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RE: [PATCH RFA MIPS] Prohibit vector modes in accumulators
- From: Matthew Fortune <Matthew dot Fortune at imgtec dot com>
- To: Robert Suchanek <Robert dot Suchanek at imgtec dot com>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
- Cc: "Catherine_Moore at mentor dot com" <Catherine_Moore at mentor dot com>
- Date: Fri, 23 Jan 2015 19:50:34 +0000
- Subject: RE: [PATCH RFA MIPS] Prohibit vector modes in accumulators
- Authentication-results: sourceware.org; auth=none
- References: <B5E67142681B53468FAF6B7C3135656244118FCB at hhmail02 dot hh dot imgtec dot org>
> 2015-01-23 Robert Suchanek <robert.suchanek@imgtec.com>
>
> * config/mips/mips.c (mips_hard_regno_mode_ok_p): Prohibit
> accumulators
> for all vector modes.
This seems like a genuine bug and although it can only be triggered by
loongson or paired-single support it probably qualifies for fixing.
My suspicion is that the switch to LRA since GCC 4.9 may be the reason
this hasn't been noticed before. Reload seemed better in some cases
at eliminating bad decisions from IRA so this may have simply never
made it through reload by fluke.
I'd like Catherine to review too since we are in stage4 without a
reproducible test case.
Matthew