diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp index e92a099753b3..37026ce0f12e 100644 --- a/llvm/lib/Target/X86/X86ISelLowering.cpp +++ b/llvm/lib/Target/X86/X86ISelLowering.cpp @@ -24757,6 +24757,8 @@ static SDValue PerformLOADCombine(SDNode *N, SelectionDAG &DAG, LoadSDNode *Ld = cast(N); EVT RegVT = Ld->getValueType(0); EVT MemVT = Ld->getMemoryVT(); + SDValue Ptr = Ld->getBasePtr(); + SDValue Chain = Ld->getChain(); SDLoc dl(Ld); const TargetLowering &TLI = DAG.getTargetLoweringInfo(); @@ -24795,6 +24797,33 @@ static SDValue PerformLOADCombine(SDNode *N, SelectionDAG &DAG, return DCI.CombineTo(N, NewVec, TF, true); } + // Conversion from x86mmx/i64 to v2i64 types is often done via stack + // store/load. Under certain conditions we can bypass the memory access and + // combine this load to use a scalar_to_vector instead. This leads to + // a reduction in the stack use, redundant emission of shuffles and create + // isel matching candidates for movq2dq instructions. + if (RegVT == MVT::v2i64 && Subtarget->hasSSE2() && Ext == ISD::EXTLOAD && + !Ld->isVolatile() && ISD::isNON_TRUNCStore(Chain.getNode())) { + + // If this load is directly stored, get the original source value. + StoreSDNode *PrevST = cast(Chain); + EVT SrcTy = PrevST->getValue().getValueType(); + if (PrevST->getBasePtr() != Ptr || + !(SrcTy == MVT::i64 || SrcTy == MVT::x86mmx)) + return SDValue(); + SDValue SrcVal = Chain.getOperand(1); + + // On 32bit systems, we can't save 64bit integers, use f64 instead. + bool Usef64 = TLI.isTypeLegal(MVT::f64) && !Subtarget->is64Bit(); + if (Usef64) + SrcVal = DAG.getNode(ISD::BITCAST, dl, MVT::f64, SrcVal); + SrcVal = DAG.getNode(ISD::SCALAR_TO_VECTOR, dl, Usef64 ? MVT::v2f64 : RegVT, + SrcVal); + + return DCI.CombineTo(N, Usef64 ? + DAG.getNode(ISD::BITCAST, dl, RegVT, SrcVal) : SrcVal, Chain); + } + return SDValue(); } diff --git a/llvm/test/CodeGen/X86/2012-01-18-vbitcast.ll b/llvm/test/CodeGen/X86/2012-01-18-vbitcast.ll index 9eb59e41ef7d..efba66be97e8 100644 --- a/llvm/test/CodeGen/X86/2012-01-18-vbitcast.ll +++ b/llvm/test/CodeGen/X86/2012-01-18-vbitcast.ll @@ -1,14 +1,15 @@ ; RUN: llc < %s -march=x86-64 -mcpu=corei7 -mtriple=x86_64-pc-win32 | FileCheck %s -;CHECK-LABEL: vcast: +; CHECK-LABEL: vcast: define <2 x i32> @vcast(<2 x float> %a, <2 x float> %b) { -;CHECK: pmovzxdq -;CHECK: pmovzxdq +; CHECK-NOT: pmovzxdq +; CHECK-NOT: pmovzxdq +; CHECK: movdqa (%{{.*}}), %[[R0:xmm[0-9]+]] %af = bitcast <2 x float> %a to <2 x i32> %bf = bitcast <2 x float> %b to <2 x i32> +; CHECK-NEXT: psubq (%{{.