[PATCH] D103661: [IR] Add utility to convert constant expression operands (of an instruction) to instructions.

[Stanislav Mekhanoshin via Phabricator via llvm-commits]

rampitec added inline comments.


================
Comment at: llvm/lib/IR/ReplaceConstant.cpp:107
+
+    if (CE->getNumOperands()) {
+      SmallPtrSet<Value *, 4> Operands2;
----------------
To address Jay's comment I think you can pass an original CE into this function and amend the if to only execute it if CE != ReplacedCE. It will then skip the operands of the expression being replaced itself. I.e.:


```
@@ -77,12 +77,13 @@ void convertConstantExprsToInstructions(Instruction *I, ConstantExpr *CE,

   // Convert constant expressions operands of I (from the set CEOperands) to
   // instructions.
-  convertConstantExprsToInstructions(I, CEOperands, Insts);
+  convertConstantExprsToInstructions(I, CEOperands, Insts, CE);
 }

 void convertConstantExprsToInstructions(Instruction *I,
                                         SmallPtrSetImpl<Value *> &Operands,
-                                        SmallPtrSetImpl<Instruction *> &Insts) {
+                                        SmallPtrSetImpl<Instruction *> &Insts,
+                                        ConstantExpr *C) {
   for (Use &U : I->operands()) {
     auto *V = U.get();

@@ -104,11 +105,9 @@ void convertConstantExprsToInstructions(Instruction *I,
     I->replaceUsesOfWith(CE, NI);
     Insts.insert(NI);

-    if (CE->getNumOperands()) {
+    if (C != CE && CE->getNumOperands()) {
      SmallPtrSet<Value *, 4> Operands2;
      for (Use &UU : CE->operands())
        Operands2.insert(UU.get());
-      convertConstantExprsToInstructions(NI, Operands2, Insts);
+      convertConstantExprsToInstructions(NI, Operands2, Insts, C);
     }

     CE->removeDeadConstantUsers();
```
Note there are never recursive constant expressions.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D103661/new/

https://reviews.llvm.org/D103661