Fix array sizes where address space is not yet known

For variables in generic address spaces, for example:

```
unsigned char V[6442450944];
...
```

the address space is not yet known when we get into
*getConstantArrayType*, it is 0. AMDGCN target's
address space 0 has 32 bits pointers, so when we
call *getPointerWidth* with 0, the array size is
trimmed to 32 bits, which is not right.

Differential Revision: https://reviews.llvm.org/D30845

llvm-svn: 298420

2 files changed, 13 insertions, 2 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index e8f98929de6..071537a051c 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -2692,8 +2692,7 @@ QualType ASTContext::getConstantArrayType(QualType EltTy,
   // Convert the array size into a canonical width matching the pointer size for
   // the target.
   llvm::APInt ArySize(ArySizeIn);
-  ArySize =
-    ArySize.zextOrTrunc(Target->getPointerWidth(getTargetAddressSpace(EltTy)));
+  ArySize = ArySize.zextOrTrunc(Target->getMaxPointerWidth());
 
   llvm::FoldingSetNodeID ID;
   ConstantArrayType::Profile(ID, EltTy, ArySize, ASM, IndexTypeQuals);
diff --git a/clang/test/CodeGenOpenCL/amdgcn-large-globals.cl b/clang/test/CodeGenOpenCL/amdgcn-large-globals.cl
new file mode 100644
index 00000000000..ea9ea618a48
--- /dev/null
+++ b/clang/test/CodeGenOpenCL/amdgcn-large-globals.cl
@@ -0,0 +1,12 @@
+// REQUIRES: amdgpu-registered-target
+// RUN: %clang_cc1 -cl-std=CL2.0 -triple amdgcn-unknown-unknown -S -emit-llvm -o - %s | FileCheck %s
+
+// CHECK: @One = common local_unnamed_addr addrspace(1) global [6442450944 x i8] zeroinitializer, align 1
+unsigned char One[6442450944];
+// CHECK: @Two = common local_unnamed_addr addrspace(1) global [6442450944 x i32] zeroinitializer, align 4
+global unsigned int Two[6442450944];
+ 
+kernel void large_globals(unsigned int id) {
+  One[id] = id;
+  Two[id + 1] = id + 1;
+}