[mips][msa] Added support for matching shf from normal IR (i.e. not intrinsics)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191302 91177308-0d34-0410-b5e6-96231b3b80d8

6 files changed, 98 insertions, 3 deletions

diff --git a/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp b/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp
index 26321c9924..2612e3ba1c 100644
--- a/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp
+++ b/lib/Target/Mips/InstPrinter/MipsInstPrinter.cpp
@@ -211,6 +211,11 @@ printFCCOperand(const MCInst *MI, int opNum, raw_ostream &O) {
   O << MipsFCCToString((Mips::CondCode)MO.getImm());
 }
 
+void MipsInstPrinter::
+printSHFMask(const MCInst *MI, int opNum, raw_ostream &O) {
+  llvm_unreachable("TODO");
+}
+
 bool MipsInstPrinter::printAlias(const char *Str, const MCInst &MI,
                                  unsigned OpNo, raw_ostream &OS) {
   OS << "\t" << Str << "\t";
diff --git a/lib/Target/Mips/InstPrinter/MipsInstPrinter.h b/lib/Target/Mips/InstPrinter/MipsInstPrinter.h
index 1253ab0c48..11590ad824 100644
--- a/lib/Target/Mips/InstPrinter/MipsInstPrinter.h
+++ b/lib/Target/Mips/InstPrinter/MipsInstPrinter.h
@@ -96,6 +96,7 @@ private:
   void printMemOperand(const MCInst *MI, int opNum, raw_ostream &O);
   void printMemOperandEA(const MCInst *MI, int opNum, raw_ostream &O);
   void printFCCOperand(const MCInst *MI, int opNum, raw_ostream &O);
+  void printSHFMask(const MCInst *MI, int opNum, raw_ostream &O);
 
   bool printAlias(const char *Str, const MCInst &MI, unsigned OpNo,
                   raw_ostream &OS);
diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index 04f90833d8..90d2cc6f29 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -225,6 +225,7 @@ const char *MipsTargetLowering::getTargetNodeName(unsigned Opcode) const {
   case MipsISD::VEXTRACT_ZEXT_ELT: return "MipsISD::VEXTRACT_ZEXT_ELT";
   case MipsISD::VNOR:              return "MipsISD::VNOR";
   case MipsISD::VSHF:              return "MipsISD::VSHF";
+  case MipsISD::SHF:               return "MipsISD::SHF";
   default:                         return NULL;
   }
 }
diff --git a/lib/Target/Mips/MipsISelLowering.h b/lib/Target/Mips/MipsISelLowering.h
index 0cb67b8d44..9e9e995918 100644
--- a/lib/Target/Mips/MipsISelLowering.h
+++ b/lib/Target/Mips/MipsISelLowering.h
@@ -174,6 +174,7 @@ namespace llvm {
 
       // Vector Shuffle with mask as an operand
       VSHF,  // Generic shuffle
+      SHF,   // 4-element set shuffle.
 
       // Combined (XOR (OR $a, $b), -1)
       VNOR,
diff --git a/lib/Target/Mips/MipsMSAInstrInfo.td b/lib/Target/Mips/MipsMSAInstrInfo.td
index 4909743e34..5592ac5690 100644
--- a/lib/Target/Mips/MipsMSAInstrInfo.td
+++ b/lib/Target/Mips/MipsMSAInstrInfo.td
@@ -23,6 +23,8 @@ def SDT_VFSetCC : SDTypeProfile<1, 3, [SDTCisInt<0>,
 def SDT_VSHF : SDTypeProfile<1, 3, [SDTCisInt<0>, SDTCisVec<0>,
                                     SDTCisInt<1>, SDTCisVec<1>,
                                     SDTCisSameAs<0, 2>, SDTCisSameAs<2, 3>]>;
+def SDT_SHF : SDTypeProfile<1, 2, [SDTCisInt<0>, SDTCisVec<0>,
+                                   SDTCisVT<1, i32>, SDTCisSameAs<0, 2>]>;
 
