diff options
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 564cec3..682ae00 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -8575,11 +8575,11 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1) && !TREE_SIDE_EFFECTS (arg1)) { tem = fold_to_nonsharp_ineq_using_bound (arg0, arg1); - if (tem) + if (tem && !operand_equal_p (tem, arg0, 0)) return fold_build2 (code, type, tem, arg1); tem = fold_to_nonsharp_ineq_using_bound (arg1, arg0); - if (tem) + if (tem && !operand_equal_p (tem, arg1, 0)) return fold_build2 (code, type, arg0, tem); } @@ -8865,6 +8865,30 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1) } } + /* Transform comparisons of the form X +- C1 CMP C2 to X CMP C2 +- C1. */ + if ((TREE_CODE (arg0) == PLUS_EXPR || TREE_CODE (arg0) == MINUS_EXPR) + && (TREE_CODE (TREE_OPERAND (arg0, 1)) == INTEGER_CST + && !TREE_OVERFLOW (TREE_OPERAND (arg0, 1)) + && !TYPE_UNSIGNED (TREE_TYPE (arg1)) + && !(flag_wrapv || flag_trapv)) + && (TREE_CODE (arg1) == INTEGER_CST + && !TREE_OVERFLOW (arg1))) + { + tree const1 = TREE_OPERAND (arg0, 1); + tree const2 = arg1; + tree variable = TREE_OPERAND (arg0, 0); + tree lhs; + int lhs_add; + lhs_add = TREE_CODE (arg0) != PLUS_EXPR; + + lhs = fold_build2 (lhs_add ? PLUS_EXPR : MINUS_EXPR, + TREE_TYPE (arg1), const2, const1); + if (TREE_CODE (lhs) == TREE_CODE (arg1) + && (TREE_CODE (lhs) != INTEGER_CST + || !TREE_OVERFLOW (lhs))) + return fold_build2 (code, type, variable, lhs); + } + if (FLOAT_TYPE_P (TREE_TYPE (arg0))) { tree targ0 = strip_float_extensions (arg0); |