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Re: [csl-arm] ARM mla costs.
- From: Paul Brook <paul at codesourcery dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Tue, 17 Oct 2006 02:04:44 +0100
- Subject: Re: [csl-arm] ARM mla costs.
- References: <200609292036.39272.paul@codesourcery.com>
On Friday 29 September 2006 20:36, Paul Brook wrote:
> The arm rtx_cost routine doesn't know about multiply-add instructions. This
> means they get given the same cost as an add with memory operands.
>
> On cores with a single-cycle multiply this is greater than the combined
> cost of separate mul and add insns.
>
> Patch below fixes this.
> Tested with cross to arm-none-eabi.
> Applied to branches/csl/sourcerygxx-4_1.
> I'll apply to mainline once it reopens.
It turns out this was a regression, so I've applied to mainline and 4.1.
> 2006-09-29 Paul Brook <paul@codesourcery.com>
>
> * config/arm/arm.c (arm_rtx_costs_1): Handle multiply-accumulate.