Messages in this thread | | | From | Tom Bjorkholm <> | Subject | Fix: bitops.h g++ compiler warnings | Date | Thu, 28 Mar 1996 17:08:09 +0100 (MET) |
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Hi,
include/asm/bitops.h has produced a set of very annoying warnings when compiling C++ programs (string constant spanned multiple lines).
Below is a fixed version of include/asm/bitops.h . (my version is 1.3.77)
--------------------- cut here --------------------------------- #ifndef _I386_BITOPS_H #define _I386_BITOPS_H
/* * Copyright 1992, Linus Torvalds. */
/* * These have to be done with inline assembly: that way the bit-setting * is guaranteed to be atomic. All bit operations return 0 if the bit * was cleared before the operation and != 0 if it was not. * * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1). */
#ifdef __SMP__ #define LOCK_PREFIX "lock ; " #define SMPVOL volatile #else #define LOCK_PREFIX "" #define SMPVOL #endif
/* * Some hacks to defeat gcc over-optimizations.. */ struct __dummy { unsigned long a[100]; }; #define ADDR (*(struct __dummy *) addr) #define CONST_ADDR (*(const struct __dummy *) addr)
extern __inline__ int set_bit(int nr, SMPVOL void * addr) { int oldbit;
__asm__ __volatile__(LOCK_PREFIX "btsl %2,%1\n\tsbbl %0,%0" :"=r" (oldbit),"=m" (ADDR) :"ir" (nr)); return oldbit; }
extern __inline__ int clear_bit(int nr, SMPVOL void * addr) { int oldbit;
__asm__ __volatile__(LOCK_PREFIX "btrl %2,%1\n\tsbbl %0,%0" :"=r" (oldbit),"=m" (ADDR) :"ir" (nr)); return oldbit; }
extern __inline__ int change_bit(int nr, SMPVOL void * addr) { int oldbit;
__asm__ __volatile__(LOCK_PREFIX "btcl %2,%1\n\tsbbl %0,%0" :"=r" (oldbit),"=m" (ADDR) :"ir" (nr)); return oldbit; }
/* * This routine doesn't need to be atomic. */ extern __inline__ int test_bit(int nr, const SMPVOL void * addr) { return 1UL & (((const unsigned int *) addr)[nr >> 5] >> (nr & 31)); }
/* * Find-bit routines.. */ extern __inline__ int find_first_zero_bit(void * addr, unsigned size) { int res;
if (!size) return 0; __asm__("\ cld;\ movl $-1,%%eax;\ xorl %%edx,%%edx;\ repe; scasl;\ je 1f;\ xorl -4(%%edi),%%eax;\ subl $4,%%edi;\ bsfl %%eax,%%edx;\ 1: subl %%ebx,%%edi;\ shll $3,%%edi;\ addl %%edi,%%edx" :"=d" (res) :"c" ((size + 31) >> 5), "D" (addr), "b" (addr) :"ax", "cx", "di"); return res; }
extern __inline__ int find_next_zero_bit (void * addr, int size, int offset) { unsigned long * p = ((unsigned long *) addr) + (offset >> 5); int set = 0, bit = offset & 31, res; if (bit) { /* * Look for zero in first byte */ __asm__("\ bsfl %1,%0;\ jne 1f;\ movl $32, %0;\ 1: " : "=r" (set) : "r" (~(*p >> bit))); if (set < (32 - bit)) return set + offset; set = 32 - bit; p++; } /* * No zero yet, search remaining full bytes for a zero */ res = find_first_zero_bit (p, size - 32 * (p - (unsigned long *) addr)); return (offset + set + res); }
/* * ffz = Find First Zero in word. Undefined if no zero exists, * so code should check against ~0UL first.. */ extern __inline__ unsigned long ffz(unsigned long word) { __asm__("bsfl %1,%0" :"=r" (word) :"r" (~word)); return word; }
#endif /* _I386_BITOPS_H */ --------------------- cut here --------------------------------- /Tom -- --------------------------------------------------------------- Tom Bjorkholm MYDATA automation AB tel: +46 8 629 09 00 Karlsbodavagen 39 fax: +46 8 629 09 09 S-161 70 Bromma, Sweden
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