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linux/arch/m68k/fpsp040/util.S
Matt Waddel e00d82d07f [PATCH] Add wording to m68k .S files to help clarify license info 
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Matt Waddel <Matt.Waddel@freescale.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-11 21:41:11 -08:00

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|
| util.sa 3.7 7/29/91
|
| This file contains routines used by other programs.
|
| ovf_res: used by overflow to force the correct
| result. ovf_r_k, ovf_r_x2, ovf_r_x3 are
| derivatives of this routine.
| get_fline: get user's opcode word
| g_dfmtou: returns the destination format.
| g_opcls: returns the opclass of the float instruction.
| g_rndpr: returns the rounding precision.
| reg_dest: write byte, word, or long data to Dn
|
|
| Copyright (C) Motorola, Inc. 1990
| All Rights Reserved
|
| For details on the license for this file, please see the
| file, README, in this same directory.
|UTIL idnt 2,1 | Motorola 040 Floating Point Software Package
|section 8
#include "fpsp.h"
|xref mem_read
.global g_dfmtou
.global g_opcls
.global g_rndpr
.global get_fline
.global reg_dest
|
| Final result table for ovf_res. Note that the negative counterparts
| are unnecessary as ovf_res always returns the sign separately from
| the exponent.
| ;+inf
EXT_PINF: .long 0x7fff0000,0x00000000,0x00000000,0x00000000
| ;largest +ext
EXT_PLRG: .long 0x7ffe0000,0xffffffff,0xffffffff,0x00000000
| ;largest magnitude +sgl in ext
SGL_PLRG: .long 0x407e0000,0xffffff00,0x00000000,0x00000000
| ;largest magnitude +dbl in ext
DBL_PLRG: .long 0x43fe0000,0xffffffff,0xfffff800,0x00000000
| ;largest -ext
tblovfl:
.long EXT_RN
.long EXT_RZ
.long EXT_RM
.long EXT_RP
.long SGL_RN
.long SGL_RZ
.long SGL_RM
.long SGL_RP
.long DBL_RN
.long DBL_RZ
.long DBL_RM
.long DBL_RP
.long error
.long error
.long error
.long error
|
| ovf_r_k --- overflow result calculation
|
| This entry point is used by kernel_ex.
|
| This forces the destination precision to be extended
|
| Input: operand in ETEMP
| Output: a result is in ETEMP (internal extended format)
|
.global ovf_r_k
ovf_r_k:
lea ETEMP(%a6),%a0 |a0 points to source operand
bclrb #sign_bit,ETEMP_EX(%a6)
sne ETEMP_SGN(%a6) |convert to internal IEEE format
|
| ovf_r_x2 --- overflow result calculation
|
| This entry point used by x_ovfl. (opclass 0 and 2)
|
| Input a0 points to an operand in the internal extended format
| Output a0 points to the result in the internal extended format
|
| This sets the round precision according to the user's FPCR unless the
| instruction is fsgldiv or fsglmul or fsadd, fdadd, fsub, fdsub, fsmul,
| fdmul, fsdiv, fddiv, fssqrt, fsmove, fdmove, fsabs, fdabs, fsneg, fdneg.
| If the instruction is fsgldiv of fsglmul, the rounding precision must be
| extended. If the instruction is not fsgldiv or fsglmul but a force-
| precision instruction, the rounding precision is then set to the force
| precision.
.global ovf_r_x2
ovf_r_x2:
btstb #E3,E_BYTE(%a6) |check for nu exception
beql ovf_e1_exc |it is cu exception
ovf_e3_exc:
movew CMDREG3B(%a6),%d0 |get the command word
andiw #0x00000060,%d0 |clear all bits except 6 and 5
cmpil #0x00000040,%d0
beql ovff_sgl |force precision is single
cmpil #0x00000060,%d0
beql ovff_dbl |force precision is double
movew CMDREG3B(%a6),%d0 |get the command word again
andil #0x7f,%d0 |clear all except operation
cmpil #0x33,%d0
beql ovf_fsgl |fsglmul or fsgldiv
cmpil #0x30,%d0
beql ovf_fsgl
bra ovf_fpcr |instruction is none of the above
| ;use FPCR
ovf_e1_exc:
movew CMDREG1B(%a6),%d0 |get command word
andil #0x00000044,%d0 |clear all bits except 6 and 2
cmpil #0x00000040,%d0
beql ovff_sgl |the instruction is force single
cmpil #0x00000044,%d0
beql ovff_dbl |the instruction is force double
movew CMDREG1B(%a6),%d0 |again get the command word
andil #0x0000007f,%d0 |clear all except the op code
cmpil #0x00000027,%d0
beql ovf_fsgl |fsglmul
cmpil #0x00000024,%d0
beql ovf_fsgl |fsgldiv
bra ovf_fpcr |none of the above, use FPCR
|
|
| Inst is either fsgldiv or fsglmul. Force extended precision.
