Commit Graph

6 Commits

Author SHA1 Message Date
Michael Kuperstein af9befa6b7 Fixes two issue in SimplifyDemandedBits of sext_in_reg:
1) We should not try to simplify if the sext has multiple uses
2) There is no need to simplify is the source value is already sign-extended.

Patch by Gil Rapaport <gil.rapaport@intel.com>

Differential Revision: http://reviews.llvm.org/D6949

llvm-svn: 229659
2015-02-18 09:43:40 +00:00
Quentin Colombet dbe33e7aa4 [X86] Lower VSELECT into SHRUNKBLEND when we shrink the bits used into the
condition to match a blend.
This prevents optimizations that work on VSELECT to perform invalid
transformations. Indeed, the optimized condition does not match the vector
boolean content that is expected and bad things may happen.

This patch yields the exact same code on the whole test-suite + specs (-O3 and
-O3 -march=core-avx2), it improves one test case (vector-blend.ll) and fixes a
bug reduced in vselect-avx.ll.

<rdar://problem/18819506>

llvm-svn: 221429
2014-11-06 02:25:03 +00:00
Adrian Prantl a0852d2be3 Revert "Temporarily revert r220777 to sort out build bot breakage."
This reverts commit r221028. Later commits depend on this and
reverting just this one causes even more bots to fail.

llvm-svn: 221041
2014-11-01 03:19:45 +00:00
Adrian Prantl cd4872399a Temporarily revert r220777 to sort out build bot breakage.
"[x86] Simplify vector selection if condition value type matches vselect value type and true value is all ones or false value is all zeros."

llvm-svn: 221028
2014-11-01 00:26:59 +00:00
Robert Khasanov 4441c4d31b [x86] Simplify vector selection if condition value type matches vselect value type and true value is all ones or false value is all zeros.
This transformation worked if selector is produced by SETCC, however SETCC is needed only if we consider to swap operands. So I replaced SETCC check for this case.
Added tests for vselect of <X x i1> values.

llvm-svn: 220777
2014-10-28 15:59:40 +00:00
Quentin Colombet 06355199f1 [X86] Fix a bug in the lowering of the mask of VSELECT.
X86 code to lower VSELECT messed a bit with the bits set in the mask of VSELECT
when it knows it can be lowered into BLEND. Indeed, only the high bits need to be
set for those and it optimizes those accordingly.
However, when the mask is a compile time constant, the lowering will be handled
by the generic optimizer and those modifications will generate bad code in the
generic optimizer.

This patch fixes that by preventing the optimization if the VSELECT will be
handled by the generic optimizer.

<rdar://problem/18675020>

llvm-svn: 220242
2014-10-20 23:13:30 +00:00