diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 26d692944487..b7aa5d1b65e4 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2007-06-05 Ian Lance Taylor + + * tree-vrp.c (compare_values_warnv): Check TREE_NO_WARNING on a + PLUS_EXPR or MINUS_EXPR node before setting *strict_overflow_p. + (extract_range_from_assert): Set TREE_NO_WARNING when creating an + expression. + (test_for_singularity): Likewise. + 2007-06-04 Ian Lance Taylor * tree-vrp.c (adjust_range_with_scev): When loop is not expected diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 81f5f88386a3..30b6c4807f81 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2007-06-05 Ian Lance Taylor + + * gcc.dg/Wstrict-overflow-19.c: New test. + 2007-06-04 Ian Lance Taylor * gcc.dg/Wstrict-overflow-18.c: New test. diff --git a/gcc/testsuite/gcc.dg/Wstrict-overflow-19.c b/gcc/testsuite/gcc.dg/Wstrict-overflow-19.c new file mode 100644 index 000000000000..daf98b0ce630 --- /dev/null +++ b/gcc/testsuite/gcc.dg/Wstrict-overflow-19.c @@ -0,0 +1,15 @@ +/* { dg-do compile } */ +/* { dg-options "-fstrict-overflow -O2 -Wstrict-overflow" } */ + +/* Don't warn about an overflow when threading jumps. We used to get + a warning from comparing bounds generated by VRP. */ + +int +bar(int a, int b, int n) +{ + if (b > a) + n = a - b; + if (a >= b) + n = 1; + return n; +} diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index f66bf5d57cb3..92d59fbdb4ee 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -771,7 +771,9 @@ compare_values_warnv (tree val1, tree val2, bool *strict_overflow_p) if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (val1))) return -2; - if (strict_overflow_p != NULL) + if (strict_overflow_p != NULL + && (code1 == SSA_NAME || !TREE_NO_WARNING (val1)) + && (code2 == SSA_NAME || !TREE_NO_WARNING (val2))) *strict_overflow_p = true; if (code1 == SSA_NAME) @@ -1177,6 +1179,8 @@ extract_range_from_assert (value_range_t *vr_p, tree expr) { tree one = build_int_cst (type, 1); max = fold_build2 (MINUS_EXPR, type, max, one); + if (EXPR_P (max)) + TREE_NO_WARNING (max) = 1; } set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv); @@ -1210,6 +1214,8 @@ extract_range_from_assert (value_range_t *vr_p, tree expr) { tree one = build_int_cst (type, 1); min = fold_build2 (PLUS_EXPR, type, min, one); + if (EXPR_P (min)) + TREE_NO_WARNING (min) = 1; } set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv); @@ -5042,6 +5048,8 @@ test_for_singularity (enum tree_code cond_code, tree op0, { tree one = build_int_cst (TREE_TYPE (op0), 1); max = fold_build2 (MINUS_EXPR, TREE_TYPE (op0), max, one); + if (EXPR_P (max)) + TREE_NO_WARNING (max) = 1; } } else if (cond_code == GE_EXPR || cond_code == GT_EXPR) @@ -5055,6 +5063,8 @@ test_for_singularity (enum tree_code cond_code, tree op0, { tree one = build_int_cst (TREE_TYPE (op0), 1); min = fold_build2 (PLUS_EXPR, TREE_TYPE (op0), min, one); + if (EXPR_P (min)) + TREE_NO_WARNING (min) = 1; } }