[llvm] [PATCH] [Xtensa] Implement FrameLowering methods and stack operation lowering. (PR #92960)

[Matt Arsenault via llvm-commits]

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@@ -48,6 +48,30 @@ XtensaInstrInfo::XtensaInstrInfo(const XtensaSubtarget &STI)
     : XtensaGenInstrInfo(Xtensa::ADJCALLSTACKDOWN, Xtensa::ADJCALLSTACKUP),
       RI(STI), STI(STI) {}
 
+Register XtensaInstrInfo::isLoadFromStackSlot(const MachineInstr &MI,
+                                              int &FrameIndex) const {
+  if (MI.getOpcode() == Xtensa::L32I) {
+    if (MI.getOperand(1).isFI() && MI.getOperand(2).isImm() &&
+        MI.getOperand(2).getImm() == 0) {
+      FrameIndex = MI.getOperand(1).getIndex();
+      return MI.getOperand(0).getReg();
+    }
+  }
+  return 0;
+}
+
+Register XtensaInstrInfo::isStoreToStackSlot(const MachineInstr &MI,
+                                             int &FrameIndex) const {
+  if (MI.getOpcode() == Xtensa::S32I) {
+    if (MI.getOperand(1).isFI() && MI.getOperand(2).isImm() &&
+        MI.getOperand(2).getImm() == 0) {
+      FrameIndex = MI.getOperand(1).getIndex();
+      return MI.getOperand(0).getReg();
+    }
+  }
+  return 0;
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arsenm wrote:

Register() 

https://github.com/llvm/llvm-project/pull/92960