diff options
Diffstat (limited to 'arch/x86/lib')
-rw-r--r-- | arch/x86/lib/memcpy_32.c | 199 | ||||
-rw-r--r-- | arch/x86/lib/memcpy_64.S | 158 | ||||
-rw-r--r-- | arch/x86/lib/memmove_64.c | 189 |
3 files changed, 465 insertions, 81 deletions
diff --git a/arch/x86/lib/memcpy_32.c b/arch/x86/lib/memcpy_32.c index 5415a9d06f53..b908a59eccf5 100644 --- a/arch/x86/lib/memcpy_32.c +++ b/arch/x86/lib/memcpy_32.c @@ -22,22 +22,187 @@ EXPORT_SYMBOL(memset); void *memmove(void *dest, const void *src, size_t n) { - int d0, d1, d2; - - if (dest < src) { - memcpy(dest, src, n); - } else { - __asm__ __volatile__( - "std\n\t" - "rep\n\t" - "movsb\n\t" - "cld" - : "=&c" (d0), "=&S" (d1), "=&D" (d2) - :"0" (n), - "1" (n-1+src), - "2" (n-1+dest) - :"memory"); - } - return dest; + int d0,d1,d2,d3,d4,d5; + char *ret = dest; + + __asm__ __volatile__( + /* Handle more 16bytes in loop */ + "cmp $0x10, %0\n\t" + "jb 1f\n\t" + + /* Decide forward/backward copy mode */ + "cmp %2, %1\n\t" + "jb 2f\n\t" + + /* + * movs instruction have many startup latency + * so we handle small size by general register. + */ + "cmp $680, %0\n\t" + "jb 3f\n\t" + /* + * movs instruction is only good for aligned case. + */ + "mov %1, %3\n\t" + "xor %2, %3\n\t" + "and $0xff, %3\n\t" + "jz 4f\n\t" + "3:\n\t" + "sub $0x10, %0\n\t" + + /* + * We gobble 16byts forward in each loop. + */ + "3:\n\t" + "sub $0x10, %0\n\t" + "mov 0*4(%1), %3\n\t" + "mov 1*4(%1), %4\n\t" + "mov %3, 0*4(%2)\n\t" + "mov %4, 1*4(%2)\n\t" + "mov 2*4(%1), %3\n\t" + "mov 3*4(%1), %4\n\t" + "mov %3, 2*4(%2)\n\t" + "mov %4, 3*4(%2)\n\t" + "lea 0x10(%1), %1\n\t" + "lea 0x10(%2), %2\n\t" + "jae 3b\n\t" + "add $0x10, %0\n\t" + "jmp 1f\n\t" + + /* + * Handle data forward by movs. + */ + ".p2align 4\n\t" + "4:\n\t" + "mov -4(%1, %0), %3\n\t" + "lea -4(%2, %0), %4\n\t" + "shr $2, %0\n\t" + "rep movsl\n\t" + "mov %3, (%4)\n\t" + "jmp 11f\n\t" + /* + * Handle data backward by movs. + */ + ".p2align 4\n\t" + "6:\n\t" + "mov (%1), %3\n\t" + "mov %2, %4\n\t" + "lea -4(%1, %0), %1\n\t" + "lea -4(%2, %0), %2\n\t" + "shr $2, %0\n\t" + "std\n\t" + "rep movsl\n\t" + "mov %3,(%4)\n\t" + "cld\n\t" + "jmp 11f\n\t" + + /* + * Start to prepare for backward copy. + */ + ".p2align 4\n\t" + "2:\n\t" + "cmp $680, %0\n\t" + "jb 5f\n\t" + "mov %1, %3\n\t" + "xor %2, %3\n\t" + "and $0xff, %3\n\t" + "jz 6b\n\t" + + /* + * Calculate copy position to tail. + */ + "5:\n\t" + "add %0, %1\n\t" + "add %0, %2\n\t" + "sub $0x10, %0\n\t" + + /* + * We gobble 16byts backward in each loop. + */ + "7:\n\t" + "sub $0x10, %0\n\t" + + "mov -1*4(%1), %3\n\t" + "mov -2*4(%1), %4\n\t" + "mov %3, -1*4(%2)\n\t" + "mov %4, -2*4(%2)\n\t" + "mov -3*4(%1), %3\n\t" + "mov -4*4(%1), %4\n\t" + "mov %3, -3*4(%2)\n\t" + "mov %4, -4*4(%2)\n\t" + "lea -0x10(%1), %1\n\t" + "lea -0x10(%2), %2\n\t" + "jae 7b\n\t" + /* + * Calculate copy position to head. + */ + "add $0x10, %0\n\t" + "sub %0, %1\n\t" + "sub %0, %2\n\t" + + /* + * Move data from 8 bytes to 15 bytes. + */ + ".p2align 4\n\t" + "1:\n\t" + "cmp $8, %0\n\t" + "jb 8f\n\t" + "mov 0*4(%1), %3\n\t" + "mov 1*4(%1), %4\n\t" + "mov -2*4(%1, %0), %5\n\t" + "mov -1*4(%1, %0), %1\n\t" + + "mov %3, 0*4(%2)\n\t" + "mov %4, 1*4(%2)\n\t" + "mov %5, -2*4(%2, %0)\n\t" + "mov %1, -1*4(%2, %0)\n\t" + "jmp 11f\n\t" + + /* + * Move data from 4 bytes to 7 bytes. + */ + ".p2align 4\n\t" + "8:\n\t" + "cmp $4, %0\n\t" + "jb 9f\n\t" + "mov 0*4(%1), %3\n\t" + "mov -1*4(%1, %0), %4\n\t" + "mov %3, 0*4(%2)\n\t" + "mov %4, -1*4(%2, %0)\n\t" + "jmp 11f\n\t" + + /* + * Move data from 2 bytes to 3 bytes. + */ + ".p2align 4\n\t" + "9:\n\t" + "cmp $2, %0\n\t" + "jb 10f\n\t" + "movw 0*2(%1), %%dx\n\t" + "movw -1*2(%1, %0), %%bx\n\t" + "movw %%dx, 0*2(%2)\n\t" + "movw %%bx, -1*2(%2, %0)\n\t" + "jmp 11f\n\t" + + /* + * Move data for 1 byte. + */ + ".p2align 4\n\t" + "10:\n\t" + "cmp $1, %0\n\t" + "jb 11f\n\t" + "movb (%1), %%cl\n\t" + "movb %%cl, (%2)\n\t" + ".p2align 4\n\t" + "11:" + : "=&c" (d0), "=&S" (d1), "=&D" (d2), + "=r" (d3),"=r" (d4), "=r"(d5) + :"0" (n), + "1" (src), + "2" (dest) + :"memory"); + + return ret; + } EXPORT_SYMBOL(memmove); diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S index bcbcd1e0f7d5..75ef61e35e38 100644 --- a/arch/x86/lib/memcpy_64.S +++ b/arch/x86/lib/memcpy_64.S @@ -40,84 +40,132 @@ ENTRY(__memcpy) ENTRY(memcpy) CFI_STARTPROC + movq %rdi, %rax /* - * Put the number of full 64-byte blocks into %ecx. - * Tail portion is handled at the end: + * Use 32bit CMP here to avoid long NOP padding. */ - movq %rdi, %rax - movl %edx, %ecx - shrl $6, %ecx - jz .Lhandle_tail + cmp $0x20, %edx + jb .Lhandle_tail - .p2align 4 -.Lloop_64: /* - * We decrement the loop index here - and the zero-flag is - * checked at the end of the loop (instructions inbetween do - * not change the zero flag): + * We check whether memory false dependece could occur, + * then jump to corresponding copy mode. */ - decl %ecx + cmp %dil, %sil + jl .Lcopy_backward + subl $0x20, %edx +.Lcopy_forward_loop: + subq $0x20, %rdx /* - * Move in blocks of 4x16 bytes: + * Move in blocks of 4x8 bytes: */ - movq 0*8(%rsi), %r11 - movq 1*8(%rsi), %r8 - movq %r11, 0*8(%rdi) - movq %r8, 1*8(%rdi) - - movq 2*8(%rsi), %r9 - movq 3*8(%rsi), %r10 - movq %r9, 2*8(%rdi) - movq %r10, 3*8(%rdi) - - movq 4*8(%rsi), %r11 - movq 5*8(%rsi), %r8 - movq %r11, 4*8(%rdi) - movq %r8, 5*8(%rdi) - - movq 6*8(%rsi), %r9 - movq 7*8(%rsi), %r10 - movq %r9, 6*8(%rdi) - movq %r10, 7*8(%rdi) - - leaq 64(%rsi), %rsi - leaq 64(%rdi), %rdi - - jnz .Lloop_64 + movq 0*8(%rsi), %r8 + movq 1*8(%rsi), %r9 + movq 2*8(%rsi), %r10 + movq 3*8(%rsi), %r11 + leaq 4*8(%rsi), %rsi + + movq %r8, 0*8(%rdi) + movq %r9, 1*8(%rdi) + movq %r10, 2*8(%rdi) + movq %r11, 3*8(%rdi) + leaq 4*8(%rdi), %rdi + jae .Lcopy_forward_loop + addq $0x20, %rdx + jmp .Lhandle_tail + +.Lcopy_backward: + /* + * Calculate copy position