[llvm] cad9107 - [InstCombine] Create new insts in foldICmpEqIntrinsicWithConstant; NFCI

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2020-01-30T23:03:16+01:00
New Revision: cad91074a65ef992a230f071b77912e42eb1a908

URL: https://github.com/llvm/llvm-project/commit/cad91074a65ef992a230f071b77912e42eb1a908
DIFF: https://github.com/llvm/llvm-project/commit/cad91074a65ef992a230f071b77912e42eb1a908.diff

LOG: [InstCombine] Create new insts in foldICmpEqIntrinsicWithConstant; NFCI

In line with current conventions, create new instructions rather
than modify two operands in place and performing manual worklist
management.

This should be NFC apart from possible worklist order changes.

Added: 
    

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

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index beb786fc8d83..de37b723ac1f 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -3025,20 +3025,16 @@ Instruction *InstCombiner::foldICmpEqIntrinsicWithConstant(ICmpInst &Cmp,
   unsigned BitWidth = C.getBitWidth();
   switch (II->getIntrinsicID()) {
   case Intrinsic::bswap:
-    Worklist.Add(II);
-    Cmp.setOperand(0, II->getArgOperand(0));
-    Cmp.setOperand(1, ConstantInt::get(Ty, C.byteSwap()));
-    return &Cmp;
+    // bswap(A) == C  ->  A == bswap(C)
+    return new ICmpInst(Cmp.getPredicate(), II->getArgOperand(0),
+                        ConstantInt::get(Ty, C.byteSwap()));
 
   case Intrinsic::ctlz:
   case Intrinsic::cttz: {
     // ctz(A) == bitwidth(A)  ->  A == 0 and likewise for !=
-    if (C == BitWidth) {
-      Worklist.Add(II);
-      Cmp.setOperand(0, II->getArgOperand(0));
-      Cmp.setOperand(1, ConstantInt::getNullValue(Ty));
-      return &Cmp;
-    }
+    if (C == BitWidth)
+      return new ICmpInst(Cmp.getPredicate(), II->getArgOperand(0),
+                          ConstantInt::getNullValue(Ty));
 
     // ctz(A) == C -> A & Mask1 == Mask2, where Mask2 only has bit C set
     // and Mask1 has bits 0..C+1 set. Similar for ctl, but for high bits.
@@ -3051,10 +3047,9 @@ Instruction *InstCombiner::foldICmpEqIntrinsicWithConstant(ICmpInst &Cmp,
       APInt Mask2 = IsTrailing
         ? APInt::getOneBitSet(BitWidth, Num)
         : APInt::getOneBitSet(BitWidth, BitWidth - Num - 1);
-      Cmp.setOperand(0, Builder.CreateAnd(II->getArgOperand(0), Mask1));
-      Cmp.setOperand(1, ConstantInt::get(Ty, Mask2));
-      Worklist.Add(II);
-      return &Cmp;
+      return new ICmpInst(Cmp.getPredicate(),
+          Builder.CreateAnd(II->getArgOperand(0), Mask1),
+          ConstantInt::get(Ty, Mask2));
     }
     break;
   }
@@ -3063,14 +3058,10 @@ Instruction *InstCombiner::foldICmpEqIntrinsicWithConstant(ICmpInst &Cmp,
     // popcount(A) == 0  ->  A == 0 and likewise for !=
     // popcount(A) == bitwidth(A)  ->  A == -1 and likewise for !=
     bool IsZero = C.isNullValue();
-    if (IsZero || C == BitWidth) {
-      Worklist.Add(II);
-      Cmp.setOperand(0, II->getArgOperand(0));
-      auto *NewOp =
-          IsZero ? Constant::getNullValue(Ty) : Constant::getAllOnesValue(Ty);
-      Cmp.setOperand(1, NewOp);
-      return &Cmp;
-    }
+    if (IsZero || C == BitWidth)
+      return new ICmpInst(Cmp.getPredicate(), II->getArgOperand(0),
+          IsZero ? Constant::getNullValue(Ty) : Constant::getAllOnesValue(Ty));
+
     break;
   }
 
@@ -3078,9 +3069,7 @@ Instruction *InstCombiner::foldICmpEqIntrinsicWithConstant(ICmpInst &Cmp,
     // uadd.sat(a, b) == 0  ->  (a | b) == 0
     if (C.isNullValue()) {
       Value *Or = Builder.CreateOr(II->getArgOperand(0), II->getArgOperand(1));
-      return replaceInstUsesWith(Cmp, Builder.CreateICmp(
-          Cmp.getPredicate(), Or, Constant::getNullValue(Ty)));
-
+      return new ICmpInst(Cmp.getPredicate(), Or, Constant::getNullValue(Ty));
     }
     break;
   }
@@ -3090,8 +3079,7 @@ Instruction *InstCombiner::foldICmpEqIntrinsicWithConstant(ICmpInst &Cmp,
     if (C.isNullValue()) {
       ICmpInst::Predicate NewPred = Cmp.getPredicate() == ICmpInst::ICMP_EQ
           ? ICmpInst::ICMP_ULE : ICmpInst::ICMP_UGT;
-      return ICmpInst::Create(Instruction::ICmp, NewPred,
-                              II->getArgOperand(0), II->getArgOperand(1));
+      return new ICmpInst(NewPred, II->getArgOperand(0), II->getArgOperand(1));
     }
     break;
   }