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author | Evan Cheng <evan.cheng@apple.com> | 2007-02-08 06:04:54 +0000 |
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committer | Evan Cheng <evan.cheng@apple.com> | 2007-02-08 06:04:54 +0000 |
commit | f50d09ad21dbb16e35460d63d23d331a2cac7a91 (patch) | |
tree | f1e80bbc2db213e6ed32bd1c0c9b29af9bbaca1c /docs/CommandGuide/llvm-link.pod | |
parent | f596a97287dc7c00486089162796dd66b627dadf (diff) |
Fixed a long standing spiller bug that's exposed by Thumb:
The code sequence before the spiller is something like:
= tMOVrr
%reg1117 = tMOVrr
%reg1078 = tLSLri %reg1117, 2
The it starts spilling:
%r0 = tRestore <fi#5>, 0
%r1 = tRestore <fi#7>, 0
%r1 = tMOVrr %r1<kill>
tSpill %r1, <fi#5>, 0
%reg1078 = tLSLri %reg1117, 2
It restores the value while processing the first tMOVrr. At this point, the
spiller remembers fi#5 is available in %r0. Next it processes the second move.
It restores the source before the move and spills the result afterwards. The
move becomes a noop and is deleted. However, a spill has been inserted and that
should invalidate reuse of %r0 for fi#5 and add reuse of %r1 for fi#5.
Therefore, %reg1117 (which is also assigned fi#5) should get %r1, not %r0.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@34039 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs/CommandGuide/llvm-link.pod')
0 files changed, 0 insertions, 0 deletions