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| author | Diego Novillo <dnovillo@redhat.com> | 2006-02-09 12:38:35 +0000 |
|---|---|---|
| committer | Diego Novillo <dnovillo@gcc.gnu.org> | 2006-02-09 07:38:35 -0500 |
| commit | 7dc32197a8f098c05d589d80ccbcc7ea51a62bea (patch) | |
| tree | 33ef846a4e5a0e2ffd2f172f144a0e07e597bf8d /gcc/tree-vrp.c | |
| parent | e10fbf96398ce612c334754e0614c998e3ec3335 (diff) | |
| download | gcc-7dc32197a8f098c05d589d80ccbcc7ea51a62bea.zip gcc-7dc32197a8f098c05d589d80ccbcc7ea51a62bea.tar.gz gcc-7dc32197a8f098c05d589d80ccbcc7ea51a62bea.tar.bz2 | |
re PR tree-optimization/26180 (wrong code due to VRP and unsigned multiplies with wraps)
PR 26180
* tree-vrp.c (vrp_int_const_binop): Detect overflow when
multiplying unsigned values.
Tidy comments.
testsuite
PR 26180
* gcc.dg/tree-ssa/pr26180.c: New test.
From-SVN: r110794
Diffstat (limited to 'gcc/tree-vrp.c')
| -rw-r--r-- | gcc/tree-vrp.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c index 80dcf39..8734f51 100644 --- a/gcc/tree-vrp.c +++ b/gcc/tree-vrp.c @@ -1191,22 +1191,24 @@ vrp_int_const_binop (enum tree_code code, tree val1, tree val2) { int checkz = compare_values (res, val1); - /* Ensure that res = val1 + val2 >= val1 + /* Ensure that res = val1 [+*] val2 >= val1 or that res = val1 - val2 <= val1. */ - if ((code == PLUS_EXPR && !(checkz == 1 || checkz == 0)) - || (code == MINUS_EXPR && !(checkz == 0 || checkz == -1))) + if (((code == PLUS_EXPR || code == MULT_EXPR) + && !(checkz == 1 || checkz == 0)) + || (code == MINUS_EXPR + && !(checkz == 0 || checkz == -1))) { res = copy_node (res); TREE_OVERFLOW (res) = 1; } } - /* If the operation overflowed but neither VAL1 nor VAL2 are - overflown, return -INF or +INF depending on the operation - and the combination of signs of the operands. */ else if (TREE_OVERFLOW (res) && !TREE_OVERFLOW (val1) && !TREE_OVERFLOW (val2)) { + /* If the operation overflowed but neither VAL1 nor VAL2 are + overflown, return -INF or +INF depending on the operation + and the combination of signs of the operands. */ int sgn1 = tree_int_cst_sgn (val1); int sgn2 = tree_int_cst_sgn (val2); |