*}}), %[[R0]] %x = sub <2 x i32> %af, %bf -;CHECK: psubq +; CHECK: ret ret <2 x i32> %x -;CHECK: ret } diff --git a/llvm/test/CodeGen/X86/lower-bitcast.ll b/llvm/test/CodeGen/X86/lower-bitcast.ll index edb8433ec30c..5fad82497b99 100644 --- a/llvm/test/CodeGen/X86/lower-bitcast.ll +++ b/llvm/test/CodeGen/X86/lower-bitcast.ll @@ -68,12 +68,13 @@ define i64 @test4(i64 %A) { %2 = bitcast <2 x i32> %add to i64 ret i64 %2 } -; FIXME: At the moment we still produce the sequence pshufd+paddd+pshufd. +; FIXME: At the moment we still produce the sequence paddd+pshufd. ; Ideally, we should fold that sequence into a single paddd. This is fixed with ; the widening legalization. ; ; CHECK-LABEL: test4 -; CHECK: pshufd +; CHECK: movd +; CHECK-NOT: pshufd ; CHECK-NEXT: paddd ; CHECK-NEXT: pshufd ; CHECK: ret diff --git a/llvm/test/CodeGen/X86/mmx-movq2dq.ll b/llvm/test/CodeGen/X86/mmx-movq2dq.ll new file mode 100644 index 000000000000..9f46da53bd7a --- /dev/null +++ b/llvm/test/CodeGen/X86/mmx-movq2dq.ll @@ -0,0 +1,29 @@ +; RUN: llc < %s -march=x86 -mattr=+mmx,+sse2 | FileCheck %s -check-prefix=X86-32 +; RUN: llc < %s -march=x86-64 -mattr=+mmx,+sse2 | FileCheck %s -check-prefix=X86-64 + +; X86-32-LABEL: test0 +; X86-64-LABEL: test0 +define i32 @test0(<1 x i64>* %v4) { + %v5 = load <1 x i64>* %v4, align 8 + %v12 = bitcast <1 x i64> %v5 to <4 x i16> + %v13 = bitcast <4 x i16> %v12 to x86_mmx + ; X86-32: pshufw $238 + ; X86-32-NOT: movq + ; X86-32-NOT: movsd + ; X86-32: movq2dq + ; X86-64: pshufw $238 + ; X86-64-NOT: movq + ; X86-64-NOT: pshufd + ; X86-64: movq2dq + ; X86-64-NEXT: movd + %v14 = tail call x86_mmx @llvm.x86.sse.pshuf.w(x86_mmx %v13, i8 -18) + %v15 = bitcast x86_mmx %v14 to <4 x i16> + %v16 = bitcast <4 x i16> %v15 to <1 x i64> + %v17 = extractelement <1 x i64> %v16, i32 0 + %v18 = bitcast i64 %v17 to <2 x i32> + %v19 = extractelement <2 x i32> %v18, i32 0 + %v20 = add i32 %v19, 32 + ret i32 %v20 +} + +declare x86_mmx @llvm.x86.sse.pshuf.w(x86_mmx, i8) diff --git a/llvm/test/CodeGen/X86/widen_load-2.ll b/llvm/test/CodeGen/X86/widen_load-2.ll index c6bd96421d75..0d5380eb3ac1 100644 --- a/llvm/test/CodeGen/X86/widen_load-2.ll +++ b/llvm/test/CodeGen/X86/widen_load-2.ll @@ -78,8 +78,7 @@ define void @add3i16(%i16vec3* nocapture sret %ret, %i16vec3* %ap, %i16vec3* %bp ; CHECK-NEXT: paddd %[[R0]], %[[R1]] ; CHECK-NEXT: pextrw $4, %[[R1]], 4(%{{.*}}) ; CHECK-NEXT: pshufb {{.*}}, %[[R1]] -; CHECK-NEXT: pmovzxdq %[[R1]], %[[R0]] -; CHECK-NEXT: movd %[[R0]], (%{{.*}}) +; CHECK-NEXT: movd %[[R1]], (%{{.*}}) %a = load %i16vec3* %ap, align 16 %b = load %i16vec3* %bp, align 16 %x = add %i16vec3 %a, %b