| commit | b777cd6c4becf0d834f8fa549315fa11918a53be | |
| author | Quentin Carbonneaux <quentin@c9x.me> | |
| Tue, 12 Mar 2019 20:15:21 +0000 (12 21:15 +0100) | ||
| committer | Quentin Carbonneaux <quentin@c9x.me> | |
| Wed, 13 Mar 2019 21:02:29 +0000 (13 22:02 +0100) | ||
| tree | 10e19572ac0f336c5248565323d6a9c71dceeed1 | treesnapshot (tar.gz zip) |
| parent | fd65f4275be6dc6603be9610e88c55b8bfc1dc62 | commitdiff |
simple heuristic to reuse stack slots
On test/spill1.ssa, the stack frame of
the function f() goes from 56 bytes to
40 bytes. That's a reduction of close
to 30%.
This patch also opens the door to
folding operations on spill slots.
For example
movl $15, %r15d
addl -X(%rbp), %r15d
movl %r15d, -X(%rbp)
should become
add $15, -X(%rbp)
when %r15d is not used afterwards.
On test/spill1.ssa, the stack frame of
the function f() goes from 56 bytes to
40 bytes. That's a reduction of close
to 30%.
This patch also opens the door to
folding operations on spill slots.
For example
movl $15, %r15d
addl -X(%rbp), %r15d
movl %r15d, -X(%rbp)
should become
add $15, -X(%rbp)
when %r15d is not used afterwards.
| spill.c | diffblobblamehistory |