303 lines
7.7 KiB
Plaintext
303 lines
7.7 KiB
Plaintext
* $NetBSD: x_snan.sa,v 1.3 1994/10/26 07:50:28 cgd Exp $
|
|
|
|
* MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP
|
|
* M68000 Hi-Performance Microprocessor Division
|
|
* M68040 Software Package
|
|
*
|
|
* M68040 Software Package Copyright (c) 1993, 1994 Motorola Inc.
|
|
* All rights reserved.
|
|
*
|
|
* THE SOFTWARE is provided on an "AS IS" basis and without warranty.
|
|
* To the maximum extent permitted by applicable law,
|
|
* MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED,
|
|
* INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
|
|
* PARTICULAR PURPOSE and any warranty against infringement with
|
|
* regard to the SOFTWARE (INCLUDING ANY MODIFIED VERSIONS THEREOF)
|
|
* and any accompanying written materials.
|
|
*
|
|
* To the maximum extent permitted by applicable law,
|
|
* IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER
|
|
* (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS
|
|
* PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR
|
|
* OTHER PECUNIARY LOSS) ARISING OF THE USE OR INABILITY TO USE THE
|
|
* SOFTWARE. Motorola assumes no responsibility for the maintenance
|
|
* and support of the SOFTWARE.
|
|
*
|
|
* You are hereby granted a copyright license to use, modify, and
|
|
* distribute the SOFTWARE so long as this entire notice is retained
|
|
* without alteration in any modified and/or redistributed versions,
|
|
* and that such modified versions are clearly identified as such.
|
|
* No licenses are granted by implication, estoppel or otherwise
|
|
* under any patents or trademarks of Motorola, Inc.
|
|
|
|
*
|
|
* x_snan.sa 3.3 7/1/91
|
|
*
|
|
* fpsp_snan --- FPSP handler for signalling NAN exception
|
|
*
|
|
* SNAN for float -> integer conversions (integer conversion of
|
|
* an SNAN) is a non-maskable run-time exception.
|
|
*
|
|
* For trap disabled the 040 does the following:
|
|
* If the dest data format is s, d, or x, then the SNAN bit in the NAN
|
|
* is set to one and the resulting non-signaling NAN (truncated if
|
|
* necessary) is transferred to the dest. If the dest format is b, w,
|
|
* or l, then garbage is written to the dest (actually the upper 32 bits
|
|
* of the mantissa are sent to the integer unit).
|
|
*
|
|
* For trap enabled the 040 does the following:
|
|
* If the inst is move_out, then the results are the same as for trap
|
|
* disabled with the exception posted. If the instruction is not move_
|
|
* out, the dest. is not modified, and the exception is posted.
|
|
*
|
|
|
|
X_SNAN IDNT 2,1 Motorola 040 Floating Point Software Package
|
|
|
|
section 8
|
|
|
|
include fpsp.h
|
|
|
|
xref get_fline
|
|
xref mem_write
|
|
xref real_snan
|
|
xref real_inex
|
|
xref fpsp_done
|
|
xref reg_dest
|
|
|
|
xdef fpsp_snan
|
|
fpsp_snan:
|
|
link a6,#-LOCAL_SIZE
|
|
fsave -(a7)
|
|
movem.l d0-d1/a0-a1,USER_DA(a6)
|
|
fmovem.x fp0-fp3,USER_FP0(a6)
|
|
fmovem.l fpcr/fpsr/fpiar,USER_FPCR(a6)
|
|
|
|
*
|
|
* Check if trap enabled
|
|
*
|
|
btst.b #snan_bit,FPCR_ENABLE(a6)
|
|
bne.b ena ;If enabled, then branch
|
|
|
|
bsr.l move_out ;else SNAN disabled
|
|
*
|
|
* It is possible to have an inex1 exception with the
|
|
* snan. If the inex enable bit is set in the FPCR, and either
|
|
* inex2 or inex1 occured, we must clean up and branch to the
|
|
* real inex handler.
|
|
*
|
|
ck_inex:
|
|
move.b FPCR_ENABLE(a6),d0
|
|
and.b FPSR_EXCEPT(a6),d0
|
|
andi.b #$3,d0
|
|
beq.w end_snan
|
|
*
|
|
* Inexact enabled and reported, and we must take an inexact exception.
