InstCombine: ((A & ~B) ^ (~A & B)) to A ^ B

[oota-llvm.git] / lib / Transforms / InstCombine / InstructionCombining.cpp

diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp
index fe3b8b41fdba4ffea041622efe20e437c141b260..e079eee7d2c4d2c446cfe7cc0f0797ab6e98174d 100644 (file)
--- a/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -1582,9 +1582,8 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
           Builder->CreateGEP(StrippedPtr, Idx, GEP.getName());
 
         // V and GEP are both pointer types --> BitCast
-        if (StrippedPtrTy->getAddressSpace() == GEP.getPointerAddressSpace())
-          return new BitCastInst(NewGEP, GEP.getType());
-        return new AddrSpaceCastInst(NewGEP, GEP.getType());
+        return CastInst::CreatePointerBitCastOrAddrSpaceCast(NewGEP,
+                                                             GEP.getType());
       }
 
       // Transform things like:
@@ -1616,9 +1615,8 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
               Builder->CreateGEP(StrippedPtr, NewIdx, GEP.getName());
 
             // The NewGEP must be pointer typed, so must the old one -> BitCast
-            if (StrippedPtrTy->getAddressSpace() == GEP.getPointerAddressSpace())
-              return new BitCastInst(NewGEP, GEP.getType());
-            return new AddrSpaceCastInst(NewGEP, GEP.getType());
+            return CastInst::CreatePointerBitCastOrAddrSpaceCast(NewGEP,
+                                                                 GEP.getType());
           }
         }
       }
@@ -1658,9 +1656,8 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
               Builder->CreateInBoundsGEP(StrippedPtr, Off, GEP.getName()) :
               Builder->CreateGEP(StrippedPtr, Off, GEP.getName());
             // The NewGEP must be pointer typed, so must the old one -> BitCast
-            if (StrippedPtrTy->getAddressSpace() == GEP.getPointerAddressSpace())
-              return new BitCastInst(NewGEP, GEP.getType());
-            return new AddrSpaceCastInst(NewGEP, GEP.getType());
+            return CastInst::CreatePointerBitCastOrAddrSpaceCast(NewGEP,
+                                                                 GEP.getType());
           }
         }
       }
@@ -1670,6 +1667,18 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
   if (!DL)
     return nullptr;
 
+  // addrspacecast between types is canonicalized as a bitcast, then an
+  // addrspacecast. To take advantage of the below bitcast + struct GEP, look
+  // through the addrspacecast.
+  if (AddrSpaceCastInst *ASC = dyn_cast<AddrSpaceCastInst>(PtrOp)) {
+    //   X = bitcast A addrspace(1)* to B addrspace(1)*
+    //   Y = addrspacecast A addrspace(1)* to B addrspace(2)*
+    //   Z = gep Y, <...constant indices...>
+    // Into an addrspacecasted GEP of the struct.
+    if (BitCastInst *BC = dyn_cast<BitCastInst>(ASC->getOperand(0)))
+      PtrOp = BC;
+  }
+
   /// See if we can simplify:
   ///   X = bitcast A* to B*
   ///   Y = gep X, <...constant indices...>
@@ -1678,11 +1687,10 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
   if (BitCastInst *BCI = dyn_cast<BitCastInst>(PtrOp)) {
     Value *Operand = BCI->getOperand(0);
     PointerType *OpType = cast<PointerType>(Operand->getType());
-    unsigned OffsetBits = DL->getPointerTypeSizeInBits(OpType);
+    unsigned OffsetBits = DL->getPointerTypeSizeInBits(GEP.getType());
     APInt Offset(OffsetBits, 0);
     if (!isa<BitCastInst>(Operand) &&
-        GEP.accumulateConstantOffset(*DL, Offset) &&
-        StrippedPtrTy->getAddressSpace() == GEP.getPointerAddressSpace()) {
+        GEP.accumulateConstantOffset(*DL, Offset)) {
 
       // If this GEP instruction doesn't move the pointer, just replace the GEP
       // with a bitcast of the real input to the dest type.
@@ -1700,6 +1708,9 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
             return &GEP;
           }
         }
+
+        if (Operand->getType()->getPointerAddressSpace() != GEP.getAddressSpace())
+          return new AddrSpaceCastInst(Operand, GEP.getType());
         return new BitCastInst(Operand, GEP.getType());
       }
 
@@ -1715,6 +1726,9 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
         if (NGEP->getType() == GEP.getType())
           return ReplaceInstUsesWith(GEP, NGEP);
         NGEP->takeName(&GEP);
+
+        if (NGEP->getType()->getPointerAddressSpace() != GEP.getAddressSpace())
+          return new AddrSpaceCastInst(NGEP, GEP.getType());
         return new BitCastInst(NGEP, GEP.getType());
       }
     }