| /* |
| * arch/xtensa/lib/hal/memcopy.S -- Core HAL library functions |
| * xthal_memcpy and xthal_bcopy |
| * |
| * This file is subject to the terms and conditions of the GNU General Public |
| * License. See the file "COPYING" in the main directory of this archive |
| * for more details. |
| * |
| * Copyright (C) 2002 - 2005 Tensilica Inc. |
| */ |
| |
| #include <variant/core.h> |
| |
| .macro src_b r, w0, w1 |
| #ifdef __XTENSA_EB__ |
| src \r, \w0, \w1 |
| #else |
| src \r, \w1, \w0 |
| #endif |
| .endm |
| |
| .macro ssa8 r |
| #ifdef __XTENSA_EB__ |
| ssa8b \r |
| #else |
| ssa8l \r |
| #endif |
| .endm |
| |
| |
| /* |
| * void *memcpy(void *dst, const void *src, size_t len); |
| * void *memmove(void *dst, const void *src, size_t len); |
| * void *bcopy(const void *src, void *dst, size_t len); |
| * |
| * This function is intended to do the same thing as the standard |
| * library function memcpy() (or bcopy()) for most cases. |
| * However, where the source and/or destination references |
| * an instruction RAM or ROM or a data RAM or ROM, that |
| * source and/or destination will always be accessed with |
| * 32-bit load and store instructions (as required for these |
| * types of devices). |
| * |
| * !!!!!!! XTFIXME: |
| * !!!!!!! Handling of IRAM/IROM has not yet |
| * !!!!!!! been implemented. |
| * |
| * The bcopy version is provided here to avoid the overhead |
| * of an extra call, for callers that require this convention. |
| * |
| * The (general case) algorithm is as follows: |
| * If destination is unaligned, align it by conditionally |
| * copying 1 and 2 bytes. |
| * If source is aligned, |
| * do 16 bytes with a loop, and then finish up with |
| * 8, 4, 2, and 1 byte copies conditional on the length; |
| * else (if source is unaligned), |
| * do the same, but use SRC to align the source data. |
| * This code tries to use fall-through branches for the common |
| * case of aligned source and destination and multiple |
| * of 4 (or 8) length. |
| * |
| * Register use: |
| * a0/ return address |
| * a1/ stack pointer |
| * a2/ return value |
| * a3/ src |
| * a4/ length |
| * a5/ dst |
| * a6/ tmp |
| * a7/ tmp |
| * a8/ tmp |
| * a9/ tmp |
| * a10/ tmp |
| * a11/ tmp |
| */ |
| |
| .text |
| .align 4 |
| .global bcopy |
| .type bcopy,@function |
| bcopy: |
| entry sp, 16 # minimal stack frame |
| # a2=src, a3=dst, a4=len |
| mov a5, a3 # copy dst so that a2 is return value |
| mov a3, a2 |
| mov a2, a5 |
| j .Lcommon # go to common code for memcpy+bcopy |
| |
| |
| /* |
| * Byte by byte copy |
| */ |
| .align 4 |
| .byte 0 # 1 mod 4 alignment for LOOPNEZ |
