================
@@ -0,0 +1,37 @@
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-compute -emit-llvm -o -
-disable-llvm-passes %s | FileCheck %s
+
+// Verify that no per variable _Init_thread instructions are emitted for
non-trivial static locals
+// These would normally be emitted by the MicrosoftCXXABI, but the DirectX
backend should exlude them
+// Instead, check for the guardvar oparations that should protect the
constructor initialization should
+// only take place once.
+
+RWBuffer<int> buf[10];
+
+void InitBuf(RWBuffer<int> buf) {
+ for (unsigned i; i < 100; i++)
+ buf[i] = 0;
+}
+
+// CHECK-NOT: _Init_thread_epoch
+// CHECK: define internal void @"?main@@YAXXZ"
+// CHECK-NEXT: entry:
+// CHECK-NEXT: [[Tmp1:%.*]] = alloca %"class.hlsl::RWBuffer"
+// CHECK-NEXT: [[Tmp2:%.*]] = load i32, ptr
+// CHECK-NEXT: [[Tmp3:%.*]] = and i32 [[Tmp2]], 1
+// CHECK-NEXT: [[Tmp4:%.*]] = icmp eq i32 [[Tmp3]], 0
+// CHECK-NEXT: br i1 [[Tmp4]]
+// CHECK-NOT: _Init_thread_header
+// CHECK: init:
+// CHECK-NEXT: = or i32 [[Tmp2]], 1
+// CHECK-NOT: _Init_thread_footer
+
+
+[shader("compute")]
+[numthreads(1,1,1)]
+void main() {
+ // A non-trivially initialized static local will get checks to verify that
it is generated just once
+ static RWBuffer<int> mybuf;
+ mybuf = buf[0];
----------------
pow2clk wrote:
That's what I'm expecting and that's fine. RWBuffer has an implicit constructor
that needs the guards. It's little different if I initialized it on the same
line as far as the guard variable protection goes. I'm using "initialization" a
bit more broadly than in the C++ context because that's what the compiler code
uses to refer to the construction execution.
You can see the calls I'm eliminating here in this link:
https://godbolt.org/z/d7djPTWP7
```llvm
tail call void @_Init_thread_header(ptr nonnull @"?$TSS0@?1??main@@YAXXZ@4HA")
#1, !dbg !75
...
br i1 %26, label %27, label %31, !dbg !75
27: ; preds = %24
...
tail call void @_Init_thread_footer(ptr nonnull
@"?$TSS0@?1??main@@YAXXZ@4HA") #1, !dbg !75
```
https://github.com/llvm/llvm-project/pull/106096
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