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Re: Compile-time floating-point expressions and subsequent detection of possible overflows etc -- during the compile-time stage.

From: Andrew Haley <aph at redhat dot com>
To: gcc-help at gcc dot gnu dot org
Date: Wed, 02 Nov 2011 09:37:23 +0000
Subject: Re: Compile-time floating-point expressions and subsequent detection of possible overflows etc -- during the compile-time stage.
References: <CAPpySAYbqZE+B-BqwW6ZY9rD9tZYG5Ru+tQ6HJOfPC13Tkonew@mail.gmail.com> <20111102090102.GA3523@xvii.vinc17.org>

On 11/02/2011 09:01 AM, Vincent Lefevre wrote:
> In ISO C99, I don't think the compiler is allowed to replace a
> floating expression with an underflow or overflow by its result
> at compile time.

But surely the "as if" rule applies here: if no conforming program
can tell the difference, a transformation is allowed.

Andrew.

Follow-Ups:
- Re: Compile-time floating-point expressions and subsequent detection of possible overflows etc -- during the compile-time stage.
  - From: leon zadorin
- Re: Compile-time floating-point expressions and subsequent detection of possible overflows etc -- during the compile-time stage.
  - From: Vincent Lefevre

References:
- Compile-time floating-point expressions and subsequent detection of possible overflows etc -- during the compile-time stage.
  - From: leon zadorin
- Re: Compile-time floating-point expressions and subsequent detection of possible overflows etc -- during the compile-time stage.
  - From: Vincent Lefevre

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