diff options
Diffstat (limited to 'util/mkelfImage/kunzip_src/arch/alpha/lib/divide.S')
| -rw-r--r-- | util/mkelfImage/kunzip_src/arch/alpha/lib/divide.S | 195 |
1 files changed, 0 insertions, 195 deletions
diff --git a/util/mkelfImage/kunzip_src/arch/alpha/lib/divide.S b/util/mkelfImage/kunzip_src/arch/alpha/lib/divide.S deleted file mode 100644 index 863e881348..0000000000 --- a/util/mkelfImage/kunzip_src/arch/alpha/lib/divide.S +++ /dev/null @@ -1,195 +0,0 @@ -/* - * cpu/ev6/divide.S - * - * (C) 1995 Linus Torvalds - * - * Alpha division.. - */ - -/* - * The alpha chip doesn't provide hardware division, so we have to do it - * by hand. The compiler expects the functions - * - * __divqu: 64-bit unsigned long divide - * __remqu: 64-bit unsigned long remainder - * __divqs/__remqs: signed 64-bit - * __divlu/__remlu: unsigned 32-bit - * __divls/__remls: signed 32-bit - * - * These are not normal C functions: instead of the normal - * calling sequence, these expect their arguments in registers - * $24 and $25, and return the result in $27. Register $28 may - * be clobbered (assembly temporary), anything else must be saved. - * - * In short: painful. - * - * This is a rather simple bit-at-a-time algorithm: it's very good - * at dividing random 64-bit numbers, but the more usual case where - * the divisor is small is handled better by the DEC algorithm - * using lookup tables. This uses much less memory, though, and is - * nicer on the cache.. Besides, I don't know the copyright status - * of the DEC code. - */ - -/* - * My temporaries: - * $0 - current bit - * $1 - shifted divisor - * $2 - modulus/quotient - * - * $23 - return address - * $24 - dividend - * $25 - divisor - * - * $27 - quotient/modulus - * $28 - compare status - */ - -#define halt .long 0 - -/* - * Select function type and registers - */ -#define mask $0 -#define divisor $1 -#define compare $28 -#define tmp1 $3 -#define tmp2 $4 - -#ifdef DIV -#define DIV_ONLY(x,y...) x,##y -#define MOD_ONLY(x,y...) -#define func(x) __div##x -#define modulus $2 -#define quotient $27 -#define GETSIGN(x) xor $24,$25,x -#define STACK 48 -#else -#define DIV_ONLY(x,y...) -#define MOD_ONLY(x,y...) x,##y -#define func(x) __rem##x -#define modulus $27 -#define quotient $2 -#define GETSIGN(x) bis $24,$24,x -#define STACK 32 -#endif - -/* - * For 32-bit operations, we need to extend to 64-bit - */ -#ifdef INTSIZE -#define ufunction func(lu) -#define sfunction func(l) -#define LONGIFY(x) zapnot x,15,x -#define SLONGIFY(x) addl x,0,x -#else -#define ufunction func(qu) -#define sfunction func(q) -#define LONGIFY(x) -#define SLONGIFY(x) -#endif - -.set noat -.align 3 -.globl ufunction -.ent ufunction -ufunction: - subq $30,STACK,$30 - .frame $30,STACK,$23 - .prologue 0 - -7: stq $1, 0($30) - bis $25,$25,divisor - stq $2, 8($30) - bis $24,$24,modulus - stq $0,16($30) - bis $31,$31,quotient - LONGIFY(divisor) - stq tmp1,24($30) - LONGIFY(modulus) - bis $31,1,mask - DIV_ONLY(stq tmp2,32($30)) - beq divisor, 9f /* div by zero */ - -#ifdef INTSIZE - /* - * shift divisor left, using 3-bit shifts for - * 32-bit divides as we can't overflow. Three-bit - * shifts will result in looping three times less - * here, but can result in two loops more later. - * Thus using a large shift isn't worth it (and - * s8add pairs better than a sll..) - */ -1: cmpult divisor,modulus,compare - s8addq divisor,$31,divisor - s8addq mask,$31,mask - bne compare,1b -#else -1: cmpult divisor,modulus,compare - blt divisor, 2f - addq divisor,divisor,divisor - addq mask,mask,mask - bne compare,1b - unop -#endif - - /* ok, start to go right again.. */ -2: DIV_ONLY(addq quotient,mask,tmp2) - srl mask,1,mask - cmpule divisor,modulus,compare - subq modulus,divisor,tmp1 - DIV_ONLY(cmovne compare,tmp2,quotient) - srl divisor,1,divisor - cmovne compare,tmp1,modulus - bne mask,2b - -9: ldq $1, 0($30) - ldq $2, 8($30) - ldq $0,16($30) - ldq tmp1,24($30) - DIV_ONLY(ldq tmp2,32($30)) - addq $30,STACK,$30 - ret $31,($23),1 - .end ufunction - -/* - * Uhh.. Ugly signed division. I'd rather not have it at all, but - * it's needed in some circumstances. There are different ways to - * handle this, really. This does: - * -a / b = a / -b = -(a / b) - * -a % b = -(a % b) - * a % -b = a % b - * which is probably not the best solution, but at least should - * have the property that (x/y)*y + (x%y) = x. - */ -.align 3 -.globl sfunction -.ent sfunction -sfunction: - subq $30,STACK,$30 - .frame $30,STACK,$23 - .prologue 0 - bis $24,$25,$28 - SLONGIFY($28) - bge $28,7b - stq $24,0($30) - subq $31,$24,$28 - stq $25,8($30) - cmovlt $24,$28,$24 /* abs($24) */ - stq $23,16($30) - subq $31,$25,$28 - stq tmp1,24($30) - cmovlt $25,$28,$25 /* abs($25) */ - unop - bsr $23,ufunction - ldq $24,0($30) - ldq $25,8($30) - GETSIGN($28) - subq $31,$27,tmp1 - SLONGIFY($28) - ldq $23,16($30) - cmovlt $28,tmp1,$27 - ldq tmp1,24($30) - addq $30,STACK,$30 - ret $31,($23),1 - .end sfunction |