Commit Graph

8 Commits

Author SHA1 Message Date
Jim Grosbach
b58f498f75 Add register-reuse to frame-index register scavenging. When a target uses
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
2009-10-07 17:12:56 +00:00
Anton Korobeynikov
5a11e02fbd Fix fallout from 12-bit stuff landing: decide whether 20 bit displacements are needed during elimination of frame indexes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75989 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-16 14:09:56 +00:00
Anton Korobeynikov
078e007c07 We already have reserved call frame regardless whether variable sized frame objects were present or not
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75987 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-16 14:09:04 +00:00
Anton Korobeynikov
ed00212f43 Implement asmprinting for odd-even regpairs
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75974 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-16 14:04:01 +00:00
Anton Korobeynikov
ef5decab53 Emit callee-saved regs spills / restores
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75943 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-16 13:51:12 +00:00
Anton Korobeynikov
ba249e41f3 Some preliminary call lowering
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75941 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-16 13:50:21 +00:00
Anton Korobeynikov
51f613fb2b Add simple frame index elimination
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75939 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-16 13:49:25 +00:00
Anton Korobeynikov
4403b930f8 Let's start another backend :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75909 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-16 13:27:25 +00:00