diff options
| author | amylaar <amylaar@138bc75d-0d04-0410-961f-82ee72b054a4> | 2001-01-05 20:42:30 +0000 |
|---|---|---|
| committer | amylaar <amylaar@138bc75d-0d04-0410-961f-82ee72b054a4> | 2001-01-05 20:42:30 +0000 |
| commit | e9a91a9e03c2a46cd9c39b6d5e7a474d34afbb27 (patch) | |
| tree | 9a0f9a440b9459868686ca70d71720180e9365ad | |
| parent | 60cb217d0a5f389aff93d2cfa3fc75a3e18d2f9d (diff) | |
| download | ppe42-gcc-e9a91a9e03c2a46cd9c39b6d5e7a474d34afbb27.tar.gz ppe42-gcc-e9a91a9e03c2a46cd9c39b6d5e7a474d34afbb27.zip | |
* cse.c (find_comparison_args): Stop if the argument is known to
be constant.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@38723 138bc75d-0d04-0410-961f-82ee72b054a4
| -rw-r--r-- | gcc/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/cse.c | 15 |
2 files changed, 19 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 95d38f2de6a..650faa7838f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,8 @@ +Fri Jan 5 20:34:06 2001 J"orn Rennecke <amylaar@redhat.com> + + * cse.c (find_comparison_args): Stop if the argument is known to + be constant. + 2001-01-05 Alexandre Oliva <aoliva@redhat.com> * config/sh/sh.md (movdf): When splitting load into pair of diff --git a/gcc/cse.c b/gcc/cse.c index f5c93530a35..8642550c512 100644 --- a/gcc/cse.c +++ b/gcc/cse.c @@ -3161,7 +3161,20 @@ find_comparison_args (code, parg1, parg2, pmode1, pmode2) p = lookup (arg1, safe_hash (arg1, GET_MODE (arg1)) & HASH_MASK, GET_MODE (arg1)); if (p) - p = p->first_same_value; + { + p = p->first_same_value; + + /* If what we compare is already known to be constant, that is as + good as it gets. + We need to break the loop in this case, because otherwise we + can have an infinite loop when looking at a reg that is known + to be a constant which is the same as a comparison of a reg + against zero which appears later in the insn stream, which in + turn is constant and the same as the comparison of the first reg + against zero... */ + if (p->is_const) + break; + } for (; p; p = p->next_same_value) { |
