Re: [Valgrind-developers] re: lazy FPU state save/restore

[Jeremy F. <je...@go...>]

On Fri, 2002-10-04 at 03:51, Julian Seward wrote:
> How much faster is "significantly faster" ?

OK, I've quantified this now.

Using the attached test program (a matrix multiply extracted from Mesa),
I'm getting the following timings (fptest compiled with -O; 600MHz PIII
laptop; --skin=none):

native execution:   0.38s
baseline valgrind: 65.35s
lazy-fp valgrind:   4.05s

In other words, Valgrind is currently 172 times slower than running
native for FP-intensive code; the lazy save-restore improves this by a
factor of 16 or so to make the valgrind overhead only about 11 times
slower than native.

I'd say that's significant.

I'm attaching my current diff against HEAD; the previous one left out
saving before JIFZ.

	J