Include optional subclass flags, such as inbounds, nsw, etc., in the

Constant uniquing tables. This allows distinct ConstantExpr objects
with the same operation and different flags.

Even though a ConstantExpr "a + b" is either always overflowing or
never overflowing (due to being a ConstantExpr), it's still necessary
to be able to represent it both with and without overflow flags at
the same time within the IR, because the safety of the flag may
depend on the context of the use. If the constant really does overflow,
it wouldn't ever be safe to use with the flag set, however the use
may be in code that is never actually executed.

This also makes it possible to merge all the flags tests into a single test.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80998 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 33 insertions, 43 deletions

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index ce2f4520c6..432b88f911 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -8086,11 +8086,11 @@ Instruction *InstCombiner::commonPointerCastTransforms(CastInst &CI) {
           // If we were able to index down into an element, create the GEP
           // and bitcast the result.  This eliminates one bitcast, potentially
           // two.
-          Value *NGEP = Builder->CreateGEP(OrigBase, NewIndices.begin(),
-                                           NewIndices.end());
+          Value *NGEP = cast<GEPOperator>(GEP)->isInBounds() ?
+            Builder->CreateInBoundsGEP(OrigBase,
+                                       NewIndices.begin(), NewIndices.end()) :
+            Builder->CreateGEP(OrigBase, NewIndices.begin(), NewIndices.end());
           NGEP->takeName(GEP);
-          if (isa<Instruction>(NGEP) && cast<GEPOperator>(GEP)->isInBounds())
-            cast<GEPOperator>(NGEP)->setIsInBounds(true);
           
           if (isa<BitCastInst>(CI))
             return new BitCastInst(NGEP, CI.getType());
@@ -8805,11 +8805,8 @@ Instruction *InstCombiner::visitBitCast(BitCastInst &CI) {
     // If we found a path from the src to dest, create the getelementptr now.
     if (SrcElTy == DstElTy) {
       SmallVector<Value*, 8> Idxs(NumZeros+1, ZeroUInt);
-      Instruction *GEP = GetElementPtrInst::Create(Src,
-                                                   Idxs.begin(), Idxs.end(), "",
-                                                   ((Instruction*) NULL));
-      cast<GEPOperator>(GEP)->setIsInBounds(true);
-      return GEP;
+      return GetElementPtrInst::CreateInBounds(Src, Idxs.begin(), Idxs.end(), "",
+                                               ((Instruction*) NULL));
     }
   }
 
@@ -10481,12 +10478,11 @@ Instruction *InstCombiner::FoldPHIArgGEPIntoPHI(PHINode &PN) {
   }
   
   Value *Base = FixedOperands[0];
-  GetElementPtrInst *GEP =
+  return cast<GEPOperator>(FirstInst)->isInBounds() ?
+    GetElementPtrInst::CreateInBounds(Base, FixedOperands.begin()+1,
+                                      FixedOperands.end()) :
     GetElementPtrInst::Create(Base, FixedOperands.begin()+1,
                               FixedOperands.end());
-  if (cast<GEPOperator>(FirstInst)->isInBounds())
-    cast<GEPOperator>(GEP)->setIsInBounds(true);
-  return GEP;
 }
 
 
@@ -10889,14 +10885,13 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
       Indices.append(GEP.idx_begin()+1, GEP.idx_end());
     }
 
-    if (!Indices.empty()) {
-      GetElementPtrInst *NewGEP =
+    if (!Indices.empty())
+      return (cast<GEPOperator>(&GEP)->isInBounds() &&
+              Src->isInBounds()) ?
+        GetElementPtrInst::CreateInBounds(Src->getOperand(0), Indices.begin(),
+                                          Indices.end(), GEP.getName()) :
         GetElementPtrInst::Create(Src->getOperand(0), Indices.begin(),
                                   Indices.end(), GEP.getName());
-      if (cast<GEPOperator>(&GEP)->isInBounds() && Src->isInBounds())
-        cast<GEPOperator>(NewGEP)->setIsInBounds(true);
-      return NewGEP;
-    }
   }
   
   // Handle gep(bitcast x) and gep(gep x, 0, 0, 0).
@@ -10926,12 +10921,11 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
         if (CATy->getElementType() == XTy->getElementType()) {
           // -> GEP i8* X, ...
           SmallVector<Value*, 8> Indices(GEP.idx_begin()+1, GEP.idx_end());
-          GetElementPtrInst *NewGEP =
+          return cast<GEPOperator>(&GEP)->isInBounds() ?
+            GetElementPtrInst::CreateInBounds(X, Indices.begin(), Indices.end(),
+                                              GEP.getName()) :
             GetElementPtrInst::Create(X, Indices.begin(), Indices.end(),
                                       GEP.getName());
-          if (cast<GEPOperator>(&GEP)->isInBounds())
-            cast<GEPOperator>(NewGEP)->setIsInBounds(true);
-          return NewGEP;
         }
         
