[llvm] [SPIR-V] Allow intrinsics with aggregate return type to reach GlobalISel (PR #108893)

[Michal Paszkowski via llvm-commits]

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@@ -462,6 +468,25 @@ generateAssignInstrs(MachineFunction &MF, SPIRVGlobalRegistry *GR,
             Def->getOpcode() != SPIRV::ASSIGN_TYPE)
           insertAssignInstr(Reg, Ty, nullptr, GR, MIB, MF.getRegInfo());
         ToErase.push_back(&MI);
+      } else if (MIOp == TargetOpcode::FAKE_USE && MI.getNumOperands() > 0) {
+        MachineInstr *MdMI = MI.getPrevNode();
+        if (MdMI && isSpvIntrinsic(*MdMI, Intrinsic::spv_value_md)) {
+          // It's an internal service info from before IRTranslator passes.
+          MachineInstr *Def = getVRegDef(MRI, MI.getOperand(0).getReg());
+          for (unsigned I = 1, E = MI.getNumOperands(); I != E && Def; ++I)
+            if (getVRegDef(MRI, MI.getOperand(I).getReg()) != Def)
+              Def = nullptr;
+          if (Def) {
+            const MDNode *MD = MdMI->getOperand(1).getMetadata();
+            StringRef ValueName =
+                cast<MDString>(MD->getOperand(1))->getString();
+            const MDNode *TypeMD = cast<MDNode>(MD->getOperand(0));
+            Type *ValueTy = getMDOperandAsType(TypeMD, 0);
+            GR->addValueAttrs(Def, std::make_pair(ValueTy, ValueName));
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michalpaszkowski wrote:

I wonder, should `ValueAttrs` store `std:string` instead of `StringRef`? I am not sure what is the lifetime of the ValueName, especially after the instruction is erased. I want to avoid mysterious errors :)

https://github.com/llvm/llvm-project/pull/108893