to tail. + */ + addq %rdx, %rsi + addq %rdx, %rdi + subq $0x20, %rdx + /* + * At most 3 ALU operations in one cycle, + * so append NOPS in the same 16bytes trunk. + */ + .p2align 4 +.Lcopy_backward_loop: + subq $0x20, %rdx + movq -1*8(%rsi), %r8 + movq -2*8(%rsi), %r9 + movq -3*8(%rsi), %r10 + movq -4*8(%rsi), %r11 + leaq -4*8(%rsi), %rsi + movq %r8, -1*8(%rdi) + movq %r9, -2*8(%rdi) + movq %r10, -3*8(%rdi) + movq %r11, -4*8(%rdi) + leaq -4*8(%rdi), %rdi + jae .Lcopy_backward_loop + /* + * Calculate copy position to head. + */ + addq $0x20, %rdx + subq %rdx, %rsi + subq %rdx, %rdi .Lhandle_tail: - movl %edx, %ecx - andl $63, %ecx - shrl $3, %ecx - jz .Lhandle_7 + cmpq $16, %rdx + jb .Lless_16bytes + /* + * Move data from 16 bytes to 31 bytes. + */ + movq 0*8(%rsi), %r8 + movq 1*8(%rsi), %r9 + movq -2*8(%rsi, %rdx), %r10 + movq -1*8(%rsi, %rdx), %r11 + movq %r8, 0*8(%rdi) + movq %r9, 1*8(%rdi) + movq %r10, -2*8(%rdi, %rdx) + movq %r11, -1*8(%rdi, %rdx) + retq .p2align 4 -.Lloop_8: - decl %ecx - movq (%rsi), %r8 - movq %r8, (%rdi) - leaq 8(%rdi), %rdi - leaq 8(%rsi), %rsi - jnz .Lloop_8 - -.Lhandle_7: - movl %edx, %ecx - andl $7, %ecx - jz .Lend +.Lless_16bytes: + cmpq $8, %rdx + jb .Lless_8bytes + /* + * Move data from 8 bytes to 15 bytes. + */ + movq 0*8(%rsi), %r8 + movq -1*8(%rsi, %rdx), %r9 + movq %r8, 0*8(%rdi) + movq %r9, -1*8(%rdi, %rdx) + retq + .p2align 4 +.Lless_8bytes: + cmpq $4, %rdx + jb .Lless_3bytes + /* + * Move data from 4 bytes to 7 bytes. + */ + movl (%rsi), %ecx + movl -4(%rsi, %rdx), %r8d + movl %ecx, (%rdi) + movl %r8d, -4(%rdi, %rdx) + retq .p2align 4 +.Lless_3bytes: + cmpl $0, %edx + je .Lend + /* + * Move data from 1 bytes to 3 bytes. + */ .Lloop_1: movb (%rsi), %r8b movb %r8b, (%rdi) incq %rdi incq %rsi - decl %ecx + decl %edx jnz .Lloop_1 .Lend: - ret + retq CFI_ENDPROC ENDPROC(memcpy) ENDPROC(__memcpy) diff --git a/arch/x86/lib/memmove_64.c b/arch/x86/lib/memmove_64.c index 0a33909bf122..6d0f0ec41b34 100644 --- a/arch/x86/lib/memmove_64.c +++ b/arch/x86/lib/memmove_64.c @@ -8,14 +8,185 @@ #undef memmove void *memmove(void *dest, const void *src, size_t count) { - if (dest < src) { - return memcpy(dest, src, count); - } else { - char *p = dest + count; - const char *s = src + count; - while (count--) - *--p = *--s; - } - return dest; + unsigned long d0,d1,d2,d3,d4,d5,d6,d7; + char *ret; + + __asm__ __volatile__( + /* Handle more 32bytes in loop */ + "mov %2, %3\n\t" + "cmp $0x20, %0\n\t" + "jb 1f\n\t" + + /* Decide forward/backward copy mode */ + "cmp %2, %1\n\t" + "jb 2f\n\t" + + /* + * movsq instruction have many startup latency + * so we handle small size by general register. + */ + "cmp $680, %0\n\t" + "jb 3f\n\t" + /* + * movsq instruction is only good for aligned case. + */ + "cmpb %%dil, %%sil\n\t" + "je 4f\n\t" + "3:\n\t" + "sub $0x20, %0\n\t" + /* + * We gobble 32byts forward in each loop. + */ + "5:\n\t" + "sub $0x20, %0\n\t" + "movq 