Andrea Arcangeli (arcangeli@mbox.queen.it)
Tue, 7 Jul 1998 21:00:39 +0200 (CEST)

What about to compile the kernel with -mregparm=3? On linux-c-programming
we made some tests and seems that using regparm(3) in the most of
functions of bzip2 improve bzip2 of 6%.


Using registers to pass parameters can' t be less efficient but _could_ be
not very more efficient.

Remeber that i386 convention of passing parameter using the stack came
only from the past.

The nasty thing is that all asm-i386 section uses "m" for reference
function arguments in the inline asm...

I just tried to compile the kernel with -regparm=1 (=3 cause gcc to not
compile since some inline function should be changed, gcc has not memory
space to save info) and the kernel crash in bread (when read the msdos
partition table, in buffer_locked(), probably due the inline asm in
test_bit() or similar).

Andrea[s] Arcangeli

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