Re: [patch] measurements, numbers about CONFIG_OPTIMIZE_INLINING=yimpact

From: Christoph Hellwig
Date: Fri Jan 09 2009 - 12:14:16 EST


On Fri, Jan 09, 2009 at 09:03:12AM -0500, jim owens wrote:
> They also know inlining may increase program object size.
> That inlining will reduce object size on many architectures
> if the function is small is just a happy side effect to them.

The problem is that the threshold for that is architecture specific.
While e.g. x86 has relatively low overhead of prologue/epilogue other
architectures like s390 have enormous overhead. So handling this in
the compiler would be optimal, but it would need at least whole-program
optimization and a compiler aware of the inline assembly to get it
half-way right.

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