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| author | Chris Lattner <sabre@nondot.org> | 2004-07-23 05:26:05 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2004-07-23 05:26:05 +0000 |
| commit | b549420cd01fbf7a594ac24c5445d7238e84e656 (patch) | |
| tree | 590a5892c34172bed7460db25ae1eef384685bb6 /llvm/lib/CodeGen/MachineCodeForInstruction.cpp | |
| parent | 6aa3c83f8d0d68d970ac6c725f3b1a90d8d75821 (diff) | |
| download | bcm5719-llvm-b549420cd01fbf7a594ac24c5445d7238e84e656.tar.gz bcm5719-llvm-b549420cd01fbf7a594ac24c5445d7238e84e656.zip | |
Force coallescing of live ranges that have a single definition, even if they
interfere. Because these intervals have a single definition, and one of them
is a copy instruction, they are always safe to merge even if their lifetimes
interfere. This slightly reduces the amount of spill code, for example on
252.eon, from:
12837 spiller - Number of loads added
7604 spiller - Number of stores added
5842 spiller - Number of register spills
18155 liveintervals - Number of identity moves eliminated after coalescing
to:
12754 spiller - Number of loads added
7585 spiller - Number of stores added
5803 spiller - Number of register spills
18262 liveintervals - Number of identity moves eliminated after coalescing
The much much bigger win would be to merge intervals with multiple definitions
(aka phi nodes) but this is not that day.
llvm-svn: 15124
Diffstat (limited to 'llvm/lib/CodeGen/MachineCodeForInstruction.cpp')
0 files changed, 0 insertions, 0 deletions
