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202 lines
5.5 KiB
C
202 lines
5.5 KiB
C
/* unaligned.h: unaligned access handler
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*
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* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _ASM_UNALIGNED_H
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#define _ASM_UNALIGNED_H
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/*
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* Unaligned accesses on uClinux can't be performed in a fault handler - the
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* CPU detects them as imprecise exceptions making this impossible.
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*
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* With the FR451, however, they are precise, and so we used to fix them up in
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* the memory access fault handler. However, instruction bundling make this
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* impractical. So, now we fall back to using memcpy.
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*/
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#ifdef CONFIG_MMU
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/*
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* The asm statement in the macros below is a way to get GCC to copy a
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* value from one variable to another without having any clue it's
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* actually doing so, so that it won't have any idea that the values
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* in the two variables are related.
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*/
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#define get_unaligned(ptr) ({ \
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typeof((*(ptr))) __x; \
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void *__ptrcopy; \
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asm("" : "=r" (__ptrcopy) : "0" (ptr)); \
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memcpy(&__x, __ptrcopy, sizeof(*(ptr))); \
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__x; \
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})
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#define put_unaligned(val, ptr) ({ \
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typeof((*(ptr))) __x = (val); \
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void *__ptrcopy; \
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asm("" : "=r" (__ptrcopy) : "0" (ptr)); \
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memcpy(__ptrcopy, &__x, sizeof(*(ptr))); \
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})
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extern int handle_misalignment(unsigned long esr0, unsigned long ear0, unsigned long epcr0);
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#else
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#define get_unaligned(ptr) \
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({ \
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typeof(*(ptr)) x; \
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const char *__p = (const char *) (ptr); \
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\
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switch (sizeof(x)) { \
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case 1: \
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x = *(ptr); \
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break; \
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case 2: \
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{ \
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uint8_t a; \
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asm(" ldub%I2 %M2,%0 \n" \
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" ldub%I3.p %M3,%1 \n" \
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" slli %0,#8,%0 \n" \
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" or %0,%1,%0 \n" \
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: "=&r"(x), "=&r"(a) \
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: "m"(__p[0]), "m"(__p[1]) \
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); \
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break; \
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} \
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\
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case 4: \
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{ \
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uint8_t a; \
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asm(" ldub%I2 %M2,%0 \n" \
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" ldub%I3.p %M3,%1 \n" \
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" slli %0,#8,%0 \n" \
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" or %0,%1,%0 \n" \
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" ldub%I4.p %M4,%1 \n" \
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" slli %0,#8,%0 \n" \
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" or %0,%1,%0 \n" \
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" ldub%I5.p %M5,%1 \n" \
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" slli %0,#8,%0 \n" \
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" or %0,%1,%0 \n" \
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: "=&r"(x), "=&r"(a) \
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: "m"(__p[0]), "m"(__p[1]), "m"(__p[2]), "m"(__p[3]) \
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); \
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break; \
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} \
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\
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case 8: \
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{ \
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union { uint64_t x; u32 y[2]; } z; \
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uint8_t a; \
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asm(" ldub%I3 %M3,%0 \n" \
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" ldub%I4.p %M4,%2 \n" \
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" slli %0,#8,%0 \n" \
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" or %0,%2,%0 \n" \
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" ldub%I5.p %M5,%2 \n" \
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" slli %0,#8,%0 \n" \
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" or %0,%2,%0 \n" \
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" ldub%I6.p %M6,%2 \n" \
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" slli %0,#8,%0 \n" \
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" or %0,%2,%0 \n" \
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" ldub%I7 %M7,%1 \n" \
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" ldub%I8.p %M8,%2 \n" \
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" slli %1,#8,%1 \n" \
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" or %1,%2,%1 \n" \
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" ldub%I9.p %M9,%2 \n" \
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" slli %1,#8,%1 \n" \
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" or %1,%2,%1 \n" \
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" ldub%I10.p %M10,%2 \n" \
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" slli %1,#8,%1 \n" \
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" or %1,%2,%1 \n" \
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: "=&r"(z.y[0]), "=&r"(z.y[1]), "=&r"(a) \
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: "m"(__p[0]), "m"(__p[1]), "m"(__p[2]), "m"(__p[3]), \
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"m"(__p[4]), "m"(__p[5]), "m"(__p[6]), "m"(__p[7]) \
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); \
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x = z.x; \
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break; \
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} \
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\
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default: \
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x = 0; \
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BUG(); \
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break; \
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} \
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\
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x; \
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})
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#define put_unaligned(val, ptr) \
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do { \
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char *__p = (char *) (ptr); \
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int x; \
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\
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switch (sizeof(*ptr)) { \
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case 2: \
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{ \
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asm(" stb%I1.p %0,%M1 \n" \
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" srli %0,#8,%0 \n" \
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" stb%I2 %0,%M2 \n" \
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: "=r"(x), "=m"(__p[1]), "=m"(__p[0]) \
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: "0"(val) \
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); \
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break; \
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} \
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\
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case 4: \
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{ \
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asm(" stb%I1.p %0,%M1 \n" \
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" srli %0,#8,%0 \n" \
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" stb%I2.p %0,%M2 \n" \
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" srli %0,#8,%0 \n" \
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" stb%I3.p %0,%M3 \n" \
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" srli %0,#8,%0 \n" \
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" stb%I4 %0,%M4 \n" \
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: "=r"(x), "=m"(__p[3]), "=m"(__p[2]), "=m"(__p[1]), "=m"(__p[0]) \
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: "0"(val) \
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); \
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break; \
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} \
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\
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case 8: \
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{ \
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uint32_t __high, __low; \
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__high = (uint64_t)val >> 32; \
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__low = val & 0xffffffff; \
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asm(" stb%I2.p %0,%M2 \n" \
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" srli %0,#8,%0 \n" \
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" stb%I3.p %0,%M3 \n" \
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" srli %0,#8,%0 \n" \
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" stb%I4.p %0,%M4 \n" \
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" srli %0,#8,%0 \n" \
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" stb%I5.p %0,%M5 \n" \
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" srli %0,#8,%0 \n" \
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" stb%I6.p %1,%M6 \n" \
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" srli %1,#8,%1 \n" \
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" stb%I7.p %1,%M7 \n" \
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" srli %1,#8,%1 \n" \
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" stb%I8.p %1,%M8 \n" \
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" srli %1,#8,%1 \n" \
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" stb%I9 %1,%M9 \n" \
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: "=&r"(__low), "=&r"(__high), "=m"(__p[7]), "=m"(__p[6]), \
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"=m"(__p[5]), "=m"(__p[4]), "=m"(__p[3]), "=m"(__p[2]), \
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"=m"(__p[1]), "=m"(__p[0]) \
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: "0"(__low), "1"(__high) \
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); \
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break; \
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} \
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\
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default: \
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*(ptr) = (val); \
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break; \
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} \
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} while(0)
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#endif
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#endif
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