no-op delay loops
From: Rasmus Villemoes
Date: Fri Nov 27 2015 - 03:53:58 EST
Hi,
It seems that gcc happily compiles
for (i = 0; i < 1000000000; ++i) ;
into simply
i = 1000000000;
(which is then usually eliminated as a dead store). At least at -O2, and
when i is not declared volatile. So it would seem that the loops at
arch/mips/pci/pci-rt2880.c:235
arch/mips/pmcs-msp71xx/msp_setup.c:80
arch/mips/sni/reset.c:35
actually don't do anything. (In the middle one, i is 'register', but
that doesn't change anything.) Is mips compiled with some special flags
that would make gcc actually emit code for the above?
Rasmus
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