8076523: assert(((ABS(iv_adjustment_in_bytes) % elt_size) == 0)) fails in superword.cpp
Summary: check that offset % mem_oper_size == 0 when alignment is verified during vectorization.
Reviewed-by: iveresov
--- a/hotspot/src/share/vm/opto/superword.cpp Thu Apr 02 10:38:36 2015 +0000
+++ b/hotspot/src/share/vm/opto/superword.cpp Thu Apr 02 17:16:39 2015 -0700
@@ -449,11 +449,13 @@
int preloop_stride = pre_end->stride_con();
int span = preloop_stride * p.scale_in_bytes();
-
- // Stride one accesses are alignable.
- if (ABS(span) == p.memory_size())
+ int mem_size = p.memory_size();
+ int offset = p.offset_in_bytes();
+ // Stride one accesses are alignable if offset is aligned to memory operation size.
+ // Offset can be unaligned when UseUnalignedAccesses is used.
+ if (ABS(span) == mem_size && (ABS(offset) % mem_size) == 0) {
return true;
-
+ }
// If initial offset from start of object is computable,
// compute alignment within the vector.
int vw = vector_width_in_bytes(p.mem());
@@ -463,7 +465,7 @@
if (init_nd->is_Con() && p.invar() == NULL) {
int init = init_nd->bottom_type()->is_int()->get_con();
- int init_offset = init * p.scale_in_bytes() + p.offset_in_bytes();
+ int init_offset = init * p.scale_in_bytes() + offset;
assert(init_offset >= 0, "positive offset from object start");
if (span > 0) {