[clang] [clang][NFCI] Use TargetInfo to determine device kernel calling convention (PR #144728)

[Nick Sarnie via cfe-commits]

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@@ -103,11 +103,11 @@ TargetCodeGenInfo::getDependentLibraryOption(llvm::StringRef Lib,
   Opt += Lib;
 }
 
-unsigned TargetCodeGenInfo::getOpenCLKernelCallingConv() const {
-  // OpenCL kernels are called via an explicit runtime API with arguments
-  // set with clSetKernelArg(), not as normal sub-functions.
+unsigned TargetCodeGenInfo::getDeviceKernelCallingConv() const {
+  // Device kernels are called via an explicit runtime API with arguments,
+  // such as set with clSetKernelArg() for OpenCL, not as normal sub-functions.
   // Return SPIR_KERNEL by default as the kernel calling convention to
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sarnex wrote:

> do we override `getDeviceKernelCallingConv` for SPIR-V target or use the default?

`SPIRVABIInfo`'s base class is `CommonSPIRTargetCodeGenInfo` and `CommonSPIRTargetCodeGenInfo` has the override, so I think it's fine.

> there is a functional change to the logic of lowering CC_DeviceKernel

Thanks, I'll remove `NFCI` to be safe.

> We can be stricter to getDeviceKernelCallingConv users and put something like llvm_unreachable("Unknown kernel calling convention"); in the base class definition

I'll try this and do it if nothing expodes




https://github.com/llvm/llvm-project/pull/144728