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Re: [PATCH] [ARC] Handle FPX NaN within optimized floating point library.

From: Joern Wolfgang Rennecke <gnu at amylaar dot uk>
To: Claudiu Zissulescu <Claudiu dot Zissulescu at synopsys dot com>, "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
Cc: "Francois dot Bedard at synopsys dot com" <Francois dot Bedard at synopsys dot com>, "jeremy dot bennett at embecosm dot com" <jeremy dot bennett at embecosm dot com>
Date: Fri, 29 Apr 2016 11:37:06 +0100
Subject: Re: [PATCH] [ARC] Handle FPX NaN within optimized floating point library.
Authentication-results: sourceware.org; auth=none
References: <5722261F dot 1070102 at amylaar dot uk> <1461924998-9190-1-git-send-email-claziss at synopsys dot com> <5723370B dot 6020904 at amylaar dot uk> <098ECE41A0A6114BB2A07F1EC238DE896618A1F3 at de02wembxa dot internal dot synopsys dot com>



On 29/04/16 11:31, Claudiu Zissulescu wrote:

It should do the job, at least for EM where the jump takes 2 cycle, and by means of using delay slots we can make all the cycles count. HS has a branch prediction mechanism, hence, filling up the delay slot doesn't have such a big impact like in EM or even earlier cpus.

No, the alternative is to hide the delay slot, so if the branch ispredicted properly, the case with

different high words should be faster without the .d suffix.

I.e. , eagerly filling the delay slot like this has a bigger - negative- impact on performance.

Follow-Ups:
- RE: [PATCH] [ARC] Handle FPX NaN within optimized floating point library.
  - From: Claudiu Zissulescu

References:
- Re: [PATCH 4/6] [ARC] Handle FPX NaN within optimized floating point library.
  - From: Joern Wolfgang Rennecke
- [PATCH] [ARC] Handle FPX NaN within optimized floating point library.
  - From: Claudiu Zissulescu
- Re: [PATCH] [ARC] Handle FPX NaN within optimized floating point library.
  - From: Joern Wolfgang Rennecke
- RE: [PATCH] [ARC] Handle FPX NaN within optimized floating point library.
  - From: Claudiu Zissulescu

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