[llvm] [SPIRV] Don't emit service function basic block names (PR #184206)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-spir-v

Author: Nick Sarnie (sarnex)

<details>
<summary>Changes</summary>

Right now if a module has a service function we always emit `OpName entry` for the service function's basic block. 

The actual service function isn't emitted and no other instruction uses the basic block `OpName` instruction, so don't emit it.

---
Full diff: https://github.com/llvm/llvm-project/pull/184206.diff


3 Files Affected:

- (modified) llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp (+4) 
- (modified) llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_function_pointers/fun-ptr-service-func.ll (+1-1) 
- (modified) llvm/test/CodeGen/SPIRV/pointers/fun-with-aggregate-arg-in-const-init.ll (+6-3) 


``````````diff
diff --git a/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp b/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp
index 86659c623ebf2..923f59917cb10 100644
--- a/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp
@@ -2668,6 +2668,10 @@ static void addMBBNames(const Module &M, const SPIRVInstrInfo &TII,
     MachineFunction *MF = MMI->getMachineFunction(F);
     if (!MF)
       continue;
+    if (MF->getFunction()
+            .getFnAttribute(SPIRV_BACKEND_SERVICE_FUN_NAME)
+            .isValid())
+      continue;
     MachineRegisterInfo &MRI = MF->getRegInfo();
     for (auto &MBB : *MF) {
       if (!MBB.hasName() || MBB.empty())
diff --git a/llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_function_pointers/fun-ptr-service-func.ll b/llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_function_pointers/fun-ptr-service-func.ll
index 4d02458b7f180..974e72c9ee4c4 100644
--- a/llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_function_pointers/fun-ptr-service-func.ll
+++ b/llvm/test/CodeGen/SPIRV/extensions/SPV_INTEL_function_pointers/fun-ptr-service-func.ll
@@ -1,4 +1,4 @@
-; RUN: llc -verify-machineinstrs -O0 -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_INTEL_function_pointers %s -o - | FileCheck %s
+; RUN: llc -verify-machineinstrs -O0 -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_INTEL_function_pointers %s -o - | FileCheck --implicit-check-not=entry %s
 ; TODO: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown --spirv-ext=+SPV_INTEL_function_pointers %s -o - -filetype=obj | spirv-val %}
 
 declare spir_func i32 @_Z12get_local_idj(i32)
diff --git a/llvm/test/CodeGen/SPIRV/pointers/fun-with-aggregate-arg-in-const-init.ll b/llvm/test/CodeGen/SPIRV/pointers/fun-with-aggregate-arg-in-const-init.ll
index ec3fd41f7de9e..7d30fde76db7f 100644
--- a/llvm/test/CodeGen/SPIRV/pointers/fun-with-aggregate-arg-in-const-init.ll
+++ b/llvm/test/CodeGen/SPIRV/pointers/fun-with-aggregate-arg-in-const-init.ll
@@ -6,6 +6,9 @@
 ; CHECK-DAG: OpExtension "SPV_INTEL_function_pointers"
 ; CHECK-DAG: OpName %[[#fArray:]] "array"
 ; CHECK-DAG: OpName %[[#fStruct:]] "struct"
+; CHECK-DAG: OpName %[[#f0:]] "f0"
+; CHECK-DAG: OpName %[[#f1:]] "f1"
+; CHECK-DAG: OpName %[[#f2:]] "f2"
 
 ; CHECK-DAG: %[[#Int8Ty:]] = OpTypeInt 8 0
 ; CHECK: %[[#GlobalInt8PtrTy:]] = OpTypePointer CrossWorkgroup %[[#Int8Ty]]
@@ -30,9 +33,9 @@
 ; CHECK: %[[#I64Const2:]] = OpConstant %[[#Int64Ty]] 2
 ; CHECK: %[[#I64Const1:]] = OpConstant %[[#Int64Ty]] 1
 ; CHECK: %[[#I64Const0:]] = OpConstantNull %[[#Int64Ty]]
-; CHECK: %[[#f0Pfn:]] = OpConstantFunctionPointerINTEL %[[#IntelFnPtrTy]] %28
-; CHECK: %[[#f1Pfn:]] = OpConstantFunctionPointerINTEL %[[#IntelFnPtrTy]] %32
-; CHECK: %[[#f2Pfn:]] = OpConstantFunctionPointerINTEL %[[#IntelFnPtrTy]] %36
+; CHECK: %[[#f0Pfn:]] = OpConstantFunctionPointerINTEL %[[#IntelFnPtrTy]] %[[#f0]]
+; CHECK: %[[#f1Pfn:]] = OpConstantFunctionPointerINTEL %[[#IntelFnPtrTy]] %[[#f1]]
+; CHECK: %[[#f2Pfn:]] = OpConstantFunctionPointerINTEL %[[#IntelFnPtrTy]] %[[#f2]]
 ; CHECK: %[[#f0Cast:]] = OpSpecConstantOp %[[#FnPtrTy]] Bitcast %[[#f0Pfn]]
 ; CHECK: %[[#f1Cast:]] = OpSpecConstantOp %[[#FnPtrTy]] Bitcast %[[#f1Pfn]]
 ; CHECK: %[[#f2Cast:]] = OpSpecConstantOp %[[#FnPtrTy]] Bitcast %[[#f2Pfn]]

``````````

</details>


https://github.com/llvm/llvm-project/pull/184206