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Re: [patch, fortran] PR 57071, some power optimizations

From: Tobias Burnus <burnus at net-b dot de>
To: Thomas Koenig <tkoenig at netcologne dot de>
Cc: "fortran at gcc dot gnu dot org" <fortran at gcc dot gnu dot org>, gcc-patches <gcc-patches at gcc dot gnu dot org>
Date: Sun, 28 Apr 2013 20:12:02 +0200
Subject: Re: [patch, fortran] PR 57071, some power optimizations
References: <517CDE9C dot 2020301 at netcologne dot de> <517CF581 dot 9010705 at net-b dot de> <517D26A2 dot 8020402 at netcologne dot de>

Thomas Koenig wrote:

Regarding PR 57073, the real case - I have never worked with
GIMPLE, so I have no real idea how to start this.

Any volunteers?  Or should we handle this in the Fortran front
end after all?

I think one should do it in the middle end. Actually, it shouldn't bethat difficult. The starting point is gcc/builtins.c's fold_builtin_powi- all ingredients are there; (1.0)**k, x**0, x**1 and x**(-1) arealready handled. Thus, only (-1)**k is missing. For "= (a)?(b):(c)"one uses "fold_build3_loc (loc, COND_EXPR, ..." and to check whether areal argument is -1, you can use "real_minus_onep".


How about writing your first middle end patch?

Tobias

References:
- [patch, fortran] PR 57071, some power optimizations
  - From: Thomas Koenig
- Re: [patch, fortran] PR 57071, some power optimizations
  - From: Tobias Burnus
- Re: [patch, fortran] PR 57071, some power optimizations
  - From: Thomas Koenig

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