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Commit 295ffb41 authored May 19, 2015 by LEROY Christophe Committed by Scott Wood Aug 07, 2015

powerpc/32: Few optimisations in memcpy



This patch adds a few optimisations in memcpy functions by using
lbzu/stbu instead of lxb/stb and by re-ordering insn inside a loop
to reduce latency due to loading

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Scott Wood <scottwood@freescale.com>

parent 0b05e2d6

arch/powerpc/lib/copy_32.S

+5 −5

Original line number	Diff line number	Diff line
		@@ -155,9 +155,9 @@ _GLOBAL(memcpy)
		mtctr r8
		beq+ 61f
		70: lbz r9,4(r4) /* do some bytes */
		stb r9,4(r6)
		addi r4,r4,1
		addi r6,r6,1
		stb r9,3(r6)
		bdnz 70b
		61: srwi. r0,r0,2
		mtctr r0
		@@ -199,10 +199,10 @@ _GLOBAL(memcpy)
		64: andi. r0,r5,3
		mtctr r0
		beq+ 65f
		40: lbz r0,4(r4)
		stb r0,4(r6)
		addi r4,r4,1
		addi r6,r6,1
		addi r4,r4,3
		addi r6,r6,3
		40: lbzu r0,1(r4)
		stbu r0,1(r6)
		bdnz 40b
		65: blr