Messages in this thread | | | Date | Tue, 7 Jul 1998 21:00:39 +0200 (CEST) | From | Andrea Arcangeli <> | Subject | -mregparm=3 |
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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%.
http://www.ee.oulu.fi/~tuukkat/regpass-test.tar.gz
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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