
+ }
+ if (change)
+ return fold (build (BIT_AND_EXPR, TREE_TYPE (t),
+ convert (TREE_TYPE (t), and0),
+ convert (TREE_TYPE (t), and1)));
+ }
+
if (!wins)
{
TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
}
return fold_convert (t, arg0);
-#if 0 /* This loses on &"foo"[0]. */
- case ARRAY_REF:
- {
- int i;
-
- /* Fold an expression like: "foo"[2] */
- if (TREE_CODE (arg0) == STRING_CST
- && TREE_CODE (arg1) == INTEGER_CST
- && compare_tree_int (arg1, TREE_STRING_LENGTH (arg0)) < 0)
- {
- t = build_int_2 (TREE_STRING_POINTER (arg0)[TREE_INT_CST_LOW (arg))], 0);
- TREE_TYPE (t) = TREE_TYPE (TREE_TYPE (arg0));
- force_fit_type (t, 0);
- }
- }
+ case VIEW_CONVERT_EXPR:
+ if (TREE_CODE (TREE_OPERAND (t, 0)) == VIEW_CONVERT_EXPR)
+ return build1 (VIEW_CONVERT_EXPR, type,
+ TREE_OPERAND (TREE_OPERAND (t, 0), 0));
return t;
-#endif /* 0 */
case COMPONENT_REF:
if (TREE_CODE (arg0) == CONSTRUCTOR)
same));
}
}
- /* In IEEE floating point, x+0 may not equal x. */
- else if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
- || flag_unsafe_math_optimizations)
- && real_zerop (arg1))
- return non_lvalue (convert (type, arg0));
- /* x+(-0) equals x, even for IEEE. */
- else if (TREE_CODE (arg1) == REAL_CST
- && REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
+
+ /* See if ARG1 is zero and X + ARG1 reduces to X. */
+ else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 0))
return non_lvalue (convert (type, arg0));
+ /* Likewise if the operands are reversed. */
+ else if (fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
+ return non_lvalue (convert (type, arg1));
+
bit_rotate:
/* (A << C1) + (A >> C2) if A is unsigned and C1+C2 is the size of A
is a rotate of A by C1 bits. */
/* (A << B) + (A >> (Z - B)) if A is unsigned and Z is the size of A
is a rotate of A by B bits. */
{
- register enum tree_code code0, code1;
+ enum tree_code code0, code1;
code0 = TREE_CODE (arg0);
code1 = TREE_CODE (arg1);
if (((code0 == RSHIFT_EXPR && code1 == LSHIFT_EXPR)
TREE_OPERAND (arg1, 0), 0)
&& TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
{
- register tree tree01, tree11;
- register enum tree_code code01, code11;
+ tree tree01, tree11;
+ enum tree_code code01, code11;
tree01 = TREE_OPERAND (arg0, 1);
tree11 = TREE_OPERAND (arg1, 1);
&& (! FLOAT_TYPE_P (type)
|| (flag_unsafe_math_optimizations && code == MULT_EXPR)))
{
- tree var0, con0, lit0, var1, con1, lit1;
+ tree var0, con0, lit0, minus_lit0;
+ tree var1, con1, lit1, minus_lit1;
/* Split both trees into variables, constants, and literals. Then
associate each group together, the constants with literals,
then the result with variables. This increases the chances of
literals being recombined later and of generating relocatable
expressions for the sum of a constant and literal. */
- var0 = split_tree (arg0, code, &con0, &lit0, 0);
- var1 = split_tree (arg1, code, &con1, &lit1, code == MINUS_EXPR);
+ var0 = split_tree (arg0, code, &con0, &lit0, &minus_lit0, 0);
+ var1 = split_tree (arg1, code, &con1, &lit1, &minus_lit1,
+ code == MINUS_EXPR);
/* Only do something if we found more than two objects. Otherwise,
nothing has changed and we risk infinite recursion. */
- if (2 < ((var0 != 0) + (var1 != 0) + (con0 != 0) + (con1 != 0)
- + (lit0 != 0) + (lit1 != 0)))