|
ovf_fsgl:
clrl %d0
bra ovf_res
ovff_sgl:
movel #0x00000001,%d0 |set single
bra ovf_res
ovff_dbl:
movel #0x00000002,%d0 |set double
bra ovf_res
|
| The precision is in the fpcr.
|
ovf_fpcr:
bfextu FPCR_MODE(%a6){#0:#2},%d0 |set round precision
bra ovf_res
|
|
| ovf_r_x3 --- overflow result calculation
|
| This entry point used by x_ovfl. (opclass 3 only)
|
| Input a0 points to an operand in the internal extended format
| Output a0 points to the result in the internal extended format
|
| This sets the round precision according to the destination size.
|
.global ovf_r_x3
ovf_r_x3:
bsr g_dfmtou |get dest fmt in d0{1:0}
| ;for fmovout, the destination format
| ;is the rounding precision
|
| ovf_res --- overflow result calculation
|
| Input:
| a0 points to operand in internal extended format
| Output:
| a0 points to result in internal extended format
|
.global ovf_res
ovf_res:
lsll #2,%d0 |move round precision to d0{3:2}
bfextu FPCR_MODE(%a6){#2:#2},%d1 |set round mode
orl %d1,%d0 |index is fmt:mode in d0{3:0}
leal tblovfl,%a1 |load a1 with table address
movel %a1@(%d0:l:4),%a1 |use d0 as index to the table
jmp (%a1) |go to the correct routine
|
|case DEST_FMT = EXT
|
EXT_RN:
leal EXT_PINF,%a1 |answer is +/- infinity
bsetb #inf_bit,FPSR_CC(%a6)
bra set_sign |now go set the sign
EXT_RZ:
leal EXT_PLRG,%a1 |answer is +/- large number
bra set_sign |now go set the sign
EXT_RM:
tstb LOCAL_SGN(%a0) |if negative overflow
beqs e_rm_pos
e_rm_neg:
leal EXT_PINF,%a1 |answer is negative infinity
orl #neginf_mask,USER_FPSR(%a6)
bra end_ovfr
e_rm_pos:
leal EXT_PLRG,%a1 |answer is large positive number
bra end_ovfr
EXT_RP:
tstb LOCAL_SGN(%a0) |if negative overflow
beqs e_rp_pos
e_rp_neg:
leal EXT_PLRG,%a1 |answer is large negative number
bsetb #neg_bit,FPSR_CC(%a6)
bra end_ovfr
e_rp_pos:
leal EXT_PINF,%a1 |answer is positive infinity
bsetb #inf_bit,FPSR_CC(%a6)
bra end_ovfr
|
|case DEST_FMT = DBL
|
DBL_RN:
leal EXT_PINF,%a1 |answer is +/- infinity
bsetb #inf_bit,FPSR_CC(%a6)
bra set_sign
DBL_RZ:
leal DBL_PLRG,%a1 |answer is +/- large number
bra set_sign |now go set the sign
DBL_RM:
tstb LOCAL_SGN(%a0) |if negative overflow
beqs d_rm_pos
d_rm_neg:
leal EXT_PINF,%a1 |answer is negative infinity
orl #neginf_mask,USER_FPSR(%a6)
bra end_ovfr |inf is same for all precisions (ext,dbl,sgl)
d_rm_pos:
leal DBL_PLRG,%a1 |answer is large positive number
bra end_ovfr
DBL_RP:
tstb LOCAL_SGN(%a0) |if negative overflow
beqs d_rp_pos
d_rp_neg:
leal DBL_PLRG,%a1 |answer is large negative number
bsetb #neg_bit,FPSR_CC(%a6)
bra end_ovfr
d_rp_pos:
leal EXT_PINF,%a1 |answer is positive infinity
bsetb #inf_bit,FPSR_CC(%a6)
bra end_ovfr
|
|case DEST_FMT = SGL
|
SGL_RN:
leal EXT_PINF,%a1 |answer is +/- infinity
bsetb #inf_bit,FPSR_CC(%a6)
bras set_sign
SGL_RZ:
leal SGL_PLRG,%a1 |answer is +/- large number
bras set_sign
SGL_RM:
tstb LOCAL_SGN(%a0) |if negative overflow
beqs s_rm_pos
s_rm_neg:
leal EXT_PINF,%a1 |answer is negative infinity
orl #neginf_mask,USER_FPSR(%a6)
bras end_ovfr
s_rm_pos:
leal SGL_PLRG,%a1 |answer is large positive number
bras end_ovfr
SGL_RP:
tstb LOCAL_SGN(%a0) |if negative overflow
beqs s_rp_pos
