diff options
| author | Jakub Jelinek <jakub@redhat.com> | 2007-12-18 01:13:29 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2007-12-18 01:13:29 +0100 |
| commit | dc7c279e97760bba05fa4d637d5652f8559eab3a (patch) | |
| tree | 8b72d93c5aed08c343fa4fbc730ba4c7f0b0b5bc /gcc/simplify-rtx.c | |
| parent | 44f37984f4e87411999989e2c3ff715a4860d9c3 (diff) | |
| download | gcc-dc7c279e97760bba05fa4d637d5652f8559eab3a.zip gcc-dc7c279e97760bba05fa4d637d5652f8559eab3a.tar.gz gcc-dc7c279e97760bba05fa4d637d5652f8559eab3a.tar.bz2 | |
re PR rtl-optimization/34490 (r128833 causes miscompilation of glibc clock_gettime.c)
PR rtl-optimization/34490
* simplify-rtx.c (simplify_const_relational_operation): If !sign,
don't reduce mmin/mmax using num_sign_bit_copies.
* gcc.c-torture/execute/20071216-1.c: New test.
From-SVN: r131023
Diffstat (limited to 'gcc/simplify-rtx.c')
| -rw-r--r-- | gcc/simplify-rtx.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index 0371339..fd14e40 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -4233,15 +4233,17 @@ simplify_const_relational_operation (enum rtx_code code, else { rtx mmin_rtx, mmax_rtx; - unsigned int sign_copies = num_sign_bit_copies (trueop0, mode); get_mode_bounds (mode, sign, mode, &mmin_rtx, &mmax_rtx); - /* Since unsigned mmin will never be interpreted as negative, use - INTVAL (and an arithmetic right shift). */ - mmin = INTVAL (mmin_rtx) >> (sign_copies - 1); - /* Since signed mmax will always be positive, use UINTVAL (and - a logical right shift). */ - mmax = UINTVAL (mmax_rtx) >> (sign_copies - 1); + mmin = INTVAL (mmin_rtx); + mmax = INTVAL (mmax_rtx); + if (sign) + { + unsigned int sign_copies = num_sign_bit_copies (trueop0, mode); + + mmin >>= (sign_copies - 1); + mmax >>= (sign_copies - 1); + } } switch (code) |