/* $Id: U3memcpy.S,v 1.2 2000/11/01 09:29:19 davem Exp $ * U3memcpy.S: UltraSparc-III optimized memcpy. * * Copyright (C) 1999, 2000 David S. Miller (davem@redhat.com) */ #ifdef __KERNEL__ #include #include #undef SMALL_COPY_USES_FPU #else #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 #define SMALL_COPY_USES_FPU #endif /* 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. */ .text .align 32 /* 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. */ .globl U3memcpy U3memcpy: /* %o0=dst, %o1=src, %o2=len */ #ifndef __KERNEL__ /* Save away original 'dst' for memcpy return value. */ mov %o0, %g3 ! A0 Group #endif /* Anything to copy at all? */ cmp %o2, 0 ! A1 ble,pn %icc, U3memcpy_short_ret ! BR /* Extremely small copy? */ cmp %o2, 31 ! A0 Group ble,pn %icc, U3memcpy_short ! BR /* Large enough to use unrolled prefetch loops? */ cmp %o2, 0x100 ! A1 bge,a,pt %icc, U3memcpy_enter ! BR Group andcc %o0, 0x3f, %g2 ! A0 ba,pt %xcc, U3memcpy_toosmall ! BR Group andcc %o0, 0x7, %g2 ! A0 .align 32 U3memcpy_short: /* Copy %o2 bytes from src to dst, one byte at a time. */ ldub [%o1 + 0x00], %o3 ! MS Group add %o1, 0x1, %o1 ! A0 add %o0, 0x1, %o0 ! A1 subcc %o2, 1, %o2 ! A0 Group bg,pt %icc, U3memcpy_short ! BR stb %o3, [%o0 + -1] ! MS Group (1-cycle stall) U3memcpy_short_ret: #ifdef __KERNEL__ retl ! BR Group (0-4 cycle stall) clr %o0 ! A0 #else retl ! BR Group (0-4 cycle stall) mov %g3, %o0 ! A0 #endif /* Here len >= (6 * 64) and condition codes reflect execution * of "andcc %o0, 0x7, %g2", done by caller. */ .align 64 U3memcpy_enter: /* Is 'dst' already aligned on an 64-byte boundary? */ be,pt %xcc, 2f ! BR /* 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 ! A0 Group sub %g0, %g2, %g2 ! A0 Group sub %o2, %g2, %o2 ! A0 Group /* Copy %g2 bytes from src to dst, one byte at a time. */ 1: ldub [%o1 + 0x00], %o3 ! MS (Group) add %o1, 0x1, %o1 ! A1 add %o0, 0x1, %o0 ! A0 Group subcc %g2, 0x1, %g2 ! A1 bg,pt %icc, 1b ! BR Group stb %o3, [%o0 + -1] ! MS Group 2: VISEntryHalf ! MS+MS and %o1, 0x7, %g1 ! A1 ba,pt %xcc, U3memcpy_begin ! BR alignaddr %o1, %g0, %o1 ! MS (Break-after) .align 64 U3memcpy_begin: prefetch [%o1 + 0x000], #one_read ! MS Group1 prefetch [%o1 + 0x040], #one_read ! MS Group2 andn %o2, (0x40 - 1), %o4 ! A0 prefetch [%o1 + 0x080], #one_read ! MS Group3 cmp %o4, 0x140 ! A0 prefetch [%o1 + 0x0c0], #one_read ! MS Group4 ldd [%o1 + 0x000], %f0 ! MS Group5 (%f0 results at G8) bge,a,pt %icc, 1f ! BR prefetch [%o1 + 0x100], #one_read ! MS Group6 1: ldd [%o1 + 0x008], %f2 ! AX (%f2 results at G9) cmp %o4, 0x180 ! A1 bge,a,pt %icc, 1f ! BR prefetch [%o1 + 0x140], #one_read ! MS