[PATCH] D159439: [AMDGPU] Add utilities to track number of user SGPRs. NFC.

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: llvm/lib/Target/AMDGPU/GCNSubtarget.h:1412
+  // Returns the size in number of SGPRs for preload user SGPR field.
+  static constexpr unsigned getNumUserSGPRForField(UserSGPRID ID) {
+    switch (ID) {
----------------
gcc 8.5.0 doesn't like this being constexpr due to the call to unreachable. I'm getting an error like

```
llvm/lib/Target/AMDGPU/GCNSubtarget.h: In static member function ‘static constexpr unsigned int llvm::GCNUserSGPRUsageInfo::getNumUserSGPRForField(llvm::GCNUserSGPRUsageInfo::UserSGPRID)’:
llvm/include/llvm/Support/ErrorHandling.h:144:36: error: call to non-‘constexpr’ function ‘void llvm::llvm_unreachable_internal(const char*, const char*, unsigned int)’
   ::llvm::llvm_unreachable_internal(msg, __FILE__, __LINE__)
   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
llvm/lib/Target/AMDGPU/GCNSubtarget.h:1431: note: in expansion of macro  llvm_unreachable’
     llvm_unreachable("Unknown UserSGPRID.");
```


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D159439/new/

https://reviews.llvm.org/D159439