[llvm] r261649 - [InstCombine] add helper function to foldCastedBitwiseLogic() ; NFCI

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Tue Feb 23 10:36:07 2016
New Revision: 261649

URL: http://llvm.org/viewvc/llvm-project?rev=261649&view=rev
Log:
[InstCombine] add helper function to foldCastedBitwiseLogic() ; NFCI

This is a straight cut and paste of the existing code and is intended to
be the first step in solving part of PR26702:
https://llvm.org/bugs/show_bug.cgi?id=26702

We should be able to reuse most of this and delete the nearly identical 
existing code in visitOr(). Then, we can enhance visitXor() to use the
same code too.

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
    llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp?rev=261649&r1=261648&r2=261649&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp Tue Feb 23 10:36:07 2016
@@ -1243,6 +1243,44 @@ static Instruction *matchDeMorgansLaws(B
   return nullptr;
 }
 
+Instruction *InstCombiner::foldCastedBitwiseLogic(BinaryOperator &I) {
+  Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
+  if (CastInst *Op0C = dyn_cast<CastInst>(Op0)) {
+    Value *Op0COp = Op0C->getOperand(0);
+    Type *SrcTy = Op0COp->getType();
+    // fold (and (cast A), (cast B)) -> (cast (and A, B))
+    if (CastInst *Op1C = dyn_cast<CastInst>(Op1)) {
+      if (Op0C->getOpcode() == Op1C->getOpcode() && // same cast kind ?
+          SrcTy == Op1C->getOperand(0)->getType() &&
+          SrcTy->isIntOrIntVectorTy()) {
+        Value *Op1COp = Op1C->getOperand(0);
+
+        // Only do this if the casts both really cause code to be generated.
+        if (ShouldOptimizeCast(Op0C->getOpcode(), Op0COp, I.getType()) &&
+            ShouldOptimizeCast(Op1C->getOpcode(), Op1COp, I.getType())) {
+          Value *NewOp = Builder->CreateAnd(Op0COp, Op1COp, I.getName());
+          return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
+        }
+
+        // If this is and(cast(icmp), cast(icmp)), try to fold this even if the
+        // cast is otherwise not optimizable.  This happens for vector sexts.
+        if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1COp))
+          if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0COp))
+            if (Value *Res = FoldAndOfICmps(LHS, RHS))
+              return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
+
+        // If this is and(cast(fcmp), cast(fcmp)), try to fold this even if the
+        // cast is otherwise not optimizable.  This happens for vector sexts.
+        if (FCmpInst *RHS = dyn_cast<FCmpInst>(Op1COp))
+          if (FCmpInst *LHS = dyn_cast<FCmpInst>(Op0COp))
+            if (Value *Res = FoldAndOfFCmps(LHS, RHS))
+              return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
+      }
+    }
+  }
+  return nullptr;
+}
+
 Instruction *InstCombiner::visitAnd(BinaryOperator &I) {
   bool Changed = SimplifyAssociativeOrCommutative(I);
   Value *Op0 = I.getOperand(0), *Op1 = I.getOperand(1);
@@ -1480,39 +1518,12 @@ Instruction *InstCombiner::visitAnd(Bina
       if (Value *Res = FoldAndOfFCmps(LHS, RHS))
         return replaceInstUsesWith(I, Res);
 
+  if (Instruction *CastedAnd = foldCastedBitwiseLogic(I))
+    return CastedAnd;
 
   if (CastInst *Op0C = dyn_cast<CastInst>(Op0)) {
     Value *Op0COp = Op0C->getOperand(0);
     Type *SrcTy = Op0COp->getType();
-    // fold (and (cast A), (cast B)) -> (cast (and A, B))
-    if (CastInst *Op1C = dyn_cast<CastInst>(Op1)) {
-      if (Op0C->getOpcode() == Op1C->getOpcode() && // same cast kind ?
-          SrcTy == Op1C->getOperand(0)->getType() &&
-          SrcTy->isIntOrIntVectorTy()) {
-        Value *Op1COp = Op1C->getOperand(0);
-
-        // Only do this if the casts both really cause code to be generated.
-        if (ShouldOptimizeCast(Op0C->getOpcode(), Op0COp, I.getType()) &&
-            ShouldOptimizeCast(Op1C->getOpcode(), Op1COp, I.getType())) {
-          Value *NewOp = Builder->CreateAnd(Op0COp, Op1COp, I.getName());
-          return CastInst::Create(Op0C->getOpcode(), NewOp, I.getType());
-        }
-
-        // If this is and(cast(icmp), cast(icmp)), try to fold this even if the
-        // cast is otherwise not optimizable.  This happens for vector sexts.
-        if (ICmpInst *RHS = dyn_cast<ICmpInst>(Op1COp))
-          if (ICmpInst *LHS = dyn_cast<ICmpInst>(Op0COp))
-            if (Value *Res = FoldAndOfICmps(LHS, RHS))
-              return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
-
-        // If this is and(cast(fcmp), cast(fcmp)), try to fold this even if the
-        // cast is otherwise not optimizable.  This happens for vector sexts.
-        if (FCmpInst *RHS = dyn_cast<FCmpInst>(Op1COp))
-          if (FCmpInst *LHS = dyn_cast<FCmpInst>(Op0COp))
-            if (Value *Res = FoldAndOfFCmps(LHS, RHS))
-              return CastInst::Create(Op0C->getOpcode(), Res, I.getType());
-      }
-    }
 
     // If we are masking off the sign bit of a floating-point value, convert
     // this to the canonical fabs intrinsic call and cast back to integer.

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h?rev=261649&r1=261648&r2=261649&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineInternal.h Tue Feb 23 10:36:07 2016
@@ -390,6 +390,7 @@ private:
   Value *EmitGEPOffset(User *GEP);
   Instruction *scalarizePHI(ExtractElementInst &EI, PHINode *PN);
   Value *EvaluateInDifferentElementOrder(Value *V, ArrayRef<int> Mask);
+  Instruction *foldCastedBitwiseLogic(BinaryOperator &I);
 
 public:
   /// \brief Inserts an instruction \p New before instruction \p Old