crtfastmath.o contains routines to set the floating point flags to a faster,
unsafe mode. Linking it in speeds up code dealing with denormals significantly
(PR14024).
For now this is only enabled on linux where I can test it and crtfastmath.o is
widely available. We may want to provide a similar file with compiler-rt
eventually and/or enable it on other platforms too.
llvm-svn: 165240
This requires fixing a latent bug -- if we used the default host triple
instead of an autodetected triple to locate GCC's installation, we
didn't go back and fix the GCC triple. Correct that with a pile of
hacks. This entire routine needs a major refactoring which I'm saving
for a subsequent commit. Essentially, the detection of the GCC triple
should be hoisted into the same routine as we locate the GCC
installation: the first is intrinsically tied to the latter. Then the
routine will just return the triple and base directory.
Also start to bring the rest of the library search path logic under
test, including locating crtbegin.o. Still need to test the multilib and
other behaviors, but there are also bugs in the way of that.
llvm-svn: 140995
This is still very much a WIP, but sysroot was completely broken before
this so we are moving closer to correctness.
The crux of this is that 'ld' (on Linux, the only place I'm touching
here) doesn't apply the sysroot to any flags given to it. Instead, the
driver must translate all the paths it adds to the link step with the
system root. This is easily observed by building a GCC that supports
sysroot, and checking its driver output.
This patch just fixes the non-multilib library search paths. We should
also use this in many other places, but first things first.
This also allows us to make the Linux 'ld' test independent of the host
system. This in turn will allow me to check in test tree configurations
based on various different distro's configuration. Again, WIP.
llvm-svn: 140990
Chandler Carruth