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author | Chad Rosier <mcrosier@apple.com> | 2011-11-17 07:15:58 +0000 |
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committer | Chad Rosier <mcrosier@apple.com> | 2011-11-17 07:15:58 +0000 |
commit | 478b06c9801f0b75c5216ce0886ac3d630d4fc7b (patch) | |
tree | 54fa90701be13d4ab0be4cfb05352cfec4de49be /lib/CodeGen/StackSlotColoring.cpp | |
parent | ec43d1f553cb440df1b435d3798063d0cba6a117 (diff) |
When fast iseling a GEP, accumulate the offset rather than emitting a series of
ADDs. MaxOffs is used as a threshold to limit the size of the offset. Tradeoffs
being: (1) If we can't materialize the large constant then we'll cause fast-isel
to bail. (2) Too large of an offset can't be directly encoded in the ADD
resulting in a MOV+ADD. Generally not a bad thing because otherwise we would
have had ADD+ADD, but on Thumb this turns into a MOVS+MOVT+ADD. Working on a fix
for that. (3) Conversely, too low of a threshold we'll miss opportunities to
coalesce ADDs.
rdar://10412592
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144886 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/StackSlotColoring.cpp')
0 files changed, 0 insertions, 0 deletions