[RISCV] Rename RISCVISD::SHFLI to RISCVISD::SHFL and don't require the second operand to be an immediate.

Prep work for adding intrinsics in the future.

Left an assert that the input is constant in ReplaceNodeResults,
as the intrinsic shouldn't go through that path.

Author: topperc

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

@@ -4296,14 +4296,16 @@ void RISCVTargetLowering::ReplaceNodeResults(SDNode *N,
     Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, NewRes));
     break;
   }
-  case RISCVISD::SHFLI: {
+  case RISCVISD::SHFL: {
     // There is no SHFLIW instruction, but we can just promote the operation.
     assert(N->getValueType(0) == MVT::i32 && Subtarget.is64Bit() &&
            "Unexpected custom legalisation");
+    assert(isa<ConstantSDNode>(N->getOperand(1)) && "Expected constant");
     SDValue NewOp0 =
         DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, N->getOperand(0));
-    SDValue NewRes =
-        DAG.getNode(RISCVISD::SHFLI, DL, MVT::i64, NewOp0, N->getOperand(1));
+    SDValue NewOp1 =
+        DAG.getNode(ISD::ANY_EXTEND, DL, MVT::i64, N->getOperand(1));
+    SDValue NewRes = DAG.getNode(RISCVISD::SHFL, DL, MVT::i64, NewOp0, NewOp1);
     // ReplaceNodeResults requires we maintain the same type for the return
     // value.
     Results.push_back(DAG.getNode(ISD::TRUNCATE, DL, MVT::i32, NewRes));
@@ -4763,9 +4765,8 @@ static SDValue combineORToSHFL(SDValue Op, SelectionDAG &DAG,
     return SDValue();
 
   SDLoc DL(Op);
-  return DAG.getNode(
-      RISCVISD::SHFLI, DL, VT, Match1->Op,
-      DAG.getTargetConstant(Match1->ShAmt, DL, Subtarget.getXLenVT()));
+  return DAG.getNode(RISCVISD::SHFL, DL, VT, Match1->Op,
+                     DAG.getConstant(Match1->ShAmt, DL, VT));
 }
 
 // Combine (GREVI (GREVI x, C2), C1) -> (GREVI x, C1^C2) when C1^C2 is
@@ -5367,12 +5368,13 @@ unsigned RISCVTargetLowering::ComputeNumSignBitsForTargetNode(
     // more precise answer could be calculated for SRAW depending on known
     // bits in the shift amount.
     return 33;
-  case RISCVISD::SHFLI: {
+  case RISCVISD::SHFL: {
     // There is no SHFLIW, but a i64 SHFLI with bit 4 of the control word
     // cleared doesn't affect bit 31. The upper 32 bits will be shuffled, but
     // will stay within the upper 32 bits. If there were more than 32 sign bits
     // before there will be at least 33 sign bits after.
     if (Op.getValueType() == MVT::i64 &&
+        isa<ConstantSDNode>(Op.getOperand(1)) &&
         (Op.getConstantOperandVal(1) & 0x10) == 0) {
       unsigned Tmp = DAG.ComputeNumSignBits(Op.getOperand(0), Depth + 1);
       if (Tmp > 32)
@@ -7107,7 +7109,7 @@ const char *RISCVTargetLowering::getTargetNodeName(unsigned Opcode) const {
   NODE_NAME_CASE(GREVIW)
   NODE_NAME_CASE(GORCI)
   NODE_NAME_CASE(GORCIW)
-  NODE_NAME_CASE(SHFLI)
+  NODE_NAME_CASE(SHFL)
   NODE_NAME_CASE(VMV_V_X_VL)
   NODE_NAME_CASE(VFMV_V_F_VL)
   NODE_NAME_CASE(VMV_X_S)

llvm/lib/Target/RISCV/RISCVISelLowering.h

@@ -96,7 +96,7 @@ enum NodeType : unsigned {
   GREVIW,
   GORCI,
   GORCIW,
-  SHFLI,
+  SHFL,
   // Vector Extension
   // VMV_V_X_VL matches the semantics of vmv.v.x but includes an extra operand
   // for the VL value to be used for the operation.

llvm/lib/Target/RISCV/RISCVInstrInfoB.td

@@ -29,7 +29,7 @@ def riscv_grevi  : SDNode<"RISCVISD::GREVI",  SDTIntBinOp>;
 def riscv_greviw : SDNode<"RISCVISD::GREVIW", SDT_RISCVIntBinOpW>;
 def riscv_gorci  : SDNode<"RISCVISD::GORCI",  SDTIntBinOp>;
 def riscv_gorciw : SDNode<"RISCVISD::GORCIW", SDT_RISCVIntBinOpW>;
-def riscv_shfli  : SDNode<"RISCVISD::SHFLI",  SDTIntBinOp>;
+def riscv_shfl   : SDNode<"RISCVISD::SHFL",   SDTIntBinOp>;
 
 def UImmLog2XLenHalfAsmOperand : AsmOperandClass {
   let Name = "UImmLog2XLenHalf";
@@ -723,7 +723,8 @@ def : Pat<(riscv_gorci GPR:$rs1, 7), (ORCB GPR:$rs1)>;
 }
 
 let Predicates = [HasStdExtZbp] in {
-def : Pat<(riscv_shfli GPR:$rs1, timm:$shamt), (SHFLI GPR:$rs1, timm:$shamt)>;
+def : Pat<(riscv_shfl GPR:$rs1, shfl_uimm:$shamt),
+          (SHFLI GPR:$rs1, shfl_uimm:$shamt)>;
 def : Pat<(riscv_grevi GPR:$rs1, timm:$shamt), (GREVI GPR:$rs1, timm:$shamt)>;
 def : Pat<(riscv_gorci GPR:$rs1, timm:$shamt), (GORCI GPR:$rs1, timm:$shamt)>;
 } // Predicates = [HasStdExtZbp]