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SubjectRe: [RFC: 2.6 patch] add -fno-tree-scev-cprop to KBUILD_CFLAGS
Adrian Bunk wrote:
> The gcc from svn that will become gcc 4.3 generates libgcc calls in
> cases like the following (on 32bit architectures):
>
> <-- snip -->
>
> static inline void timespec_add_ns(struct timespec *a, u64 ns)
> {
> ...
> while(ns >= NSEC_PER_SEC) {
> ns -= NSEC_PER_SEC;
> a->tv_sec++;
> }
> ...
>
> <-- snip -->
>
> It can make sense to emit assembler code doing division for such C code -
> that doesn't seem to be something that would generally be wrong.

It can be a pretty huge performance regression, so gcc ought to be fixed.


Bernd
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