| # (0 mod 4 alignment for LBEG) |
| .Lbytecopy: |
| #if XCHAL_HAVE_LOOPS |
| loopnez a4, .Lbytecopydone |
| #else /* !XCHAL_HAVE_LOOPS */ |
| beqz a4, .Lbytecopydone |
| add a7, a3, a4 # a7 = end address for source |
| #endif /* !XCHAL_HAVE_LOOPS */ |
| .Lnextbyte: |
| l8ui a6, a3, 0 |
| addi a3, a3, 1 |
| s8i a6, a5, 0 |
| addi a5, a5, 1 |
| #if !XCHAL_HAVE_LOOPS |
| blt a3, a7, .Lnextbyte |
| #endif /* !XCHAL_HAVE_LOOPS */ |
| .Lbytecopydone: |
| retw |
| |
| /* |
| * Destination is unaligned |
| */ |
| |
| .align 4 |
| .Ldst1mod2: # dst is only byte aligned |
| _bltui a4, 7, .Lbytecopy # do short copies byte by byte |
| |
| # copy 1 byte |
| l8ui a6, a3, 0 |
| addi a3, a3, 1 |
| addi a4, a4, -1 |
| s8i a6, a5, 0 |
| addi a5, a5, 1 |
| _bbci.l a5, 1, .Ldstaligned # if dst is now aligned, then |
| # return to main algorithm |
| .Ldst2mod4: # dst 16-bit aligned |
| # copy 2 bytes |
| _bltui a4, 6, .Lbytecopy # do short copies byte by byte |
| l8ui a6, a3, 0 |
| l8ui a7, a3, 1 |
| addi a3, a3, 2 |
| addi a4, a4, -2 |
| s8i a6, a5, 0 |
| s8i a7, a5, 1 |
| addi a5, a5, 2 |
| j .Ldstaligned # dst is now aligned, return to main algorithm |
| |
| .align 4 |
| .global memcpy |
| .type memcpy,@function |
| memcpy: |
| .global memmove |
| .type memmove,@function |
| memmove: |
| |
| entry sp, 16 # minimal stack frame |
| # a2/ dst, a3/ src, a4/ len |
| mov a5, a2 # copy dst so that a2 is return value |
| .Lcommon: |
| _bbsi.l a2, 0, .Ldst1mod2 # if dst is 1 mod 2 |
| _bbsi.l a2, 1, .Ldst2mod4 # if dst is 2 mod 4 |
| .Ldstaligned: # return here from .Ldst?mod? once dst is aligned |
| srli a7, a4, 4 # number of loop iterations with 16B |
| # per iteration |
| movi a8, 3 # if source is not aligned, |
| _bany a3, a8, .Lsrcunaligned # then use shifting copy |
| /* |
| * Destination and source are word-aligned, use word copy. |
| */ |
| # copy 16 bytes per iteration for word-aligned dst and word-aligned src |
| #if XCHAL_HAVE_LOOPS |
| loopnez a7, .Loop1done |
| #else /* !XCHAL_HAVE_LOOPS */ |
| beqz a7, .Loop1done |
| slli a8, a7, 4 |
| add a8, a8, a3 # a8 = end of last 16B source chunk |
| #endif /* !XCHAL_HAVE_LOOPS */ |
| .Loop1: |
| l32i a6, a3, 0 |
| l32i a7, a3, 4 |
| s32i a6, a5, 0 |
| l32i a6, a3, 8 |
| s32i a7, a5, 4 |
| l32i a7, a3, 12 |
| s32i a6, a5, 8 |
| addi a3, a3, 16 |
| s32i a7, a5, 12 |
| addi a5, a5, 16 |
| #if !XCHAL_HAVE_LOOPS |
| blt a3, a8, .Loop1 |
| #endif /* !XCHAL_HAVE_LOOPS */ |
| .Loop1done: |
| bbci.l a4, 3, .L2 |
| # copy 8 bytes |
| l32i a6, a3, 0 |
| l32i a7, a3, 4 |
| addi a3, a3, 8 |
| s32i a6, a5, 0 |
| s32i a7, a5, 4 |
| addi a5, a5, 8 |
| .L2: |
| bbsi.l a4, 2, .L3 |
