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| author | Richard Kenner <kenner@gcc.gnu.org> | 1993-12-27 08:48:58 -0500 |
|---|---|---|
| committer | Richard Kenner <kenner@gcc.gnu.org> | 1993-12-27 08:48:58 -0500 |
| commit | fab446b8c31883fece1b0b2f5ed7b2cfbf48f241 (patch) | |
| tree | ba74c9815654aa4b106129ec87fcd1361515ce98 /gcc | |
| parent | a83afb65d0230c597dc69793f4a266fe7df3240d (diff) | |
| download | gcc-fab446b8c31883fece1b0b2f5ed7b2cfbf48f241.zip gcc-fab446b8c31883fece1b0b2f5ed7b2cfbf48f241.tar.gz gcc-fab446b8c31883fece1b0b2f5ed7b2cfbf48f241.tar.bz2 | |
(fold): Simplify more FP ops if -ffast-math.
From-SVN: r6335
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/fold-const.c | 28 |
1 files changed, 17 insertions, 11 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 6424737..82e63a7 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -3766,7 +3766,9 @@ fold (expr) /* Convert A - (-B) to A + B. */ else if (TREE_CODE (arg1) == NEGATE_EXPR) return fold (build (PLUS_EXPR, type, arg0, TREE_OPERAND (arg1, 0))); - else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT) + + else if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT + || flag_fast_math) { /* Except with IEEE floating point, 0-x equals -x. */ if (! wins && real_zerop (arg0)) @@ -3774,16 +3776,18 @@ fold (expr) /* Except with IEEE floating point, x-0 equals x. */ if (real_zerop (arg1)) return non_lvalue (convert (type, arg0)); + } - /* Fold &x - &x. This can happen from &x.foo - &x. - This is unsafe for certain floats even in non-IEEE formats. - In IEEE, it is unsafe because it does wrong for NaNs. - Also note that operand_equal_p is always false if an operand - is volatile. */ + /* Fold &x - &x. This can happen from &x.foo - &x. + This is unsafe for certain floats even in non-IEEE formats. + In IEEE, it is unsafe because it does wrong for NaNs. + Also note that operand_equal_p is always false if an operand + is volatile. */ + + if (operand_equal_p (arg0, arg1, + FLOAT_TYPE_P (type) && ! flag_fast_math)) + return convert (type, integer_zero_node); - if (operand_equal_p (arg0, arg1, FLOAT_TYPE_P (type))) - return convert (type, integer_zero_node); - } goto associate; case MULT_EXPR: @@ -3807,7 +3811,8 @@ fold (expr) else { /* x*0 is 0, except for IEEE floating point. */ - if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT + if ((TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT + || flag_fast_math) && real_zerop (arg1)) return omit_one_operand (type, arg1, arg0); /* In IEEE floating point, x*1 is not equivalent to x for snans. @@ -4630,7 +4635,8 @@ fold (expr) if (TREE_CODE_CLASS (TREE_CODE (arg0)) == '<' && (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT - || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0)))) + || ! FLOAT_TYPE_P (TREE_TYPE (TREE_OPERAND (arg0, 0))) + || flag_fast_math) && operand_equal_for_comparison_p (TREE_OPERAND (arg0, 0), arg1, TREE_OPERAND (arg0, 1))) { |