| /* Copyright (C) 2008-2023 Free Software Foundation, Inc. |
| Contributor: Joern Rennecke <joern.rennecke@embecosm.com> |
| on behalf of Synopsys Inc. |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify it under |
| the terms of the GNU General Public License as published by the Free |
| Software Foundation; either version 3, or (at your option) any later |
| version. |
| |
| GCC 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 General Public License |
| for more details. |
| |
| Under Section 7 of GPL version 3, you are granted additional |
| permissions described in the GCC Runtime Library Exception, version |
| 3.1, as published by the Free Software Foundation. |
| |
| You should have received a copy of the GNU General Public License and |
| a copy of the GCC Runtime Library Exception along with this program; |
| see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include "arc-ieee-754.h" |
| #if 0 /* DEBUG */ |
| .global __adddf3 |
| .balign 4 |
| __adddf3: |
| push_s blink |
| push_s r2 |
| push_s r3 |
| push_s r0 |
| bl.d __adddf3_c |
| push_s r1 |
| ld_s r2,[sp,12] |
| ld_s r3,[sp,8] |
| st_s r0,[sp,12] |
| st_s r1,[sp,8] |
| pop_s r1 |
| bl.d __adddf3_asm |
| pop_s r0 |
| pop_s r3 |
| pop_s r2 |
| pop_s blink |
| cmp r0,r2 |
| cmp.eq r1,r3 |
| jeq_s [blink] |
| bl abort |
| .global __subdf3 |
| .balign 4 |
| __subdf3: |
| push_s blink |
| push_s r2 |
| push_s r3 |
| push_s r0 |
| bl.d __subdf3_c |
| push_s r1 |
| ld_s r2,[sp,12] |
| ld_s r3,[sp,8] |
| st_s r0,[sp,12] |
| st_s r1,[sp,8] |
| pop_s r1 |
| bl.d __subdf3_asm |
| pop_s r0 |
| pop_s r3 |
| pop_s r2 |
| pop_s blink |
| cmp r0,r2 |
| cmp.eq r1,r3 |
| jeq_s [blink] |
| bl abort |
| #define __adddf3 __adddf3_asm |
| #define __subdf3 __subdf3_asm |
| #endif /* DEBUG */ |
| /* N.B. This is optimized for ARC700. |
| ARC600 has very different scheduling / instruction selection criteria. */ |
| |
| /* inputs: DBL0, DBL1 (r0-r3) |
| output: DBL0 (r0, r1) |
| clobber: r2-r10, r12, flags |
| All NaN highword bits must be 1. NaN low word is random. */ |
| |
| .balign 4 |
| .global __adddf3 |
| .global __subdf3 |
| .long 0x7ff00000 ; exponent mask |
| FUNC(__adddf3) |
| FUNC(__subdf3) |
| __subdf3: |
| bxor_l DBL1H,DBL1H,31 |
| __adddf3: |
| ld r9,[pcl,-8] |
| bmsk r4,DBL0H,30 |
| xor r10,DBL0H,DBL1H |
| and r6,DBL1H,r9 |
| sub.f r12,r4,r6 |
| asr_s r12,r12,20 |
| blo .Ldbl1_gt |
| brhs r4,r9,.Linf_nan |
| brhs r12,32,.Large_shift |
| brne r12,0,.Lsmall_shift |
| brge r10,0,.Ladd_same_exp ; r12 == 0 |
| |
| /* After subtracting, we need to normalize; when shifting to place the |
| leading 1 into position for the implicit 1 and adding that to DBL0H, |