+ if (2 < ((var0 != 0) + (var1 != 0)
+ + (con0 != 0) + (con1 != 0)
+ + (lit0 != 0) + (lit1 != 0)
+ + (minus_lit0 != 0) + (minus_lit1 != 0)))
{
+ /* Recombine MINUS_EXPR operands by using PLUS_EXPR. */
+ if (code == MINUS_EXPR)
+ code = PLUS_EXPR;
+
var0 = associate_trees (var0, var1, code, type);
con0 = associate_trees (con0, con1, code, type);
lit0 = associate_trees (lit0, lit1, code, type);
+ minus_lit0 = associate_trees (minus_lit0, minus_lit1, code, type);
+
+ /* Preserve the MINUS_EXPR if the negative part of the literal is
+ greater than the positive part. Otherwise, the multiplicative
+ folding code (i.e extract_muldiv) may be fooled in case
+ unsigned constants are substracted, like in the following
+ example: ((X*2 + 4) - 8U)/2. */
+ if (minus_lit0 && lit0)
+ {
+ if (tree_int_cst_lt (lit0, minus_lit0))
+ {
+ minus_lit0 = associate_trees (minus_lit0, lit0,
+ MINUS_EXPR, type);
+ lit0 = 0;
+ }
+ else
+ {
+ lit0 = associate_trees (lit0, minus_lit0,
+ MINUS_EXPR, type);
+ minus_lit0 = 0;
+ }
+ }
+ if (minus_lit0)
+ {
+ if (con0 == 0)
+ return convert (type, associate_trees (var0, minus_lit0,
+ MINUS_EXPR, type));
+ else
+ {
+ con0 = associate_trees (con0, minus_lit0,
+ MINUS_EXPR, type);
+ return convert (type, associate_trees (var0, con0,
+ PLUS_EXPR, type));
+ }
+ }
+
con0 = associate_trees (con0, lit0, code, type);
return convert (type, associate_trees (var0, con0, code, type));
}
}
binary:
-#if defined (REAL_IS_NOT_DOUBLE) && ! defined (REAL_ARITHMETIC)
- if (TREE_CODE (arg1) == REAL_CST)
- return t;
-#endif /* REAL_IS_NOT_DOUBLE, and no REAL_ARITHMETIC */
if (wins)
t1 = const_binop (code, arg0, arg1, 0);
if (t1 != NULL_TREE)
TREE_OPERAND (arg0, 1)));
}
- else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
- || flag_unsafe_math_optimizations)
- {
- /* Except with IEEE floating point, 0-x equals -x. */
- if (! wins && real_zerop (arg0))
- return negate_expr (convert (type, arg1));
- /* Except with IEEE floating point, x-0 equals x. */
- if (real_zerop (arg1))
- return non_lvalue (convert (type, arg0));
- }
+ /* See if ARG1 is zero and X - ARG1 reduces to X. */
+ else if (fold_real_zero_addition_p (TREE_TYPE (arg0), arg1, 1))
+ return non_lvalue (convert (type, arg0));
+
+ /* (ARG0 - ARG1) is the same as (-ARG1 + ARG0). So check whether
+ ARG0 is zero and X + ARG0 reduces to X, since that would mean
+ (-ARG1 + ARG0) reduces to -ARG1. */
+ else if (!wins && fold_real_zero_addition_p (TREE_TYPE (arg1), arg0, 0))
+ return negate_expr (convert (type, arg1));
/* Fold &x - &x. This can happen from &x.foo - &x.
This is unsafe for certain floats even in non-IEEE formats.
}
else
{
- /* x*0 is 0, except for IEEE floating point. */
- if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
- || flag_unsafe_math_optimizations)
+ /* Maybe fold x * 0 to 0. The expressions aren't the same
+ when x is NaN, since x * 0 is also NaN. Nor are they the
+ same in modes with signed zeros, since multiplying a
+ negative value by 0 gives -0, not +0. */
+ if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))
+ && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg0)))
&& real_zerop (arg1))
return omit_one_operand (type, arg1, arg0);
/* In IEEE floating point, x*1 is not equivalent to x for snans.
