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Re: Can a float volatile asm be used as optimization barrier?
- From: kevin diggs <diggskevin38 at gmail dot com>
- To: Ian Lance Taylor <iant at google dot com>
- Cc: Parmenides <mobile dot parmenides at gmail dot com>, Gcc mailing list <gcc-help at gcc dot gnu dot org>
- Date: Fri, 1 Jul 2011 13:06:05 -0500
- 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>
Hi,
Something like:
#define add(new) \
({int __old; \
asm("addl %1,%0\n\t" \
:"=g"(__old) \
:"g"(new)); \
\
__old; \
})
int tst(int in)
{
int y;
y=add(in);
return y;
}
kevin