1. The PR proceeds with a backend target hook to allow front-ends to
determine what target features are available in a compilation based on
the CPU name.
2. Fix a backend target feature bug that supports HTM for
Power8/9/10/11. However, HTM is only supported on Power8/9 according to
the ISA.
3. All target features that are hardcoded in PPC.cpp can be retrieved
from the backend target feature. I have double-checked that the
hardcoded logic for inferring target features from the CPU in the
frontend(PPC.cpp) is the same as in PPC.td.
The reland patch addressed the comment
https://github.com/llvm/llvm-project/pull/137670#discussion_r2143541120
This reverts commit 9208b343e962b9f1140ee345c0050a3920bdcbf2.
TargetParser shouldn't re-run the PPC subtarget tablegen target, it
should define its own `-gen-ppc-target-def` rule like all the other
targets do in llvm/include/llvm/TargetParser/CMakeLists.txt .
One user reported that there are incorrect CMake dependencies after this
change, so I will roll this back in the meantime.
1. The PR proceeds with a backend target hook to allow front-ends to
determine what target features are available in a compilation based on
the CPU name.
2. Fix a backend target feature bug that supports HTM for
Power8/9/10/11. However, HTM is only supported on Power8/9 according to
the ISA.
3. All target features that are hardcoded in PPC.cpp can be retrieved
from the backend target feature. I have double-checked that the
hardcoded logic for inferring target features from the CPU in the
frontend(PPC.cpp) is the same as in PPC.td.
This patch turns on support for CR bit accesses for Power8 and above. The reason
why CR bits are turned on as the default for Power8 and above is that because
later architectures make use of builtins and instructions that require CR bit
accesses (such as the use of setbc in the vector string isolate predicate
and bcd builtins on Power10).
This patch also adds the clang portion to allow for turning on CR bits in the
front end if the user so desires to.
Differential Revision: https://reviews.llvm.org/D124060