so we can do this anyway. */
if (real_onep (arg1))
return non_lvalue (convert (type, arg0));
+
+ /* Transform x * -1.0 into -x. This should be safe for NaNs,
+ signed zeros and signed infinities, but is currently
+ restricted to "unsafe math optimizations" just in case. */
+ if (flag_unsafe_math_optimizations
+ && real_minus_onep (arg1))
+ return fold (build1 (NEGATE_EXPR, type, arg0));
+
/* x*2 is x+x */
- if (! wins && real_twop (arg1) && global_bindings_p () == 0
+ if (! wins && real_twop (arg1)
+ && (*lang_hooks.decls.global_bindings_p) () == 0
&& ! contains_placeholder_p (arg0))
{
tree arg = save_expr (arg0);
if (t1 != NULL_TREE)
return t1;
/* Simplify ((int)c & 0x377) into (int)c, if c is unsigned char. */
- if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == NOP_EXPR
- && TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg1, 0))))
- {
- unsigned int prec
- = TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (arg1, 0)));
-
- if (prec < BITS_PER_WORD && prec < HOST_BITS_PER_WIDE_INT
- && (~TREE_INT_CST_LOW (arg0)
- & (((HOST_WIDE_INT) 1 << prec) - 1)) == 0)
- return build1 (NOP_EXPR, type, TREE_OPERAND (arg1, 0));
- }
if (TREE_CODE (arg1) == INTEGER_CST && TREE_CODE (arg0) == NOP_EXPR
&& TREE_UNSIGNED (TREE_TYPE (TREE_OPERAND (arg0, 0))))
{
goto binary;
case RDIV_EXPR:
- /* In most cases, do nothing with a divide by zero. */
-#if !defined (REAL_IS_NOT_DOUBLE) || defined (REAL_ARITHMETIC)
-#ifndef REAL_INFINITY
- if (TREE_CODE (arg1) == REAL_CST && real_zerop (arg1))
+ /* Don't touch a floating-point divide by zero unless the mode
+ of the constant can represent infinity. */
+ if (TREE_CODE (arg1) == REAL_CST
+ && !MODE_HAS_INFINITIES (TYPE_MODE (TREE_TYPE (arg1)))
+ && real_zerop (arg1))
return t;
-#endif
-#endif /* not REAL_IS_NOT_DOUBLE, or REAL_ARITHMETIC */
/* (-A) / (-B) -> A / B */
if (TREE_CODE (arg0) == NEGATE_EXPR && TREE_CODE (arg1) == NEGATE_EXPR)
case GT_EXPR:
case LE_EXPR:
case GE_EXPR:
+ /* If one arg is a real or integer constant, put it last. */
+ if ((TREE_CODE (arg0) == INTEGER_CST
+ && TREE_CODE (arg1) != INTEGER_CST)
+ || (TREE_CODE (arg0) == REAL_CST
+ && TREE_CODE (arg0) != REAL_CST))
+ {
+ TREE_OPERAND (t, 0) = arg1;
+ TREE_OPERAND (t, 1) = arg0;
+ arg0 = TREE_OPERAND (t, 0);
+ arg1 = TREE_OPERAND (t, 1);
+ code = swap_tree_comparison (code);
+ TREE_SET_CODE (t, code);
+ }
+
if (FLOAT_TYPE_P (TREE_TYPE (arg0)))
{
/* (-a) CMP (-b) -> b CMP a */
&& REAL_VALUE_MINUS_ZERO (TREE_REAL_CST (arg1)))
return fold (build (code, type, arg0,
build_real (TREE_TYPE (arg1), dconst0)));
- }
- /* If one arg is a constant integer, put it last. */
- if (TREE_CODE (arg0) == INTEGER_CST
- && TREE_CODE (arg1) != INTEGER_CST)
- {
- TREE_OPERAND (t, 0) = arg1;
- TREE_OPERAND (t, 1) = arg0;
- arg0 = TREE_OPERAND (t, 0);
- arg1 = TREE_OPERAND (t, 1);
- code = swap_tree_comparison (code);
- TREE_SET_CODE (t, code);
+ /* If this is a comparison of a real constant with a PLUS_EXPR
+ or a MINUS_EXPR of a real constant, we can convert it into a
+ comparison with a revised real constant as long as no overflow
+ occurs when unsafe_math_optimizations are enabled. */
+ if (flag_unsafe_math_optimizations
+ && TREE_CODE (arg1) == REAL_CST
+ && (TREE_CODE (arg0) == PLUS_EXPR
+ || TREE_CODE (arg0) == MINUS_EXPR)
+ && TREE_CODE (TREE_OPERAND (arg0, 1)) == REAL_CST
+ && 0 != (tem = const_binop (TREE_CODE (arg0) == PLUS_EXPR
+ ? MINUS_EXPR : PLUS_EXPR,
+ arg1, TREE_OPERAND (arg0, 1), 0))
+ && ! TREE_CONSTANT_OVERFLOW (tem))
+ return fold (build (code, type, TREE_OPERAND (arg0, 0), tem));
}
/* Convert foo++ == CONST into ++foo == CONST + INCR.
