| /**************************************************************************** |
| * libs/libc/machine/xtensa/arch_memcpy.S |
| * |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. The |
| * ASF licenses this file to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance with the |
| * License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| * License for the specific language governing permissions and limitations |
| * under the License. |
| * |
| ****************************************************************************/ |
| |
| /**************************************************************************** |
| * Included Files |
| ****************************************************************************/ |
| |
| #include "xtensa_asm.h" |
| |
| #include <arch/chip/core-isa.h> |
| #include <arch/xtensa/xtensa_abi.h> |
| |
| #include "libc.h" |
| |
| #ifdef LIBC_BUILD_MEMCPY |
| |
| /**************************************************************************** |
| * Pre-processor Macros |
| ****************************************************************************/ |
| |
| /* set to 1 when running on ISS (simulator) with the |
| lint or ferret client, or 0 to save a few cycles */ |
| |
| #define SIM_CHECKS_ALIGNMENT 0 |
| |
| /**************************************************************************** |
| * Public Functions |
| ****************************************************************************/ |
| |
| .section .text |
| .begin schedule |
| .literal_position |
| |
| .local .Ldst1mod2 |
| .local .Ldst2mod4 |
| .local .Lbytecopy |
| |
| .align 4 |
| .global memcpy |
| .type memcpy, @function |
| memcpy: |
| ENTRY(16) |
| /* a2 = dst, a3 = src, a4 = len */ |
| |
| mov a5, a2 # copy dst so that a2 is return value |
| bbsi.l a2, 0, .Ldst1mod2 |
| bbsi.l a2, 1, .Ldst2mod4 |
| .Ldstaligned: |
| |
| /* Get number of loop iterations with 16B per iteration. */ |
| srli a7, a4, 4 |
| |
| /* Check if source is aligned. */ |
| slli a8, a3, 30 |
| bnez a8, .Lsrcunaligned |
| |
| /* Destination and source are word-aligned, use word copy. */ |
| #if XCHAL_HAVE_LOOPS |
| loopnez a7, 2f |
| #else |
| beqz a7, 2f |
| slli a8, a7, 4 |
| add a8, a8, a3 # a8 = end of last 16B source chunk |
| #endif |
| 1: 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 |
| bltu a3, a8, 1b |
| #endif |
| |
| /* Copy any leftover pieces smaller than 16B. */ |
| 2: bbci.l a4, 3, 3f |
| |
| /* 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 |
| |
| 3: bbsi.l a4, 2, 4f |
| bbsi.l a4, 1, 5f |
| bbsi.l a4, 0, 6f |
| RET(16) |
| |
| # .align 4 |
| /* Copy 4 bytes. */ |
| 4: l32i a6, a3, 0 |
| addi a3, a3, 4 |
| s32i a6, a5, 0 |
| addi a5, a5, 4 |
| bbsi.l a4, 1, 5f |
| bbsi.l a4, 0, 6f |
| RET(16) |
| |
| /* Copy 2 bytes. */ |
| 5: l16ui a6, a3, 0 |
| addi a3, a3, 2 |
| s16i a6, a5, 0 |
| addi a5, a5, 2 |
| bbsi.l a4, 0, 6f |
| RET(16) |
| |
| /* Copy 1 byte. */ |
| 6: l8ui a6, a3, 0 |
| s8i a6, a5, 0 |
| |
| .Ldone: |
| RET(16) |
| |
| /* Destination is aligned; source is unaligned. */ |
| |
| # .align 4 |
| .Lsrcunaligned: |
| /* Avoid loading anything for zero-length copies. */ |
| beqz a4, .Ldone |
| |
| /* Copy 16 bytes per iteration for word-aligned dst and |
| unaligned src. */ |
| ssa8 a3 # set shift amount from byte offset |
| #if XCHAL_UNALIGNED_LOAD_EXCEPTION || SIM_CHECKS_ALIGNMENT |
| srli a11, a8, 30 # 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, 2f |
| #else |
| beqz a7, 2f |
| slli a10, a7, 4 |
| add a10, a10, a3 # a10 = end of last 16B source chunk |
| #endif |
| 1: 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 |
| bltu a3, a10, 1b |
| #endif |
| |
| 2: bbci.l a4, 3, 3f |
| |
| /* 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 |
| |
| 3: bbci.l a4, 2, 4f |
| |
| /* 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 |
| 4: |
| #if XCHAL_UNALIGNED_LOAD_EXCEPTION || SIM_CHECKS_ALIGNMENT |
| add a3, a3, a11 # readjust a3 with correct misalignment |
| #endif |
| bbsi.l a4, 1, 5f |
| bbsi.l a4, 0, 6f |
| RET(16) |
| |
| /* Copy 2 bytes. */ |
| 5: 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, 6f |
| RET(16) |
| |
| /* Copy 1 byte. */ |
| 6: l8ui a6, a3, 0 |
| s8i a6, a5, 0 |
| RET(16) |
| |
| # .align XCHAL_INST_FETCH_WIDTH |
| __memcpy_aux: |
| |
| /* Skip bytes to get proper alignment for three-byte loop */ |
| # .skip XCHAL_INST_FETCH_WIDTH - 3 |
| |
| .Lbytecopy: |
| #if XCHAL_HAVE_LOOPS |
| loopnez a4, 2f |
| #else |
| beqz a4, 2f |
| add a7, a3, a4 # a7 = end address for source |
| #endif |
| 1: l8ui a6, a3, 0 |
| addi a3, a3, 1 |
| s8i a6, a5, 0 |
| addi a5, a5, 1 |
| #if !XCHAL_HAVE_LOOPS |
| bltu a3, a7, 1b |
| #endif |
| 2: RET(16) |
| |
| /* Destination is unaligned. */ |
| |
| # .align 4 |
| .Ldst1mod2: # dst is only byte aligned |
| |
| /* Do short copies byte-by-byte. */ |
| bltui a4, 7, .Lbytecopy |
| |
| /* Copy 1 byte. */ |
| l8ui a6, a3, 0 |
| addi a3, a3, 1 |
| addi a4, a4, -1 |
| s8i a6, a5, 0 |
| addi a5, a5, 1 |
| |
| /* Return to main algorithm if dst is now aligned. */ |
| bbci.l a5, 1, .Ldstaligned |
| |
| .Ldst2mod4: # dst has 16-bit alignment |
| |
| /* Do short copies byte-by-byte. */ |
| bltui a4, 6, .Lbytecopy |
| |
| /* Copy 2 bytes. */ |
| 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 |
| |
| /* dst is now aligned; return to main algorithm. */ |
| j .Ldstaligned |
| |
| .end schedule |
| |
| .size memcpy, . - memcpy |
| |
| #endif |
