📄 memcpy.s
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/* Copy SIZE bytes from SRC to DEST. For UltraSPARC-III. Copyright (C) 2001, 2003 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by David S. Miller (davem@redhat.com) The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */#include <sysdep.h>#define ASI_BLK_P 0xf0#define FPRS_FEF 0x04#define VISEntryHalf rd %fprs, %o5; wr %g0, FPRS_FEF, %fprs#define VISExitHalf and %o5, FPRS_FEF, %o5; wr %o5, 0x0, %fprs#ifndef XCC#define USE_BPR#define XCC xcc#endif .register %g2,#scratch .register %g3,#scratch .register %g6,#scratch .text .align 32ENTRY(bcopy) sub %o1, %o0, %o4 mov %o0, %g4 cmp %o4, %o2 mov %o1, %o0 bgeu,pt %XCC, 100f mov %g4, %o1#ifndef USE_BPR srl %o2, 0, %o2#endif brnz,pn %o2, 220f add %o0, %o2, %o0 retl nopEND(bcopy) /* Special/non-trivial issues of this code: * * 1) %o5 is preserved from VISEntryHalf to VISExitHalf * 2) Only low 32 FPU registers are used so that only the * lower half of the FPU register set is dirtied by this * code. This is especially important in the kernel. * 3) This code never prefetches cachelines past the end * of the source buffer. * * The cheetah's flexible spine, oversized liver, enlarged heart, * slender muscular body, and claws make it the swiftest hunter * in Africa and the fastest animal on land. Can reach speeds * of up to 2.4GB per second. */ .align 32ENTRY(memcpy)100: /* %o0=dst, %o1=src, %o2=len */ mov %o0, %g5 cmp %o2, 0 be,pn %XCC, out218: or %o0, %o1, %o3 cmp %o2, 16 bleu,a,pn %XCC, small_copy or %o3, %o2, %o3 cmp %o2, 256 blu,pt %XCC, medium_copy andcc %o3, 0x7, %g0 ba,pt %xcc, enter andcc %o0, 0x3f, %g2 /* Here len >= 256 and condition codes reflect execution * of "andcc %o0, 0x7, %g2", done by caller. */ .align 64enter: /* Is 'dst' already aligned on an 64-byte boundary? */ be,pt %XCC, 2f /* Compute abs((dst & 0x3f) - 0x40) into %g2. This is the number * of bytes to copy to make 'dst' 64-byte aligned. We pre- * subtract this from 'len'. */ sub %g2, 0x40, %g2 sub %g0, %g2, %g2 sub %o2, %g2, %o2 /* Copy %g2 bytes from src to dst, one byte at a time. */1: ldub [%o1 + 0x00], %o3 add %o1, 0x1, %o1 add %o0, 0x1, %o0 subcc %g2, 0x1, %g2 bg,pt %XCC, 1b stb %o3, [%o0 + -1]2: VISEntryHalf and %o1, 0x7, %g1 ba,pt %xcc, begin alignaddr %o1, %g0, %o1 .align 64begin: prefetch [%o1 + 0x000], #one_read prefetch [%o1 + 0x040], #one_read andn %o2, (0x40 - 1), %o4 prefetch [%o1 + 0x080], #one_read prefetch [%o1 + 0x0c0], #one_read ldd [%o1 + 0x000], %f0 prefetch [%o1 + 0x100], #one_read ldd [%o1 + 0x008], %f2 prefetch [%o1 + 0x140], #one_read ldd [%o1 + 0x010], %f4 prefetch [%o1 + 0x180], #one_read faligndata %f0, %f2, %f16 ldd [%o1 + 0x018], %f6 faligndata %f2, %f4, %f18 ldd [%o1 + 0x020], %f8 faligndata %f4, %f6, %f20 ldd [%o1 + 0x028], %f10 faligndata %f6, %f8, %f22 ldd [%o1 + 0x030], %f12 faligndata %f8, %f10, %f24 ldd [%o1 + 0x038], %f14 faligndata %f10, %f12, %f26 ldd [%o1 + 0x040], %f0 sub %o4, 0x80, %o4 add %o1, 0x40, %o1 ba,pt %xcc, loop srl %o4, 6, %o3 .align 