 def MipsVAllNonZero : SDNode<"MipsISD::VALL_NONZERO", SDT_MipsVecCond>;
 def MipsVAnyNonZero : SDNode<"MipsISD::VANY_NONZERO", SDT_MipsVecCond>;
@@ -39,6 +41,7 @@ def MipsVUMin : SDNode<"MipsISD::VUMIN", SDTIntBinOp,
 def MipsVNOR : SDNode<"MipsISD::VNOR", SDTIntBinOp,
                       [SDNPCommutative, SDNPAssociative]>;
 def MipsVSHF : SDNode<"MipsISD::VSHF", SDT_VSHF>;
+def MipsSHF : SDNode<"MipsISD::SHF", SDT_SHF>;
 
 def vsetcc : SDNode<"ISD::SETCC", SDT_VSetCC>;
 def vfsetcc : SDNode<"ISD::SETCC", SDT_VFSetCC>;
@@ -1074,6 +1077,16 @@ class MSA_I8_X_DESC_BASE<string instr_asm, SDPatternOperator OpNode,
   InstrItinClass Itinerary = itin;
 }
 
+class MSA_I8_SHF_DESC_BASE<string instr_asm, RegisterClass RCWD,
+                           RegisterClass RCWS = RCWD,
+                           InstrItinClass itin = NoItinerary> {
+  dag OutOperandList = (outs RCWD:$wd);
+  dag InOperandList = (ins RCWS:$ws, uimm8:$u8);
+  string AsmString = !strconcat(instr_asm, "\t$wd, $ws, $u8");
+  list<dag> Pattern = [(set RCWD:$wd, (MipsSHF immZExt8:$u8, RCWS:$ws))];
+  InstrItinClass Itinerary = itin;
+}
+
 class MSA_I10_LDI_DESC_BASE<string instr_asm, RegisterClass RCWD,
                             InstrItinClass itin = NoItinerary> {
   dag OutOperandList = (outs RCWD:$wd);
@@ -2066,9 +2079,9 @@ class SAT_U_H_DESC : MSA_BIT_H_DESC_BASE<"sat_u.h", int_mips_sat_u_h, MSA128H>;
 class SAT_U_W_DESC : MSA_BIT_W_DESC_BASE<"sat_u.w", int_mips_sat_u_w, MSA128W>;
 class SAT_U_D_DESC : MSA_BIT_D_DESC_BASE<"sat_u.d", int_mips_sat_u_d, MSA128D>;
 
-class SHF_B_DESC : MSA_I8_X_DESC_BASE<"shf.b", int_mips_shf_b, MSA128B>;
-class SHF_H_DESC : MSA_I8_X_DESC_BASE<"shf.h", int_mips_shf_h, MSA128H>;
-class SHF_W_DESC : MSA_I8_X_DESC_BASE<"shf.w", int_mips_shf_w, MSA128W>;
+class SHF_B_DESC : MSA_I8_SHF_DESC_BASE<"shf.b", MSA128B>;
+class SHF_H_DESC : MSA_I8_SHF_DESC_BASE<"shf.h", MSA128H>;
+class SHF_W_DESC : MSA_I8_SHF_DESC_BASE<"shf.w", MSA128W>;
 
 class SLD_B_DESC : MSA_3R_DESC_BASE<"sld.b", int_mips_sld_b, MSA128B>;
 class SLD_H_DESC : MSA_3R_DESC_BASE<"sld.h", int_mips_sld_h, MSA128H>;
diff --git a/lib/Target/Mips/MipsSEISelLowering.cpp b/lib/Target/Mips/MipsSEISelLowering.cpp
index 929e91eb60..b79e5321b6 100644
--- a/lib/Target/Mips/MipsSEISelLowering.cpp
+++ b/lib/Target/Mips/MipsSEISelLowering.cpp
@@ -1428,6 +1428,11 @@ SDValue MipsSETargetLowering::lowerINTRINSIC_WO_CHAIN(SDValue Op,
   case Intrinsic::mips_pcnt_w:
   case Intrinsic::mips_pcnt_d:
     return lowerMSAUnaryIntr(Op, DAG, ISD::CTPOP);
+  case Intrinsic::mips_shf_b:
+  case Intrinsic::mips_shf_h:
+  case Intrinsic::mips_shf_w:
+    return DAG.getNode(MipsISD::SHF, SDLoc(Op), Op->getValueType(0),
+                       Op->getOperand(2), Op->getOperand(1));
   case Intrinsic::mips_sll_b:
   case Intrinsic::mips_sll_h:
   case Intrinsic::mips_sll_w:
@@ -1735,6 +1740,72 @@ SDValue MipsSETargetLowering::lowerBUILD_VECTOR(SDValue Op,
   return SDValue();
 }
 
