[llvm] [RISCV][GISEL] Legalize G_INSERT_SUBVECTOR (PR #108859)

[Thorsten Schütt via llvm-commits]

================
@@ -915,6 +921,152 @@ bool RISCVLegalizerInfo::legalizeSplatVector(MachineInstr &MI,
   return true;
 }
 
+static LLT getLMUL1Ty(LLT VecTy) {
+  assert(VecTy.getElementType().getSizeInBits() <= 64 &&
+         "Unexpected vector LLT");
+  return LLT::scalable_vector(RISCV::RVVBitsPerBlock /
+                                  VecTy.getElementType().getSizeInBits(),
+                              VecTy.getElementType());
+}
+
+bool RISCVLegalizerInfo::legalizeInsertSubvector(MachineInstr &MI,
+                                                 MachineIRBuilder &MIB) const {
+  GInsertSubvector &IS = cast<GInsertSubvector>(MI);
+
+  MachineRegisterInfo &MRI = *MIB.getMRI();
+
+  Register Dst = IS.getOperand(0).getReg();
----------------
tschuett wrote:

`IS.getReg(0);`

https://github.com/llvm/llvm-project/pull/108859