diff options
Diffstat (limited to 'gcc/fold-const.c')
| -rw-r--r-- | gcc/fold-const.c | 26 |
1 files changed, 21 insertions, 5 deletions
diff --git a/gcc/fold-const.c b/gcc/fold-const.c index 2e89969..be0c461 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -6014,6 +6014,7 @@ fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1) tree arg01 = TREE_OPERAND (arg0, 1); unsigned HOST_WIDE_INT lpart; HOST_WIDE_INT hpart; + bool neg_overflow; int overflow; /* We have to do this the hard way to detect unsigned overflow. @@ -6024,6 +6025,7 @@ fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1) TREE_INT_CST_HIGH (arg1), &lpart, &hpart); prod = build_int_cst_wide (TREE_TYPE (arg00), lpart, hpart); prod = force_fit_type (prod, -1, overflow, false); + neg_overflow = false; if (TYPE_UNSIGNED (TREE_TYPE (arg0))) { @@ -6046,6 +6048,7 @@ fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1) switch (tree_int_cst_sgn (arg1)) { case -1: + neg_overflow = true; lo = int_const_binop (MINUS_EXPR, prod, tmp, 0); hi = prod; break; @@ -6083,7 +6086,8 @@ fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1) break; case 1: - lo = int_const_binop (PLUS_EXPR, prod, tmp, 0); + neg_overflow = true; + lo = int_const_binop (PLUS_EXPR, prod, tmp, 0); hi = prod; break; @@ -6114,22 +6118,34 @@ fold_div_compare (enum tree_code code, tree type, tree arg0, tree arg1) case LT_EXPR: if (TREE_OVERFLOW (lo)) - return omit_one_operand (type, integer_one_node, arg00); + { + tmp = neg_overflow ? integer_zero_node : integer_one_node; + return omit_one_operand (type, tmp, arg00); + } return fold_build2 (LT_EXPR, type, arg00, lo); case LE_EXPR: if (TREE_OVERFLOW (hi)) - return omit_one_operand (type, integer_one_node, arg00); + { + tmp = neg_overflow ? integer_zero_node : integer_one_node; + return omit_one_operand (type, tmp, arg00); + } return fold_build2 (LE_EXPR, type, arg00, hi); case GT_EXPR: if (TREE_OVERFLOW (hi)) - return omit_one_operand (type, integer_zero_node, arg00); + { + tmp = neg_overflow ? integer_one_node : integer_zero_node; + return omit_one_operand (type, tmp, arg00); + } return fold_build2 (GT_EXPR, type, arg00, hi); case GE_EXPR: if (TREE_OVERFLOW (lo)) - return omit_one_operand (type, integer_zero_node, arg00); + { + tmp = neg_overflow ? integer_one_node : integer_zero_node; + return omit_one_operand (type, tmp, arg00); + } return fold_build2 (GE_EXPR, type, arg00, lo); default: |