|
|
*
|
|
take_inex:
|
|
move.b #INEX_VEC,EXC_VEC+1(a6)
|
|
movem.l USER_DA(a6),d0-d1/a0-a1
|
|
fmovem.x USER_FP0(a6),fp0-fp3
|
|
fmovem.l USER_FPCR(a6),fpcr/fpsr/fpiar
|
|
frestore (a7)+
|
|
unlk a6
|
|
bra.l real_inex
|
|
*
|
|
* SNAN is enabled. Check if inst is move_out.
|
|
* Make any corrections to the 040 output as necessary.
|
|
*
|
|
ena:
|
|
btst.b #5,CMDREG1B(a6) ;if set, inst is move out
|
|
beq.w not_out
|
|
|
|
bsr.l move_out
|
|
|
|
report_snan:
|
|
move.b (a7),VER_TMP(a6)
|
|
cmpi.b #VER_40,(a7) ;test for orig unimp frame
|
|
bne.b ck_rev
|
|
moveq.l #13,d0 ;need to zero 14 lwords
|
|
bra.b rep_con
|
|
ck_rev:
|
|
moveq.l #11,d0 ;need to zero 12 lwords
|
|
rep_con:
|
|
clr.l (a7)
|
|
loop1:
|
|
clr.l -(a7) ;clear and dec a7
|
|
dbra.w d0,loop1
|
|
move.b VER_TMP(a6),(a7) ;format a busy frame
|
|
move.b #BUSY_SIZE-4,1(a7)
|
|
move.l USER_FPSR(a6),FPSR_SHADOW(a6)
|
|
or.l #sx_mask,E_BYTE(a6)
|
|
movem.l USER_DA(a6),d0-d1/a0-a1
|
|
fmovem.x USER_FP0(a6),fp0-fp3
|
|
fmovem.l USER_FPCR(a6),fpcr/fpsr/fpiar
|
|
frestore (a7)+
|
|
unlk a6
|
|
bra.l real_snan
|
|
*
|
|
* Exit snan handler by expanding the unimp frame into a busy frame
|
|
*
|
|
end_snan:
|
|
bclr.b #E1,E_BYTE(a6)
|
|
|
|
move.b (a7),VER_TMP(a6)
|
|
cmpi.b #VER_40,(a7) ;test for orig unimp frame
|
|
bne.b ck_rev2
|
|
moveq.l #13,d0 ;need to zero 14 lwords
|
|
bra.b rep_con2
|
|
ck_rev2:
|
|
moveq.l #11,d0 ;need to zero 12 lwords
|
|
rep_con2:
|
|
clr.l (a7)
|
|
loop2:
|
|
clr.l -(a7) ;clear and dec a7
|
|
dbra.w d0,loop2
|
|
move.b VER_TMP(a6),(a7) ;format a busy frame
|
|
move.b #BUSY_SIZE-4,1(a7) ;write busy size
|
|
move.l USER_FPSR(a6),FPSR_SHADOW(a6)
|
|
or.l #sx_mask,E_BYTE(a6)
|
|
movem.l USER_DA(a6),d0-d1/a0-a1
|
|
fmovem.x USER_FP0(a6),fp0-fp3
|
|
fmovem.l USER_FPCR(a6),fpcr/fpsr/fpiar
|
|
frestore (a7)+
|
|
unlk a6
|
|
bra.l fpsp_done
|
|
|
|
*
|
|
* Move_out
|
|
*
|
|
move_out:
|
|
move.l EXC_EA(a6),a0 ;get <ea> from exc frame
|
|
|
|
bfextu CMDREG1B(a6){3:3},d0 ;move rx field to d0{2:0}
|
|
tst.l d0 ;check for long
|
|
beq.b sto_long ;branch if move_out long
|
|
|
|
cmpi.l #4,d0 ;check for word
|
|
beq.b sto_word ;branch if move_out word
|
|
|
|
cmpi.l #6,d0 ;check for byte
|
|
beq.b sto_byte ;branch if move_out byte
|
|
|
|
*
|
|
* Not byte, word or long
|
|
*
|
|
rts
|
|
*
|
|
* Get the 32 most significant bits of etemp mantissa
|
|
*
|
|
sto_long:
|
|
move.l ETEMP_HI(a6),d1
|
|
move.l #4,d0 ;load byte count
|
|
*
|
|
* Set signalling nan bit
|
|
*
|
|
bset.l #30,d1
|
|
*
|
|
* Store to the users destination address
|
|
*
|
|
tst.l a0 ;check if <ea> is 0
|
|
beq.b wrt_dn ;destination is a data register
