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Re: Loop Unroll

From: David Brown <david at westcontrol dot com>
To: gcc-help at gcc dot gnu dot org
Date: Thu, 05 May 2011 15:31:12 +0200
Subject: Re: Loop Unroll
References: <BANLkTi=M1YMRTSW1vwEdGg-LpNs0bOMVgw@mail.gmail.com> <BANLkTimdEuzQdj+9hVL791pO3Kedm_i5qg@mail.gmail.com> <22442_1304600381_4DC29F3D_22442_4196_1_4DC29F3A.5050804@thalesgroup.com>

On 05/05/2011 14:59, VAUGHAN Jay wrote:

On 05/05/2011 02:08 PM, Francis Girard wrote:
How may we _easily_ know whether the compiler did indeed unroll a loop
or not in C/C++ ?
Look at the assembly output and see for yourself.

I don't know if that counts as "easily", but I can't think of any other reliable way.

Perhaps you could time the program and see if it runs faster - if you can't tell the difference in time, then it probably doesn't matter if the loop was unrolled.

References:
- Re: Loop Unroll
  - From: Francis Girard
- Re: Loop Unroll
  - From: VAUGHAN Jay

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