| commit | b978890b9bd9b8ca196a964956ed2da7c44357ce | |
| author | Guilherme Ottoni <ottoni@fb.com> | |
| Mon, 4 Nov 2013 21:26:28 +0000 (4 13:26 -0800) | ||
| committer | Sara Golemon <sgolemon@fb.com> | |
| Tue, 5 Nov 2013 17:20:46 +0000 (5 09:20 -0800) | ||
| tree | 71953ee47d2609a46b5989c68da720ddda2551e0 | treesnapshot (tar.gz zip) |
| parent | 71201e29337ade6d5f88da62a09c2ac9b2a9dd7e | commitdiff |
Avoid DV initializer loop in prologues for small number of DVs
We were always generating a loop like:
0xd800252: mov eax, 0x1
0xd800257: sub rbx, 0x10
0xd80025b: inc eax
0xd80025d: mov byte ptr [rbx+0x8], 0x0
0xd800261: cmp eax, 0x2
0xd800264: jl 0xd800257
to set the DVs that didn't get a value passed in to Uninit.
This diff unrolls the loop for small number of values to be
initialized.
Reviewed By: @jdelong
Differential Revision: D1041394
We were always generating a loop like:
0xd800252: mov eax, 0x1
0xd800257: sub rbx, 0x10
0xd80025b: inc eax
0xd80025d: mov byte ptr [rbx+0x8], 0x0
0xd800261: cmp eax, 0x2
0xd800264: jl 0xd800257
to set the DVs that didn't get a value passed in to Uninit.
This diff unrolls the loop for small number of values to be
initialized.
Reviewed By: @jdelong
Differential Revision: D1041394
| hphp/runtime/vm/jit/func-prologues-x64.cpp | diffblobblamehistory |