[PATCH] D45900: CodeGen: Fix invalid bitcast for lifetime.start/end

[Yaxun Liu via Phabricator via cfe-commits]

yaxunl created this revision.
yaxunl added a reviewer: rjmccall.

lifetime.start/end expects pointer argument in alloca address space.
However in C++ a temporary variable is in default address space.

This patch casts the pointer argument of lifetime.start/end to
alloca address space if necessary.

It only affects targets with non-zero alloca address space.


https://reviews.llvm.org/D45900

Files:
  lib/CodeGen/CGDecl.cpp
  lib/CodeGen/CGExpr.cpp
  lib/CodeGen/CodeGenFunction.h
  test/CodeGenCXX/amdgcn_declspec_get.cpp


Index: test/CodeGenCXX/amdgcn_declspec_get.cpp
===================================================================
--- /dev/null
+++ test/CodeGenCXX/amdgcn_declspec_get.cpp
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -triple amdgcn-amd-amdhsa -emit-llvm -O3 -fdeclspec \
+// RUN:     -disable-llvm-passes -o - %s | FileCheck %s 
+
+int get_x();
+
+struct A {
+   __declspec(property(get = _get_x)) int x;
+   static int _get_x(void) {
+     return get_x();
+   };
+};
+
+extern const A a;
+
+// CHECK-LABEL: define void @_Z4testv()
+// CHECK:  %i = alloca i32, align 4, addrspace(5)
+// CHECK:  %[[ii:.*]] = addrspacecast i32 addrspace(5)* %i to i32*
+// CHECK:  %[[cast1:.*]] = addrspacecast i32* %[[ii]] to i8 addrspace(5)*
+// CHECK:  call void @llvm.lifetime.start.p5i8(i64 4, i8 addrspace(5)* %[[cast1]])
+// CHECK:  %call = call i32 @_ZN1A6_get_xEv()
+// CHECK:  store i32 %call, i32* %[[ii]]
+// CHECK:  %[[cast2:.*]] = addrspacecast i32* %[[ii]] to i8 addrspace(5)*
+// CHECK:  call void @llvm.lifetime.end.p5i8(i64 4, i8 addrspace(5)* %[[cast2]])
+void test()
+{
+  int i = a.x;
+}
Index: lib/CodeGen/CodeGenFunction.h
===================================================================
--- lib/CodeGen/CodeGenFunction.h
+++ lib/CodeGen/CodeGenFunction.h
@@ -2072,6 +2072,9 @@
   /// Emit a cast to void* in the appropriate address space.
   llvm::Value *EmitCastToVoidPtr(llvm::Value *value);
 
+  /// Emit a cast to void* in alloca address space.
+  llvm::Value *EmitCastToVoidPtrInAllocaAddrSpace(llvm::Value *V);
+
   /// EvaluateExprAsBool - Perform the usual unary conversions on the specified
   /// expression and compare the result against zero, returning an Int1Ty value.
   llvm::Value *EvaluateExprAsBool(const Expr *E);
Index: lib/CodeGen/CGExpr.cpp
===================================================================
--- lib/CodeGen/CGExpr.cpp
+++ lib/CodeGen/CGExpr.cpp
@@ -59,6 +59,18 @@
   return Builder.CreateBitCast(value, destType);
 }
 
+llvm::Value *
+CodeGenFunction::EmitCastToVoidPtrInAllocaAddrSpace(llvm::Value *V) {
+  if (V->getType()->getPointerAddressSpace() !=
+      CGM.getDataLayout().getAllocaAddrSpace()) {
+    return getTargetHooks().performAddrSpaceCast(
+        *this, V, getASTAllocaAddressSpace(), LangAS::Default, AllocaInt8PtrTy,
+        /*non-null*/ true);
+  } else {
+    return Builder.CreateBitCast(V, AllocaInt8PtrTy);
+  }
+}
+
 /// CreateTempAlloca - This creates a alloca and inserts it into the entry
 /// block.
 Address CodeGenFunction::CreateTempAlloca(llvm::Type *Ty, CharUnits Align,
Index: lib/CodeGen/CGDecl.cpp
===================================================================
--- lib/CodeGen/CGDecl.cpp
+++ lib/CodeGen/CGDecl.cpp
@@ -966,15 +966,15 @@
     return nullptr;
 
   llvm::Value *SizeV = llvm::ConstantInt::get(Int64Ty, Size);
-  Addr = Builder.CreateBitCast(Addr, AllocaInt8PtrTy);
+  Addr = EmitCastToVoidPtrInAllocaAddrSpace(Addr);
   llvm::CallInst *C =
       Builder.CreateCall(CGM.getLLVMLifetimeStartFn(), {SizeV, Addr});
   C->setDoesNotThrow();
   return SizeV;
 }
 
 void CodeGenFunction::EmitLifetimeEnd(llvm::Value *Size, llvm::Value *Addr) {
-  Addr = Builder.CreateBitCast(Addr, AllocaInt8PtrTy);
+  Addr = EmitCastToVoidPtrInAllocaAddrSpace(Addr);
   llvm::CallInst *C =
       Builder.CreateCall(CGM.getLLVMLifetimeEndFn(), {Size, Addr});
   C->setDoesNotThrow();


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