[llvm] [SPIR-V] Add Fragment execution model (PR #141787)

[Nathan Gauër via llvm-commits]

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@@ -439,10 +441,21 @@ bool SPIRVCallLowering::lowerFormalArguments(MachineIRBuilder &MIRBuilder,
 
   // Handle entry points and function linkage.
   if (isEntryPoint(F)) {
+    SPIRV::ExecutionModel::ExecutionModel ExecutionModel =
+        getExecutionModel(*ST, F);
     auto MIB = MIRBuilder.buildInstr(SPIRV::OpEntryPoint)
-                   .addImm(static_cast<uint32_t>(getExecutionModel(*ST, F)))
+                   .addImm(static_cast<uint32_t>(ExecutionModel))
                    .addUse(FuncVReg);
     addStringImm(F.getName(), MIB);
+
+    if (ExecutionModel == SPIRV::ExecutionModel::Fragment) {
+      // SPIR-V common validation: Fragment requires OriginUpperLeft or
+      // OriginLowerLeft VUID-StandaloneSpirv-OriginLowerLeft-04653: Fragment
+      // must declare OriginUpperLeft.
+      MIRBuilder.buildInstr(SPIRV::OpExecutionMode)
+          .addUse(FuncVReg)
+          .addImm(static_cast<uint32_t>(SPIRV::ExecutionMode::OriginUpperLeft));
+    }
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Keenuts wrote:

Sure!

https://github.com/llvm/llvm-project/pull/141787