Allow DataLayout to specify addrspace for allocas.

LLVM makes several assumptions about address space 0. However,
alloca is presently constrained to always return this address space.
There's no real way to avoid using alloca, so without this
there is no way to opt out of these assumptions.

The problematic assumptions include:
- That the pointer size used for the stack is the same size as
  the code size pointer, which is also the maximum sized pointer.

- That 0 is an invalid, non-dereferencable pointer value.

These are problems for AMDGPU because alloca is used to
implement the private address space, which uses a 32-bit
index as the pointer value. Other pointers are 64-bit
and behave more like LLVM's notion of generic address
space. By changing the address space used for allocas,
we can change our generic pointer type to be LLVM's generic
pointer type which does have similar properties.

llvm-svn: 299888

1 files changed, 7 insertions, 7 deletions

diff --git a/llvm/lib/Transforms/Utils/InlineFunction.cpp b/llvm/lib/Transforms/Utils/InlineFunction.cpp
index b486df8e818..5d6fbc3325f 100644
--- a/llvm/lib/Transforms/Utils/InlineFunction.cpp
+++ b/llvm/lib/Transforms/Utils/InlineFunction.cpp
@@ -1225,6 +1225,7 @@ static Value *HandleByValArgument(Value *Arg, Instruction *TheCall,
   Type *AggTy = ArgTy->getElementType();
 
   Function *Caller = TheCall->getFunction();
+  const DataLayout &DL = Caller->getParent()->getDataLayout();
 
   // If the called function is readonly, then it could not mutate the caller's
   // copy of the byval'd memory.  In this case, it is safe to elide the copy and
@@ -1238,31 +1239,30 @@ static Value *HandleByValArgument(Value *Arg, Instruction *TheCall,
 
     AssumptionCache *AC =
         IFI.GetAssumptionCache ? &(*IFI.GetAssumptionCache)(*Caller) : nullptr;
-    const DataLayout &DL = Caller->getParent()->getDataLayout();
 
     // If the pointer is already known to be sufficiently aligned, or if we can
     // round it up to a larger alignment, then we don't need a temporary.
     if (getOrEnforceKnownAlignment(Arg, ByValAlignment, DL, TheCall, AC) >=
         ByValAlignment)
       return Arg;
-    
+
     // Otherwise, we have to make a memcpy to get a safe alignment.  This is bad
     // for code quality, but rarely happens and is required for correctness.
   }
 
   // Create the alloca.  If we have DataLayout, use nice alignment.
-  unsigned Align =
-      Caller->getParent()->getDataLayout().getPrefTypeAlignment(AggTy);
+  unsigned Align = DL.getPrefTypeAlignment(AggTy);
 
   // If the byval had an alignment specified, we *must* use at least that
   // alignment, as it is required by the byval argument (and uses of the
   // pointer inside the callee).
   Align = std::max(Align, ByValAlignment);
-  
-  Value *NewAlloca = new AllocaInst(AggTy, nullptr, Align, Arg->getName(), 
+
+  Value *NewAlloca = new AllocaInst(AggTy, DL.getAllocaAddrSpace(),
+                                    nullptr, Align, Arg->getName(),
                                     &*Caller->begin()->begin());
   IFI.StaticAllocas.push_back(cast<AllocaInst>(NewAlloca));
-  
+
   // Uses of the argument in the function should use our new alloca
   // instead.
   return NewAlloca;