AMDGPU/SI: Give up in promote alloca when a pointer may be captured.

Differential Revision:
  http://reviews.llvm.org/D28970

Reviewer:
  Matt

llvm-svn: 292966

2 files changed, 51 insertions, 0 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp b/llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp
index 5de73698323..b78777f391e 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUPromoteAlloca.cpp
@@ -21,6 +21,7 @@
 #include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/Triple.h"
 #include "llvm/ADT/Twine.h"
+#include "llvm/Analysis/CaptureTracking.h"
 #include "llvm/Analysis/ValueTracking.h"
 #include "llvm/IR/Attributes.h"
 #include "llvm/IR/BasicBlock.h"
@@ -608,6 +609,9 @@ bool AMDGPUPromoteAlloca::collectUsesWithPtrTypes(
     }
 
     if (UseInst->getOpcode() == Instruction::AddrSpaceCast) {
+      // Give up if the pointer may be captured.
+      if (PointerMayBeCaptured(UseInst, true, true))
+        return false;
       // Don't collect the users of this.
       WorkList.push_back(User);
       continue;
diff --git a/llvm/test/CodeGen/AMDGPU/addrspacecast-captured.ll b/llvm/test/CodeGen/AMDGPU/addrspacecast-captured.ll
new file mode 100644
index 00000000000..481a3e2b31b
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/addrspacecast-captured.ll
@@ -0,0 +1,47 @@
+; RUN: opt -S -mtriple=amdgcn-unknown-amdhsa -mcpu=kaveri -amdgpu-promote-alloca < %s | FileCheck %s
+
+; Nothing should be done if the addrspacecast is captured.
+
+declare void @consume_ptr2int(i32) #0
+
+; CHECK-LABEL: @addrspacecast_captured(
+; CHECK: %data = alloca i32, align 4
+; CHECK: %cast = addrspacecast i32* %data to i32 addrspace(4)*
+; CHECK: %ptr2int = ptrtoint i32 addrspace(4)* %cast to i32
+; CHECK: store i32 %ptr2int, i32 addrspace(1)* %out
+define void @addrspacecast_captured(i32 addrspace(1)* %out) #0 {
+entry:
+  %data = alloca i32, align 4
+  %cast = addrspacecast i32* %data to i32 addrspace(4)*
+  %ptr2int = ptrtoint i32 addrspace(4)* %cast to i32
+  store i32 %ptr2int, i32 addrspace(1)* %out
+  ret void
+}
+
+; CHECK-LABEL: @addrspacecast_captured_store(
+; CHECK: %data = alloca i32, align 4
+; CHECK: %cast = addrspacecast i32* %data to i32 addrspace(4)*
+; CHECK: store i32 addrspace(4)* %cast, i32 addrspace(4)* addrspace(1)* %out
+define void @addrspacecast_captured_store(i32 addrspace(4)* addrspace(1)* %out) #0 {
+entry:
+  %data = alloca i32, align 4
+  %cast = addrspacecast i32* %data to i32 addrspace(4)*
+  store i32 addrspace(4)* %cast, i32 addrspace(4)* addrspace(1)* %out
+  ret void
+}
+
+; CHECK-LABEL: @addrspacecast_captured_call(
+; CHECK: %data = alloca i32, align 4
+; CHECK: %cast = addrspacecast i32* %data to i32 addrspace(4)*
+; CHECK: %ptr2int = ptrtoint i32 addrspace(4)* %cast to i32
+; CHECK: call void @consume_ptr2int(i32 %ptr2int)
+define void @addrspacecast_captured_call() #0 {
+entry:
+  %data = alloca i32, align 4
+  %cast = addrspacecast i32* %data to i32 addrspace(4)*
+  %ptr2int = ptrtoint i32 addrspace(4)* %cast to i32
+  call void @consume_ptr2int(i32 %ptr2int)
+  ret void
+}
+
+attributes #0 = { nounwind }