[llvm] [DirectX] Propagate shader flags mask of callees to callers (PR #118306)

[S. Bharadwaj Yadavalli via llvm-commits]

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@@ -61,6 +66,21 @@ void ModuleShaderFlags::initialize(const Module &M) {
     CombinedSFMask.merge(CSF);
   }
   llvm::sort(FunctionFlags);
+  // Propagate shader flag mask of functions to their callers.
+  while (!WorkList.empty()) {
+    const Function *Func = WorkList.pop_back_val();
+    if (!Func->user_empty()) {
+      const ComputedShaderFlags &FuncSF = getFunctionFlags(Func);
+      // Update mask of callers with that of Func
+      for (const auto User : Func->users()) {
+        if (const CallInst *CI = dyn_cast<CallInst>(User)) {
+          const Function *Caller = CI->getParent()->getParent();
+          if (mergeFunctionShaderFlags(Caller, FuncSF))
+            WorkList.push_back(Caller);
+        }
+      }
+    }
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bharadwajy wrote:

Changed per suggested LLVM coding style.

https://github.com/llvm/llvm-project/pull/118306