[llvm] 3c2b185 - [InstCombine] Avoid ConstantExpr::getSelect() use (NFCI)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2023-02-27T16:32:11+01:00
New Revision: 3c2b1853d17065680c2bdac3623ad1fac4f215ec

URL: https://github.com/llvm/llvm-project/commit/3c2b1853d17065680c2bdac3623ad1fac4f215ec
DIFF: https://github.com/llvm/llvm-project/commit/3c2b1853d17065680c2bdac3623ad1fac4f215ec.diff

LOG: [InstCombine] Avoid ConstantExpr::getSelect() use (NFCI)

Instead let IRBuilder take care of constant folding.

In preparation for removing select constantexprs.

Added: 
    

Modified: 
    llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp

Removed: 
    


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diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
index b585de05e9ea6..b7fe9ff239a3f 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -1082,7 +1082,8 @@ static Instruction *foldClampRangeOfTwo(IntrinsicInst *II,
 
 /// If this min/max has a constant operand and an operand that is a matching
 /// min/max with a constant operand, constant-fold the 2 constant operands.
-static Instruction *reassociateMinMaxWithConstants(IntrinsicInst *II) {
+static Value *reassociateMinMaxWithConstants(IntrinsicInst *II,
+                                             IRBuilderBase &Builder) {
   Intrinsic::ID MinMaxID = II->getIntrinsicID();
   auto *LHS = dyn_cast<IntrinsicInst>(II->getArgOperand(0));
   if (!LHS || LHS->getIntrinsicID() != MinMaxID)
@@ -1095,12 +1096,10 @@ static Instruction *reassociateMinMaxWithConstants(IntrinsicInst *II) {
 
   // max (max X, C0), C1 --> max X, (max C0, C1) --> max X, NewC
   ICmpInst::Predicate Pred = MinMaxIntrinsic::getPredicate(MinMaxID);
-  Constant *CondC = ConstantExpr::getICmp(Pred, C0, C1);
-  Constant *NewC = ConstantExpr::getSelect(CondC, C0, C1);
-
-  Module *Mod = II->getModule();
-  Function *MinMax = Intrinsic::getDeclaration(Mod, MinMaxID, II->getType());
-  return CallInst::Create(MinMax, {LHS->getArgOperand(0), NewC});
+  Value *CondC = Builder.CreateICmp(Pred, C0, C1);
+  Value *NewC = Builder.CreateSelect(CondC, C0, C1);
+  return Builder.CreateIntrinsic(MinMaxID, II->getType(),
+                                 {LHS->getArgOperand(0), NewC});
 }
 
 /// If this min/max has a matching min/max operand with a constant, try to push
@@ -1572,8 +1571,8 @@ Instruction *InstCombinerImpl::visitCallInst(CallInst &CI) {
         if (Instruction *R = FoldOpIntoSelect(*II, Sel))
           return R;
 
-    if (Instruction *NewMinMax = reassociateMinMaxWithConstants(II))
-      return NewMinMax;
+    if (Value *NewMinMax = reassociateMinMaxWithConstants(II, Builder))
+      return replaceInstUsesWith(*II, NewMinMax);
 
     if (Instruction *R = reassociateMinMaxWithConstantInOperand(II, Builder))
       return R;