[PATCH] [x86] add the -mrecip driver flag and process its options
Sanjay Patel
spatel at rotateright.com
Sat Apr 11 15:24:50 PDT 2015
Hi hfinkel, andreadb, alexr,
This is the front-end counterpart to D8982.
The option parsing implementation is based on maintaining compatibility with gcc; gcc documentation for this flag:
https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/i386-and-x86-64-Options.html#index-mrecip_003dopt-1627
Note that PowerPC could have its own -mrecip options if further compatibility is desired:
https://gcc.gnu.org/onlinedocs/gcc-4.9.2/gcc/RS_002f6000-and-PowerPC-Options.html#index-mrecip-2289
With this flag in place, customers will have fine-grain control over reciprocal estimate codegen, so we may choose to align with gcc's optimization behavior for that. Eg, LLVM could generate reciprocal square root by default when -ffast-math is on. This was requested in PR21385 ( https://llvm.org/bugs/show_bug.cgi?id=21385 ).
http://reviews.llvm.org/D8989
Files:
include/clang/Driver/Options.td
lib/Driver/Tools.cpp
test/Driver/x86_features.c
EMAIL PREFERENCES
http://reviews.llvm.org/settings/panel/emailpreferences/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: D8989.23644.patch
Type: text/x-patch
Size: 6786 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20150411/e53fd073/attachment.bin>
More information about the cfe-commits
mailing list