s_rp_neg:
leal SGL_PLRG,%a1 |answer is large negative number
bsetb #neg_bit,FPSR_CC(%a6)
bras end_ovfr
s_rp_pos:
leal EXT_PINF,%a1 |answer is positive infinity
bsetb #inf_bit,FPSR_CC(%a6)
bras end_ovfr
set_sign:
tstb LOCAL_SGN(%a0) |if negative overflow
beqs end_ovfr
neg_sign:
bsetb #neg_bit,FPSR_CC(%a6)
end_ovfr:
movew LOCAL_EX(%a1),LOCAL_EX(%a0) |do not overwrite sign
movel LOCAL_HI(%a1),LOCAL_HI(%a0)
movel LOCAL_LO(%a1),LOCAL_LO(%a0)
rts
|
| ERROR
|
error:
rts
|
| get_fline --- get f-line opcode of interrupted instruction
|
| Returns opcode in the low word of d0.
|
get_fline:
movel USER_FPIAR(%a6),%a0 |opcode address
movel #0,-(%a7) |reserve a word on the stack
leal 2(%a7),%a1 |point to low word of temporary
movel #2,%d0 |count
bsrl mem_read
movel (%a7)+,%d0
rts
|
| g_rndpr --- put rounding precision in d0{1:0}
|
| valid return codes are:
| 00 - extended
| 01 - single
| 10 - double
|
| begin
| get rounding precision (cmdreg3b{6:5})
| begin
| case opclass = 011 (move out)
| get destination format - this is the also the rounding precision
|
| case opclass = 0x0
| if E3
| *case RndPr(from cmdreg3b{6:5} = 11 then RND_PREC = DBL
| *case RndPr(from cmdreg3b{6:5} = 10 then RND_PREC = SGL
| case RndPr(from cmdreg3b{6:5} = 00 | 01
| use precision from FPCR{7:6}
| case 00 then RND_PREC = EXT
| case 01 then RND_PREC = SGL
| case 10 then RND_PREC = DBL
| else E1
| use precision in FPCR{7:6}
| case 00 then RND_PREC = EXT
| case 01 then RND_PREC = SGL
| case 10 then RND_PREC = DBL
| end
|
g_rndpr:
bsr g_opcls |get opclass in d0{2:0}
cmpw #0x0003,%d0 |check for opclass 011
bnes op_0x0
|
| For move out instructions (opclass 011) the destination format
| is the same as the rounding precision. Pass results from g_dfmtou.
|
bsr g_dfmtou
rts
op_0x0:
btstb #E3,E_BYTE(%a6)
beql unf_e1_exc |branch to e1 underflow
unf_e3_exc:
movel CMDREG3B(%a6),%d0 |rounding precision in d0{10:9}
bfextu %d0{#9:#2},%d0 |move the rounding prec bits to d0{1:0}
cmpil #0x2,%d0
beql unff_sgl |force precision is single
cmpil #0x3,%d0 |force precision is double
beql unff_dbl
movew CMDREG3B(%a6),%d0 |get the command word again
andil #0x7f,%d0 |clear all except operation
cmpil #0x33,%d0
beql unf_fsgl |fsglmul or fsgldiv
cmpil #0x30,%d0
beql unf_fsgl |fsgldiv or fsglmul
bra unf_fpcr
unf_e1_exc:
movel CMDREG1B(%a6),%d0 |get 32 bits off the stack, 1st 16 bits
| ;are the command word
andil #0x00440000,%d0 |clear all bits except bits 6 and 2
cmpil #0x00400000,%d0
beql unff_sgl |force single
cmpil #0x00440000,%d0 |force double
beql unff_dbl
movel CMDREG1B(%a6),%d0 |get the command word again
andil #0x007f0000,%d0 |clear all bits except the operation
cmpil #0x00270000,%d0
beql unf_fsgl |fsglmul
cmpil #0x00240000,%d0
beql unf_fsgl |fsgldiv
bra unf_fpcr
|
| Convert to return format. The values from cmdreg3b and the return
| values are:
| cmdreg3b return precision
| -------- ------ ---------
| 00,01 0 ext
| 10 1 sgl
| 11 2 dbl
| Force single
|
unff_sgl:
movel #1,%d0 |return 1
rts
|
| Force double
|
unff_dbl:
movel #2,%d0 |return 2
rts
|
| Force extended
|
unf_fsgl:
movel #0,%d0
rts
|
| Get rounding precision set in FPCR{7:6}.
