implementation of the function is equivalent, so no need to provide
the target-specific version until/unless it needs to do something.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110465 91177308-0d34-0410-b5e6-96231b3b80d8
This is the beginning of purely symbolic subregister indices, but we need a bit
of jiggling before the explicit numeric indices can be completely removed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104492 91177308-0d34-0410-b5e6-96231b3b80d8
is preparatory to having PEI's scavenged frame index value reuse logic
properly distinguish types of frame values (e.g., whether the value is
stack-pointer relative or frame-pointer relative).
No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98086 91177308-0d34-0410-b5e6-96231b3b80d8
a virtual register to eliminate a frame index, it can return that register
and the constant stored there to PEI to track. When scavenging to allocate
for those registers, PEI then tracks the last-used register and value, and
if it is still available and matches the value for the next index, reuses
the existing value rather and removes the re-materialization instructions.
Fancier tracking and adjustment of scavenger allocations to keep more
values live for longer is possible, but not yet implemented and would likely
be better done via a different, less special-purpose, approach to the
problem.
eliminateFrameIndex() is modified so the target implementations can return
the registers they wish to be tracked for reuse.
ARM Thumb1 implements and utilizes the new mechanism. All other targets are
simply modified to adjust for the changed eliminateFrameIndex() prototype.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83467 91177308-0d34-0410-b5e6-96231b3b80d8
default implementation. Update comment on the default version, which made it
sound like most targets override it. Currently only X86 and SystemZ override
this method.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82651 91177308-0d34-0410-b5e6-96231b3b80d8