| we increment the exponent. Thus, we have to subtract one more than |
| the shift count from the exponent beforehand. Iff the exponent drops thus |
| below zero (before adding in the fraction with the leading one), we have |
| generated a denormal number. Denormal handling is basicallly reducing the |
| shift count so that we produce a zero exponent instead; however, this way |
| the shift count can become zero (if we started out with exponent 1). |
| Therefore, a simple min operation is not good enough, since we don't |
| want to handle a zero normalizing shift in the main path. |
| On the plus side, we don't need to check for denorm input, the result |
| of subtracing these looks just the same as denormals generated during |
| subtraction. */ |
| bmsk r7,DBL1H,30 |
| cmp r4,r7 |
| cmp.eq DBL0L,DBL1L |
| blo .L_rsub_same_exp |
| sub.f DBL0L,DBL0L,DBL1L |
| bmsk r12,DBL0H,19 |
| bic DBL1H,DBL0H,r12 |
| sbc.f r4,r4,r7 |
| beq_l .Large_cancel |
| norm DBL1L,r4 |
| b.d .Lsub_done_same_exp |
| sub r12,DBL1L,9 |
| |
| .balign 4 |
| .Linf_nan: |
| ; If both inputs are inf, but with different signs, the result is NaN. |
| asr r12,r10,31 |
| or_s DBL1H,DBL1H,r12 |
| j_s.d [blink] |
| or.eq DBL0H,DBL0H,DBL1H |
| |
| .balign 4 |
| .L_rsub_same_exp: |
| rsub.f DBL0L,DBL0L,DBL1L |
| bmsk r12,DBL1H,19 |
| bic_s DBL1H,DBL1H,r12 |
| sbc.f r4,r7,r4 |
| beq_l .Large_cancel |
| norm DBL1L,r4 |
| |
| sub r12,DBL1L,9 |
| .Lsub_done_same_exp: |
| asl_s r12,r12,20 |
| sub_s DBL1L,DBL1L,10 |
| sub DBL0H,DBL1H,r12 |
| xor.f 0,DBL0H,DBL1H |
| bmi .Ldenorm |
| .Lpast_denorm: |
| neg_s r12,DBL1L |
| lsr r7,DBL0L,r12 |
| asl r12,r4,DBL1L |
| asl_s DBL0L,DBL0L,DBL1L |
| add_s r12,r12,r7 |
| j_s.d [blink] |
| add_l DBL0H,DBL0H,r12 |
| .balign 4 |
| .Ladd_same_exp: |
| /* This is a special case because we can't test for need to shift |
| down by checking if bit 20 of DBL0H changes. OTOH, here we know |
| that we always need to shift down. */ |
| ; The implicit 1 of DBL0 is not shifted together with the |
| ; fraction, thus effectively doubled, compensating for not setting |
| ; implicit1 for DBL1 |
| add_s r12,DBL0L,DBL1L |
| lsr.f 0,r12,2 ; round to even |
| breq r6,0,.Ldenorm_add |
| adc.f DBL0L,DBL0L,DBL1L |
| sub r7,DBL1H,DBL0H |
| sub1 r7,r7,r9 ; boost exponent by 2/2 |
| rrc DBL0L,DBL0L |
| asr.f r7,r7 ; DBL1.fraction/2 - DBL0.fraction/2 ; exp++ |
| add.cs.f DBL0L,DBL0L,0x80000000 |
| add_l DBL0H,DBL0H,r7 ; DBL0.implicit1 not shifted for DBL1.implicit1 |
| add.cs DBL0H,DBL0H,1 |
| bic.f 0,r9,DBL0H ; check for overflow -> infinity. |
| jne_l [blink] |
| and DBL0H,DBL0H,0xfff00000 |
| j_s.d [blink] |
| mov_s DBL0L,0 |
| .balign 4 |
| .Large_shift: |
| brhs r12,55,.Lret_dbl0 |
| bmsk_s DBL1H,DBL1H,19 |
