Incorrect fallthrough when no cpu help is available

[llvmbot]

Bugzilla Link	744
Resolution	WONTFIX
Resolved on	Mar 01, 2008 20:57
Version	1.7
OS	All
Reporter	LLVM Bugzilla Contributor

Extended Description

why does "llc -march=x86 -mcpu=help empty.bc" provide actual help,
"llc -march=c -mcpu=help empty.bc" wants to generate empty.c?
Maybe the latter case should say: "sorry no cpu help avaialable" and exit?

[lattner]

Verified, the C backend doesn't use the normal code generator bits that look at -mcpu and -mattr, so it
just ignore them. It would be nice to fix it so it emitted a useful message.

-Chris

[lattner]

Fixed. Patch here:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20060424/034398.html

[lattner]

Urg, wrong bug. :(

[lattner]

the mcpu and mattr facilities are a feature of the native llvm code generators (libcodegen) and aren't used by other targets like the CBE and MSIL backends. This is like setting unswitch-threshold in opt when not running loop unswitch.

-Chris