From a086536858ad0eb51c58074af2fc2c89ba9c1f5e Mon Sep 17 00:00:00 2001 From: Stuart Menefy Date: Thu, 11 Nov 2010 18:26:31 +0000 Subject: sh: Ensure ST40-300 BogoMIPS value is consistent A strange variation was seen in the BogoMIPS figure for the ST40-300. This was eventually tracked down to sensitivity to the alignment of the loop. So add an align directive to ensure this doesn't occur. Signed-off-by: Stuart Menefy Signed-off-by: Paul Mundt --- arch/sh/lib/delay.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/sh/lib/delay.c b/arch/sh/lib/delay.c index faa8f86..0901b2f 100644 --- a/arch/sh/lib/delay.c +++ b/arch/sh/lib/delay.c @@ -10,6 +10,16 @@ void __delay(unsigned long loops) { __asm__ __volatile__( + /* + * ST40-300 appears to have an issue with this code, + * normally taking two cycles each loop, as with all + * other SH variants. If however the branch and the + * delay slot straddle an 8 byte boundary, this increases + * to 3 cycles. + * This align directive ensures this doesn't occur. + */ + ".balign 8\n\t" + "tst %0, %0\n\t" "1:\t" "bf/s 1b\n\t" -- cgit v1.1