Group7 1: ldd [%o1 + 0x010], %f4 ! AX (%f4 results at G10) cmp %o4, 0x1c0 ! A1 bge,a,pt %icc, 1f ! BR prefetch [%o1 + 0x180], #one_read ! MS Group8 1: faligndata %f0, %f2, %f16 ! FGA Group9 (%f16 at G12) ldd [%o1 + 0x018], %f6 ! AX (%f6 results at G12) faligndata %f2, %f4, %f18 ! FGA Group10 (%f18 results at G13) ldd [%o1 + 0x020], %f8 ! MS (%f8 results at G13) faligndata %f4, %f6, %f20 ! FGA Group12 (1-cycle stall,%f20 at G15) ldd [%o1 + 0x028], %f10 ! MS (%f10 results at G15) faligndata %f6, %f8, %f22 ! FGA Group13 (%f22 results at G16) ldd [%o1 + 0x030], %f12 ! MS (%f12 results at G16) faligndata %f8, %f10, %f24 ! FGA Group15 (1-cycle stall,%f24 at G18) ldd [%o1 + 0x038], %f14 ! MS (%f14 results at G18) faligndata %f10, %f12, %f26 ! FGA Group16 (%f26 results at G19) ldd [%o1 + 0x040], %f0 ! MS (%f0 results at G19) /* We only use the first loop if len > (7 * 64). */ subcc %o4, 0x1c0, %o4 ! A0 Group17 bg,pt %icc, U3memcpy_loop1 ! BR add %o1, 0x40, %o1 ! A1 add %o4, 0x140, %o4 ! A0 Group18 ba,pt %xcc, U3memcpy_loop2 ! BR srl %o4, 6, %o3 ! A0 Group19 nop nop nop nop nop nop nop /* This loop performs the copy and queues new prefetches. * We drop into the second loop when len <= (5 * 64). Note * that this (5 * 64) factor has been subtracted from len * already. */ U3memcpy_loop1: ldd [%o1 + 0x008], %f2 ! MS Group2 (%f2 results at G5) faligndata %f12, %f14, %f28 ! FGA (%f28 results at G5) ldd [%o1 + 0x010], %f4 ! MS Group3 (%f4 results at G6) faligndata %f14, %f0, %f30 ! FGA Group4 (1-cycle stall, %f30 at G7) stda %f16, [%o0] ASI_BLK_P ! MS ldd [%o1 + 0x018], %f6 ! AX (%f6 results at G7) faligndata %f0, %f2, %f16 ! FGA Group12 (7-cycle stall) ldd [%o1 + 0x020], %f8 ! MS (%f8 results at G15) faligndata %f2, %f4, %f18 ! FGA Group13 (%f18 results at G16) ldd [%o1 + 0x028], %f10 ! MS (%f10 results at G16) faligndata %f4, %f6, %f20 ! FGA Group14 (%f20 results at G17) ldd [%o1 + 0x030], %f12 ! MS (%f12 results at G17) faligndata %f6, %f8, %f22 ! FGA Group15 (%f22 results at G18) ldd [%o1 + 0x038], %f14 ! MS (%f14 results at G18) faligndata %f8, %f10, %f24 ! FGA Group16 (%f24 results at G19) ldd [%o1 + 0x040], %f0 ! AX (%f0 results at G19) prefetch [%o1 + 0x180], #one_read ! MS faligndata %f10, %f12, %f26 ! FGA Group17 (%f26 results at G20) subcc %o4, 0x40, %o4 ! A0 add %o1, 0x40, %o1 ! A1 bg,pt %xcc, U3memcpy_loop1 ! BR add %o0, 0x40, %o0 ! A0 Group18 U3memcpy_loop2_enter: mov 5, %o3 ! A1 /* This loop performs on the copy, no new prefetches are * queued. We do things this way so that we do not perform * any spurious prefetches past the end of the src buffer. */ U3memcpy_loop2: ldd [%o1 + 0x008], %f2 ! MS faligndata %f12, %f14, %f28 ! FGA Group2 ldd [%o1 + 0x010], %f4 ! MS faligndata %f14, %f0, %f30 ! FGA Group4 (1-cycle stall) stda %f16, [%o0] ASI_BLK_P ! MS ldd [%o1 + 0x018], %f6 ! AX faligndata %f0, %f2, %f16 ! FGA Group12 (7-cycle stall) ldd [%o1 + 0x020], %f8 ! MS faligndata %f2, %f4, %f18 ! FGA Group13 ldd [%o1 + 0x028], %f10 ! MS faligndata %f4, %f6, %f20 ! FGA Group14 ldd [%o1 + 0x030], %f12 ! MS faligndata %f6, %f8, %f22 ! FGA Group15 ldd [%o1 + 0x038], %f14 ! MS faligndata %f8, %f10, %f24 ! FGA Group16 ldd [%o1 + 0x040], %f0 ! AX faligndata %f10, %f12, %f26 ! FGA Group17 subcc %o3, 0x01, %o3 ! A0 add %o1, 0x40, %o1 ! A1 bg,pt %xcc, U3memcpy_loop2 ! BR add %o0, 0x40, %o0 ! A0 Group18 /* Finally we copy the last full 64-byte block. */ U3memcpy_loopfini: ldd [%o1 + 0x008], %f2 ! MS faligndata %f12, %f14, %f28 ! FGA ldd [%o1 + 0x010], %f4 ! MS Group19 faligndata %f14, %f0, %f30 ! FGA stda %f16, [%o0] ASI_BLK_P ! MS Group20 ldd [%o1 + 0x018], %f6 ! AX faligndata %f0, %f2, %f16 ! FGA Group11 (7-cycle stall) ldd [%o1 + 0x020], %f8 ! MS faligndata %f2, %f4, %f18 ! FGA Group12 ldd [%o1 + 0x028], %f10 ! MS faligndata %f4, %f6, %f20 ! FGA Group13 ldd [%o1 + 0x030], %f12 ! MS faligndata %f6, %f8, %f22 ! FGA Group14 ldd [%o1 + 0x038], %f14 ! MS faligndata %f8, %f10, %f24 ! FGA Group15 cmp %g1, 0 ! A0 be,pt %icc, 1f ! BR add %o0, 0x40, %o0 ! A1 ldd [%o1 + 0x040], %f0 ! MS 1: faligndata %f10, %f12, %f26 ! FGA Group16 faligndata %f12, %f14, %f28 ! FGA Group17 faligndata %f14, %f0, %f30 ! FGA Group18 stda %f16, [%o0] ASI_BLK_P ! MS add %o0, 0x40, %o0 ! A0 add %o1, 0x40, %o1 ! A1 membar #Sync ! MS Group26 (7-cycle stall) /* 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 just like similar * code found in U3memcpy_toosmall processing. */ U3memcpy_loopend: and %o2, 0x3f, %o2 ! A0 Group andcc %o2, 0x38, %g2 ! A0 Group be,pn %icc, U3memcpy_endcruft ! BR subcc %g2, 0x8, %g2 ! A1 be,pn %icc, U3memcpy_endcruft ! BR Group cmp %g1, 0 ! A0 be,a,pt %icc, 1f ! BR Group ldd [%o1 + 0x00], %f0 ! MS 1: ldd [%o1 + 0x08], %f2 ! MS Group add %o1, 0x8, %o1 ! A0 sub %o2, 0x8, %o2 ! A1 subcc %g2, 0x8, %g2 ! A0 Group faligndata %f0, %f2, %f8 ! FGA Group std %f8, [%o0 + 0x00] ! MS (XXX does it stall here? XXX) be,pn %icc, U3memcpy_endcruft ! BR add %o0, 0x8, %o0 ! A0 ldd [%o1 + 0x08], %f0 ! MS Group add %o1, 0x8, %o1 ! A0 sub %o2, 0x8, %o2 ! A1 subcc %g2, 0x8, %g2 ! A0 Group faligndata %f2, %f0, %f8 ! FGA std %f8, [%o0 + 0x00] ! MS (XXX does it stall here? XXX) bne,pn %icc, 1b ! BR add %o0, 0x8, %o0 ! A0 Group /* 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. */ U3memcpy_endcruft: cmp %o2, 0 add %o1, %g1, %o1 VISExitHalf be,pn %icc, U3memcpy_short_ret nop ba,a,pt %xcc, U3memcpy_short /* If we get here, then 32 <= len < (6 * 64) */ U3memcpy_toosmall: #ifdef SMALL_COPY_USES_FPU /* Is 'dst' already aligned on an 8-byte boundary? */ be,pt %xcc, 2f ! BR Group /* Compute abs((dst & 7) - 8) into %g2. This is the number * of bytes to copy to make 'dst' 8-byte aligned. We pre- * subtract this from 'len'. */ sub %g2, 0x8, %g2 ! A0 sub %g0, %g2, %g2 ! A0 Group (reg-dep) sub %o2, %g2, %o2 ! A0 Group (reg-dep) /* Copy %g2 bytes from src to dst, one byte at a time. */ 1: ldub [%o1 + 0x00], %o3 ! MS (Group) (%o3 in 3 cycles) add %o1, 0x1, %o1 ! A1 add %o0, 0x1, %o0 ! A0 Group subcc %g2, 0x1, %g2 ! A1 bg,pt %icc, 1b ! BR Group stb %o3, [%o0 + -1] ! MS Group 2: VISEntryHalf ! MS+MS /* Compute (len - (len % 8)) into %g2. This is guarenteed * to be nonzero. */ andn %o2, 0x7, %g2 ! A0 Group /* You may read this and believe that it allows reading * one 8-byte longword past the end of src. It actually * does not, as %g2 is subtracted as loads are done from * src, so we always stop before running off the end. * Also, we are guarenteed to have at least 0x10 bytes * to move here. */ sub %g2, 0x8, %g2 ! A0 Group (reg-dep) alignaddr %o1, %g0, %g1 ! MS (Break-after) ldd [%g1 + 0x00], %f0 ! MS Group (1-cycle stall) add %g1, 0x8, %g1 ! A0 1: ldd [%g1 + 0x00], %f2 ! MS Group add %g1, 0x8, %g1 ! A0 sub %o2, 0x8, %o2 ! A1 subcc %g2, 0x8, %g2 ! A0 Group faligndata %f0, %f2, %f8 ! FGA Group (1-cycle stall) std %f8, [%o0 + 0x00] ! MS Group (2-cycle stall) add %o1, 0x8, %o1 ! A0 be,pn %icc, 2f ! BR add %o0, 0x8, %o0 ! A1 ldd [%g1 + 0x00], %f0 ! MS Group add %g1, 0x8, %g1 ! A0 sub %o2, 0x8, %o2 ! A1 subcc %g2, 0x8, %g2 ! A0 Group faligndata %f2, %f0, %f8 ! FGA Group (1-cycle stall) std %f8, [%o0 + 0x00] ! MS Group (2-cycle stall) add %o1, 0x8, %o1 ! A0 bne,pn %icc, 1b ! BR add %o0, 0x8, %o0 ! A1 /* Nothing left to copy? */ 2: cmp %o2, 0 ! A0 Group VISExitHalf ! A0+MS be,pn %icc, U3memcpy_short_ret ! BR Group nop ! A0 ba,a,pt %xcc, U3memcpy_short ! BR Group #else /* !(SMALL_COPY_USES_FPU) */ xor %o1, %o0, %g2 andcc %g2, 0x7, %g0 bne,pn %icc, U3memcpy_short andcc %o1, 0x7, %g2 be,pt %xcc, 2f sub %g2, 0x8, %g2 sub %g0, %g2, %g2 sub %o2, %g2, %o2 1: ldub [%o1 + 0x00], %o3 add %o1, 0x1, %o1 add %o0, 0x1, %o0 subcc %g2, 0x1, %g2 bg,pt %icc, 1b stb %o3, [%o0 + -1] 2: andn %o2, 0x7, %g2 sub %o2, %g2, %o2 3: ldx [%o1 + 0x00], %o3 add %o1, 0x8, %o1 add %o0, 0x8, %o0 subcc %g2, 0x8, %g2 bg,pt %icc, 3b stx %o3, [%o0 + -8] cmp %o2, 0 bne,pn %icc, U3memcpy_short nop ba,a,pt %xcc, U3memcpy_short_ret #endif /* !(SMALL_COPY_USES_FPU) */