|| integer_onep (folded_compare))
return omit_one_operand (type, folded_compare, varop);
- unsigned_type = type_for_size (size, 1);
+ unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
precision = TYPE_PRECISION (unsigned_type);
mask = build_int_2 (~0, ~0);
TREE_TYPE (mask) = unsigned_type;
|| integer_onep (folded_compare))
return omit_one_operand (type, folded_compare, varop);
- unsigned_type = type_for_size (size, 1);
+ unsigned_type = (*lang_hooks.types.type_for_size)(size, 1);
precision = TYPE_PRECISION (unsigned_type);
mask = build_int_2 (~0, ~0);
TREE_TYPE (mask) = TREE_TYPE (varop);
}
}
- /* Change X >= CST to X > (CST - 1) if CST is positive. */
+ /* Comparisons with the highest or lowest possible integer of
+ the specified size will have known values and an unsigned
+ <= 0x7fffffff can be simplified. */
+ {
+ int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
+
+ if (TREE_CODE (arg1) == INTEGER_CST
+ && ! TREE_CONSTANT_OVERFLOW (arg1)
+ && width <= HOST_BITS_PER_WIDE_INT
+ && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
+ || POINTER_TYPE_P (TREE_TYPE (arg1))))
+ {
+ if (TREE_INT_CST_HIGH (arg1) == 0
+ && (TREE_INT_CST_LOW (arg1)
+ == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
+ && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
+ switch (TREE_CODE (t))
+ {
+ case GT_EXPR:
+ return omit_one_operand (type,
+ convert (type, integer_zero_node),
+ arg0);
+ case GE_EXPR:
+ TREE_SET_CODE (t, EQ_EXPR);
+ break;
+
+ case LE_EXPR:
+ return omit_one_operand (type,
+ convert (type, integer_one_node),
+ arg0);
+ case LT_EXPR:
+ TREE_SET_CODE (t, NE_EXPR);
+ break;
+
+ default:
+ break;
+ }
+
+ else if (TREE_INT_CST_HIGH (arg1) == -1
+ && (TREE_INT_CST_LOW (arg1)
+ == ((unsigned HOST_WIDE_INT) -1 << (width - 1)))
+ && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
+ switch (TREE_CODE (t))
+ {
+ case LT_EXPR:
+ return omit_one_operand (type,
+ convert (type, integer_zero_node),
+ arg0);
+ case LE_EXPR:
+ TREE_SET_CODE (t, EQ_EXPR);
+ break;
+
+ case GE_EXPR:
+ return omit_one_operand (type,
+ convert (type, integer_one_node),
+ arg0);
+ case GT_EXPR:
+ TREE_SET_CODE (t, NE_EXPR);
+ break;
+
+ default:
+ break;
+ }
+
+ else if (TREE_INT_CST_HIGH (arg1) == 0
+ && (TREE_INT_CST_LOW (arg1)
+ == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
+ && TREE_UNSIGNED (TREE_TYPE (arg1))
+ /* signed_type does not work on pointer types. */
+ && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
+ {
+ if (TREE_CODE (t) == LE_EXPR || TREE_CODE (t) == GT_EXPR)
+ {
+ tree st0, st1;
+ st0 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg0));
+ st1 = (*lang_hooks.types.signed_type) (TREE_TYPE (arg1));
+ return fold
+ (build (TREE_CODE (t) == LE_EXPR ? GE_EXPR: LT_EXPR,
+ type, convert (st0, arg0),
+ convert (st1, integer_zero_node)));
+ }
+ }
+ else if (TREE_INT_CST_HIGH (arg1) == 0
+ && (TREE_INT_CST_LOW (arg1)
+ == ((unsigned HOST_WIDE_INT) 2 << (width - 1)) - 1)
+ && TREE_UNSIGNED (TREE_TYPE (arg1)))
+ switch (TREE_CODE (t))
+ {
+ case GT_EXPR:
+ return omit_one_operand (type,
+ convert (type, integer_zero_node),
+ arg0);
+ case GE_EXPR:
+ TREE_SET_CODE (t, EQ_EXPR);
+ break;
+
+ case LE_EXPR:
+ return omit_one_operand (type,
+ convert (type, integer_one_node),
+ arg0);
