[llvm] [AMDGPU] Add new llvm.amdgcn.wave.shuffle intrinsic (PR #167372)

[Jay Foad via llvm-commits]

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@@ -3852,6 +3854,129 @@ bool AMDGPUInstructionSelector::selectWaveAddress(MachineInstr &MI) const {
   return true;
 }
 
+bool AMDGPUInstructionSelector::selectWaveShuffleIntrin(
+    MachineInstr &MI) const {
+  assert(MI.getNumOperands() == 4);
+  MachineBasicBlock *MBB = MI.getParent();
+  const DebugLoc &DL = MI.getDebugLoc();
+
+  Register DstReg = MI.getOperand(0).getReg();
+  Register ValReg = MI.getOperand(2).getReg();
+  Register IdxReg = MI.getOperand(3).getReg();
+
+  const LLT DstTy = MRI->getType(DstReg);
+  unsigned DstSize = DstTy.getSizeInBits();
+  const RegisterBank *DstRB = RBI.getRegBank(DstReg, *MRI, TRI);
+  const TargetRegisterClass *DstRC =
+      TRI.getRegClassForSizeOnBank(DstSize, *DstRB);
+
+  assert(DstTy == LLT::scalar(32));
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jayfoad wrote:

Same here, I think you can return false.

https://github.com/llvm/llvm-project/pull/167372