|
|
|
|
move.l d1,-(a7) ;move the snan onto the stack
|
|
move.l a0,a1 ;load dest addr into a1
|
|
move.l a7,a0 ;load src addr of snan into a0
|
|
bsr.l mem_write ;write snan to user memory
|
|
move.l (a7)+,d1 ;clear off stack
|
|
rts
|
|
*
|
|
* Get the 16 most significant bits of etemp mantissa
|
|
*
|
|
sto_word:
|
|
move.l ETEMP_HI(a6),d1
|
|
move.l #2,d0 ;load byte count
|
|
*
|
|
* Set signalling nan bit
|
|
*
|
|
bset.l #30,d1
|
|
*
|
|
* Store to the users destination address
|
|
*
|
|
tst.l a0 ;check if <ea> is 0
|
|
beq.b wrt_dn ;destination is a data register
|
|
|
|
move.l d1,-(a7) ;move the snan onto the stack
|
|
move.l a0,a1 ;load dest addr into a1
|
|
move.l a7,a0 ;point to low word
|
|
bsr.l mem_write ;write snan to user memory
|
|
move.l (a7)+,d1 ;clear off stack
|
|
rts
|
|
*
|
|
* Get the 8 most significant bits of etemp mantissa
|
|
*
|
|
sto_byte:
|
|
move.l ETEMP_HI(a6),d1
|
|
move.l #1,d0 ;load byte count
|
|
*
|
|
* Set signalling nan bit
|
|
*
|
|
bset.l #30,d1
|
|
*
|
|
* Store to the users destination address
|
|
*
|
|
tst.l a0 ;check if <ea> is 0
|
|
beq.b wrt_dn ;destination is a data register
|
|
move.l d1,-(a7) ;move the snan onto the stack
|
|
move.l a0,a1 ;load dest addr into a1
|
|
move.l a7,a0 ;point to source byte
|
|
bsr.l mem_write ;write snan to user memory
|
|
move.l (a7)+,d1 ;clear off stack
|
|
rts
|
|
|
|
*
|
|
* wrt_dn --- write to a data register
|
|
*
|
|
* We get here with D1 containing the data to write and D0 the
|
|
* number of bytes to write: 1=byte,2=word,4=long.
|
|
*
|
|
wrt_dn:
|
|
move.l d1,L_SCR1(a6) ;data
|
|
move.l d0,-(a7) ;size
|
|
bsr.l get_fline ;returns fline word in d0
|
|
move.l d0,d1
|
|
andi.l #$7,d1 ;d1 now holds register number
|
|
move.l (sp)+,d0 ;get original size
|
|
cmpi.l #4,d0
|
|
beq.b wrt_long
|
|
cmpi.l #2,d0
|
|
bne.b wrt_byte
|
|
wrt_word:
|
|
or.l #$8,d1
|
|
bra.l reg_dest
|
|
wrt_long:
|
|
or.l #$10,d1
|
|
bra.l reg_dest
|
|
wrt_byte:
|
|
bra.l reg_dest
|
|
*
|
|
* Check if it is a src nan or dst nan
|
|
*
|
|
not_out:
|
|
move.l DTAG(a6),d0
|
|
bfextu d0{0:3},d0 ;isolate dtag in lsbs
|
|
|
|
cmpi.b #3,d0 ;check for nan in destination
|
|
bne.b issrc ;destination nan has priority
|
|
dst_nan:
|
|
btst.b #6,FPTEMP_HI(a6) ;check if dest nan is an snan
|
|
bne.b issrc ;no, so check source for snan
|
|
move.w FPTEMP_EX(a6),d0
|
|
bra.b cont
|
|
issrc:
|
|
move.w ETEMP_EX(a6),d0
|
|
cont:
|
|
btst.l #15,d0 ;test for sign of snan
|
|
beq.b clr_neg
|
|
bset.b #neg_bit,FPSR_CC(a6)
|
|
bra.w report_snan
|
|
clr_neg:
|
|
bclr.b #neg_bit,FPSR_CC(a6)
|
|
bra.w report_snan
|
|
|
|
end
|