[llvm-branch-commits] [llvm] AMDGPU/GlobalISel: Add waterfall lowering in regbanklegalize (PR #142790)

[Petar Avramovic via llvm-branch-commits]

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@@ -57,6 +57,226 @@ void RegBankLegalizeHelper::findRuleAndApplyMapping(MachineInstr &MI) {
   lower(MI, Mapping, WaterfallSgprs);
 }
 
+bool RegBankLegalizeHelper::executeInWaterfallLoop(
+    MachineIRBuilder &B, iterator_range<MachineBasicBlock::iterator> Range,
+    SmallSet<Register, 4> &SGPROperandRegs) {
+  // Track use registers which have already been expanded with a readfirstlane
+  // sequence. This may have multiple uses if moving a sequence.
+  DenseMap<Register, Register> WaterfalledRegMap;
+
+  MachineBasicBlock &MBB = B.getMBB();
+  MachineFunction &MF = B.getMF();
+
+  const SIRegisterInfo *TRI = ST.getRegisterInfo();
+  const TargetRegisterClass *WaveRC = TRI->getWaveMaskRegClass();
+  unsigned MovExecOpc, MovExecTermOpc, XorTermOpc, AndSaveExecOpc, ExecReg;
+  if (ST.isWave32()) {
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petar-avramovic wrote:

it is instantiated per ST, MRI pair, not per function

https://github.com/llvm/llvm-project/pull/142790