Add support for several vector shifts operations while in AVX mode. Fix PR10581

llvm-svn: 137067

2 files changed, 116 insertions, 10 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index 792d68c2c83..b2329470aba 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -883,7 +883,7 @@ X86TargetLowering::X86TargetLowering(X86TargetMachine &TM)
     setOperationAction(ISD::SINT_TO_FP,         MVT::v4i32, Legal);
   }
 
-  if (Subtarget->hasSSE41()) {
+  if (Subtarget->hasSSE41() || Subtarget->hasAVX()) {
     setOperationAction(ISD::FFLOOR,             MVT::f32,   Legal);
     setOperationAction(ISD::FCEIL,              MVT::f32,   Legal);
     setOperationAction(ISD::FTRUNC,             MVT::f32,   Legal);
@@ -922,10 +922,11 @@ X86TargetLowering::X86TargetLowering(X86TargetMachine &TM)
     }
   }
 
-  if (Subtarget->hasSSE2()) {
+  if (Subtarget->hasSSE2() || Subtarget->hasAVX()) {
     setOperationAction(ISD::SRL,               MVT::v2i64, Custom);
     setOperationAction(ISD::SRL,               MVT::v4i32, Custom);
     setOperationAction(ISD::SRL,               MVT::v16i8, Custom);
+    setOperationAction(ISD::SRL,               MVT::v8i16, Custom);
 
     setOperationAction(ISD::SHL,               MVT::v2i64, Custom);
     setOperationAction(ISD::SHL,               MVT::v4i32, Custom);
@@ -935,7 +936,7 @@ X86TargetLowering::X86TargetLowering(X86TargetMachine &TM)
     setOperationAction(ISD::SRA,               MVT::v8i16, Custom);
   }
 
-  if (Subtarget->hasSSE42())
+  if (Subtarget->hasSSE42() || Subtarget->hasAVX())
     setOperationAction(ISD::VSETCC,             MVT::v2i64, Custom);
 
   if (!UseSoftFloat && Subtarget->hasAVX()) {
@@ -975,6 +976,19 @@ X86TargetLowering::X86TargetLowering(X86TargetMachine &TM)
     setOperationAction(ISD::CONCAT_VECTORS,     MVT::v32i8,  Custom);
     setOperationAction(ISD::CONCAT_VECTORS,     MVT::v16i16, Custom);
 
+    setOperationAction(ISD::SRL,               MVT::v4i64, Custom);
+    setOperationAction(ISD::SRL,               MVT::v8i32, Custom);
+    setOperationAction(ISD::SRL,               MVT::v16i16, Custom);
+    setOperationAction(ISD::SRL,               MVT::v32i8, Custom);
+
+    setOperationAction(ISD::SHL,               MVT::v4i64, Custom);
+    setOperationAction(ISD::SHL,               MVT::v8i32, Custom);
+    setOperationAction(ISD::SHL,               MVT::v16i16, Custom);
+    setOperationAction(ISD::SHL,               MVT::v32i8, Custom);
+
+    setOperationAction(ISD::SRA,               MVT::v8i32, Custom);
+    setOperationAction(ISD::SRA,               MVT::v16i16, Custom);
+
     // Custom lower several nodes for 256-bit types.
     for (unsigned i = (unsigned)MVT::FIRST_VECTOR_VALUETYPE;
                   i <= (unsigned)MVT::LAST_VECTOR_VALUETYPE; ++i) {
@@ -9195,11 +9209,42 @@ SDValue X86TargetLowering::LowerShift(SDValue Op, SelectionDAG &DAG) const {
   DebugLoc dl = Op.getDebugLoc();
   SDValue R = Op.getOperand(0);
   SDValue Amt = Op.getOperand(1);
-
   LLVMContext *Context = DAG.getContext();
 
-  // Must have SSE2.
-  if (!Subtarget->hasSSE2()) return SDValue();
+  if (!(Subtarget->hasSSE2() || Subtarget->hasAVX()))
+    return SDValue();
+
+  // Decompose 256-bit shifts into smaller 128-bit shifts.
+  if (VT.getSizeInBits() == 256) {
+    int NumElems = VT.getVectorNumElements();
+    MVT EltVT = VT.getVectorElementType().getSimpleVT();
+    EVT NewVT = MVT::getVectorVT(EltVT, NumElems/2);
+
+    // Extract the two vectors
+    SDValue V1 = Extract128BitVector(R, DAG.getConstant(0, MVT::i32), DAG, dl);
+    SDValue V2 = Extract128BitVector(R, DAG.getConstant(NumElems/2, MVT::i32),
+                                     DAG, dl);
+
+    // Recreate the shift amount vectors
+    SmallVector<SDValue, 4> Amt1Csts;
+    SmallVector<SDValue, 4> Amt2Csts;
+    for (int i = 0; i < NumElems/2; ++i)
+      Amt1Csts.push_back(Amt->getOperand(i));
+    for (int i = NumElems/2; i < NumElems; ++i)
+      Amt2Csts.push_back(Amt->getOperand(i));
+
+    SDValue Amt1 = DAG.getNode(ISD::BUILD_VECTOR, dl, NewVT,
+                               &Amt1Csts[0], NumElems/2);
+    SDValue Amt2 = DAG.getNode(ISD::BUILD_VECTOR, dl, NewVT,
+                               &Amt2Csts[0], NumElems/2);
+
+    // Issue new vector shifts for the smaller types
+    V1 = DAG.getNode(Op.getOpcode(), dl, NewVT, V1, Amt1);
+    V2 = DAG.getNode(Op.getOpcode(), dl, NewVT, V2, Amt2);
+
+    // Concatenate the result back
+    return DAG.getNode(ISD::CONCAT_VECTORS, dl, VT, V1, V2);
+  }
 