+ case LT_EXPR:
+ TREE_SET_CODE (t, NE_EXPR);
+ break;
+
+ default:
+ break;
+ }
+ }
+ }
+
+ /* Change X >= C to X > C-1 and X < C to X <= C-1 if C is positive. */
if (TREE_CODE (arg1) == INTEGER_CST
&& TREE_CODE (arg0) != INTEGER_CST
&& tree_int_cst_sgn (arg1) > 0)
}
}
+ /* An unsigned comparison against 0 can be simplified. */
+ if (integer_zerop (arg1)
+ && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
+ || POINTER_TYPE_P (TREE_TYPE (arg1)))
+ && TREE_UNSIGNED (TREE_TYPE (arg1)))
+ {
+ switch (TREE_CODE (t))
+ {
+ case GT_EXPR:
+ code = NE_EXPR;
+ TREE_SET_CODE (t, NE_EXPR);
+ break;
+ case LE_EXPR:
+ code = EQ_EXPR;
+ TREE_SET_CODE (t, EQ_EXPR);
+ break;
+ case GE_EXPR:
+ return omit_one_operand (type,
+ convert (type, integer_one_node),
+ arg0);
+ case LT_EXPR:
+ return omit_one_operand (type,
+ convert (type, integer_zero_node),
+ arg0);
+ default:
+ break;
+ }
+ }
+
/* If this is an EQ or NE comparison of a constant with a PLUS_EXPR or
a MINUS_EXPR of a constant, we can convert it into a comparison with
a revised constant as long as no overflow occurs. */
|| TREE_CODE (arg0) == ROUND_MOD_EXPR)
&& integer_pow2p (TREE_OPERAND (arg0, 1)))
{
- tree newtype = unsigned_type (TREE_TYPE (arg0));
+ tree newtype = (*lang_hooks.types.unsigned_type) (TREE_TYPE (arg0));
tree newmod = build (TREE_CODE (arg0), newtype,
convert (newtype, TREE_OPERAND (arg0, 0)),
convert (newtype, TREE_OPERAND (arg0, 1)));
&& TREE_CODE (arg0) == BIT_AND_EXPR
&& integer_pow2p (TREE_OPERAND (arg0, 1))
&& operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
- return build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
- arg0, integer_zero_node);
+ return fold (build (code == EQ_EXPR ? NE_EXPR : EQ_EXPR, type,
+ arg0, integer_zero_node));
+
+ /* If we have (A & C) != 0 where C is the sign bit of A, convert
+ this into A < 0. Similarly for (A & C) == 0 into A >= 0. */
+ if ((code == EQ_EXPR || code == NE_EXPR)
+ && TREE_CODE (arg0) == BIT_AND_EXPR
+ && integer_zerop (arg1))
+ {
+ tree arg00 = sign_bit_p (TREE_OPERAND (arg0, 0),
+ TREE_OPERAND (arg0, 1));
+ if (arg00 != NULL_TREE)
+ {
+ tree stype = (*lang_hooks.types.signed_type) (TREE_TYPE (arg00));
+ return fold (build (code == EQ_EXPR ? GE_EXPR : LT_EXPR, type,
+ convert (stype, arg00),
+ convert (stype, integer_zero_node)));
+ }
+ }
/* If X is unsigned, convert X < (1 << Y) into X >> Y == 0
and similarly for >= into !=. */
}
}
- /* An unsigned comparison against 0 can be simplified. */
- if (integer_zerop (arg1)
- && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
- || POINTER_TYPE_P (TREE_TYPE (arg1)))
- && TREE_UNSIGNED (TREE_TYPE (arg1)))
- {
- switch (TREE_CODE (t))
- {
- case GT_EXPR:
- code = NE_EXPR;
- TREE_SET_CODE (t, NE_EXPR);
- break;
- case LE_EXPR:
- code = EQ_EXPR;
- TREE_SET_CODE (t, EQ_EXPR);
- break;
- case GE_EXPR:
- return omit_one_operand (type,
- convert (type, integer_one_node),
- arg0);
- case LT_EXPR:
- return omit_one_operand (type,
- convert (type, integer_zero_node),
- arg0);
- default:
- break;
- }
- }
-
- /* Comparisons with the highest or lowest possible integer of
- the specified size will have known values and an unsigned
- <= 0x7fffffff can be simplified. */
- {
- int width = GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (arg1)));
