diff options
Diffstat (limited to 'sysdeps/alpha/divrem.h')
| -rw-r--r-- | sysdeps/alpha/divrem.h | 308 |
1 files changed, 173 insertions, 135 deletions
diff --git a/sysdeps/alpha/divrem.h b/sysdeps/alpha/divrem.h index eaf892b3c6..b83908dc9f 100644 --- a/sysdeps/alpha/divrem.h +++ b/sysdeps/alpha/divrem.h @@ -1,25 +1,25 @@ /* Copyright (C) 1996 Free Software Foundation, Inc. Contributed by David Mosberger (davidm@cs.arizona.edu). -This file is part of the GNU C Library. + This file is part of the GNU C Library. -The GNU C Library is free software; you can redistribute it and/or -modify it under the terms of the GNU Library General Public License as -published by the Free Software Foundation; either version 2 of the -License, or (at your option) any later version. + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. -The GNU C Library is distributed in the hope that it will be useful, -but WITHOUT ANY WARRANTY; without even the implied warranty of -MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU -Library General Public License for more details. + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. -You should have received a copy of the GNU Library General Public -License along with the GNU C Library; see the file COPYING.LIB. If -not, write to the Free Software Foundation, Inc., 675 Mass Ave, -Cambridge, MA 02139, USA. */ + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If + not, write to the Free Software Foundation, Inc., 675 Mass Ave, + Cambridge, MA 02139, USA. */ /* The current Alpha chips don't provide hardware for integer -division. The C compiler expects the functions + division. The C compiler expects the functions __divqu: 64-bit unsigned long divide __remqu: 64-bit unsigned long remainder @@ -27,10 +27,10 @@ division. The C compiler expects the functions __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 t10 and t11, and -return the result in t12 (aka pv). Register AT may be clobbered -(assembly temporary), anything else must be saved. */ + These are not normal C functions: instead of the normal calling + sequence, these expect their arguments in registers t10 and t11, and + return the result in t12 (aka pv). Register AT may be clobbered + (assembly temporary), anything else must be saved. */ #include <sysdep.h> @@ -41,147 +41,185 @@ return the result in t12 (aka pv). Register AT may be clobbered # include <machine/pal.h> #endif -#ifdef DEBUG -# define arg1 a0 -# define arg2 a1 -# define result v0 -# define mask t0 -# define tmp0 t1 -# define tmp1 t2 -# define sign t3 -# define retaddr ra -#else -# define arg1 t10 -# define arg2 t11 -# define result t12 -# define mask v0 -# define tmp0 t0 -# define tmp1 t1 -# define sign t2 -# define retaddr t9 -#endif +#define mask v0 +#define divisor t0 +#define compare AT +#define tmp1 t2 +#define tmp2 t3 +#define retaddr t9 +#define arg1 t10 +#define arg2 t11 +#define result t12 -# define divisor arg2 #if IS_REM -# define dividend result -# define quotient arg1 -# define GETDIVIDEND bis arg1,zero,dividend +# define DIV_ONLY(x,y...) +# define REM_ONLY(x,y...) x,##y +# define modulus result +# define quotient t1 +# define GETSIGN(x) mov arg1, x +# define STACK 32 #else -# define dividend arg1 -# define quotient result -# define GETDIVIDEND +# define DIV_ONLY(x,y...) x,##y +# define REM_ONLY(x,y...) +# define modulus t1 +# define quotient result +# define GETSIGN(x) xor arg1, arg2, x +# define STACK 48 #endif #if SIZE == 8 -# define LONGIFYarg1 GETDIVIDEND -# define LONGIFYarg2 -#else -# if SIGNED -# define LONGIFYarg1 addl arg1,zero,dividend -# define LONGIFYarg2 addl arg2,zero,divisor -# else -# define LONGIFYarg1 zapnot arg1,0x0f,dividend -# define LONGIFYarg2 zapnot arg2,0x0f,divisor -# endif -#endif - -#if SIGNED -# define SETSIGN(sign,reg,tmp) subq zero,reg,tmp; cmovlt sign,tmp,reg -# if IS_REM -# define GETSIGN(x,y,s) bis x,zero,s -# else -# define GETSIGN(x,y,s) xor x,y,s -# endif +# define LONGIFY(x,y) mov x,y +# define SLONGIFY(x,y) mov x,y +# define _SLONGIFY(x) +# define NEG(x,y) negq x,y #else -# define SETSIGN(sign,reg,tmp) -# define