[llvm] [AMDGPU] expand-fp: unify scalarization (NFC) (PR #158588)

[Frederik Harwath via llvm-commits]

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@@ -1004,55 +1002,37 @@ static bool runImpl(Function &F, const TargetLowering &TLI,
     return false;
 
   for (auto &I : instructions(F)) {
-    switch (I.getOpcode()) {
-    case Instruction::FRem: {
-      Type *Ty = I.getType();
-      // TODO: This pass doesn't handle scalable vectors.
-      if (Ty->isScalableTy())
-        continue;
-
-      if (targetSupportsFrem(TLI, Ty) ||
-          !FRemExpander::canExpandType(Ty->getScalarType()))
-        continue;
-
-      Replace.push_back(&I);
-      Modified = true;
+    Type *Ty = I.getType();
+    // TODO: This pass doesn't handle scalable vectors.
+    if (Ty->isScalableTy())
+      continue;
 
+    switch (I.getOpcode()) {
+    case Instruction::FRem:
+      if (!targetSupportsFrem(TLI, Ty) &&
+          FRemExpander::canExpandType(Ty->getScalarType())) {
+        enqueueInstruction(I, Replace, ReplaceVector);
----------------
frederik-h wrote:

> That's something that I also didn't really understand. I can try to get rid of it and see what breaks, if anything.

It's just because of the way the pass iterates the instructions, i.e. the IR changes invalidate the iterator. Both queues can be removed easily. I'd prefer to do this in a follow-up PR immediately after this one.

https://github.com/llvm/llvm-project/pull/158588