diff options
author | Arlie Davis <[email protected]> | 2015-09-17 15:19:24 -0700 |
---|---|---|
committer | Andreas Boll <[email protected]> | 2016-01-21 15:03:53 +0100 |
commit | daa775b58e6dcc800dd611678b32cb1c5184f5b0 (patch) | |
tree | 7be0b3e9aa6a19610f5239db9ec82e609e431bab /doxygen | |
parent | daa0fd7843dfc3f2f209a1b755df01f4dbc8122f (diff) |
mesa: Reduce libGL.so binary size by about 15%
This patch significantly reduces the size of the libGL.so binary. It does
not change the (externally visible) behavior of libGL.so at all.
gl_gentable.py generates a function, _glapi_create_table_from_handle.
This function allocates a large dispatch table, consisting of 1300 or so
function pointers, and fills this dispatch table by doing symbol lookups
on a given shared library. Previously, gl_gentable.py would generate a
single, very large _glapi_create_table_from_handle function, with a short
cluster of lines for each entry point (function). The idiom it generates
was a NULL check, a call to snprintf, a call to dlsym / GetProcAddress,
and then a store into the dispatch table. Since this function processes
a large number of entry points, this code is duplicated many times over.
We can encode the same information much more compactly, by using a lookup
table. The previous total size of _glapi_create_table_from_handle on x64
was 125848 bytes. By using a lookup table, the size of
_glapi_create_table_from_handle (and the related lookup tables) is reduced
to 10840 bytes. In other words, this enormous function is reduced by 91%.
The size of the entire libGL.so binary (measured when stripped) itself drops
by 15%.
So the purpose of this change is to reduce the binary size, which frees up
disk space, memory, etc.
size lib/libGL.so.1.2.0 on my system shows (Andreas)
text data bss dec hex filename
565947 11256 2720 579923 8d953 lib/libGL.so.1.2.0 before
469211 21848 2720 493779 788d3 lib/libGL.so.1.2.0 after
v2: Incorporate Matt's feedback.
Reviewed-by: Ian Romanick <[email protected]>
Reviewed-by: Jeremy Huddleston Sequoia <[email protected]>
Tested-by: Jeremy Huddleston Sequoia <[email protected]>
Signed-off-by: Andreas Boll <[email protected]>
Diffstat (limited to 'doxygen')
0 files changed, 0 insertions, 0 deletions