[Hexagon] Handle shifts of short vectors of i8

diff --git a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
index 94411b2..f2076a6 100644 (file)
--- a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
@@ -2345,7 +2345,49 @@ HexagonTargetLowering::getVectorShiftByInt(SDValue Op, SelectionDAG &DAG)
 
 SDValue
 HexagonTargetLowering::LowerVECTOR_SHIFT(SDValue Op, SelectionDAG &DAG) const {
-  return getVectorShiftByInt(Op, DAG);
+  const SDLoc &dl(Op);
+
+  // First try to convert the shift (by vector) to a shift by a scalar.
+  // If we first split the shift, the shift amount will become 'extract
+  // subvector', and will no longer be recognized as scalar.
+  SDValue Res = Op;
+  if (SDValue S = getVectorShiftByInt(Op, DAG))
+    Res = S;
+
+  MVT ResTy = ty(Res);
+  if (ResTy.getVectorElementType() != MVT::i8)
+    return Res;
+
+  // For shifts of i8, extend the inputs to i16, then truncate back to i8.
+  assert(ResTy.getVectorElementType() == MVT::i8);
+  unsigned Opc = Res.getOpcode();
+  switch (Opc) {
+  case HexagonISD::VASR:
+  case HexagonISD::VLSR:
+  case HexagonISD::VASL:
+    break;
+  default:
+    // No instructions for shifts by non-scalars.
+    return SDValue();
+  }
+
+  SDValue Val = Res.getOperand(0), Amt = Res.getOperand(1);
+
+  auto ShiftPartI8 = [&dl, &DAG, this](unsigned Opc, SDValue V, SDValue A) {
+    MVT Ty = ty(V);
+    MVT ExtTy = MVT::getVectorVT(MVT::i16, Ty.getVectorNumElements());
+    SDValue ExtV = Opc == HexagonISD::VASR ? DAG.getSExtOrTrunc(V, dl, ExtTy)
+                                           : DAG.getZExtOrTrunc(V, dl, ExtTy);
+    SDValue ExtS = DAG.getNode(Opc, dl, ExtTy, {ExtV, A});
+    return DAG.getZExtOrTrunc(ExtS, dl, Ty);
+  };
+
+  if (ResTy.getSizeInBits() == 32)
+    return ShiftPartI8(Opc, Val, Amt);
+
+  auto [LoV, HiV] = opSplit(Val, dl, DAG);
+  return DAG.getNode(ISD::CONCAT_VECTORS, dl, ResTy,
+                     {ShiftPartI8(Opc, LoV, Amt), ShiftPartI8(Opc, HiV, Amt)});
 }
 
