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Commit a0865368 authored by Stuart Menefy's avatar Stuart Menefy Committed by Paul Mundt
Browse files

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: default avatarStuart Menefy <stuart.menefy@st.com>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 795abaf1

arch/sh/lib/delay.c

+10 −0
Original line number Original line Diff line number Diff line
@@ -10,6 +10,16 @@ 
void __delay(unsigned long loops)

void __delay(unsigned long loops)

{

{

	__asm__ __volatile__(

	__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"

		"tst	%0, %0\n\t"

		"1:\t"

		"1:\t"

		"bf/s	1b\n\t"

		"bf/s	1b\n\t"