-
- if (TREE_CODE (arg1) == INTEGER_CST
- && ! TREE_CONSTANT_OVERFLOW (arg1)
- && width <= HOST_BITS_PER_WIDE_INT
- && (INTEGRAL_TYPE_P (TREE_TYPE (arg1))
- || POINTER_TYPE_P (TREE_TYPE (arg1))))
- {
- if (TREE_INT_CST_HIGH (arg1) == 0
- && (TREE_INT_CST_LOW (arg1)
- == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
- && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
- switch (TREE_CODE (t))
- {
- case GT_EXPR:
- return omit_one_operand (type,
- convert (type, integer_zero_node),
- arg0);
- case GE_EXPR:
- TREE_SET_CODE (t, EQ_EXPR);
- break;
-
- case LE_EXPR:
- return omit_one_operand (type,
- convert (type, integer_one_node),
- arg0);
- case LT_EXPR:
- TREE_SET_CODE (t, NE_EXPR);
- break;
-
- default:
- break;
- }
-
- else if (TREE_INT_CST_HIGH (arg1) == -1
- && (- TREE_INT_CST_LOW (arg1)
- == ((unsigned HOST_WIDE_INT) 1 << (width - 1)))
- && ! TREE_UNSIGNED (TREE_TYPE (arg1)))
- switch (TREE_CODE (t))
- {
- case LT_EXPR:
- return omit_one_operand (type,
- convert (type, integer_zero_node),
- arg0);
- case LE_EXPR:
- TREE_SET_CODE (t, EQ_EXPR);
- break;
-
- case GE_EXPR:
- return omit_one_operand (type,
- convert (type, integer_one_node),
- arg0);
- case GT_EXPR:
- TREE_SET_CODE (t, NE_EXPR);
- break;
-
- default:
- break;
- }
-
- else if (TREE_INT_CST_HIGH (arg1) == 0
- && (TREE_INT_CST_LOW (arg1)
- == ((unsigned HOST_WIDE_INT) 1 << (width - 1)) - 1)
- && TREE_UNSIGNED (TREE_TYPE (arg1))
- /* signed_type does not work on pointer types. */
- && INTEGRAL_TYPE_P (TREE_TYPE (arg1)))
-
- switch (TREE_CODE (t))
- {
- case LE_EXPR:
- return fold (build (GE_EXPR, type,
- convert (signed_type (TREE_TYPE (arg0)),
- arg0),
- convert (signed_type (TREE_TYPE (arg1)),
- integer_zero_node)));
- case GT_EXPR:
- return fold (build (LT_EXPR, type,
- convert (signed_type (TREE_TYPE (arg0)),
- arg0),
- convert (signed_type (TREE_TYPE (arg1)),
- integer_zero_node)));
-
- default:
- break;
- }
- }
- }
-
/* If we are comparing an expression that just has comparisons
of two integer values, arithmetic expressions of those comparisons,
and constants, we can simplify it. There are only three cases
fold (build (code, type, imag0, imag1))));
}
+ /* Optimize comparisons of strlen vs zero to a compare of the
+ first character of the string vs zero. To wit,
+ strlen(ptr) == 0 => *ptr == 0
+ strlen(ptr) != 0 => *ptr != 0
+ Other cases should reduce to one of these two (or a constant)
+ due to the return value of strlen being unsigned. */
+ if ((code == EQ_EXPR || code == NE_EXPR)
+ && integer_zerop (arg1)
+ && TREE_CODE (arg0) == CALL_EXPR
+ && TREE_CODE (TREE_OPERAND (arg0, 0)) == ADDR_EXPR)
+ {
+ tree fndecl = TREE_OPERAND (TREE_OPERAND (arg0, 0), 0);
+ tree arglist;
+
+ if (TREE_CODE (fndecl) == FUNCTION_DECL
+ && DECL_BUILT_IN (fndecl)
+ && DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_MD
+ && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_STRLEN
+ && (arglist = TREE_OPERAND (arg0, 1))
+ && TREE_CODE (TREE_TYPE (TREE_VALUE (arglist))) == POINTER_TYPE
+ && ! TREE_CHAIN (arglist))
+ return fold (build (code, type,
+ build1 (INDIRECT_REF, char_type_node,
+ TREE_VALUE(arglist)),
+ integer_zero_node));
+ }
+
/* From here on, the only cases we handle are when the result is
known to be a constant.
