[SPIR-V] SPIR-V back-end is generating duplicate IDs

[gfxstrand]

We're trying to switch the Mesa OpenCL infra over to using the SPIR-V back-end in LLVM and a bunch of OpenCL CTS tests are failing to validate with:

(file=input,line=0,column=0,index=494): Id 46 is defined more than once

[karolherbst]

Okay, I've tracked this one down. It is caused by this static: https://github.com/llvm/llvm-project/blob/main/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.h#L225

The ModuleAnalysisInfo class contains a BBNumToRegMap map that gets reused between translation units. So if the pointer of the parent accidentally ends up the same address as one from a different translation unit, this will return an id allocated in a different translation unit.

We do compilations in parallel, but each is using a different clang invocation.

[karolherbst]

From 1581b469cfa79778487233aca160d7d64cdc21b7 Mon Sep 17 00:00:00 2001
From: Karol Herbst <kherbst@redhat.com>
Date: Sat, 27 Sep 2025 00:00:50 +0200
Subject: [PATCH] fix?

---
 llvm/lib/Target/SPIRV/SPIRVAsmPrinter.cpp     | 2 +-
 llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp | 2 +-
 llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.h   | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/Target/SPIRV/SPIRVAsmPrinter.cpp b/llvm/lib/Target/SPIRV/SPIRVAsmPrinter.cpp
index c2a6e51913a0..c0fb217e8006 100644
--- a/llvm/lib/Target/SPIRV/SPIRVAsmPrinter.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVAsmPrinter.cpp
@@ -611,7 +611,7 @@ void SPIRVAsmPrinter::outputModuleSections() {
   // Get the global subtarget to output module-level info.
   ST = static_cast<const SPIRVTargetMachine &>(TM).getSubtargetImpl();
   TII = ST->getInstrInfo();
-  MAI = &SPIRVModuleAnalysis::MAI;
+  MAI = &getAnalysis<SPIRVModuleAnalysis>().MAI;
   assert(ST && TII && MAI && M && "Module analysis is required");
   // Output instructions according to the Logical Layout of a Module:
   // 1,2. All OpCapability instructions, then optional OpExtension instructions.
diff --git a/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp b/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp
index a95f393b7560..1c7ad5ba2175 100644
--- a/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.cpp
@@ -2126,7 +2126,7 @@ static void patchPhis(const Module &M, SPIRVGlobalRegistry *GR,
   }
 }
 
-struct SPIRV::ModuleAnalysisInfo SPIRVModuleAnalysis::MAI;
+// struct SPIRV::ModuleAnalysisInfo SPIRVModuleAnalysis::MAI;
 
 void SPIRVModuleAnalysis::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.addRequired<TargetPassConfig>();
diff --git a/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.h b/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.h
index 41c792a98534..4e9ca064b8d3 100644
--- a/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.h
+++ b/llvm/lib/Target/SPIRV/SPIRVModuleAnalysis.h
@@ -222,7 +222,7 @@ public:
 
   bool runOnModule(Module &M) override;
   void getAnalysisUsage(AnalysisUsage &AU) const override;
-  static struct SPIRV::ModuleAnalysisInfo MAI;
+  struct SPIRV::ModuleAnalysisInfo MAI;
 
 private:
   void setBaseInfo(const Module &M);
-- 
2.51.0

seems to do the trick