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| author | Roger Sayle <roger@eyesopen.com> | 2003-05-23 03:46:53 +0000 |
|---|---|---|
| committer | Roger Sayle <sayle@gcc.gnu.org> | 2003-05-23 03:46:53 +0000 |
| commit | 18c2511ccbc14dc2899b0fb6ec60935ac87087c2 (patch) | |
| tree | 5b38df8d0da0fa5e04c432815e2f600b41d5f2e5 /gcc/fold-const.c | |
| parent | a8e097d6db75fdb7fb530bd571647a656376fe97 (diff) | |
| download | gcc-18c2511ccbc14dc2899b0fb6ec60935ac87087c2.zip gcc-18c2511ccbc14dc2899b0fb6ec60935ac87087c2.tar.gz gcc-18c2511ccbc14dc2899b0fb6ec60935ac87087c2.tar.bz2 | |
real.c (real_maxval): New function to return the largest finite value representable in a given mode (i.e.
* real.c (real_maxval): New function to return the largest finite
value representable in a given mode (i.e. FLT_MAX and DBL_MAX).
* real.h (real_maxval): Prototype here.
* fold-const.c (fold_inf_compare): Transform comparisons against
+-Infinity into comparisons against DBL_MAX (or equivalent).
* gcc.c-torture/execute/ieee/inf-2.c: New test case.
From-SVN: r67112
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 40 |
1 files changed, 33 insertions, 7 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index eb65795..6a4e229 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -4820,15 +4820,23 @@ fold_inf_compare (code, type, arg0, arg1) enum tree_code code; tree type, arg0, arg1; { + enum machine_mode mode; + REAL_VALUE_TYPE max; + tree temp; + bool neg; + + mode = TYPE_MODE (TREE_TYPE (arg0)); + /* For negative infinity swap the sense of the comparison. */ - if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1))) + neg = REAL_VALUE_NEGATIVE (TREE_REAL_CST (arg1)); + if (neg) code = swap_tree_comparison (code); switch (code) { case GT_EXPR: /* x > +Inf is always false, if with ignore sNANs. */ - if (HONOR_SNANS (TYPE_MODE (TREE_TYPE (arg0)))) + if (HONOR_SNANS (mode)) return NULL_TREE; return omit_one_operand (type, convert (type, integer_zero_node), @@ -4836,7 +4844,7 @@ fold_inf_compare (code, type, arg0, arg1) case LE_EXPR: /* x <= +Inf is always true, if we don't case about NaNs. */ - if (! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0)))) + if (! HONOR_NANS (mode)) return omit_one_operand (type, convert (type, integer_one_node), arg0); @@ -4850,10 +4858,28 @@ fold_inf_compare (code, type, arg0, arg1) } break; - case EQ_EXPR: /* ??? x == +Inf is x > DBL_MAX */ - case GE_EXPR: /* ??? x >= +Inf is x > DBL_MAX */ - case LT_EXPR: /* ??? x < +Inf is x <= DBL_MAX */ - case NE_EXPR: /* ??? x != +Inf is !(x > DBL_MAX) */ + case EQ_EXPR: + case GE_EXPR: + /* x == +Inf and x >= +Inf are always equal to x > DBL_MAX. */ + real_maxval (&max, neg, mode); + return fold (build (neg ? LT_EXPR : GT_EXPR, type, + arg0, build_real (TREE_TYPE (arg0), max))); + + case LT_EXPR: + /* x < +Inf is always equal to x <= DBL_MAX. */ + real_maxval (&max, neg, mode); + return fold (build (neg ? GE_EXPR : LE_EXPR, type, + arg0, build_real (TREE_TYPE (arg0), max))); + + case NE_EXPR: + /* x != +Inf is always equal to !(x > DBL_MAX). */ + real_maxval (&max, neg, mode); + if (! HONOR_NANS (mode)) + return fold (build (neg ? GE_EXPR : LE_EXPR, type, + arg0, build_real (TREE_TYPE (arg0), max))); + temp = fold (build (neg ? LT_EXPR : GT_EXPR, type, + arg0, build_real (TREE_TYPE (arg0), max))); + return fold (build1 (TRUTH_NOT_EXPR, type, temp)); default: break; |