Summary:
The PC_32 DWARF register is for a 32-bit process address space which we
don't implement in AMDGCN; another way of putting this is that the size
of the PC register is not a function of the wavefront size. If we ever
implement a 32-bit process address space we will need to add two more
DwarfFlavours i.e. we will need to represent the product of (wave32,
wave64) x (64-bit address space, 32-bit address space).
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D76732
FAILED: unittests/Target/AMDGPU/AMDGPUTests
...
ld.lld: error: undefined symbol: llvm::MCRegisterInfo::getLLVMRegNum(unsigned int, bool) const
>>> referenced by DwarfRegMappings.cpp:60 (/usr/local/google/home/maskray/llvm/llvm/unittests/Target/AMDGPU/DwarfRegMappings.cpp:60)
>>> unittests/Target/AMDGPU/CMakeFiles/AMDGPUTests.dir/DwarfRegMappings.cpp.o:(AMDGPUDwarfRegMappingTests_TestWave64DwarfRegMapping_Test::TestBody())
>>> referenced by DwarfRegMappings.cpp:82 (/usr/local/google/home/maskray/llvm/llvm/unittests/Target/AMDGPU/DwarfRegMappings.cpp:82)
>>> unittests/Target/AMDGPU/CMakeFiles/AMDGPUTests.dir/DwarfRegMappings.cpp.o:(AMDGPUDwarfRegMappingTests_TestWave32DwarfRegMapping_Test::TestBody())
A -DBUILD_SHARED_LIBS=off build is good because AMDGPUCodeGen pulls in MC.
A -DBUILD_SHARED_LIBS=on build requires all direct dependencies (MC) to be listed becuase llvm/cmake/modules/HandleLLVMOptions.cmake uses -Wl,-z,defs
Implement the DWARF register mapping described in llvm/docs/AMDGPUUsage.rst.
This enables generating appropriate DWARF register numbers for wave64 and
wave32 modes.