| brne r6,0,.Lno_denorm_large_shift |
| brhi.d r12,33,.Lfixed_denorm_large_shift |
| sub_s r12,r12,1 |
| breq r12,31, .Lfixed_denorm_small_shift |
| .Lshift32: |
| mov_s r12,DBL1L |
| mov_s DBL1L,DBL1H |
| brlt.d r10,0,.Lsub |
| mov_s DBL1H,0 |
| b_s .Ladd |
| .Ldenorm_add: |
| cmp_s r12,DBL1L |
| mov_s DBL0L,r12 |
| j_s.d [blink] |
| adc DBL0H,r4,DBL1H |
| |
| .Lret_dbl0: |
| j_s [blink] |
| .balign 4 |
| .Lsmall_shift: |
| breq.d r6,0,.Ldenorm_small_shift |
| bmsk_s DBL1H,DBL1H,19 |
| bset_s DBL1H,DBL1H,20 |
| .Lfixed_denorm_small_shift: |
| neg r8,r12 |
| asl r4,DBL1H,r8 |
| lsr_l DBL1H,DBL1H,r12 |
| lsr r5,DBL1L,r12 |
| asl r12,DBL1L,r8 |
| brge.d r10,0,.Ladd |
| or DBL1L,r4,r5 |
| /* subtract, abs(DBL0) > abs(DBL1) */ |
| /* DBL0H, DBL0L: original values |
| DBL1H, DBL1L: fraction with explicit leading 1, shifted into place |
| r4: orig. DBL0H & 0x7fffffff |
| r6: orig. DBL1H & 0x7ff00000 |
| r9: 0x7ff00000 |
| r10: orig. DBL0H ^ DBL1H |
| r12: guard bits */ |
| .balign 4 |
| .Lsub: |
| neg.f r12,r12 |
| mov_s r7,DBL1H |
| bmsk r5,DBL0H,19 |
| sbc.f DBL0L,DBL0L,DBL1L |
| bic DBL1H,DBL0H,r5 |
| bset r5,r5,20 |
| sbc.f r4,r5,r7 |
| beq_l .Large_cancel_sub |
| norm DBL1L,r4 |
| bmsk r6,DBL1H,30 |
| .Lsub_done: |
| sub_s DBL1L,DBL1L,9 |
| breq DBL1L,1,.Lsub_done_noshift |
| asl r5,DBL1L,20 |
| sub_s DBL1L,DBL1L,1 |
| brlo r6,r5,.Ldenorm_sub |
| sub DBL0H,DBL1H,r5 |
| .Lpast_denorm_sub: |
| neg_s DBL1H,DBL1L |
| lsr r6,r12,DBL1H |
| asl_s r12,r12,DBL1L |
| and r8,r6,1 |
| add1.f 0,r8,r12 |
| add.ne.f r12,r12,r12 |
| asl r8,DBL0L,DBL1L |
| lsr r12,DBL0L,DBL1H |
| adc.f DBL0L,r8,r6 |
| asl r5,r4,DBL1L |
| add_s DBL0H,DBL0H,r12 |
| j_s.d [blink] |
| adc DBL0H,DBL0H,r5 |
| |
| .balign 4 |
| .Lno_denorm_large_shift: |
| breq.d r12,32,.Lshift32 |
| bset_l DBL1H,DBL1H,20 |
| .Lfixed_denorm_large_shift: |
| neg r8,r12 |
| asl r4,DBL1H,r8 |
| lsr r5,DBL1L,r12 |
| asl.f 0,DBL1L,r8 |
| lsr DBL1L,DBL1H,r12 |
| or r12,r4,r5 |
| tst.eq r12,1 |
| or.ne r12,r12,2 |
| brlt.d r10,0,.Lsub |
| mov_s DBL1H,0 |
| b_l .Ladd |
| |
| ; If a denorm is produced without shifting, we have an exact result - |
| ; no need for rounding. |
| .balign 4 |
| .Ldenorm_sub: |
| lsr DBL1L,r6,20 |
| xor DBL0H,r6,DBL1H |
| brne.d DBL1L,1,.Lpast_denorm_sub |
| sub_s DBL1L,DBL1L,1 |
| .Lsub_done_noshift: |
| add.f 0,r12,r12 |
| btst.eq DBL0L,0 |
| cmp.eq r12,r12 |
| add.cs.f DBL0L,DBL0L,1 |
| bclr r4,r4,20 |
| j_s.d [blink] |
| adc DBL0H,DBL1H,r4 |
| |
| .balign 4 |
| .Ldenorm_small_shift: |
| brne.d r12,1,.Lfixed_denorm_small_shift |
| sub_l r12,r12,1 |
| brlt r10,0,.Lsub |
| .Ladd: ; bit 20 of DBL1H is clear and bit 0 of r12 does not matter |
| add.f DBL0L,DBL0L,DBL1L |
| add_s DBL1H,DBL1H,DBL0H |
