[llvm] r245728 - [opaque pointer type]: Pass explicit pointee type when building a constant GEP.

[David Blaikie via llvm-commits]

Author: dblaikie
Date: Fri Aug 21 15:16:51 2015
New Revision: 245728

URL: http://llvm.org/viewvc/llvm-project?rev=245728&view=rev
Log:
[opaque pointer type]: Pass explicit pointee type when building a constant GEP.

Gets a bit tricky in the ValueMapper, of course - not sure if we should
just expose a list of explicit types for each Value so that the
ValueMapper can be neutral to these special cases (it's OK for things
like load, where the explicit type is the result type - but when that's
not the case, it means plumbing through another "special" type... )

Modified:
    llvm/trunk/include/llvm/IR/Constants.h
    llvm/trunk/lib/IR/Constants.cpp
    llvm/trunk/lib/Transforms/Utils/ValueMapper.cpp

Modified: llvm/trunk/include/llvm/IR/Constants.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/Constants.h?rev=245728&r1=245727&r2=245728&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/Constants.h (original)
+++ llvm/trunk/include/llvm/IR/Constants.h Fri Aug 21 15:16:51 2015
@@ -1175,7 +1175,8 @@ public:
   /// gets constant-folded, the type changes, or the expression is otherwise
   /// canonicalized.  This parameter should almost always be \c false.
   Constant *getWithOperands(ArrayRef<Constant *> Ops, Type *Ty,
-                            bool OnlyIfReduced = false) const;
+                            bool OnlyIfReduced = false,
+                            Type *SrcTy = nullptr) const;
 
   /// getAsInstruction - Returns an Instruction which implements the same
   /// operation as this ConstantExpr. The instruction is not linked to any basic

Modified: llvm/trunk/lib/IR/Constants.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Constants.cpp?rev=245728&r1=245727&r2=245728&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Constants.cpp (original)
+++ llvm/trunk/lib/IR/Constants.cpp Fri Aug 21 15:16:51 2015
@@ -1245,7 +1245,7 @@ ConstantExpr::getWithOperandReplaced(uns
 /// operands replaced with the specified values.  The specified array must
 /// have the same number of operands as our current one.
 Constant *ConstantExpr::getWithOperands(ArrayRef<Constant *> Ops, Type *Ty,
-                                        bool OnlyIfReduced) const {
+                                        bool OnlyIfReduced, Type *SrcTy) const {
   assert(Ops.size() == getNumOperands() && "Operand count mismatch!");
 
   // If no operands changed return self.
@@ -1283,10 +1283,13 @@ Constant *ConstantExpr::getWithOperands(
   case Instruction::ShuffleVector:
     return ConstantExpr::getShuffleVector(Ops[0], Ops[1], Ops[2],
                                           OnlyIfReducedTy);
-  case Instruction::GetElementPtr:
-    return ConstantExpr::getGetElementPtr(nullptr, Ops[0], Ops.slice(1),
-                                          cast<GEPOperator>(this)->isInBounds(),
-                                          OnlyIfReducedTy);
+  case Instruction::GetElementPtr: {
+    auto *GEPO = cast<GEPOperator>(this);
+    assert(SrcTy || (Ops[0]->getType() == getOperand(0)->getType()));
+    return ConstantExpr::getGetElementPtr(
+        SrcTy ? SrcTy : GEPO->getSourceElementType(), Ops[0], Ops.slice(1),
+        GEPO->isInBounds(), OnlyIfReducedTy);
+  }
   case Instruction::ICmp:
   case Instruction::FCmp:
     return ConstantExpr::getCompare(getPredicate(), Ops[0], Ops[1],

Modified: llvm/trunk/lib/Transforms/Utils/ValueMapper.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/ValueMapper.cpp?rev=245728&r1=245727&r2=245728&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/ValueMapper.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/ValueMapper.cpp Fri Aug 21 15:16:51 2015
@@ -19,6 +19,7 @@
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/Metadata.h"
+#include "llvm/IR/Operator.h"
 using namespace llvm;
 
 // Out of line method to get vtable etc for class.
@@ -127,9 +128,13 @@ Value *llvm::MapValue(const Value *V, Va
       Ops.push_back(MapValue(cast<Constant>(C->getOperand(OpNo)), VM,
                              Flags, TypeMapper, Materializer));
   }
-  
+  Type *NewSrcTy = nullptr;
+  if (TypeMapper)
+    if (auto *GEPO = dyn_cast<GEPOperator>(C))
+      NewSrcTy = TypeMapper->remapType(GEPO->getSourceElementType());
+
   if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
-    return VM[V] = CE->getWithOperands(Ops, NewTy);
+    return VM[V] = CE->getWithOperands(Ops, NewTy, false, NewSrcTy);
   if (isa<ConstantArray>(C))
     return VM[V] = ConstantArray::get(cast<ArrayType>(NewTy), Ops);
   if (isa<ConstantStruct>(C))