make doNotOptimizeAway work with clang
authorMainak Mandal <mmandal@fb.com>
Wed, 26 Aug 2015 17:42:59 +0000 (10:42 -0700)
committerSara Golemon <sgolemon@fb.com>
Mon, 31 Aug 2015 20:24:55 +0000 (13:24 -0700)
commita3c67e006de0e32ecad1bc406ab74ca767e4caee
tree42d3ad8b0f21b79ea4e0e401ae80201be8ab3025
parent148045d0d4ce7145d6fa90f76a132c6bfb1efcb3
make doNotOptimizeAway work with clang

Summary: Projects depending on benchmark library fail to build with clang with the following error
```
./folly/Benchark.h:263:16: error: inline asm not supported yet: don't know how to handle tied indirect register inputs
```

I am not an expert here, just tried to take an approach similar to the MSVC compiler clause

Reviewed By: @andralex, @yfeldblum

Differential Revision: D2368670
folly/Benchmark.h