[llvm] [ARM] Use DenseSet instead of DenseMap. NFC (PR #131978)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-arm

Author: Craig Topper (topperc)

<details>
<summary>Changes</summary>

The value in the map is set to "true" when something is added to the map.

Techncally this:

  if (!DefRegs.contains(Reg))

will set the value in the map to false if it didn't alrady exist, and this is used to indicate the value wasn't in the map. This only occurs after all the "true" values have already been added to the map.

---
Full diff: https://github.com/llvm/llvm-project/pull/131978.diff


1 Files Affected:

- (modified) llvm/lib/Target/ARM/ARMISelLowering.cpp (+3-3) 


``````````diff
diff --git a/llvm/lib/Target/ARM/ARMISelLowering.cpp b/llvm/lib/Target/ARM/ARMISelLowering.cpp
index 1fb68fa85f7b6..234abefe75ee7 100644
--- a/llvm/lib/Target/ARM/ARMISelLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMISelLowering.cpp
@@ -11366,12 +11366,12 @@ void ARMTargetLowering::EmitSjLjDispatchBlock(MachineInstr &MI,
            II = BB->rbegin(), IE = BB->rend(); II != IE; ++II) {
       if (!II->isCall()) continue;
 
-      DenseMap<unsigned, bool> DefRegs;
+      DenseSet<unsigned> DefRegs;
       for (MachineInstr::mop_iterator
              OI = II->operands_begin(), OE = II->operands_end();
            OI != OE; ++OI) {
         if (!OI->isReg()) continue;
-        DefRegs[OI->getReg()] = true;
+        DefRegs.insert(OI->getReg());
       }
 
       MachineInstrBuilder MIB(*MF, &*II);
@@ -11386,7 +11386,7 @@ void ARMTargetLowering::EmitSjLjDispatchBlock(MachineInstr &MI,
           continue;
         if (!Subtarget->isThumb() && !ARM::GPRRegClass.contains(Reg))
           continue;
-        if (!DefRegs[Reg])
+        if (!DefRegs.contains(Reg))
           MIB.addReg(Reg, RegState::ImplicitDefine | RegState::Dead);
       }
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/131978