Commit Graph

2 Commits

Author SHA1 Message Date
Simon Pilgrim 5b65f28fe7 [X86][FastISel] Teach how to select SSE4A nontemporal stores.
Add FastISel support for SSE4A scalar float / double non-temporal stores

Follow up to D13698

Differential Revision: http://reviews.llvm.org/D13773

llvm-svn: 250610
2015-10-17 13:04:42 +00:00
Andrea Di Biagio c47edbef4c [x86][FastISel] Teach how to select nontemporal stores.
This patch teaches x86 fast-isel how to select nontemporal stores.

On x86, we can use MOVNTI for nontemporal stores of doublewords/quadwords.
Instructions (V)MOVNTPS/PD/DQ can be used for SSE2/AVX aligned nontemporal
vector stores.

Before this patch, fast-isel always selected 'movd/movq' instead of 'movnti'
for doubleword/quadword nontemporal stores. In the case of nontemporal stores
of aligned vectors, fast-isel always selected movaps/movapd/movdqa instead of
movntps/movntpd/movntdq.

With this patch, if we use SSE2/AVX intrinsics for nontemporal stores we now
always get the expected (V)MOVNT instructions.
The lack of fast-isel support for nontemporal stores was spotted when analyzing
the -O0 codegen for nontemporal stores.

Differential Revision: http://reviews.llvm.org/D13698

llvm-svn: 250285
2015-10-14 10:03:13 +00:00