[IR] Fix mayReadFromMemory() for writeonly calls
Current implementation of Instruction::mayReadFromMemory()
returns !doesNotAccessMemory() which is !ReadNone. This
does not take into account that the writeonly attribute
also indicates that the call does not read from memory.
The patch changes the predicate to !doesNotReadMemory()
that reflects the intended behavior.
Differential Revision: https://reviews.llvm.org/D69086
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375389 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/IR/Instruction.cpp b/lib/IR/Instruction.cpp
index ba5629d..b157c7b 100644
--- a/lib/IR/Instruction.cpp
+++ b/lib/IR/Instruction.cpp
@@ -524,7 +524,7 @@
case Instruction::Call:
case Instruction::Invoke:
case Instruction::CallBr:
- return !cast<CallBase>(this)->doesNotAccessMemory();
+ return !cast<CallBase>(this)->doesNotReadMemory();
case Instruction::Store:
return !cast<StoreInst>(this)->isUnordered();
}
diff --git a/test/CodeGen/AMDGPU/llvm.amdgcn.ds.gws.init.ll b/test/CodeGen/AMDGPU/llvm.amdgcn.ds.gws.init.ll
index a7a8fa7..9c39593 100644
--- a/test/CodeGen/AMDGPU/llvm.amdgcn.ds.gws.init.ll
+++ b/test/CodeGen/AMDGPU/llvm.amdgcn.ds.gws.init.ll
@@ -114,7 +114,7 @@
; LOOP: s_mov_b32 m0, -1
; LOOP: ds_write_b32
define amdgpu_kernel void @gws_init_save_m0_init_constant_offset(i32 %val) #0 {
- store i32 1, i32 addrspace(3)* @lds
+ store volatile i32 1, i32 addrspace(3)* @lds
call void @llvm.amdgcn.ds.gws.init(i32 %val, i32 10)
store i32 2, i32 addrspace(3)* @lds
ret void
diff --git a/test/Transforms/EarlyCSE/writeonly.ll b/test/Transforms/EarlyCSE/writeonly.ll
new file mode 100644
index 0000000..0a3cd1c
--- /dev/null
+++ b/test/Transforms/EarlyCSE/writeonly.ll
@@ -0,0 +1,15 @@
+; RUN: opt -S -early-cse < %s | FileCheck %s
+
+@var = global i32 undef
+declare void @foo() nounwind
+
+define void @test() {
+; CHECK-LABEL: @test(
+; CHECK-NOT: store
+ store i32 1, i32* @var
+; CHECK: call void @foo()
+ call void @foo() writeonly
+; CHECK: store i32 2, i32* @var
+ store i32 2, i32* @var
+ ret void
+}
