[clang] [llvm] [DirectX] Set Shader Flag DisableOptimizations (PR #126813)

[S. Bharadwaj Yadavalli via cfe-commits]

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@@ -212,20 +230,24 @@ PreservedAnalyses ShaderFlagsAnalysisPrinter::run(Module &M,
 bool ShaderFlagsAnalysisWrapper::runOnModule(Module &M) {
   DXILResourceTypeMap &DRTM =
       getAnalysis<DXILResourceTypeWrapperPass>().getResourceTypeMap();
+  const ModuleMetadataInfo MMDI =
+      getAnalysis<DXILMetadataAnalysisWrapperPass>().getModuleMetadata();
 
-  MSFI.initialize(M, DRTM);
+  MSFI.initialize(M, DRTM, MMDI);
   return false;
 }
 
 void ShaderFlagsAnalysisWrapper::getAnalysisUsage(AnalysisUsage &AU) const {
   AU.setPreservesAll();
   AU.addRequiredTransitive<DXILResourceTypeWrapperPass>();
+  AU.addRequired<DXILMetadataAnalysisWrapperPass>();
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bharadwajy wrote:

> This change causes DXIL Module Metadata analysis pass to run before DXIL Shader Flag Analysis because it is now needed `MMDI.EntryPropertyVec[0].Entry->hasFnAttribute( llvm::Attribute::OptimizeNone);` to initialize ModuleShaderFlags.
> 
> I think before we never intended to fetch fn attributes since you were using `dx.disable_optimizations`. 

Yes, that was the proposed mechanism in PR #126813. This PR supersedes that following the feedback there.

> Does that make optnone a one off here or are there other attributes that could use this pattern?

The list of entry function information collected by Metadata Analysis pass is leveraged in this pass to look at `optnone` of each of the entry functions. Similarly it can be leveraged by other passes that require access to entry function information - for example, a pass that would want to query for entry function declaration with`HLSLWaveSizeAttr`.

Entry functions can be collected during the call graph traversal in this pass to query for `optnone` attribute. I just chose to leverage the same info that would be built in Metadata Analysis pass.

https://github.com/llvm/llvm-project/pull/126813