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microblaze: Fix unaligned issue on MMU system with BS=0 DIV=1 

Unaligned code use shift for finding register operand.
There is used BSRLI(r8,r8,2) macro which is expand for BS=0, DIV=1
by
	ori rD, r0, (1 << imm);	\
	idivu rD, rD, rA

but if rD is equal rA then ori instruction rewrite value which
should be devide.

The patch remove this macro which use idivu instruction because
idivu takes 32/34 cycles. The highest shifting is 20 which takes
20 cycles.

Signed-off-by: Michal Simek <monstr@monstr.eu>
This commit is contained in:
Michal Simek 2011-01-28 13:14:58 +01:00
parent 026a207879
commit 9c749e177c
1 changed files with 0 additions and 4 deletions
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4
arch/microblaze/kernel/hw_exception_handler.S
View File

@ -147,10 +147,6 @@
#if CONFIG_XILINX_MICROBLAZE0_USE_BARREL > 0
#define BSRLI(rD, rA, imm) \
bsrli rD, rA, imm
#elif CONFIG_XILINX_MICROBLAZE0_USE_DIV > 0
#define BSRLI(rD, rA, imm) \
ori rD, r0, (1 << imm); \
idivu rD, rD, rA
#else
#define BSRLI(rD, rA, imm) BSRLI ## imm (rD, rA)
/* Only the used shift constants defined here - add more if needed */