As discussed on PR26491, we are missing the opportunity to make use of the smaller MOVHLPS instruction because we set both arguments of a SHUFPD when using it to lower a single input shuffle.
This patch sets the lowered argument to UNDEF if that shuffle element is undefined. This in turn makes it easier for target shuffle combining to decode UNDEF shuffle elements, allowing combines to MOVHLPS to occur.
A fix to match against MOVHPD stores was necessary as well.
This builds on the improved MOVLHPS/MOVHLPS lowering and memory folding support added in D16956
Adding similar support for SHUFPS will have to wait until have better support for target combining of binary shuffles.
Differential Revision: https://reviews.llvm.org/D23027
llvm-svn: 279430
We currently only allow exact matches of shuffle mask patterns during target shuffle combining.
This patch relaxes this to permit SM_SentinelUndef in the combined shuffle to always be accepted as well as allowing exact matching of the SM_SentinelZero value.
I've adjusted some tests that were requiring exact shuffle masks to now include undef values.
Differential Revision: http://reviews.llvm.org/D21495
llvm-svn: 273119
X86ISD::ADDSUB, X86ISD::(F)HADD, X86ISD::(F)HSUB should not be selected
if the operand types do not match the result type because vector type
legalization cannot deal with this for custom nodes.
Testcase X86ISD::ADDSUB is attached. I could not create a testcase for
the FHADD/FHSUB cases because of: https://llvm.org/bugs/show_bug.cgi?id=23296
Differential Revision: http://reviews.llvm.org/D9120
llvm-svn: 235367
that we don't use VSELECT and directly emit an addsub synthetic node.
Also remove a stale comment referencing VSELECT.
The test case is updated to use 'core2' which only has SSE3, not SSE4.1,
and it still passes. Previously it would not because we lacked
sufficient blend support to legalize the VSELECT.
llvm-svn: 217849
This patch teaches the backend how to combine a build_vector that implements
an 'addsub' between packed float vectors into a sequence of vector add
and vector sub followed by a VSELECT.
The new VSELECT is expected to be lowered into a BLENDI.
At ISel stage, the sequence 'vector add + vector sub + BLENDI' is
pattern-matched against ISel patterns added at r211427 to select
'addsub' instructions.
Added three more ISel patterns for ADDSUB.
Added test sse3-avx-addsub-2.ll to verify that we correctly emit 'addsub'
instructions.
llvm-svn: 211679
Simon Pilgrim