diff options
| -rw-r--r-- | llvm/lib/Target/X86/X86ISelLowering.cpp | 7 | ||||
| -rw-r--r-- | llvm/test/CodeGen/X86/vector-shuffle-combining-avx2.ll | 4 |
2 files changed, 9 insertions, 2 deletions
diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index e19041651be..ea1270e9cc8 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -32257,6 +32257,13 @@ bool X86TargetLowering::SimplifyDemandedVectorEltsForTargetNode( MVT SrcVT = Src.getSimpleValueType(); if (!SrcVT.isVector()) return false; + // Don't bother broadcasting if we just need the 0'th element. + if (DemandedElts == 1) { + if(Src.getValueType() != VT) + Src = widenSubVector(VT.getSimpleVT(), Src, false, Subtarget, TLO.DAG, + SDLoc(Op)); + return TLO.CombineTo(Op, Src); + } APInt SrcUndef, SrcZero; APInt SrcElts = APInt::getOneBitSet(SrcVT.getVectorNumElements(), 0); if (SimplifyDemandedVectorElts(Src, SrcElts, SrcUndef, SrcZero, TLO, diff --git a/llvm/test/CodeGen/X86/vector-shuffle-combining-avx2.ll b/llvm/test/CodeGen/X86/vector-shuffle-combining-avx2.ll index 95d53ace5d3..2ea0f1ab3e7 100644 --- a/llvm/test/CodeGen/X86/vector-shuffle-combining-avx2.ll +++ b/llvm/test/CodeGen/X86/vector-shuffle-combining-avx2.ll @@ -313,7 +313,7 @@ define <4 x float> @combine_vpbroadcast_pshufb_as_vpbroadcastss128(<4 x float> % define <8 x float> @combine_vpbroadcast_permd_as_vpbroadcastss256(<4 x float> %a) { ; CHECK-LABEL: combine_vpbroadcast_permd_as_vpbroadcastss256: ; CHECK: # %bb.0: -; CHECK-NEXT: vbroadcastss %xmm0, %ymm0 +; CHECK-NEXT: # kill: def $xmm0 killed $xmm0 def $ymm0 ; CHECK-NEXT: vbroadcastss %xmm0, %ymm0 ; CHECK-NEXT: ret{{[l|q]}} %1 = shufflevector <4 x float> %a, <4 x float> undef, <8 x i32> zeroinitializer @@ -324,7 +324,7 @@ define <8 x float> @combine_vpbroadcast_permd_as_vpbroadcastss256(<4 x float> %a define <4 x double> @combine_vpbroadcast_permd_as_vpbroadcastsd256(<2 x double> %a) { ; CHECK-LABEL: combine_vpbroadcast_permd_as_vpbroadcastsd256: ; CHECK: # %bb.0: -; CHECK-NEXT: vbroadcastsd %xmm0, %ymm0 +; CHECK-NEXT: # kill: def $xmm0 killed $xmm0 def $ymm0 ; CHECK-NEXT: vbroadcastsd %xmm0, %ymm0 ; CHECK-NEXT: ret{{[l|q]}} %1 = shufflevector <2 x double> %a, <2 x double> undef, <4 x i32> zeroinitializer |
