[RISCV] Add a encodeLMUL function to RISCVVType. NFC

This moves the encoding handling out of the assembly parser.

Reviewed By: khchen, frasercrmck

Differential Revision: https://reviews.llvm.org/D123553

diff --git a/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp b/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
index 2954f9d..ffa30b2 100644 (file)
--- a/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
+++ b/llvm/lib/Target/RISCV/AsmParser/RISCVAsmParser.cpp
@@ -1776,9 +1776,7 @@ OperandMatchResultTy RISCVAsmParser::parseVTypeI(OperandVector &Operands) {
     else
       goto MatchFail;
 
-    unsigned LmulLog2 = Log2_32(Lmul);
-    RISCVII::VLMUL VLMUL =
-        static_cast<RISCVII::VLMUL>(Fractional ? 8 - LmulLog2 : LmulLog2);
+    RISCVII::VLMUL VLMUL = RISCVVType::encodeLMUL(Lmul, Fractional);
 
     unsigned VTypeI =
         RISCVVType::encodeVTYPE(VLMUL, Sew, TailAgnostic, MaskAgnostic);

diff --git a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVBaseInfo.h b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVBaseInfo.h
index 5826a2c..56c217e 100644 (file)
--- a/llvm/lib/Target/RISCV/MCTargetDesc/RISCVBaseInfo.h
+++ b/llvm/lib/Target/RISCV/MCTargetDesc/RISCVBaseInfo.h
@@ -383,6 +383,12 @@ inline static RISCVII::VLMUL getVLMUL(unsigned VType) {
 // Decode VLMUL into 1,2,4,8 and fractional indicator.
 std::pair<unsigned, bool> decodeVLMUL(RISCVII::VLMUL VLMUL);
 
+inline static RISCVII::VLMUL encodeLMUL(unsigned LMUL, bool Fractional) {
+  assert(isValidLMUL(LMUL, Fractional) && "Unsupported LMUL");
+  unsigned LmulLog2 = Log2_32(LMUL);
+  return static_cast<RISCVII::VLMUL>(Fractional ? 8 - LmulLog2 : LmulLog2);
+}
+
 inline static unsigned decodeVSEW(unsigned VSEW) {
   assert(VSEW < 8 && "Unexpected VSEW value");
   return 1 << (VSEW + 3);