GETSIGN(x,y,s) +# define LONGIFY(x,y) zapnot x,15,y +# define SLONGIFY(x,y) sextl x,y +# define _SLONGIFY(x) sextl x,x +# define NEG(x,y) negl x,y #endif .set noreorder .set noat - .ent FUNC_NAME - .globl FUNC_NAME - -#define FRAME_SIZE 0x30 + .ent UFUNC_NAME + .globl UFUNC_NAME - .align 5 -FUNC_NAME: + .align 3 +UFUNC_NAME: + lda sp, -STACK(sp) + .frame sp, STACK, retaddr, 0 #ifdef PROF - lda sp, -0x18(sp) - stq ra, 0x00(sp) - stq pv, 0x08(sp) - stq gp, 0x10(sp) + stq ra, 0(sp) + stq pv, 8(sp) + stq gp, 16(sp) br AT, 1f 1: ldgp gp, 0(AT) mov retaddr, ra - jsr AT, _mcount + lda AT, _mcount + jsr AT, (AT), _mcount - ldq ra, 0x00(sp) - ldq pv, 0x08(sp) - ldq gp, 0x10(sp) - lda sp, 0x18(sp) + ldq ra, 0(sp) + ldq pv, 8(sp) + ldq gp, 16(sp) #endif - .frame sp, FRAME_SIZE, retaddr, 0 - lda sp,-FRAME_SIZE(sp) - .prologue 1 - stq arg1,0x00(sp) - LONGIFYarg1 - stq arg2,0x08(sp) - LONGIFYarg2 - stq mask,0x10(sp) - bis zero,1,mask - stq tmp0,0x18(sp) - bis zero,zero,quotient - stq tmp1,0x20(sp) - beq divisor,$divbyzero - stq sign,0x28(sp) - GETSIGN(dividend,divisor,sign) -#if SIGNED - subq zero,dividend,tmp0 - subq zero,divisor,tmp1 - cmovlt dividend,tmp0,dividend - cmovlt divisor,tmp1,divisor + .prologue 0 + +$udiv: + stq t0, 0(sp) + LONGIFY (arg2, divisor) + stq t1, 8(sp) + LONGIFY (arg1, modulus) + stq v0, 16(sp) + clr quotient + stq tmp1, 24(sp) + ldiq mask, 1 + DIV_ONLY(stq tmp2,32(sp)) + + beq divisor, $divbyzero + + .align 3 +#if SIZE == 8 + /* Shift divisor left. */ +1: cmpult divisor, modulus, compare + blt divisor, 2f + addq divisor, divisor, divisor + addq mask, mask, mask + bne compare, 1b + unop +2: +#else + /* Shift divisor left using 3-bit shifts as we can't overflow. + This results in looping three times less here, but up to + two more times later. Thus using a large shift isn't worth it. */ +1: cmpult divisor, modulus, compare + s8addq divisor, zero, divisor + s8addq mask, zero, mask + bne compare, 1b #endif - /* - * Shift divisor left until either bit 63 is set or until it - * is at least as big as the dividend: - */ - .align 3 -1: cmpule dividend,divisor,AT - blt divisor,2f - blbs AT,2f - addq mask,mask,mask - addq divisor,divisor,divisor - br 1b - - .align 3 -2: addq mask,quotient,tmp0 - cmpule divisor,dividend,AT - subq dividend,divisor,tmp1 - srl divisor,1,divisor - srl mask,1,mask - cmovlbs AT,tmp0,quotient - cmovlbs AT,tmp1,dividend - bne mask,2b - - ldq arg1,0x00(sp) - SETSIGN(sign,result,tmp0) -$done: ldq arg2,0x08(sp) - ldq mask,0x10(sp) - ldq tmp0,0x18(sp) - ldq tmp1,0x20(sp) - ldq sign,0x28(sp) - lda sp,FRAME_SIZE(sp) - ret zero,(retaddr),0 + + /* Now go back to the right. */ +3: 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, 3b + +$done: ldq t0, 0(sp) + ldq t1, 8(sp) + ldq v0, 16(sp) + ldq tmp1, 24(sp) + DIV_ONLY(ldq tmp2, 32(sp)) + lda sp, STACK(sp) + ret zero, (retaddr), 1 $divbyzero: - lda a0,GEN_INTDIV(zero) + mov a0, tmp1 + ldiq a0, GEN_INTDIV call_pal PAL_gentrap - bis zero,zero,result /* if trap returns, return 0 */ - ldq arg1,0x00(sp) + mov tmp1, a0 + clr result /* If trap returns, return zero. */ br $done - END(FUNC_NAME) + .end UFUNC_NAME + + .ent SFUNC_NAME + .globl SFUNC_NAME + + .align 3 +SFUNC_NAME: + lda sp, -STACK(sp) + .frame sp, STACK, retaddr, 0 +#ifdef PROF + stq ra, 0(sp) + stq pv, 8(sp) + stq gp, 16(sp) + + br AT, 1f +1: ldgp gp, 0(AT) + + mov retaddr, ra + jsr AT, _mcount + + ldq ra, 0(sp) + ldq pv, 8(sp) + ldq gp, 16(sp) +#endif + .prologue 0 + + or arg1, arg2, AT + _SLONGIFY(AT) + bge AT, $udiv /* don't need to mess with signs */ + + /* Save originals and find absolute values. */ + stq arg1, 0(sp) + NEG (arg1, AT) + stq arg2, 8(sp) + cmovge AT, AT, arg1 + stq retaddr, 16(sp) + NEG (arg2, AT) + stq tmp1, 24(sp) + cmovge AT, AT, arg2 + + /* Do the unsigned division. */ + bsr retaddr, UFUNC_NAME + + /* Restore originals and adjust the sign of the result. */ + ldq arg1, 0(sp) + ldq arg2, 8(sp) + GETSIGN (AT) + NEG (result, tmp1) + _SLONGIFY(AT) + ldq retaddr, 16(sp) + cmovlt AT, tmp1, result + ldq tmp1, 24(sp) + + lda sp, STACK(sp) + ret zero, (retaddr), 1 + + .end SFUNC_NAME |