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Diffstat (limited to 'arch/parisc/lib/milli/divU.S')
| -rw-r--r-- | arch/parisc/lib/milli/divU.S | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/arch/parisc/lib/milli/divU.S b/arch/parisc/lib/milli/divU.S new file mode 100644 index 0000000..9287fe2 --- /dev/null +++ b/arch/parisc/lib/milli/divU.S @@ -0,0 +1,235 @@ +/* 32 and 64-bit millicode, original author Hewlett-Packard + adapted for gcc by Paul Bame <bame@debian.org> + and Alan Modra <alan@linuxcare.com.au>. + + Copyright 2001, 2002, 2003 Free Software Foundation, Inc. + + This file is part of GCC and is released under the terms of + of the GNU General Public License as published by the Free Software + Foundation; either version 2, or (at your option) any later version. + See the file COPYING in the top-level GCC source directory for a copy + of the license. */ + +#include "milli.h" + +#ifdef L_divU +/* ROUTINE: $$divU + . + . Single precision divide for unsigned integers. + . + . Quotient is truncated towards zero. + . Traps on divide by zero. + + INPUT REGISTERS: + . arg0 == dividend + . arg1 == divisor + . mrp == return pc + . sr0 == return space when called externally + + OUTPUT REGISTERS: + . arg0 = undefined + . arg1 = undefined + . ret1 = quotient + + OTHER REGISTERS AFFECTED: + . r1 = undefined + + SIDE EFFECTS: + . Causes a trap under the following conditions: + . divisor is zero + . Changes memory at the following places: + . NONE + + PERMISSIBLE CONTEXT: + . Unwindable. + . Does not create a stack frame. + . Suitable for internal or external millicode. + . Assumes the special millicode register conventions. + + DISCUSSION: + . Branchs to other millicode routines using BE: + . $$divU_# for 3,5,6,7,9,10,12,14,15 + . + . For selected small divisors calls the special divide by constant + . routines written by Karl Pettis. These are: 3,5,6,7,9,10,12,14,15. */ + +RDEFINE(temp,r1) +RDEFINE(retreg,ret1) /* r29 */ +RDEFINE(temp1,arg0) + SUBSPA_MILLI_DIV + ATTR_MILLI + .export $$divU,millicode + .import $$divU_3,millicode + .import $$divU_5,millicode + .import $$divU_6,millicode + .import $$divU_7,millicode + .import $$divU_9,millicode + .import $$divU_10,millicode + .import $$divU_12,millicode + .import $$divU_14,millicode + .import $$divU_15,millicode + .proc + .callinfo millicode + .entry +GSYM($$divU) +/* The subtract is not nullified since it does no harm and can be used + by the two cases that branch back to "normal". */ + ldo -1(arg1),temp /* is there at most one bit set ? */ + and,= arg1,temp,r0 /* if so, denominator is power of 2 */ + b LREF(regular_seq) + addit,= 0,arg1,0 /* trap for zero dvr */ + copy arg0,retreg + extru,= arg1,15,16,temp /* test denominator with 0xffff0000 */ + extru retreg,15,16,retreg /* retreg = retreg >> 16 */ + or arg1,temp,arg1 /* arg1 = arg1 | (arg1 >> 16) */ + ldi 0xcc,temp1 /* setup 0xcc in temp1 */ + extru,= arg1,23,8,temp /* test denominator with 0xff00 */ + extru retreg,23,24,retreg /* retreg = retreg >> 8 */ + or arg1,temp,arg1 /* arg1 = arg1 | (arg1 >> 8) */ + ldi 0xaa,temp /* setup 0xaa in temp */ + extru,= arg1,27,4,r0 /* test denominator with 0xf0 */ + extru retreg,27,28,retreg /* retreg = retreg >> 4 */ + and,= arg1,temp1,r0 /* test denominator with 0xcc */ + extru retreg,29,30,retreg /* retreg = retreg >> 2 */ + and,= arg1,temp,r0 /* test denominator with 0xaa */ + extru retreg,30,31,retreg /* retreg = retreg >> 1 */ + MILLIRETN + nop +LSYM(regular_seq) + comib,>= 15,arg1,LREF(special_divisor) + subi 0,arg1,temp /* clear carry, negate the divisor */ + ds r0,temp,r0 /* set V-bit to 1 */ +LSYM(normal) + add arg0,arg0,retreg /* shift msb bit into carry */ + ds r0,arg1,temp /* 1st divide step, if no carry */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 2nd divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 3rd divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 4th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 5th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 6th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 7th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 8th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 9th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 10th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 11th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 12th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 13th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 14th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 15th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 16th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 17th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 18th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 19th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 20th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 21st divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 22nd divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 23rd divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 24th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 25th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 26th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 27th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 28th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 29th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 30th divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 31st divide step */ + addc retreg,retreg,retreg /* shift retreg with/into carry */ + ds temp,arg1,temp /* 32nd divide step, */ + MILLIRET + addc retreg,retreg,retreg /* shift last retreg bit into retreg */ + +/* Handle the cases where divisor is a small constant or has high bit on. */ +LSYM(special_divisor) +/* blr arg1,r0 */ +/* comib,>,n 0,arg1,LREF(big_divisor) ; nullify previous instruction */ + +/* Pratap 8/13/90. The 815 Stirling chip set has a bug that prevents us from + generating such a blr, comib sequence. A problem in nullification. So I + rewrote this code. */ + +#if defined(CONFIG_64BIT) +/* Clear the upper 32 bits of the arg1 register. We are working with + small divisors (and 32-bit unsigned integers) We must not be mislead + by "1" bits left in the upper 32 bits. */ + depd %r0,31,32,%r25 +#endif + comib,> 0,arg1,LREF(big_divisor) + nop + blr arg1,r0 + nop + +LSYM(zero_divisor) /* this label is here to provide external visibility */ + addit,= 0,arg1,0 /* trap for zero dvr */ + nop + MILLIRET /* divisor == 1 */ + copy arg0,retreg + MILLIRET /* divisor == 2 */ + extru arg0,30,31,retreg + MILLI_BEN($$divU_3) /* divisor == 3 */ + nop + MILLIRET /* divisor == 4 */ + extru arg0,29,30,retreg + MILLI_BEN($$divU_5) /* divisor == 5 */ + nop + MILLI_BEN($$divU_6) /* divisor == 6 */ + nop + MILLI_BEN($$divU_7) /* divisor == 7 */ + nop + MILLIRET /* divisor == 8 */ + extru arg0,28,29,retreg + MILLI_BEN($$divU_9) /* divisor == 9 */ + nop + MILLI_BEN($$divU_10) /* divisor == 10 */ + nop + b LREF(normal) /* divisor == 11 */ + ds r0,temp,r0 /* set V-bit to 1 */ + MILLI_BEN($$divU_12) /* divisor == 12 */ + nop + b LREF(normal) /* divisor == 13 */ + ds r0,temp,r0 /* set V-bit to 1 */ + MILLI_BEN($$divU_14) /* divisor == 14 */ + nop + MILLI_BEN($$divU_15) /* divisor == 15 */ + nop + +/* Handle the case where the high bit is on in the divisor. + Compute: if( dividend>=divisor) quotient=1; else quotient=0; + Note: dividend>==divisor iff dividend-divisor does not borrow + and not borrow iff carry. */ +LSYM(big_divisor) + sub arg0,arg1,r0 + MILLIRET + addc r0,r0,retreg + .exit + .procend + .end +#endif |