| add.cs DBL1H,DBL1H,1 |
| xor_l DBL0H,DBL0H,DBL1H |
| bbit0 DBL0H,20,.Lno_shiftdown |
| lsr.f DBL0H,DBL1H |
| and r4,DBL0L,2 |
| bmsk DBL0H,DBL0H,18 |
| sbc DBL0H,DBL1H,DBL0H |
| rrc.f DBL0L,DBL0L |
| or.f r12,r12,r4 |
| cmp.eq r12,r12 |
| add.cs.f DBL0L,DBL0L,1 |
| bic.f 0,r9,DBL0H ; check for generating infinity with possible ... |
| jne.d [blink] ; ... non-zero fraction |
| add.cs DBL0H,DBL0H,1 |
| mov_s DBL0L,0 |
| bmsk DBL1H,DBL0H,19 |
| j_s.d [blink] |
| bic_s DBL0H,DBL0H,DBL1H |
| .Lno_shiftdown: |
| mov_s DBL0H,DBL1H |
| add.f 0,r12,r12 |
| btst.eq DBL0L,0 |
| cmp.eq r12,r12 |
| add.cs.f DBL0L,DBL0L,1 |
| j_s.d [blink] |
| add.cs DBL0H,DBL0H,1 |
| .balign 4 |
| .Ldenorm: |
| bmsk DBL0H,DBL1H,30 |
| lsr r12,DBL0H,20 |
| xor_s DBL0H,DBL0H,DBL1H |
| sub_l DBL1L,r12,1 |
| bgt .Lpast_denorm |
| j_s.d [blink] |
| add_l DBL0H,DBL0H,r4 |
| |
| .balign 4 |
| .Large_cancel: |
| ;DBL0L: mantissa DBL1H: sign & exponent |
| norm.f DBL1L,DBL0L |
| bmsk DBL0H,DBL1H,30 |
| add_s DBL1L,DBL1L,22 |
| mov.mi DBL1L,21 |
| add_s r12,DBL1L,1 |
| asl_s r12,r12,20 |
| beq_s .Lret0 |
| brhs.d DBL0H,r12,.Lpast_denorm_large_cancel |
| sub DBL0H,DBL1H,r12 |
| bmsk DBL0H,DBL1H,30 |
| lsr r12,DBL0H,20 |
| xor_s DBL0H,DBL0H,DBL1H |
| sub.f DBL1L,r12,1 |
| jle [blink] |
| .Lpast_denorm_large_cancel: |
| rsub.f r7,DBL1L,32 |
| lsr r7,DBL0L,r7 |
| asl_s DBL0L,DBL0L,DBL1L |
| mov.ls r7,DBL0L |
| add_s DBL0H,DBL0H,r7 |
| j_s.d [blink] |
| mov.ls DBL0L,0 |
| .Lret0: |
| j_s.d [blink] |
| mov_l DBL0H,0 |
| |
| /* r4:DBL0L:r12 : unnormalized result fraction |
| DBL1H: result sign and exponent */ |
| /* When seeing large cancellation, only the topmost guard bit might be set. */ |
| .balign 4 |
| .Large_cancel_sub: |
| norm.f DBL1L,DBL0L |
| bpnz.d 0f |
| bmsk DBL0H,DBL1H,30 |
| mov r5,22<<20 |
| bne.d 1f |
| mov_s DBL1L,21 |
| bset r5,r5,5+20 |
| add_s DBL1L,DBL1L,32 |
| brne r12,0,1f |
| j_s.d [blink] |
| mov_l DBL0H,0 |
| .balign 4 |
| 0: add r5,DBL1L,23 |
| asl r5,r5,20 |
| add_s DBL1L,DBL1L,22 |
| 1: brlo DBL0H,r5,.Ldenorm_large_cancel_sub |
| sub DBL0H,DBL1H,r5 |
| .Lpast_denorm_large_cancel_sub: |
| rsub.f r7,DBL1L,32 |
| lsr r12,r12,r7 |
| lsr r7,DBL0L,r7 |
| asl_s DBL0L,DBL0L,DBL1L |
| add.ge DBL0H,DBL0H,r7 |
| add_s DBL0L,DBL0L,r12 |
| add.lt DBL0H,DBL0H,DBL0L |
| mov.eq DBL0L,r12 |
| j_s.d [blink] |
| mov.lt DBL0L,0 |
| .balign 4 |
| .Ldenorm_large_cancel_sub: |
| lsr r5,DBL0H,20 |
| xor_s DBL0H,DBL0H,DBL1H |
| brgt.d r5,1,.Lpast_denorm_large_cancel_sub |
| sub DBL1L,r5,1 |
| j_l [blink] ; denorm, no shift -> no rounding needed. |
| |
| /* r4: DBL0H & 0x7fffffff |
| r6: DBL1H & 0x7ff00000 |
| r9: 0x7ff00000 |
| r10: sign difference |
| r12: shift count (negative) */ |
