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[Bug tree-optimization/17884] [4.0 Regression] asm 'volatile' is not honored as documented
- From: "fjahanian at apple dot com" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: 7 Oct 2004 20:37:31 -0000
- Subject: [Bug tree-optimization/17884] [4.0 Regression] asm 'volatile' is not honored as documented
- References: <20041007193056.17884.fjahanian@apple.com>
- Reply-to: gcc-bugzilla at gcc dot gnu dot org
------- Additional Comments From fjahanian at apple dot com 2004-10-07 20:37 -------
From: http://gcc.gnu.org/onlinedocs/gcc-3.4.0/gcc/Extended-Asm.html#Extended%20Asm
The volatile keyword indicates that the instruction has important side-effects. GCC will not delete a
volatile asm if it is reachable. (The instruction can still be deleted if GCC can prove that control-flow
will never reach the location of the instruction.) In addition, GCC will not reschedule instructions across
a volatile asm instruction.
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17884