         if (const ArrayType *XATy = dyn_cast<ArrayType>(XTy->getElementType())){
@@ -10959,10 +10953,9 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
         Value *Idx[2];
         Idx[0] = Constant::getNullValue(Type::getInt32Ty(*Context));
         Idx[1] = GEP.getOperand(1);
-        Value *NewGEP =
+        Value *NewGEP = cast<GEPOperator>(&GEP)->isInBounds() ?
+          Builder->CreateInBoundsGEP(X, Idx, Idx + 2, GEP.getName()) :
           Builder->CreateGEP(X, Idx, Idx + 2, GEP.getName());
-        if (cast<GEPOperator>(&GEP)->isInBounds())
-          cast<GEPOperator>(NewGEP)->setIsInBounds(true);
         // V and GEP are both pointer types --> BitCast
         return new BitCastInst(NewGEP, GEP.getType());
       }
@@ -11019,9 +11012,9 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
           Value *Idx[2];
           Idx[0] = Constant::getNullValue(Type::getInt32Ty(*Context));
           Idx[1] = NewIdx;
-          Value *NewGEP = Builder->CreateGEP(X, Idx, Idx + 2, GEP.getName());
-          if (cast<GEPOperator>(&GEP)->isInBounds())
-            cast<GEPOperator>(NewGEP)->setIsInBounds(true);
+          Value *NewGEP = cast<GEPOperator>(&GEP)->isInBounds() ?
+            Builder->CreateInBoundsGEP(X, Idx, Idx + 2, GEP.getName()) :
+            Builder->CreateGEP(X, Idx, Idx + 2, GEP.getName());
           // The NewGEP must be pointer typed, so must the old one -> BitCast
           return new BitCastInst(NewGEP, GEP.getType());
         }
@@ -11069,10 +11062,11 @@ Instruction *InstCombiner::visitGetElementPtrInst(GetElementPtrInst &GEP) {
       const Type *InTy =
         cast<PointerType>(BCI->getOperand(0)->getType())->getElementType();
       if (FindElementAtOffset(InTy, Offset, NewIndices, TD, Context)) {
-        Value *NGEP = Builder->CreateGEP(BCI->getOperand(0), NewIndices.begin(),
-                                         NewIndices.end());
-        if (cast<GEPOperator>(&GEP)->isInBounds())
-          cast<GEPOperator>(NGEP)->setIsInBounds(true);
+        Value *NGEP = cast<GEPOperator>(&GEP)->isInBounds() ?
+          Builder->CreateInBoundsGEP(BCI->getOperand(0), NewIndices.begin(),
+                                     NewIndices.end()) :
+          Builder->CreateGEP(BCI->getOperand(0), NewIndices.begin(),
+                             NewIndices.end());
         
         if (NGEP->getType() == GEP.getType())
           return ReplaceInstUsesWith(GEP, NGEP);
@@ -11115,9 +11109,8 @@ Instruction *InstCombiner::visitAllocationInst(AllocationInst &AI) {
       Value *Idx[2];
       Idx[0] = NullIdx;
       Idx[1] = NullIdx;
-      Value *V = GetElementPtrInst::Create(New, Idx, Idx + 2,
-                                           New->getName()+".sub", It);
-      cast<GEPOperator>(V)->setIsInBounds(true);
+      Value *V = GetElementPtrInst::CreateInBounds(New, Idx, Idx + 2,
+                                                   New->getName()+".sub", It);
 
       // Now make everything use the getelementptr instead of the original
       // allocation.
@@ -11486,11 +11479,9 @@ static Instruction *InstCombineStoreToCast(InstCombiner &IC, StoreInst &SI) {
   
   // SIOp0 is a pointer to aggregate and this is a store to the first field,
   // emit a GEP to index into its first field.
-  if (!NewGEPIndices.empty()) {
-    CastOp = IC.Builder->CreateGEP(CastOp, NewGEPIndices.begin(),
-                                   NewGEPIndices.end());
-    cast<GEPOperator>(CastOp)->setIsInBounds(true);
-  }
+  if (!NewGEPIndices.empty())
+    CastOp = IC.Builder->CreateInBoundsGEP(CastOp, NewGEPIndices.begin(),
+                                           NewGEPIndices.end());
   
   NewCast = IC.Builder->CreateCast(opcode, SIOp0, CastDstTy,
                                    SIOp0->getName()+".c");
@@ -12160,8 +12151,7 @@ Instruction *InstCombiner::visitExtractElementInst(ExtractElementInst &EI) {
                                             PointerType::get(EI.getType(), AS),
                                             I->getOperand(0)->getName());
         Value *GEP =
-          Builder->CreateGEP(Ptr, EI.getOperand(1), I->getName()+".gep");
-        cast<GEPOperator>(GEP)->setIsInBounds(true);
+          Builder->CreateInBoundsGEP(Ptr, EI.getOperand(1), I->getName()+".gep");
         
         LoadInst *Load = Builder->CreateLoad(GEP, "tmp");