| .balign 4 |
| .Ldbl1_gt: |
| brhs r6,r9,.Lret_dbl1 ; inf or NaN |
| neg r8,r12 |
| brhs r8,32,.Large_shift_dbl0 |
| .Lsmall_shift_dbl0: |
| breq.d r6,0,.Ldenorm_small_shift_dbl0 |
| bmsk_s DBL0H,DBL0H,19 |
| bset_s DBL0H,DBL0H,20 |
| .Lfixed_denorm_small_shift_dbl0: |
| asl r4,DBL0H,r12 |
| lsr DBL0H,DBL0H,r8 |
| lsr r5,DBL0L,r8 |
| asl r12,DBL0L,r12 |
| brge.d r10,0,.Ladd_dbl1_gt |
| or DBL0L,r4,r5 |
| /* subtract, abs(DBL0) < abs(DBL1) */ |
| /* DBL0H, DBL0L: fraction with explicit leading 1, shifted into place |
| DBL1H, DBL1L: original values |
| r6: orig. DBL1H & 0x7ff00000 |
| r9: 0x7ff00000 |
| r12: guard bits */ |
| .balign 4 |
| .Lrsub: |
| neg.f r12,r12 |
| bmsk r7,DBL1H,19 |
| mov_s r5,DBL0H |
| sbc.f DBL0L,DBL1L,DBL0L |
| bic DBL1H,DBL1H,r7 |
| bset r7,r7,20 |
| sbc.f r4,r7,r5 |
| beq_l .Large_cancel_sub |
| norm DBL1L,r4 |
| b_l .Lsub_done ; note: r6 is already set up. |
| |
| .Lret_dbl1: |
| mov_s DBL0H,DBL1H |
| j_s.d [blink] |
| mov_l DBL0L,DBL1L |
| .balign 4 |
| .Ldenorm_small_shift_dbl0: |
| sub.f r8,r8,1 |
| bne.d .Lfixed_denorm_small_shift_dbl0 |
| add_s r12,r12,1 |
| brlt r10,0,.Lrsub |
| .Ladd_dbl1_gt: ; bit 20 of DBL0H is clear and bit 0 of r12 does not matter |
| add.f DBL0L,DBL0L,DBL1L |
| add_s DBL0H,DBL0H,DBL1H |
| add.cs DBL0H,DBL0H,1 |
| xor DBL1H,DBL0H,DBL1H |
| bbit0 DBL1H,20,.Lno_shiftdown_dbl1_gt |
| lsr.f DBL1H,DBL0H |
| and r4,DBL0L,2 |
| bmsk DBL1H,DBL1H,18 |
| sbc DBL0H,DBL0H,DBL1H |
| rrc.f DBL0L,DBL0L |
| or.f r12,r12,r4 |
| cmp.eq r12,r12 |
| add.cs.f DBL0L,DBL0L,1 |
| bic.f 0,r9,DBL0H ; check for generating infinity with possible ... |
| jne.d [blink] ; ... non-zero fraction |
| add.cs DBL0H,DBL0H,1 |
| mov_s DBL0L,0 |
| bmsk DBL1H,DBL0H,19 |
| j_s.d [blink] |
| bic_s DBL0H,DBL0H,DBL1H |
| .Lno_shiftdown_dbl1_gt: |
| add.f 0,r12,r12 |
| btst.eq DBL0L,0 |
| cmp.eq r12,r12 |
| add.cs.f DBL0L,DBL0L,1 |
| j_s.d [blink] |
| add.cs DBL0H,DBL0H,1 |
| |
| .balign 4 |
| .Large_shift_dbl0: |
| brhs r8,55,.Lret_dbl1 |
| bmsk_s DBL0H,DBL0H,19 |
| brne r6,0,.Lno_denorm_large_shift_dbl0 |
| add_s r12,r12,1 |
| brne.d r8,33,.Lfixed_denorm_large_shift_dbl0 |
| sub r8,r8,1 |
| bset_s DBL0H,DBL0H,20 |
| .Lshift32_dbl0: |
| mov_s r12,DBL0L |
| mov_s DBL0L,DBL0H |
| brlt.d r10,0,.Lrsub |
| mov_s DBL0H,0 |
| b_s .Ladd_dbl1_gt |
| |
| .balign 4 |
| .Lno_denorm_large_shift_dbl0: |
| breq.d r8,32,.Lshift32_dbl0 |
| bset_l DBL0H,DBL0H,20 |
| .Lfixed_denorm_large_shift_dbl0: |
| asl r4,DBL0H,r12 |
| lsr r5,DBL0L,r8 |
| asl.f 0,DBL0L,r12 |
| lsr DBL0L,DBL0H,r8 |
| or r12,r4,r5 |
| tst.eq r12,1 |
| or.ne r12,r12,2 |
| brlt.d r10,0,.Lrsub |
| mov_s DBL0H,0 |
| b_l .Ladd_dbl1_gt |
| ENDFUNC(__adddf3) |
| ENDFUNC(__subdf3) |
