[PATCHv2, MIPS] Add support for O32 FPXX and program header based ABI information

[Joseph S. Myers]

On Fri, 16 May 2014, Matthew Fortune wrote:

> I don't understand the use-case that would want a whole module (and/or
> subset of modules within one library) to freely deploy an ISA extension
> but have no overall marking to that extent. Such global enablement must be

It's the most basic, obvious, longstanding way of using an ISA feature 
conditionally: compile different source files with different options and 
then use "if" conditionals to choose between them.  Support things like 
IFUNCs and "target" attributes as well, sure, but first support the most 
basic form that does not require any special language features at all.

For building source files with different options, in the IFUNC case, see 
for example sysdeps/x86_64/fpu/multiarch/Makefile.

Design options to support that sort of basic usage before getting into 
anything more complicated such as (optional) Solaris-style checks of 
hardware support (which, as can be seen from recent gcc-patches 
discussion, are a persistent cause of problems in the Solaris case; 
people, and GCC testcases, don't expect such checks, so special cases are 
needed for them all over the place).

-- 
Joseph S. Myers
joseph@codesourcery.com