This simplifies many of the target description files since it is common
for register classes to be related or contain sequences of numbered
registers.
I have verified that this doesn't change the files generated by TableGen
for ARM and X86. It alters the allocation order of MBlaze GPR and Mips
FGR32 registers, but I believe the change is benign.
llvm-svn: 133105
The register allocators automatically filter out reserved registers and
place the callee saved registers last in the allocation order, so custom
methods are no longer necessary just for that.
Some targets still use custom allocation orders:
ARM/Thumb: The high registers are removed from GPR in thumb mode. The
NEON allocation orders prefer to use non-VFP2 registers first.
X86: The GR8 classes omit AH-DH in x86-64 mode to avoid REX trouble.
SystemZ: Some of the allocation orders are omitting R12 aliases without
explanation. I don't understand this target well enough to fix that. It
looks like all the boilerplate could be removed by reserving the right
registers.
llvm-svn: 132781
A Register with subregisters must also provide SubRegIndices for adressing the
subregisters. TableGen automatically inherits indices for sub-subregisters to
minimize typing.
CompositeIndices may be specified for the weirder cases such as the XMM sub_sd
index that returns the same register, and ARM NEON Q registers where both D
subregs have ssub_0 and ssub_1 sub-subregs.
It is now required that all subregisters are named by an index, and a future
patch will also require inherited subregisters to be named. This is necessary to
allow composite subregister indices to be reduced to a single index.
llvm-svn: 104704
A Register with subregisters must also provide SubRegIndices for adressing the
subregisters. TableGen automatically inherits indices for sub-subregisters to
minimize typing.
CompositeIndices may be specified for the weirder cases such as the XMM sub_sd
index that returns the same register, and ARM NEON Q registers where both D
subregs have ssub_0 and ssub_1 sub-subregs.
It is now required that all subregisters are named by an index, and a future
patch will also require inherited subregisters to be named. This is necessary to
allow composite subregister indices to be reduced to a single index.
llvm-svn: 104654
structure that represents a mapping without any dependencies on SubRegIndex
numbering.
This brings us closer to being able to remove the explicit SubRegIndex
numbering, and it is now possible to specify any mapping without inventing
*_INVALID register classes.
llvm-svn: 104563