| bbsi.l a4, 1, .L4 |
| bbsi.l a4, 0, .L5 |
| retw |
| .L3: |
| # copy 4 bytes |
| l32i a6, a3, 0 |
| addi a3, a3, 4 |
| s32i a6, a5, 0 |
| addi a5, a5, 4 |
| bbsi.l a4, 1, .L4 |
| bbsi.l a4, 0, .L5 |
| retw |
| .L4: |
| # copy 2 bytes |
| l16ui a6, a3, 0 |
| addi a3, a3, 2 |
| s16i a6, a5, 0 |
| addi a5, a5, 2 |
| bbsi.l a4, 0, .L5 |
| retw |
| .L5: |
| # copy 1 byte |
| l8ui a6, a3, 0 |
| s8i a6, a5, 0 |
| retw |
| |
| /* |
| * Destination is aligned, Source is unaligned |
| */ |
| |
| .align 4 |
| .Lsrcunaligned: |
| _beqz a4, .Ldone # avoid loading anything for zero-length copies |
| # copy 16 bytes per iteration for word-aligned dst and unaligned src |
| ssa8 a3 # set shift amount from byte offset |
| #define SIM_CHECKS_ALIGNMENT 1 /* set to 1 when running on ISS (simulator) with the |
| lint or ferret client, or 0 to save a few cycles */ |
| #if XCHAL_UNALIGNED_LOAD_EXCEPTION || SIM_CHECKS_ALIGNMENT |
| and a11, a3, a8 # save unalignment offset for below |
| sub a3, a3, a11 # align a3 |
| #endif |
| l32i a6, a3, 0 # load first word |
| #if XCHAL_HAVE_LOOPS |
| loopnez a7, .Loop2done |
| #else /* !XCHAL_HAVE_LOOPS */ |
| beqz a7, .Loop2done |
| slli a10, a7, 4 |
| add a10, a10, a3 # a10 = end of last 16B source chunk |
| #endif /* !XCHAL_HAVE_LOOPS */ |
| .Loop2: |
| l32i a7, a3, 4 |
| l32i a8, a3, 8 |
| src_b a6, a6, a7 |
| s32i a6, a5, 0 |
| l32i a9, a3, 12 |
| src_b a7, a7, a8 |
| s32i a7, a5, 4 |
| l32i a6, a3, 16 |
| src_b a8, a8, a9 |
| s32i a8, a5, 8 |
| addi a3, a3, 16 |
| src_b a9, a9, a6 |
| s32i a9, a5, 12 |
| addi a5, a5, 16 |
| #if !XCHAL_HAVE_LOOPS |
| blt a3, a10, .Loop2 |
| #endif /* !XCHAL_HAVE_LOOPS */ |
| .Loop2done: |
| bbci.l a4, 3, .L12 |
| # copy 8 bytes |
| l32i a7, a3, 4 |
| l32i a8, a3, 8 |
| src_b a6, a6, a7 |
| s32i a6, a5, 0 |
| addi a3, a3, 8 |
| src_b a7, a7, a8 |
| s32i a7, a5, 4 |
| addi a5, a5, 8 |
| mov a6, a8 |
| .L12: |
| bbci.l a4, 2, .L13 |
| # copy 4 bytes |
| l32i a7, a3, 4 |
| addi a3, a3, 4 |
| src_b a6, a6, a7 |
| s32i a6, a5, 0 |
| addi a5, a5, 4 |
| mov a6, a7 |
| .L13: |
| #if XCHAL_UNALIGNED_LOAD_EXCEPTION || SIM_CHECKS_ALIGNMENT |
| add a3, a3, a11 # readjust a3 with correct misalignment |
| #endif |
| bbsi.l a4, 1, .L14 |
| bbsi.l a4, 0, .L15 |
| .Ldone: retw |
| .L14: |
| # copy 2 bytes |
| l8ui a6, a3, 0 |
| l8ui a7, a3, 1 |
| addi a3, a3, 2 |
| s8i a6, a5, 0 |
| s8i a7, a5, 1 |
| addi a5, a5, 2 |
| bbsi.l a4, 0, .L15 |
| retw |
| .L15: |
| # copy 1 byte |
| l8ui a6, a3, 0 |
| s8i a6, a5, 0 |
| retw |
| |
| /* |
| * Local Variables: |
| * mode:fundamental |
| * comment-start: "# " |
| * comment-start-skip: "# *" |
| * End: |
| */ |