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- #include <string.h>
- #include "memcopy.h"
- #include <endian.h>
- #if __BYTE_ORDER == __BIG_ENDIAN
- # define CMP_LT_OR_GT(a, b) ((a) > (b) ? 1 : -1)
- #else
- # define CMP_LT_OR_GT(a, b) memcmp_bytes ((a), (b))
- #endif
- #if __BYTE_ORDER != __BIG_ENDIAN
- static __inline__ int
- memcmp_bytes (op_t a, op_t b)
- {
- long int srcp1 = (long int) &a;
- long int srcp2 = (long int) &b;
- op_t a0, b0;
- do
- {
- a0 = ((byte *) srcp1)[0];
- b0 = ((byte *) srcp2)[0];
- srcp1 += 1;
- srcp2 += 1;
- }
- while (a0 == b0);
- return a0 - b0;
- }
- #endif
- static int
- memcmp_common_alignment (long int srcp1, long int srcp2, size_t len)
- {
- op_t a0, a1;
- op_t b0, b1;
- switch (len % 4)
- {
- default:
- case 2:
- a0 = ((op_t *) srcp1)[0];
- b0 = ((op_t *) srcp2)[0];
- srcp1 -= 2 * OPSIZ;
- srcp2 -= 2 * OPSIZ;
- len += 2;
- goto do1;
- case 3:
- a1 = ((op_t *) srcp1)[0];
- b1 = ((op_t *) srcp2)[0];
- srcp1 -= OPSIZ;
- srcp2 -= OPSIZ;
- len += 1;
- goto do2;
- case 0:
- if (OP_T_THRES <= 3 * OPSIZ && len == 0)
- return 0;
- a0 = ((op_t *) srcp1)[0];
- b0 = ((op_t *) srcp2)[0];
- goto do3;
- case 1:
- a1 = ((op_t *) srcp1)[0];
- b1 = ((op_t *) srcp2)[0];
- srcp1 += OPSIZ;
- srcp2 += OPSIZ;
- len -= 1;
- if (OP_T_THRES <= 3 * OPSIZ && len == 0)
- goto do0;
-
- }
- do
- {
- a0 = ((op_t *) srcp1)[0];
- b0 = ((op_t *) srcp2)[0];
- if (a1 != b1)
- return CMP_LT_OR_GT (a1, b1);
- do3:
- a1 = ((op_t *) srcp1)[1];
- b1 = ((op_t *) srcp2)[1];
- if (a0 != b0)
- return CMP_LT_OR_GT (a0, b0);
- do2:
- a0 = ((op_t *) srcp1)[2];
- b0 = ((op_t *) srcp2)[2];
- if (a1 != b1)
- return CMP_LT_OR_GT (a1, b1);
- do1:
- a1 = ((op_t *) srcp1)[3];
- b1 = ((op_t *) srcp2)[3];
- if (a0 != b0)
- return CMP_LT_OR_GT (a0, b0);
- srcp1 += 4 * OPSIZ;
- srcp2 += 4 * OPSIZ;
- len -= 4;
- }
- while (len != 0);
-
- do0:
- if (a1 != b1)
- return CMP_LT_OR_GT (a1, b1);
- return 0;
- }
- static int
- memcmp_not_common_alignment (long int srcp1, long int srcp2, size_t len)
- {
- op_t a0, a1, a2, a3;
- op_t b0, b1, b2, b3;
- op_t x;
- int shl, shr;
-
- shl = 8 * (srcp1 % OPSIZ);
- shr = 8 * OPSIZ - shl;
-
- srcp1 &= -OPSIZ;
- switch (len % 4)
- {
- default:
- case 2:
- a1 = ((op_t *) srcp1)[0];
- a2 = ((op_t *) srcp1)[1];
- b2 = ((op_t *) srcp2)[0];
- srcp1 -= 1 * OPSIZ;
- srcp2 -= 2 * OPSIZ;
- len += 2;
- goto do1;
- case 3:
- a0 = ((op_t *) srcp1)[0];
- a1 = ((op_t *) srcp1)[1];
- b1 = ((op_t *) srcp2)[0];
- srcp2 -= 1 * OPSIZ;
- len += 1;
- goto do2;
- case 0:
- if (OP_T_THRES <= 3 * OPSIZ && len == 0)
- return 0;
- a3 = ((op_t *) srcp1)[0];
- a0 = ((op_t *) srcp1)[1];
- b0 = ((op_t *) srcp2)[0];
- srcp1 += 1 * OPSIZ;
- goto do3;
- case 1:
- a2 = ((op_t *) srcp1)[0];
- a3 = ((op_t *) srcp1)[1];
- b3 = ((op_t *) srcp2)[0];
- srcp1 += 2 * OPSIZ;
- srcp2 += 1 * OPSIZ;
- len -= 1;
- if (OP_T_THRES <= 3 * OPSIZ && len == 0)
- goto do0;
-
- }
- do
- {
- a0 = ((op_t *) srcp1)[0];
- b0 = ((op_t *) srcp2)[0];
- x = MERGE(a2, shl, a3, shr);
- if (x != b3)
- return CMP_LT_OR_GT (x, b3);
- do3:
- a1 = ((op_t *) srcp1)[1];
- b1 = ((op_t *) srcp2)[1];
- x = MERGE(a3, shl, a0, shr);
- if (x != b0)
- return CMP_LT_OR_GT (x, b0);
- do2:
- a2 = ((op_t *) srcp1)[2];
- b2 = ((op_t *) srcp2)[2];
- x = MERGE(a0, shl, a1, shr);
- if (x != b1)
- return CMP_LT_OR_GT (x, b1);
- do1:
- a3 = ((op_t *) srcp1)[3];
- b3 = ((op_t *) srcp2)[3];
- x = MERGE(a1, shl, a2, shr);
- if (x != b2)
- return CMP_LT_OR_GT (x, b2);
- srcp1 += 4 * OPSIZ;
- srcp2 += 4 * OPSIZ;
- len -= 4;
- }
- while (len != 0);
-
- do0:
- x = MERGE(a2, shl, a3, shr);
- if (x != b3)
- return CMP_LT_OR_GT (x, b3);
- return 0;
- }
- int
- memcmp (const __ptr_t s1, const __ptr_t s2, size_t len)
- {
- op_t a0;
- op_t b0;
- long int srcp1 = (long int) s1;
- long int srcp2 = (long int) s2;
- op_t res;
- if (len >= OP_T_THRES)
- {
-
- while (srcp2 % OPSIZ != 0)
- {
- a0 = ((byte *) srcp1)[0];
- b0 = ((byte *) srcp2)[0];
- srcp1 += 1;
- srcp2 += 1;
- res = a0 - b0;
- if (res != 0)
- return res;
- len -= 1;
- }
-
- if (srcp1 % OPSIZ == 0)
- res = memcmp_common_alignment (srcp1, srcp2, len / OPSIZ);
- else
- res = memcmp_not_common_alignment (srcp1, srcp2, len / OPSIZ);
- if (res != 0)
- return res;
-
- srcp1 += len & -OPSIZ;
- srcp2 += len & -OPSIZ;
- len %= OPSIZ;
- }
-
- while (len != 0)
- {
- a0 = ((byte *) srcp1)[0];
- b0 = ((byte *) srcp2)[0];
- srcp1 += 1;
- srcp2 += 1;
- res = a0 - b0;
- if (res != 0)
- return res;
- len -= 1;
- }
- return 0;
- }
- libc_hidden_weak(memcmp)
- #ifdef __UCLIBC_SUSV3_LEGACY__
- strong_alias(memcmp,bcmp)
- #endif
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