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Fix bzero() for 64-bit.

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The existing implementation of bzero incorrectly clears bytes when the
start address is not word aligned. Fix it by using REG_SHI macro which
works on both 32 and 64 bit.

Submitted by:	Artem Belevich (fbsdlist at src cx)
This commit is contained in:
jchandra 2011-02-22 07:49:51 +00:00
parent a8ca1e2aac
commit 33cfbb02c4
1 changed files with 1 additions and 19 deletions
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20
lib/libc/mips/string/bzero.S
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@ -58,27 +58,9 @@ LEAF(bzero)
PTR_SUBU a3, zero, a0 # compute # bytes to word align address
and a3, a3, SZREG-1
beq a3, zero, 1f # skip if word aligned
#if SZREG == 4
PTR_SUBU a1, a1, a3 # subtract from remaining count
SWHI zero, 0(a0) # clear 1, 2, or 3 bytes to align
REG_SHI zero, 0(a0) # clear 1, 2, or 3 bytes to align
PTR_ADDU a0, a0, a3
#endif
#if SZREG == 8
PTR_SUBU a1, a1, a3 # subtract from remaining count
PTR_ADDU a0, a0, a3 # align dst to next word
sll a3, a3, 3 # bits to bytes
li a2, -1 # make a mask
#if _BYTE_ORDER == _BIG_ENDIAN
REG_SRLV a2, a2, a3 # we want to keep the MSB bytes
#endif
#if _BYTE_ORDER == _LITTLE_ENDIAN
REG_SLLV a2, a2, a3 # we want to keep the LSB bytes
#endif
nor a2, zero, a2 # complement the mask
REG_L v0, -SZREG(a0) # load the word to partially clear
and v0, v0, a2 # clear the bytes
REG_S v0, -SZREG(a0) # store it back
#endif
1:
and v0, a1, SZREG-1 # compute number of words left
PTR_SUBU a3, a1, v0