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| author | Alexandre Oliva <aoliva@redhat.com> | 2018-12-06 23:18:19 +0000 |
|---|---|---|
| committer | Alexandre Oliva <aoliva@gcc.gnu.org> | 2018-12-06 23:18:19 +0000 |
| commit | 695be0923410ad753e9d7bc377f992406f904e94 (patch) | |
| tree | adaf137bbb4c1eb8f14668db5114718686bee04c /gcc | |
| parent | 4cbb7085f078ad25f7f11855d91c143e1189e89b (diff) | |
| download | gcc-695be0923410ad753e9d7bc377f992406f904e94.zip gcc-695be0923410ad753e9d7bc377f992406f904e94.tar.gz gcc-695be0923410ad753e9d7bc377f992406f904e94.tar.bz2 | |
avoid null ptr deref in cselib_record_sets
Jeff Law tells me h8300-elf fails gcc.c-torture/compile/pr49029.c
with -O2 -g -mint32 -mh. This patch fixes it.
The problem is that strict low part handling in cselib_record_sets
assumes src_elt is not NULL. That src_elt is taken from a strict low
part set, but it won't always have a src_elt to begin with. In this
case, it's because src is a volatile MEM; we don't record values for
those.
Although we could fix the problem by testing for a NULL src_elt before
creating the zero extends corresponding to strict low part sets of
formerly const0_rtx REGs, there's no point in recording the additional
set that we won't be able to use anyway.
We could still record that the whole register has a zero-extend of
the value stored in the narrower-mode strict low part of the register,
but is that of any use? I guess not, but if we find otherwise, we can
change that later.
for gcc/ChangeLog
* cselib.c (cselib_record_sets): Skip strict low part sets
with NULL src_elt.
From-SVN: r266873
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/cselib.c | 1 |
2 files changed, 6 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index dc59688..2dc7f43 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +2018-12-06 Alexandre Oliva <aoliva@redhat.com> + + * cselib.c (cselib_record_sets): Skip strict low part sets + with NULL src_elt. + 2018-12-06 Paul A. Clarke <pc@us.ibm.com> PR target/88316 diff --git a/gcc/cselib.c b/gcc/cselib.c index 6d3a407..4a68439 100644 --- a/gcc/cselib.c +++ b/gcc/cselib.c @@ -2616,6 +2616,7 @@ cselib_record_sets (rtx_insn *insn) preserves the upper bits that di:SI=zero_extend(flags:CCNO<=0). */ scalar_int_mode mode; if (dest != orig + && sets[i].src_elt && cselib_record_sets_hook && REG_P (dest) && HARD_REGISTER_P (dest) |