missing implied subtarget features

[sunfishcode]

Bugzilla Link	1530
Resolution	FIXED
Resolved on	Feb 22, 2010 12:50
Version	trunk
OS	All
CC	@isanbard

Extended Description

llc -march=x86-64 -mcpu=opteron

gives this message:

Warning: 64-bit processors all have at least SSE2.

Looking at the code in lib/Target/SubtargetFeature.cpp,
SetImpliedBits isn't called for the base CPU's feature
bits, so even though "opteron" has the 64-bit feature
and 64-bit implies SSE2, -mcpu=opteron doesn't
automatically enable SSE2.

[isanbard]

We weren't setting implied features when looking at the CPU's features.

http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20070625/050818.html

-bw