diff options
Diffstat (limited to 'sysdeps/s390/s390-32/memcpy.S')
| -rw-r--r-- | sysdeps/s390/s390-32/memcpy.S | 37 |
1 files changed, 21 insertions, 16 deletions
diff --git a/sysdeps/s390/s390-32/memcpy.S b/sysdeps/s390/s390-32/memcpy.S index 4bbec7c633..9c4b840928 100644 --- a/sysdeps/s390/s390-32/memcpy.S +++ b/sysdeps/s390/s390-32/memcpy.S @@ -1,4 +1,4 @@ -/* Set a block of memory to some byte value. For IBM S390 +/* memcpy - copy a block from source to destination. S/390 version. Copyright (C) 2000, 2001 Free Software Foundation, Inc. Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com). @@ -17,25 +17,30 @@ write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ -/* - * R2 = address to destination memory area - * R3 = address to source memory area - * R4 = number of bytes to copy - */ +/* INPUT PARAMETERS + %r2 = address of destination memory area + %r3 = address of source memory area + %r4 = number of bytes to copy. */ #include "sysdep.h" #include "asm-syntax.h" .text ENTRY(memcpy) - ltr %r5,%r4 + ltr %r4,%r4 + jz .L3 + ahi %r4,-1 # length - 1 + lr %r1,%r2 # copy destination address + lr %r5,%r4 + sra %r5,8 jz .L1 - lr %r4,%r3 # %r4/%r5 = source ptr/len - lr %r3,%r5 # %r2/%r3 = dest ptr/len - lr %r0,%r2 # save source address -.L0: mvcle %r2,%r4,0 # thats it, MVCLE is your friend - jo .L0 - lr %r2,%r0 # return value is source address -.L1: - br %r14 -END(memset) +.L0: mvc 0(256,%r1),0(%r3) # move in 256 byte chunks + la %r1,256(%r1) + la %r3,256(%r3) + brct %r5,.L0 +.L1: bras %r5,.L2 # setup base pointer for execute + mvc 0(1,%r1),0(%r3) # instruction for execute +.L2: ex %r4,0(%r5) # execute mvc with length ((%r4)&255)+1 +.L3: br %r14 +END(memcpy) + |