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108 lines
2.1 KiB
108 lines
2.1 KiB
/* SPDX-License-Identifier: GPL-2.0-only */ |
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/* |
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* Copyright (C) 2013 Regents of the University of California |
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*/ |
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#include <linux/linkage.h> |
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#include <asm/asm.h> |
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/* void *memcpy(void *, const void *, size_t) */ |
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ENTRY(__memcpy) |
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WEAK(memcpy) |
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move t6, a0 /* Preserve return value */ |
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/* Defer to byte-oriented copy for small sizes */ |
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sltiu a3, a2, 128 |
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bnez a3, 4f |
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/* Use word-oriented copy only if low-order bits match */ |
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andi a3, t6, SZREG-1 |
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andi a4, a1, SZREG-1 |
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bne a3, a4, 4f |
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beqz a3, 2f /* Skip if already aligned */ |
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/* |
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* Round to nearest double word-aligned address |
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* greater than or equal to start address |
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*/ |
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andi a3, a1, ~(SZREG-1) |
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addi a3, a3, SZREG |
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/* Handle initial misalignment */ |
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sub a4, a3, a1 |
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1: |
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lb a5, 0(a1) |
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addi a1, a1, 1 |
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sb a5, 0(t6) |
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addi t6, t6, 1 |
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bltu a1, a3, 1b |
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sub a2, a2, a4 /* Update count */ |
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2: |
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andi a4, a2, ~((16*SZREG)-1) |
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beqz a4, 4f |
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add a3, a1, a4 |
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3: |
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REG_L a4, 0(a1) |
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REG_L a5, SZREG(a1) |
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REG_L a6, 2*SZREG(a1) |
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REG_L a7, 3*SZREG(a1) |
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REG_L t0, 4*SZREG(a1) |
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REG_L t1, 5*SZREG(a1) |
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REG_L t2, 6*SZREG(a1) |
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REG_L t3, 7*SZREG(a1) |
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REG_L t4, 8*SZREG(a1) |
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REG_L t5, 9*SZREG(a1) |
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REG_S a4, 0(t6) |
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REG_S a5, SZREG(t6) |
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REG_S a6, 2*SZREG(t6) |
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REG_S a7, 3*SZREG(t6) |
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REG_S t0, 4*SZREG(t6) |
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REG_S t1, 5*SZREG(t6) |
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REG_S t2, 6*SZREG(t6) |
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REG_S t3, 7*SZREG(t6) |
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REG_S t4, 8*SZREG(t6) |
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REG_S t5, 9*SZREG(t6) |
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REG_L a4, 10*SZREG(a1) |
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REG_L a5, 11*SZREG(a1) |
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REG_L a6, 12*SZREG(a1) |
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REG_L a7, 13*SZREG(a1) |
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REG_L t0, 14*SZREG(a1) |
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REG_L t1, 15*SZREG(a1) |
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addi a1, a1, 16*SZREG |
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REG_S a4, 10*SZREG(t6) |
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REG_S a5, 11*SZREG(t6) |
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REG_S a6, 12*SZREG(t6) |
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REG_S a7, 13*SZREG(t6) |
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REG_S t0, 14*SZREG(t6) |
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REG_S t1, 15*SZREG(t6) |
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addi t6, t6, 16*SZREG |
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bltu a1, a3, 3b |
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andi a2, a2, (16*SZREG)-1 /* Update count */ |
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4: |
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/* Handle trailing misalignment */ |
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beqz a2, 6f |
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add a3, a1, a2 |
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/* Use word-oriented copy if co-aligned to word boundary */ |
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or a5, a1, t6 |
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or a5, a5, a3 |
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andi a5, a5, 3 |
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bnez a5, 5f |
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7: |
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lw a4, 0(a1) |
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addi a1, a1, 4 |
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sw a4, 0(t6) |
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addi t6, t6, 4 |
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bltu a1, a3, 7b |
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ret |
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5: |
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lb a4, 0(a1) |
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addi a1, a1, 1 |
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sb a4, 0(t6) |
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addi t6, t6, 1 |
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bltu a1, a3, 5b |
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6: |
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ret |
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END(__memcpy)
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