64loop: ldd [%o1 + 0x008], %f2 faligndata %f12, %f14, %f28 ldd [%o1 + 0x010], %f4 faligndata %f14, %f0, %f30 stda %f16, [%o0] ASI_BLK_P ldd [%o1 + 0x018], %f6 faligndata %f0, %f2, %f16 ldd [%o1 + 0x020], %f8 faligndata %f2, %f4, %f18 ldd [%o1 + 0x028], %f10 faligndata %f4, %f6, %f20 ldd [%o1 + 0x030], %f12 faligndata %f6, %f8, %f22 ldd [%o1 + 0x038], %f14 faligndata %f8, %f10, %f24 ldd [%o1 + 0x040], %f0 prefetch [%o1 + 0x180], #one_read faligndata %f10, %f12, %f26 subcc %o3, 0x01, %o3 add %o1, 0x40, %o1 bg,pt %XCC, loop add %o0, 0x40, %o0 /* Finally we copy the last full 64-byte block. */loopfini: ldd [%o1 + 0x008], %f2 faligndata %f12, %f14, %f28 ldd [%o1 + 0x010], %f4 faligndata %f14, %f0, %f30 stda %f16, [%o0] ASI_BLK_P ldd [%o1 + 0x018], %f6 faligndata %f0, %f2, %f16 ldd [%o1 + 0x020], %f8 faligndata %f2, %f4, %f18 ldd [%o1 + 0x028], %f10 faligndata %f4, %f6, %f20 ldd [%o1 + 0x030], %f12 faligndata %f6, %f8, %f22 ldd [%o1 + 0x038], %f14 faligndata %f8, %f10, %f24 cmp %g1, 0 be,pt %XCC, 1f add %o0, 0x40, %o0 ldd [%o1 + 0x040], %f01: faligndata %f10, %f12, %f26 faligndata %f12, %f14, %f28 faligndata %f14, %f0, %f30 stda %f16, [%o0] ASI_BLK_P add %o0, 0x40, %o0 add %o1, 0x40, %o1 membar #Sync /* Now we copy the (len modulo 64) bytes at the end. * Note how we borrow the %f0 loaded above. * * Also notice how this code is careful not to perform a * load past the end of the src buffer. */loopend: and %o2, 0x3f, %o2 andcc %o2, 0x38, %g2 be,pn %XCC, endcruft subcc %g2, 0x8, %g2 be,pn %XCC, endcruft cmp %g1, 0 be,a,pt %XCC, 1f ldd [%o1 + 0x00], %f01: ldd [%o1 + 0x08], %f2 add %o1, 0x8, %o1 sub %o2, 0x8, %o2 subcc %g2, 0x8, %g2 faligndata %f0, %f2, %f8 std %f8, [%o0 + 0x00] be,pn %XCC, endcruft add %o0, 0x8, %o0 ldd [%o1 + 0x08], %f0 add %o1, 0x8, %o1 sub %o2, 0x8, %o2 subcc %g2, 0x8, %g2 faligndata %f2, %f0, %f8 std %f8, [%o0 + 0x00] bne,pn %XCC, 1b add %o0, 0x8, %o0 /* If anything is left, we copy it one byte at a time. * Note that %g1 is (src & 0x3) saved above before the * alignaddr was performed. */endcruft: cmp %o2, 0 add %o1, %g1, %o1 VISExitHalf be,pn %XCC, out sub %o0, %o1, %o3 andcc %g1, 0x7, %g0 bne,pn %icc, small_copy_unaligned andcc %o2, 0x8, %g0 be,pt %icc, 1f nop ldx [%o1], %o5 stx %o5, [%o1 + %o3] add %o1, 0x8, %o11: andcc %o2, 0x4, %g0 be,pt %icc, 1f nop lduw [%o1], %o5 stw %o5, [%o1 + %o3] add %o1, 0x4, %o11: andcc %o2, 0x2, %g0 be,pt %icc, 1f nop lduh [%o1], %o5 sth %o5, [%o1 + %o3] add %o1, 0x2, %o11: andcc %o2, 0x1, %g0 be,pt %icc, out nop ldub [%o1], %o5 ba,pt %xcc, out stb %o5, [%o1 + %o3]medium_copy: /* 16 < len <= 64 */ bne,pn %XCC, small_copy_unaligned sub %o0, %o1, %o3medium_copy_aligned: andn %o2, 0x7, %o4 and %o2, 0x7, %o21: subcc %o4, 0x8, %o4 ldx [%o1], %o5 stx %o5, [%o1 + %o3] bgu,pt %XCC, 1b add %o1, 0x8, %o1 andcc %o2, 0x4, %g0 be,pt %XCC, 1f nop sub %o2, 0x4, %o2 lduw [%o1], %o5 stw %o5, [%o1 + %o3] add %o1, 0x4, %o11: cmp %o2, 0 be,pt %XCC, out nop ba,pt %xcc, small_copy_unaligned nop⌨️ 快捷键说明
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