ACC registers are a combination of four consecutive vector registers.
If the vector registers are assigned first this often forces a number
of copies to appear just before the ACC register is created. If the ACC
register is assigned first then fewer copies are generated when the vector
registers are assigned.
This patch tries to force the register allocator to assign the ACC registers first
and then the UACC registers and then the vector pair registers. It does this
by changing the priority of the register classes.
This patch also adds hints to help the register allocator assign UACC registers from
known ACC registers and vector pair registers from known UACC registers.
Reviewed By: nemanjai
Differential Revision: https://reviews.llvm.org/D105854
This patch includes the following updates to the load/store refactoring effort introduced in D93370:
- Update various VSX patterns that use to "force" an XForm, to instead just XForm.
This allows the ability for the patterns to compute the most optimal addressing
mode (and to produce a DForm instruction when possible)
- Update pattern and test case for the LXVD2X/STXVD2X intrinsics
- Update LIT test cases that use to use the XForm instruction to use the DForm instruction
Differential Revision: https://reviews.llvm.org/D95115
On PowerPC, VSRpRC represents the pairs of even and odd VSX register,
and VRRC corresponds to higher 32 VSX registers. In some cases, extra
copies are produced when handling incoming VRRC arguments with VSRpRC.
This patch changes allocation order of VSRpRC to eliminate this kind of
copy.
Stack frame sizes may increase if allocating non-volatile registers, and
some other vector copies happen. They need fix in future changes.
Reviewed By: nemanjai
Differential Revision: https://reviews.llvm.org/D104855
Relaxing superclass constraint for VSX register classes helps reducing
32-byte spills and copies when register pressure is high.
In test case affected, some of them introduces more copies due to new
allocation order. However, this patch should not be the root cause, and
we may be able to fix it in other places of register allocation.
Reviewed By: nemanjai
Differential Revision: https://reviews.llvm.org/D104006
On PPC, the vector pair instructions are independent from MMA.
This patch renames the vector pair LLVM intrinsics and Clang builtins to replace the _mma_ prefix by _vsx_ in their names.
We also move the vector pair type/intrinsic/builtin tests to their own files.
Differential Revision: https://reviews.llvm.org/D91974
Stefan Pintilie