   // Optimize shl/srl/sra with constant shift amount.
   if (isSplatVector(Amt.getNode())) {
@@ -9250,9 +9295,6 @@ SDValue X86TargetLowering::LowerShift(SDValue Op, SelectionDAG &DAG) const {
   }
 
   // Lower SHL with variable shift amount.
-  // Cannot lower SHL without SSE2 or later.
-  if (!Subtarget->hasSSE2()) return SDValue();
-
   if (VT == MVT::v4i32 && Op->getOpcode() == ISD::SHL) {
     Op = DAG.getNode(ISD::INTRINSIC_WO_CHAIN, dl, VT,
                      DAG.getConstant(Intrinsic::x86_sse2_pslli_d, MVT::i32),
@@ -12099,7 +12141,7 @@ static SDValue PerformShiftCombine(SDNode* N, SelectionDAG &DAG,
   // all elements are shifted by the same amount.  We can't do this in legalize
   // because the a constant vector is typically transformed to a constant pool
   // so we have no knowledge of the shift amount.
-  if (!Subtarget->hasSSE2())
+  if (!(Subtarget->hasSSE2() || Subtarget->hasAVX()))
     return SDValue();
 
   if (VT != MVT::v2i64 && VT != MVT::v4i32 && VT != MVT::v8i16)
diff --git a/llvm/test/CodeGen/X86/avx-shift.ll b/llvm/test/CodeGen/X86/avx-shift.ll
new file mode 100644
index 00000000000..791194fc1c7
--- /dev/null
+++ b/llvm/test/CodeGen/X86/avx-shift.ll
@@ -0,0 +1,64 @@
+; RUN: llc < %s -mtriple=x86_64-apple-darwin -mcpu=corei7-avx -mattr=+avx | FileCheck %s
+
+;;; Shift left
+; CHECK: vpslld
+; CHECK: vpslld
+define <8 x i32> @vshift00(<8 x i32> %a) nounwind readnone {
+  %s = shl <8 x i32> %a, <i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32
+2>
+  ret <8 x i32> %s
+}
+
+; CHECK: vpsllw
+; CHECK: vpsllw
+define <16 x i16> @vshift01(<16 x i16> %a) nounwind readnone {
+  %s = shl <16 x i16> %a, <i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2>
+  ret <16 x i16> %s
+}
+
+; CHECK: vpsllq
+; CHECK: vpsllq
+define <4 x i64> @vshift02(<4 x i64> %a) nounwind readnone {
+  %s = shl <4 x i64> %a, <i64 2, i64 2, i64 2, i64 2>
+  ret <4 x i64> %s
+}
+
+;;; Logical Shift right
+; CHECK: vpsrld
+; CHECK: vpsrld
+define <8 x i32> @vshift03(<8 x i32> %a) nounwind readnone {
+  %s = lshr <8 x i32> %a, <i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32
+2>
+  ret <8 x i32> %s
+}
+
+; CHECK: vpsrlw
+; CHECK: vpsrlw
+define <16 x i16> @vshift04(<16 x i16> %a) nounwind readnone {
+  %s = lshr <16 x i16> %a, <i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2>
+  ret <16 x i16> %s
+}
+
+; CHECK: vpsrlq
+; CHECK: vpsrlq
+define <4 x i64> @vshift05(<4 x i64> %a) nounwind readnone {
+  %s = lshr <4 x i64> %a, <i64 2, i64 2, i64 2, i64 2>
+  ret <4 x i64> %s
+}
+
+;;; Arithmetic Shift right
+; CHECK: vpsrad
+; CHECK: vpsrad
+define <8 x i32> @vshift06(<8 x i32> %a) nounwind readnone {
+  %s = ashr <8 x i32> %a, <i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32 2, i32
+2>
+  ret <8 x i32> %s
+}
+
+; CHECK: vpsraw
+; CHECK: vpsraw
+define <16 x i16> @vshift07(<16 x i16> %a) nounwind readnone {
+  %s = ashr <16 x i16> %a, <i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2, i16 2>
+  ret <16 x i16> %s
+}
+