TREE_TYPE (t1) = type;
if (TREE_CODE (type) == BOOLEAN_TYPE)
- return truthvalue_conversion (t1);
+ return (*lang_hooks.truthvalue_conversion) (t1);
return t1;
case COND_EXPR:
/* If we have A op B ? A : C, we may be able to convert this to a
simpler expression, depending on the operation and the values
- of B and C. IEEE floating point prevents this though,
- because A or B might be -0.0 or a NaN. */
+ of B and C. Signed zeros prevent all of these transformations,
+ for reasons given above each one. */
if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<'
- && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
- || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))
- || flag_unsafe_math_optimizations)
&& operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0),
- arg1, TREE_OPERAND (arg0, 1)))
+ arg1, TREE_OPERAND (arg0, 1))
+ && !HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (arg1))))
{
tree arg2 = TREE_OPERAND (t, 2);
enum tree_code comp_code = TREE_CODE (arg0);
STRIP_NOPS (arg2);
- /* If we have A op 0 ? A : -A, this is A, -A, abs (A), or abs (-A),
- depending on the comparison operation. */
+ /* If we have A op 0 ? A : -A, consider applying the following
+ transformations:
+
+ A == 0? A : -A same as -A
+ A != 0? A : -A same as A
+ A >= 0? A : -A same as abs (A)
+ A > 0? A : -A same as abs (A)
+ A <= 0? A : -A same as -abs (A)
+ A < 0? A : -A same as -abs (A)
+
+ None of these transformations work for modes with signed
+ zeros. If A is +/-0, the first two transformations will
+ change the sign of the result (from +0 to -0, or vice
+ versa). The last four will fix the sign of the result,
+ even though the original expressions could be positive or
+ negative, depending on the sign of A.
+
+ Note that all these transformations are correct if A is
+ NaN, since the two alternatives (A and -A) are also NaNs. */
if ((FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 1)))
? real_zerop (TREE_OPERAND (arg0, 1))
: integer_zerop (TREE_OPERAND (arg0, 1)))
negate_expr
(convert (TREE_TYPE (TREE_OPERAND (t, 1)),
arg1))));
-
case NE_EXPR:
return pedantic_non_lvalue (convert (type, arg1));
case GE_EXPR:
case GT_EXPR:
if (TREE_UNSIGNED (TREE_TYPE (arg1)))
- arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
+ arg1 = convert ((*lang_hooks.types.signed_type)
+ (TREE_TYPE (arg1)), arg1);
return pedantic_non_lvalue
(convert (type, fold (build1 (ABS_EXPR,
TREE_TYPE (arg1), arg1))));
case LE_EXPR:
case LT_EXPR:
if (TREE_UNSIGNED (TREE_TYPE (arg1)))
- arg1 = convert (signed_type (TREE_TYPE (arg1)), arg1);
+ arg1 = convert ((lang_hooks.types.signed_type)
+ (TREE_TYPE (arg1)), arg1);
return pedantic_non_lvalue
(negate_expr (convert (type,
fold (build1 (ABS_EXPR,
abort ();
}
- /* If this is A != 0 ? A : 0, this is simply A. For ==, it is
- always zero. */
+ /* A != 0 ? A : 0 is simply A, unless A is -0. Likewise
+ A == 0 ? A : 0 is always 0 unless A is -0. Note that
+ both transformations are correct when A is NaN: A != 0
+ is then true, and A == 0 is false. */
if (integer_zerop (TREE_OPERAND (arg0, 1)) && integer_zerop (arg2))
{
return pedantic_non_lvalue (convert (type, integer_zero_node));
}
- /* If this is A op B ? A : B, this is either A, B, min (A, B),
- or max (A, B), depending on the operation. */
-
+ /* Try some transformations of A op B ? A : B.
