Support subtarget based predefines

[llvmbot]

Bugzilla Link	3634
Resolution	WORKSFORME
Resolved on	Feb 22, 2010 12:54
Version	unspecified
OS	Windows XP
Reporter	LLVM Bugzilla Contributor
CC	@efriedma-quic

Extended Description

clang should predefine certain macros based on the subtarget settings.

ddunbar@frank:tmp$ echo "SSE3" | gcc -P -E - -msse3

1
ddunbar@frank:tmp$ echo "SSE3" | xcc -P -E - -msse3
xcc: Unknown host 'linux', using generic host information.
SSE3

[lattner]

taking a look at this.

[lattner]

This is basically done, but needs driver work before it can be turned on:
http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20090302/013369.html

[efriedma-quic]

Seems to work now; I'm not sure when it got fixed.