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Re: Can a float volatile asm be used as optimization barrier?
- From: Parmenides <mobile dot parmenides at gmail dot com>
- To: Ian Lance Taylor <iant at google dot com>
- Cc: Gcc mailing list <gcc-help at gcc dot gnu dot org>
- Date: Sat, 2 Jul 2011 07:01:21 +0800
- Subject: Re: Can a float volatile asm be used as optimization barrier?
- References: <BANLkTimAxWqon69u=weK-32WcdZbJAeEMg@mail.gmail.com> <mcr39iz80w4.fsf@coign.corp.google.com> <BANLkTin1i4OTNAi_oDbrV9E1Sj5CMxn7Lg@mail.gmail.com> <mcrr569oqx0.fsf@coign.corp.google.com>
> This is exactly what the manual says. ?The asm has no side-effects
> except to change __old. ?And __old is not used, which means that any
> statements which assign a value to __old are unnecessary and may be
> removed. ?Since the only effect of the asm is to change __old, it is
> removed.
I really have gotten a misunstanding about the manual. ;-)
Thanks a lot.