+// Lower VECTOR_SHUFFLE into SHF (if possible).
+//
+// SHF splits the vector into blocks of four elements, then shuffles these
+// elements according to a <4 x i2> constant (encoded as an integer immediate).
+//
+// It is therefore possible to lower into SHF when the mask takes the form:
+//   <a, b, c, d, a+4, b+4, c+4, d+4, a+8, b+8, c+8, d+8, ...>
+// When undef's appear they are treated as if they were whatever value is
+// necessary in order to fit the above form.
+//
+// For example:
+//   %2 = shufflevector <8 x i16> %0, <8 x i16> undef,
+//                      <8 x i32> <i32 3, i32 2, i32 1, i32 0,
+//                                 i32 7, i32 6, i32 5, i32 4>
+// is lowered to:
+//   (SHF_H $w0, $w1, 27)
+// where the 27 comes from:
+//   3 + (2 << 2) + (1 << 4) + (0 << 6)
+static SDValue lowerVECTOR_SHUFFLE_SHF(SDValue Op, EVT ResTy,
+                                       SmallVector<int, 16> Indices,
+                                       SelectionDAG &DAG) {
+  int SHFIndices[4] = { -1, -1, -1, -1 };
+
+  if (Indices.size() < 4)
+    return SDValue();
+
+  for (unsigned i = 0; i < 4; ++i) {
+    for (unsigned j = i; j < Indices.size(); j += 4) {
+      int Idx = Indices[j];
+
+      // Convert from vector index to 4-element subvector index
+      // If an index refers to an element outside of the subvector then give up
+      if (Idx != -1) {
+        Idx -= 4 * (j / 4);
+        if (Idx < 0 || Idx >= 4)
+          return SDValue();
+      }
+
+      // If the mask has an undef, replace it with the current index.
+      // Note that it might still be undef if the current index is also undef
+      if (SHFIndices[i] == -1)
+        SHFIndices[i] = Idx;
+
+      // Check that non-undef values are the same as in the mask. If they
+      // aren't then give up
+      if (!(Idx == -1 || Idx == SHFIndices[i]))
+        return SDValue();
+    }
+  }
+
+  // Calculate the immediate. Replace any remaining undefs with zero
+  APInt Imm(32, 0);
+  for (int i = 3; i >= 0; --i) {
+    int Idx = SHFIndices[i];
+
+    if (Idx == -1)
+      Idx = 0;
+
+    Imm <<= 2;
+    Imm |= Idx & 0x3;
+  }
+
+  return DAG.getNode(MipsISD::SHF, SDLoc(Op), ResTy,
+                     DAG.getConstant(Imm, MVT::i32), Op->getOperand(0));
+}
+
 // Lower VECTOR_SHUFFLE into VSHF.
 //
 // This mostly consists of converting the shuffle indices in Indices into a
@@ -1802,6 +1873,9 @@ SDValue MipsSETargetLowering::lowerVECTOR_SHUFFLE(SDValue Op,
   for (int i = 0; i < ResTyNumElts; ++i)
     Indices.push_back(Node->getMaskElt(i));
 
+  SDValue Result = lowerVECTOR_SHUFFLE_SHF(Op, ResTy, Indices, DAG);
+  if (Result.getNode())
+    return Result;
   return lowerVECTOR_SHUFFLE_VSHF(Op, ResTy, Indices, DAG);
 }