commit 51892874ba08f3ac0d9b1fcf3893c8516693a88e
author Steven Perron <stevenperron@google.com> Wed May 10 04:03:40 2023 -0400
committer GitHub <noreply@github.com> Wed May 10 10:03:40 2023 +0200
tree 94ffc596d0c81d70aa41379b13050bc9cfe1bdc0
parent e803fe67177cebbce014b69707243361a5d8aefe

Run ADCE when the printf extension is used. (#5215)

This is for
https://github.com/microsoft/DirectXShaderCompiler/issues/5136.

source/opt/aggressive_dead_code_elim_pass.cpp

diff --git a/source/opt/aggressive_dead_code_elim_pass.cpp b/source/opt/aggressive_dead_code_elim_pass.cpp
index 51a6524..1645638 100644
--- a/source/opt/aggressive_dead_code_elim_pass.cpp
+++ b/source/opt/aggressive_dead_code_elim_pass.cpp
@@ -156,7 +156,8 @@
            "Expecting an import of an extension's instruction set.");
     const std::string extension_name = inst.GetInOperand(0).AsString();
     if (spvtools::utils::starts_with(extension_name, "NonSemantic.") &&
-        extension_name != "NonSemantic.Shader.DebugInfo.100") {
+        (extension_name != "NonSemantic.Shader.DebugInfo.100") &&
+        (extension_name != "NonSemantic.DebugPrintf")) {
       return false;
     }
   }

test/opt/aggressive_dead_code_elim_test.cpp

diff --git a/test/opt/aggressive_dead_code_elim_test.cpp b/test/opt/aggressive_dead_code_elim_test.cpp
index 0d94151..83aab3c 100644
--- a/test/opt/aggressive_dead_code_elim_test.cpp
+++ b/test/opt/aggressive_dead_code_elim_test.cpp
@@ -7857,6 +7857,33 @@
   SinglePassRunAndMatch<AggressiveDCEPass>(text, true, false, false);
 }
 
+TEST_F(AggressiveDCETest, RemoveWhenUsingPrintfExtension) {
+  // Remove dead n_out output variable from module
+  const std::string text = R"(
+; CHECK: OpExtInstImport "NonSemantic.DebugPrintf"
+; CHECK-NOT: OpVariable
+               OpCapability Shader
+          %1 = OpExtInstImport "NonSemantic.DebugPrintf"
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %main "main"
+               OpExecutionMode %main LocalSize 8 8 1
+               OpSource HLSL 660
+               OpName %main "main"
+       %uint = OpTypeInt 32 0
+       %void = OpTypeVoid
+          %5 = OpTypeFunction %void
+%_ptr_Function_uint = OpTypePointer Function %uint
+       %main = OpFunction %void None %5
+          %7 = OpLabel
+          %8 = OpVariable %_ptr_Function_uint Function
+               OpReturn
+               OpFunctionEnd
+)";
+
+  SetTargetEnv(SPV_ENV_VULKAN_1_3);
+  SinglePassRunAndMatch<AggressiveDCEPass>(text, true);
+}
+
 }  // namespace
 }  // namespace opt
 }  // namespace spvtools