This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: [MIPS]question about floating point conditional branch
- From: Richard Sandiford <rdsandiford at googlemail dot com>
- To: "Eric Fisher" <joefoxreal at gmail dot com>
- Cc: gcc at gcc dot gnu dot org
- Date: Mon, 10 Nov 2008 20:23:25 +0000
- Subject: Re: [MIPS]question about floating point conditional branch
- References: <d6afecde0811030141i50651927naaed34b079ae6fa9@mail.gmail.com>
"Eric Fisher" <joefoxreal@gmail.com> writes:
> In mips.md, conditional branch insns are all set with the attribute
> value 'branch'. But floating point instructions such as bc1f will
> reserve falu unit instead of ialu. So there's a problem when you try
> to describe pipeline for 'branch' insns. Define the ialu as the
> reservation for all 'branch' insns? Is it OK?
It's certainly OK to split to "branch" into "ibranch" and "fbranch"
if there's a use for it. The only reason we haven't done so up till
now is because no-one's really needed to.
That's the way things usually work the "type" attribute:
it starts out as coarse-grained as possible, then we add new
classifications when we need them.
Richard