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| author | Jakub Jelinek <jakub@redhat.com> | 2017-10-13 19:19:12 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2017-10-13 19:19:12 +0200 |
| commit | e7176f75d6b2dd56059dad5920c770dade79df95 (patch) | |
| tree | 7ac0495b4cd1c60e5a022d19c0de3ce667bdd725 /libgcc/libgcc2.c | |
| parent | 8de7190350263d381df5c12cfbbfb4191b8d3973 (diff) | |
| download | gcc-e7176f75d6b2dd56059dad5920c770dade79df95.zip gcc-e7176f75d6b2dd56059dad5920c770dade79df95.tar.gz gcc-e7176f75d6b2dd56059dad5920c770dade79df95.tar.bz2 | |
re PR target/82274 (__builtin_mul_overflow fails to detect overflow for int64_t when compiled with -m32)
PR target/82274
* internal-fn.c (expand_mul_overflow): If both operands have
the same highpart of -1 or 0 and the topmost bit of lowpart
is different, overflow is if res <= 0 rather than res < 0.
* libgcc2.c (__mulvDI3): If both operands have
the same highpart of -1 and the topmost bit of lowpart is 0,
multiplication overflows even if both lowparts are 0.
* gcc.dg/pr82274-1.c: New test.
* gcc.dg/pr82274-2.c: New test.
From-SVN: r253734
Diffstat (limited to 'libgcc/libgcc2.c')
| -rw-r--r-- | libgcc/libgcc2.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/libgcc/libgcc2.c b/libgcc/libgcc2.c index 5d3c69f..83f865a 100644 --- a/libgcc/libgcc2.c +++ b/libgcc/libgcc2.c @@ -375,7 +375,8 @@ __mulvDI3 (DWtype u, DWtype v) } else { - if (uu.s.high == (Wtype) -1 && vv.s.high == (Wtype) - 1) + if ((uu.s.high & vv.s.high) == (Wtype) -1 + && (uu.s.low | vv.s.low) != 0) { DWunion ww = {.ll = (UDWtype) (UWtype) uu.s.low * (UDWtype) (UWtype) vv.s.low}; |