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- /*
- * String handling functions.
- *
- * Copyright IBM Corp. 2012
- */
- #include <linux/linkage.h>
- /*
- * memset implementation
- *
- * This code corresponds to the C construct below. We do distinguish
- * between clearing (c == 0) and setting a memory array (c != 0) simply
- * because nearly all memset invocations in the kernel clear memory and
- * the xc instruction is preferred in such cases.
- *
- * void *memset(void *s, int c, size_t n)
- * {
- * if (likely(c == 0))
- * return __builtin_memset(s, 0, n);
- * return __builtin_memset(s, c, n);
- * }
- */
- ENTRY(memset)
- ltgr %r4,%r4
- bzr %r14
- ltgr %r3,%r3
- jnz .Lmemset_fill
- aghi %r4,-1
- srlg %r3,%r4,8
- ltgr %r3,%r3
- lgr %r1,%r2
- jz .Lmemset_clear_rest
- .Lmemset_clear_loop:
- xc 0(256,%r1),0(%r1)
- la %r1,256(%r1)
- brctg %r3,.Lmemset_clear_loop
- .Lmemset_clear_rest:
- larl %r3,.Lmemset_xc
- ex %r4,0(%r3)
- br %r14
- .Lmemset_fill:
- stc %r3,0(%r2)
- cghi %r4,1
- lgr %r1,%r2
- ber %r14
- aghi %r4,-2
- srlg %r3,%r4,8
- ltgr %r3,%r3
- jz .Lmemset_fill_rest
- .Lmemset_fill_loop:
- mvc 1(256,%r1),0(%r1)
- la %r1,256(%r1)
- brctg %r3,.Lmemset_fill_loop
- .Lmemset_fill_rest:
- larl %r3,.Lmemset_mvc
- ex %r4,0(%r3)
- br %r14
- .Lmemset_xc:
- xc 0(1,%r1),0(%r1)
- .Lmemset_mvc:
- mvc 1(1,%r1),0(%r1)
- /*
- * memcpy implementation
- *
- * void *memcpy(void *dest, const void *src, size_t n)
- */
- ENTRY(memcpy)
- ltgr %r4,%r4
- bzr %r14
- aghi %r4,-1
- srlg %r5,%r4,8
- ltgr %r5,%r5
- lgr %r1,%r2
- jnz .Lmemcpy_loop
- .Lmemcpy_rest:
- larl %r5,.Lmemcpy_mvc
- ex %r4,0(%r5)
- br %r14
- .Lmemcpy_loop:
- mvc 0(256,%r1),0(%r3)
- la %r1,256(%r1)
- la %r3,256(%r3)
- brctg %r5,.Lmemcpy_loop
- j .Lmemcpy_rest
- .Lmemcpy_mvc:
- mvc 0(1,%r1),0(%r3)
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