0*8(%1), %4\n\t" + "movq 1*8(%1), %5\n\t" + "movq 2*8(%1), %6\n\t" + "movq 3*8(%1), %7\n\t" + "leaq 4*8(%1), %1\n\t" + + "movq %4, 0*8(%2)\n\t" + "movq %5, 1*8(%2)\n\t" + "movq %6, 2*8(%2)\n\t" + "movq %7, 3*8(%2)\n\t" + "leaq 4*8(%2), %2\n\t" + "jae 5b\n\t" + "addq $0x20, %0\n\t" + "jmp 1f\n\t" + /* + * Handle data forward by movsq. + */ + ".p2align 4\n\t" + "4:\n\t" + "movq %0, %8\n\t" + "movq -8(%1, %0), %4\n\t" + "lea -8(%2, %0), %5\n\t" + "shrq $3, %8\n\t" + "rep movsq\n\t" + "movq %4, (%5)\n\t" + "jmp 13f\n\t" + /* + * Handle data backward by movsq. + */ + ".p2align 4\n\t" + "7:\n\t" + "movq %0, %8\n\t" + "movq (%1), %4\n\t" + "movq %2, %5\n\t" + "leaq -8(%1, %0), %1\n\t" + "leaq -8(%2, %0), %2\n\t" + "shrq $3, %8\n\t" + "std\n\t" + "rep movsq\n\t" + "cld\n\t" + "movq %4, (%5)\n\t" + "jmp 13f\n\t" + + /* + * Start to prepare for backward copy. + */ + ".p2align 4\n\t" + "2:\n\t" + "cmp $680, %0\n\t" + "jb 6f \n\t" + "cmp %%dil, %%sil\n\t" + "je 7b \n\t" + "6:\n\t" + /* + * Calculate copy position to tail. + */ + "addq %0, %1\n\t" + "addq %0, %2\n\t" + "subq $0x20, %0\n\t" + /* + * We gobble 32byts backward in each loop. + */ + "8:\n\t" + "subq $0x20, %0\n\t" + "movq -1*8(%1), %4\n\t" + "movq -2*8(%1), %5\n\t" + "movq -3*8(%1), %6\n\t" + "movq -4*8(%1), %7\n\t" + "leaq -4*8(%1), %1\n\t" + + "movq %4, -1*8(%2)\n\t" + "movq %5, -2*8(%2)\n\t" + "movq %6, -3*8(%2)\n\t" + "movq %7, -4*8(%2)\n\t" + "leaq -4*8(%2), %2\n\t" + "jae 8b\n\t" + /* + * Calculate copy position to head. + */ + "addq $0x20, %0\n\t" + "subq %0, %1\n\t" + "subq %0, %2\n\t" + "1:\n\t" + "cmpq $16, %0\n\t" + "jb 9f\n\t" + /* + * Move data from 16 bytes to 31 bytes. + */ + "movq 0*8(%1), %4\n\t" + "movq 1*8(%1), %5\n\t" + "movq -2*8(%1, %0), %6\n\t" + "movq -1*8(%1, %0), %7\n\t" + "movq %4, 0*8(%2)\n\t" + "movq %5, 1*8(%2)\n\t" + "movq %6, -2*8(%2, %0)\n\t" + "movq %7, -1*8(%2, %0)\n\t" + "jmp 13f\n\t" + ".p2align 4\n\t" + "9:\n\t" + "cmpq $8, %0\n\t" + "jb 10f\n\t" + /* + * Move data from 8 bytes to 15 bytes. + */ + "movq 0*8(%1), %4\n\t" + "movq -1*8(%1, %0), %5\n\t" + "movq %4, 0*8(%2)\n\t" + "movq %5, -1*8(%2, %0)\n\t" + "jmp 13f\n\t" + "10:\n\t" + "cmpq $4, %0\n\t" + "jb 11f\n\t" + /* + * Move data from 4 bytes to 7 bytes. + */ + "movl (%1), %4d\n\t" + "movl -4(%1, %0), %5d\n\t" + "movl %4d, (%2)\n\t" + "movl %5d, -4(%2, %0)\n\t" + "jmp 13f\n\t" + "11:\n\t" + "cmp $2, %0\n\t" + "jb 12f\n\t" + /* + * Move data from 2 bytes to 3 bytes. + */ + "movw (%1), %4w\n\t" + "movw -2(%1, %0), %5w\n\t" + "movw %4w, (%2)\n\t" + "movw %5w, -2(%2, %0)\n\t" + "jmp 13f\n\t" + "12:\n\t" + "cmp $1, %0\n\t" + "jb 13f\n\t" + /* + * Move data for 1 byte. + */ + "movb (%1), %4b\n\t" + "movb %4b, (%2)\n\t" + "13:\n\t" + : "=&d" (d0), "=&S" (d1), "=&D" (d2), "=&a" (ret) , + "=r"(d3), "=r"(d4), "=r"(d5), "=r"(d6), "=&c" (d7) + :"0" (count), + "1" (src), + "2" (dest) + :"memory"); + + return ret; + } EXPORT_SYMBOL(memmove); |