diff options
| author | Segher Boessenkool <segher@kernel.crashing.org> | 2016-05-14 01:01:40 +0200 |
|---|---|---|
| committer | Segher Boessenkool <segher@gcc.gnu.org> | 2016-05-14 01:01:40 +0200 |
| commit | 85ca20c9516879edf92356ee5d8a5c567db085a0 (patch) | |
| tree | 310b3ae6402e5929bff678da27c70f03f786eb77 | |
| parent | aa4b467b680f230ab11922d1e29695e1eaba12af (diff) | |
| download | gcc-85ca20c9516879edf92356ee5d8a5c567db085a0.zip gcc-85ca20c9516879edf92356ee5d8a5c567db085a0.tar.gz gcc-85ca20c9516879edf92356ee5d8a5c567db085a0.tar.bz2 | |
combine: Don't call extract_left_shift with count < 0 (PR67483)
If the compiled program does a shift by a negative amount, combine will
happily work with that, but it shouldn't then do an undefined operation
in GCC itself. This patch fixes the first case mentioned in the bug
report (I haven't been able to reproduce the second case, on trunk at
least).
PR rtl-optimization/67483
* combine.c (make_compound_operation): Don't call extract_left_shift
with negative shift amounts.
From-SVN: r236232
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/combine.c | 1 |
2 files changed, 7 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 5133b37..7178c7c 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2016-05-13 Segher Boessenkool <segher@kernel.crashing.org> + + PR rtl-optimization/67483 + * combine.c (make_compound_operation): Don't call extract_left_shift + with negative shift amounts. + 2016-05-13 Jakub Jelinek <jakub@redhat.com> PR bootstrap/71071 diff --git a/gcc/combine.c b/gcc/combine.c index 3554f51..cd864cc 100644 --- a/gcc/combine.c +++ b/gcc/combine.c @@ -8037,6 +8037,7 @@ make_compound_operation (rtx x, enum rtx_code in_code) && ! (GET_CODE (lhs) == SUBREG && (OBJECT_P (SUBREG_REG (lhs)))) && CONST_INT_P (rhs) + && INTVAL (rhs) >= 0 && INTVAL (rhs) < HOST_BITS_PER_WIDE_INT && INTVAL (rhs) < mode_width && (new_rtx = extract_left_shift (lhs, INTVAL (rhs))) != 0) |