[llvm] [SPIR-V] Add support for inline SPIR-V types (PR #125316)

[Cassandra Beckley via llvm-commits]

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@@ -2868,6 +2868,61 @@ static SPIRVType *getSampledImageType(const TargetExtType *OpaqueType,
   return GR->getOrCreateOpTypeSampledImage(OpaqueImageType, MIRBuilder);
 }
 
+static SPIRVType *getInlineSpirvType(const TargetExtType *ExtensionType,
+                                     MachineIRBuilder &MIRBuilder,
+                                     SPIRVGlobalRegistry *GR) {
+  assert(ExtensionType->getNumIntParameters() == 3 &&
+         "Inline SPIR-V type builtin takes an opcode, size, and alignment "
+         "parameter");
+  auto Opcode = ExtensionType->getIntParameter(0);
+
+  return GR->getOrCreateUnknownType(
+      ExtensionType, MIRBuilder, Opcode,
+      [&ExtensionType, &GR, &MIRBuilder](llvm::MachineInstrBuilder Instr) {
----------------
cassiebeckley wrote:

The reason is that not all the arguments are registers. `spirv.IntegralConstant` and passing in a normal type are lowered to register uses, but `spirv.Literal` is lowered as an immediate integer. I wasn't sure the best way to represent this – a tagged union like Rust's enum types would work well, but that doesn't seem to be as common a pattern in LLVM.

https://github.com/llvm/llvm-project/pull/125316