+
+ A == B? A : B same as B
+ A != B? A : B same as A
+ A >= B? A : B same as max (A, B)
+ A > B? A : B same as max (B, A)
+ A <= B? A : B same as min (A, B)
+ A < B? A : B same as min (B, A)
+
+ As above, these transformations don't work in the presence
+ of signed zeros. For example, if A and B are zeros of
+ opposite sign, the first two transformations will change
+ the sign of the result. In the last four, the original
+ expressions give different results for (A=+0, B=-0) and
+ (A=-0, B=+0), but the transformed expressions do not.
+
+ The first two transformations are correct if either A or B
+ is a NaN. In the first transformation, the condition will
+ be false, and B will indeed be chosen. In the case of the
+ second transformation, the condition A != B will be true,
+ and A will be chosen.
+
+ The conversions to max() and min() are not correct if B is
+ a number and A is not. The conditions in the original
+ expressions will be false, so all four give B. The min()
+ and max() versions would give a NaN instead. */
if (operand_equal_for_comparison_p (TREE_OPERAND (arg0, 1),
arg2, TREE_OPERAND (arg0, 0)))
{
operand which will be used if they are equal first
so that we can convert this back to the
corresponding COND_EXPR. */
- return pedantic_non_lvalue
- (convert (type, fold (build (MIN_EXPR, comp_type,
- (comp_code == LE_EXPR
- ? comp_op0 : comp_op1),
- (comp_code == LE_EXPR
- ? comp_op1 : comp_op0)))));
+ if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
+ return pedantic_non_lvalue
+ (convert (type, fold (build (MIN_EXPR, comp_type,
+ (comp_code == LE_EXPR
+ ? comp_op0 : comp_op1),
+ (comp_code == LE_EXPR
+ ? comp_op1 : comp_op0)))));
break;
case GE_EXPR:
case GT_EXPR:
- return pedantic_non_lvalue
- (convert (type, fold (build (MAX_EXPR, comp_type,
- (comp_code == GE_EXPR
- ? comp_op0 : comp_op1),
- (comp_code == GE_EXPR
- ? comp_op1 : comp_op0)))));
+ if (!HONOR_NANS (TYPE_MODE (TREE_TYPE (arg1))))
+ return pedantic_non_lvalue
+ (convert (type, fold (build (MAX_EXPR, comp_type,
+ (comp_code == GE_EXPR
+ ? comp_op0 : comp_op1),
+ (comp_code == GE_EXPR
+ ? comp_op1 : comp_op0)))));
break;
default:
abort ();
case FLOOR_DIV_EXPR:
case ROUND_DIV_EXPR:
return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
- && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
+ && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
case TRUNC_MOD_EXPR:
case CEIL_MOD_EXPR:
case FLOOR_MOD_EXPR:
return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
case MIN_EXPR:
return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
- && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
+ && tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
case MAX_EXPR:
return tree_expr_nonnegative_p (TREE_OPERAND (t, 0))
- || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
+ || tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
case MODIFY_EXPR:
return tree_expr_nonnegative_p (TREE_OPERAND (t, 1));
case BIND_EXPR:
return tree_expr_nonnegative_p (TREE_OPERAND (t, 0));
case RTL_EXPR:
return rtl_expr_nonnegative_p (RTL_EXPR_RTL (t));
-
+
default:
if (truth_value_p (TREE_CODE (t)))
/* Truth values evaluate to 0 or 1, which is nonnegative. */
return CONST_DOUBLE_HIGH (r) >= 0;
return 0;
+ case CONST_VECTOR:
+ {
+ int units, i;
+ rtx elt;
+
+ units = CONST_VECTOR_NUNITS (r);
+
+ for (i = 0; i < units; ++i)
+ {
+ elt = CONST_VECTOR_ELT (r, i);
+ if (!rtl_expr_nonnegative_p (elt))
+ return 0;
+ }
+
+ return 1;
+ }
+
case SYMBOL_REF:
case LABEL_REF:
/* These are always nonnegative. */
return 0;
}
}
+
+#include "gt-fold-const.h"
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