diff options
Diffstat (limited to 'gcc/alias.c')
| -rw-r--r-- | gcc/alias.c | 15 |
1 files changed, 6 insertions, 9 deletions
diff --git a/gcc/alias.c b/gcc/alias.c index 88a3b7e..fbc4e10 100644 --- a/gcc/alias.c +++ b/gcc/alias.c @@ -326,17 +326,11 @@ ao_ref_from_mem (ao_ref *ref, const_rtx mem) ref->ref_alias_set = MEM_ALIAS_SET (mem); - /* If MEM_OFFSET or MEM_SIZE are unknown we have to punt. - Keep points-to related information though. */ + /* If MEM_OFFSET or MEM_SIZE are unknown what we got from MEM_EXPR + is conservative, so trust it. */ if (!MEM_OFFSET_KNOWN_P (mem) || !MEM_SIZE_KNOWN_P (mem)) - { - ref->ref = NULL_TREE; - ref->offset = 0; - ref->size = -1; - ref->max_size = -1; - return true; - } + return true; /* If the base decl is a parameter we can have negative MEM_OFFSET in case of promoted subregs on bigendian targets. Trust the MEM_EXPR @@ -345,6 +339,9 @@ ao_ref_from_mem (ao_ref *ref, const_rtx mem) && (MEM_SIZE (mem) + MEM_OFFSET (mem)) * BITS_PER_UNIT == ref->size) return true; + /* Otherwise continue and refine size and offset we got from analyzing + MEM_EXPR by using MEM_SIZE and MEM_OFFSET. */ + ref->offset += MEM_OFFSET (mem) * BITS_PER_UNIT; ref->size = MEM_SIZE (mem) * BITS_PER_UNIT; |