From 9233e73bf3e519fb9b7307cc674ce926fee5376b Mon Sep 17 00:00:00 2001 From: Simon Pilgrim Date: Thu, 7 Jan 2016 11:34:27 +0000 Subject: [PATCH] [X86][AVX] Match broadcast loads through a bitcast AVX1 v8i32/v4i64 shuffles are bitcasted to v8f32/v4f64, this patch peeks through bitcasts to check for a load node to allow broadcasts to occur. Follow up to D15310 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257055 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Target/X86/X86ISelLowering.cpp | 9 +++++++-- test/CodeGen/X86/2012-01-12-extract-sv.ll | 4 +--- test/CodeGen/X86/avx-vbroadcast.ll | 10 ++-------- 3 files changed, 10 insertions(+), 13 deletions(-) diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp index d32146b32cf..06def2cacd8 100644 --- a/lib/Target/X86/X86ISelLowering.cpp +++ b/lib/Target/X86/X86ISelLowering.cpp @@ -8163,6 +8163,11 @@ static SDValue lowerVectorShuffleAsBroadcast(SDLoc DL, MVT VT, SDValue V, break; } + // Peek through any bitcast (only useful for loads). + SDValue BC = V; + while (BC.getOpcode() == ISD::BITCAST) + BC = BC.getOperand(0); + // Check if this is a broadcast of a scalar. We special case lowering // for scalars so that we can more effectively fold with loads. // First, look through bitcast: if the original value has a larger element @@ -8182,10 +8187,10 @@ static SDValue lowerVectorShuffleAsBroadcast(SDLoc DL, MVT VT, SDValue V, // Only AVX2 has register broadcasts. if (!Subtarget->hasAVX2() && !isShuffleFoldableLoad(V)) return SDValue(); - } else if (MayFoldLoad(V) && !cast(V)->isVolatile()) { + } else if (MayFoldLoad(BC) && !cast(BC)->isVolatile()) { // If we are broadcasting a load that is only used by the shuffle // then we can reduce the vector load to the broadcasted scalar load. - LoadSDNode *Ld = cast(V); + LoadSDNode *Ld = cast(BC); SDValue BaseAddr = Ld->getOperand(1); EVT AddrVT = BaseAddr.getValueType(); EVT SVT = VT.getScalarType(); diff --git a/test/CodeGen/X86/2012-01-12-extract-sv.ll b/test/CodeGen/X86/2012-01-12-extract-sv.ll index 92ec107a007..6950641a08a 100644 --- a/test/CodeGen/X86/2012-01-12-extract-sv.ll +++ b/test/CodeGen/X86/2012-01-12-extract-sv.ll @@ -3,9 +3,7 @@ define void @endless_loop() { ; CHECK-LABEL: endless_loop: ; CHECK-NEXT: # BB#0: -; CHECK-NEXT: vmovaps (%eax), %ymm0 -; CHECK-NEXT: vextractf128 $1, %ymm0, %xmm0 -; CHECK-NEXT: vmovsldup {{.*#+}} xmm0 = xmm0[0,0,2,2] +; CHECK-NEXT: vbroadcastss (%eax), %ymm0 ; CHECK-NEXT: vmovddup {{.*#+}} xmm1 = xmm0[0,0] ; CHECK-NEXT: vinsertf128 $1, %xmm1, %ymm0, %ymm1 ; CHECK-NEXT: vxorps %xmm2, %xmm2, %xmm2 diff --git a/test/CodeGen/X86/avx-vbroadcast.ll b/test/CodeGen/X86/avx-vbroadcast.ll index 86b0628aa0b..837333a0b1f 100644 --- a/test/CodeGen/X86/avx-vbroadcast.ll +++ b/test/CodeGen/X86/avx-vbroadcast.ll @@ -130,10 +130,7 @@ entry: define <8 x i32> @load_splat_8i32_8i32_55555555(<8 x i32>* %ptr) nounwind uwtable readnone ssp { ; CHECK-LABEL: load_splat_8i32_8i32_55555555: ; CHECK: ## BB#0: ## %entry -; CHECK-NEXT: vmovaps (%rdi), %ymm0 -; CHECK-NEXT: vextractf128 $1, %ymm0, %xmm0 -; CHECK-NEXT: vpermilps {{.*#+}} xmm0 = xmm0[1,1,1,1] -; CHECK-NEXT: vinsertf128 $1, %xmm0, %ymm0, %ymm0 +; CHECK-NEXT: vbroadcastss 20(%rdi), %ymm0 ; CHECK-NEXT: retq entry: %ld = load <8 x i32>, <8 x i32>* %ptr @@ -201,10 +198,7 @@ entry: define <4 x i64> @load_splat_4i64_4i64_2222(<4 x i64>* %ptr) nounwind uwtable readnone ssp { ; CHECK-LABEL: load_splat_4i64_4i64_2222: ; CHECK: ## BB#0: ## %entry -; CHECK-NEXT: vmovapd (%rdi), %ymm0 -; CHECK-NEXT: vextractf128 $1, %ymm0, %xmm0 -; CHECK-NEXT: vmovddup {{.*#+}} xmm0 = xmm0[0,0] -; CHECK-NEXT: vinsertf128 $1, %xmm0, %ymm0, %ymm0 +; CHECK-NEXT: vbroadcastsd 16(%rdi), %ymm0 ; CHECK-NEXT: retq entry: %ld = load <4 x i64>, <4 x i64>* %ptr -- 2.34.1