Enable the __builtin_ia32_crc* acceleration functions for gcc-4.7
authorBrian Pane <brianp@fb.com>
Sat, 18 Jan 2014 01:09:01 +0000 (17:09 -0800)
committerJordan DeLong <jdelong@fb.com>
Sun, 19 Jan 2014 01:40:04 +0000 (17:40 -0800)
commit18bedc2337227ea846e2269dc166dbcee686a111
tree63a5ac73ca640fe9ab57ae1011ea37e70cf034ca
parent5cbaa0fd22adcaf860c6237f90c43e92bd3e6679
Enable the __builtin_ia32_crc* acceleration functions for gcc-4.7

Summary:
Adjusted the ifdefs to allow the use of the hardware CRC instructions
when compiling with gcc-4.7.x

Test Plan:
Built with gcc-4.7.1, ran the unit tests, verified that they ran the
hardware-accelerated code path

Reviewed By: saramg@fb.com

FB internal diff: D1134567
folly/Checksum.cpp