[AMDGPU] Consider loads from flat addrspace to be potentially divergent

In general we can't assume flat loads are uniform, and cases where we can prove
they are should be handled through infer-address-spaces.

Differential Revision: https://reviews.llvm.org/D50991

llvm-svn: 340343

1 files changed, 15 insertions, 0 deletions

diff --git a/llvm/test/Analysis/DivergenceAnalysis/AMDGPU/loads.ll b/llvm/test/Analysis/DivergenceAnalysis/AMDGPU/loads.ll
new file mode 100644
index 00000000000..51be053e9dd
--- /dev/null
+++ b/llvm/test/Analysis/DivergenceAnalysis/AMDGPU/loads.ll
@@ -0,0 +1,15 @@
+; RUN: opt -mtriple=amdgcn-- -analyze -divergence %s | FileCheck %s
+
+; Test that we consider loads from flat and private addrspaces to be divergent.
+
+; CHECK: DIVERGENT: %val = load i32, i32* %flat, align 4
+define amdgpu_kernel void @flat_load(i32* %flat) {
+  %val = load i32, i32* %flat, align 4
+  ret void
+}
+
+; CHECK: DIVERGENT: %val = load i32, i32 addrspace(5)* %priv, align 4
+define amdgpu_kernel void @private_load(i32 addrspace(5)* %priv) {
+  %val = load i32, i32 addrspace(5)* %priv, align 4
+  ret void
+}