[llvm] [SPIR-V] Add OpSMulExtended and OpUMulExtended builtin support (PR #187474)

[via llvm-commits]

================
@@ -1996,6 +1996,54 @@ static bool generateICarryBorrowInst(const SPIRV::IncomingCall *Call,
   return true;
 }
 
+// We expect a builtin
+//     Name(ptr sret([RetType]) %result, Type %operand1, Type %operand2)
+// where %result is a pointer to where the result of the builtin execution
+// is to be stored, and generate the following instructions:
+//     Res = Opcode RetType Operand1 Operand2
+//     OpStore RetVariable Res
+static bool generateMulExtendedInst(const SPIRV::IncomingCall *Call,
+                                    MachineIRBuilder &MIRBuilder,
+                                    SPIRVGlobalRegistry *GR) {
+  const SPIRV::DemangledBuiltin *Builtin = Call->Builtin;
+  unsigned Opcode =
+      SPIRV::lookupNativeBuiltin(Builtin->Name, Builtin->Set)->Opcode;
+  assert((Opcode == SPIRV::OpUMulExtended || Opcode == SPIRV::OpSMulExtended) &&
+         "Expected OpUMulExtended or OpSMulExtended");
+
+  Register SRetReg = Call->Arguments[0];
+  SPIRVTypeInst PtrRetType = GR->getSPIRVTypeForVReg(SRetReg);
+  SPIRVTypeInst RetType = GR->getPointeeType(PtrRetType);
+  if (!RetType)
+    report_fatal_error("The first parameter must be a pointer");
+  if (RetType->getOpcode() != SPIRV::OpTypeStruct)
+    report_fatal_error("Expected struct type result for the extended "
+                       "multiplication builtins");
+
+  SPIRVTypeInst OpType1 = GR->getSPIRVTypeForVReg(Call->Arguments[1]);
+  SPIRVTypeInst OpType2 = GR->getSPIRVTypeForVReg(Call->Arguments[2]);
+  if (!OpType1 || !OpType2 || OpType1 != OpType2)
+    report_fatal_error("Operands must have the same type");
----------------
idubinov wrote:

And also, the same type as both members of return structure

https://github.com/llvm/llvm-project/pull/187474