[llvm] [AMDGPU] MCExpr-ify MC layer kernel descriptor (PR #80855)

[Pierre van Houtryve via llvm-commits]

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@@ -420,38 +421,43 @@ uint16_t AMDGPUAsmPrinter::getAmdhsaKernelCodeProperties(
   return KernelCodeProperties;
 }
 
-amdhsa::kernel_descriptor_t AMDGPUAsmPrinter::getAmdhsaKernelDescriptor(
-    const MachineFunction &MF,
-    const SIProgramInfo &PI) const {
+MCKernelDescriptor
+AMDGPUAsmPrinter::getAmdhsaKernelDescriptor(const MachineFunction &MF,
+                                            const SIProgramInfo &PI) const {
   const GCNSubtarget &STM = MF.getSubtarget<GCNSubtarget>();
   const Function &F = MF.getFunction();
   const SIMachineFunctionInfo *Info = MF.getInfo<SIMachineFunctionInfo>();
 
-  amdhsa::kernel_descriptor_t KernelDescriptor;
-  memset(&KernelDescriptor, 0x0, sizeof(KernelDescriptor));
+  MCKernelDescriptor KernelDescriptor;
 
   assert(isUInt<32>(PI.ScratchSize));
   assert(isUInt<32>(PI.getComputePGMRSrc1(STM)));
   assert(isUInt<32>(PI.getComputePGMRSrc2()));
 
-  KernelDescriptor.group_segment_fixed_size = PI.LDSSize;
-  KernelDescriptor.private_segment_fixed_size = PI.ScratchSize;
+  KernelDescriptor.group_segment_fixed_size =
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Pierre-vh wrote:

nit: can you create a small lambda to hide the redundancy? Something like `CreateExpr` that'd call `MCConstantExpr` & pass the context for us, so we just need to pass the first arg.

https://github.com/llvm/llvm-project/pull/80855