 SDValue

diff --git a/llvm/test/CodeGen/Hexagon/vect/vect-shifts.ll b/llvm/test/CodeGen/Hexagon/vect/vect-shifts.ll
new file mode 100644 (file)
index 0000000..db1c454
--- /dev/null
+++ b/llvm/test/CodeGen/Hexagon/vect/vect-shifts.ll
@@ -0,0 +1,239 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -march=hexagon < %s | FileCheck %s
+
+define <4 x i8> @f0(<4 x i8> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f0:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vsxtbh(r0)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vasrh(r1:0,#1)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r0 = vtrunehb(r1:0)
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = ashr <4 x i8> %a0, <i8 1, i8 1, i8 1, i8 1>
+  ret <4 x i8> %v0
+}
+
+define <4 x i8> @f1(<4 x i8> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f1:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vzxtbh(r0)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vlsrh(r1:0,#1)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r0 = vtrunehb(r1:0)
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = lshr <4 x i8> %a0, <i8 1, i8 1, i8 1, i8 1>
+  ret <4 x i8> %v0
+}
+
+define <4 x i8> @f2(<4 x i8> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f2:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vzxtbh(r0)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vaslh(r1:0,#1)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r0 = vtrunehb(r1:0)
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = shl <4 x i8> %a0, <i8 1, i8 1, i8 1, i8 1>
+  ret <4 x i8> %v0
+}
+
+
+define <8 x i8> @f3(<8 x i8> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f3:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r3:2 = vsxtbh(r1)
+; CHECK-NEXT:     r5:4 = vsxtbh(r0)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vasrh(r5:4,#1)
+; CHECK-NEXT:     r3:2 = vasrh(r3:2,#1)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r0 = vtrunehb(r1:0)
+; CHECK-NEXT:     r1 = vtrunehb(r3:2)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = ashr <8 x i8> %a0, <i8 1, i8 1, i8 1, i8 1, i8 1, i8 1, i8 1, i8 1>
+  ret <8 x i8> %v0
+}
+
+define <8 x i8> @f4(<8 x i8> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f4:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r3:2 = vzxtbh(r1)
+; CHECK-NEXT:     r5:4 = vzxtbh(r0)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vlsrh(r5:4,#1)
+; CHECK-NEXT:     r3:2 = vlsrh(r3:2,#1)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r0 = vtrunehb(r1:0)
+; CHECK-NEXT:     r1 = vtrunehb(r3:2)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = lshr <8 x i8> %a0, <i8 1, i8 1, i8 1, i8 1, i8 1, i8 1, i8 1, i8 1>
+  ret <8 x i8> %v0
+}
+
+define <8 x i8> @f5(<8 x i8> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f5:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r3:2 = vzxtbh(r1)
+; CHECK-NEXT:     r5:4 = vzxtbh(r0)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vaslh(r5:4,#1)
+; CHECK-NEXT:     r3:2 = vaslh(r3:2,#1)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r0 = vtrunehb(r1:0)
+; CHECK-NEXT:     r1 = vtrunehb(r3:2)
+; CHECK-NEXT:    }
+; CHECK-NEXT:    {
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = shl <8 x i8> %a0, <i8 1, i8 1, i8 1, i8 1, i8 1, i8 1, i8 1, i8 1>
+  ret <8 x i8> %v0
+}
+
+
+define <2 x i16> @f6(<2 x i16> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f6:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vasrh(r1:0,#1)
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = ashr <2 x i16> %a0, <i16 1, i16 1>
+  ret <2 x i16> %v0
+}
+
+define <2 x i16> @f7(<2 x i16> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f7:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vlsrh(r1:0,#1)
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = lshr <2 x i16> %a0, <i16 1, i16 1>
+  ret <2 x i16> %v0
+}
+
+define <2 x i16> @f8(<2 x i16> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f8:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vaslh(r1:0,#1)
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = shl <2 x i16> %a0, <i16 1, i16 1>
+  ret <2 x i16> %v0
+}
+
+
+define <4 x i16> @f9(<4 x i16> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f9:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vasrh(r1:0,#1)
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = ashr <4 x i16> %a0, <i16 1, i16 1, i16 1, i16 1>
+  ret <4 x i16> %v0
+}
+
+define <4 x i16> @f10(<4 x i16> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f10:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vlsrh(r1:0,#1)
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = lshr <4 x i16> %a0, <i16 1, i16 1, i16 1, i16 1>
+  ret <4 x i16> %v0
+}
+
+define <4 x i16> @f11(<4 x i16> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f11:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vaslh(r1:0,#1)
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = shl <4 x i16> %a0, <i16 1, i16 1, i16 1, i16 1>
+  ret <4 x i16> %v0
+}
+
+
+define <2 x i32> @f12(<2 x i32> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f12:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vasrw(r1:0,#1)
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = ashr <2 x i32> %a0, <i32 1, i32 1>
+  ret <2 x i32> %v0
+}
+
+define <2 x i32> @f13(<2 x i32> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f13:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vlsrw(r1:0,#1)
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = lshr <2 x i32> %a0, <i32 1, i32 1>
+  ret <2 x i32> %v0
+}
+
+define <2 x i32> @f14(<2 x i32> %a0) unnamed_addr #0 {
+; CHECK-LABEL: f14:
+; CHECK:       // %bb.0: // %b0
+; CHECK-NEXT:    {
+; CHECK-NEXT:     r1:0 = vaslw(r1:0,#1)
+; CHECK-NEXT:     jumpr r31
+; CHECK-NEXT:    }
+b0:
+  %v0 = shl <2 x i32> %a0, <i32 1, i32 1>
+  ret <2 x i32> %v0
+}
+
+attributes #0 = { nounwind }