|
unf_fpcr:
movel USER_FPCR(%a6),%d0 |rounding precision bits in d0{7:6}
bfextu %d0{#24:#2},%d0 |move the rounding prec bits to d0{1:0}
rts
|
| g_opcls --- put opclass in d0{2:0}
|
g_opcls:
btstb #E3,E_BYTE(%a6)
beqs opc_1b |if set, go to cmdreg1b
opc_3b:
clrl %d0 |if E3, only opclass 0x0 is possible
rts
opc_1b:
movel CMDREG1B(%a6),%d0
bfextu %d0{#0:#3},%d0 |shift opclass bits d0{31:29} to d0{2:0}
rts
|
| g_dfmtou --- put destination format in d0{1:0}
|
| If E1, the format is from cmdreg1b{12:10}
| If E3, the format is extended.
|
| Dest. Fmt.
| extended 010 -> 00
| single 001 -> 01
| double 101 -> 10
|
g_dfmtou:
btstb #E3,E_BYTE(%a6)
beqs op011
clrl %d0 |if E1, size is always ext
rts
op011:
movel CMDREG1B(%a6),%d0
bfextu %d0{#3:#3},%d0 |dest fmt from cmdreg1b{12:10}
cmpb #1,%d0 |check for single
bnes not_sgl
movel #1,%d0
rts
not_sgl:
cmpb #5,%d0 |check for double
bnes not_dbl
movel #2,%d0
rts
not_dbl:
clrl %d0 |must be extended
rts
|
|
| Final result table for unf_sub. Note that the negative counterparts
| are unnecessary as unf_sub always returns the sign separately from
| the exponent.
| ;+zero
EXT_PZRO: .long 0x00000000,0x00000000,0x00000000,0x00000000
| ;+zero
SGL_PZRO: .long 0x3f810000,0x00000000,0x00000000,0x00000000
| ;+zero
DBL_PZRO: .long 0x3c010000,0x00000000,0x00000000,0x00000000
| ;smallest +ext denorm
EXT_PSML: .long 0x00000000,0x00000000,0x00000001,0x00000000
| ;smallest +sgl denorm
SGL_PSML: .long 0x3f810000,0x00000100,0x00000000,0x00000000
| ;smallest +dbl denorm
DBL_PSML: .long 0x3c010000,0x00000000,0x00000800,0x00000000
|
| UNF_SUB --- underflow result calculation
|
| Input:
| d0 contains round precision
| a0 points to input operand in the internal extended format
|
| Output:
| a0 points to correct internal extended precision result.
|
tblunf:
.long uEXT_RN
.long uEXT_RZ
.long uEXT_RM
.long uEXT_RP
.long uSGL_RN
.long uSGL_RZ
.long uSGL_RM
.long uSGL_RP
.long uDBL_RN
.long uDBL_RZ
.long uDBL_RM
.long uDBL_RP
.long uDBL_RN
.long uDBL_RZ
.long uDBL_RM
.long uDBL_RP
.global unf_sub
unf_sub:
lsll #2,%d0 |move round precision to d0{3:2}
bfextu FPCR_MODE(%a6){#2:#2},%d1 |set round mode
orl %d1,%d0 |index is fmt:mode in d0{3:0}
leal tblunf,%a1 |load a1 with table address
movel %a1@(%d0:l:4),%a1 |use d0 as index to the table
jmp (%a1) |go to the correct routine
|
|case DEST_FMT = EXT
|
uEXT_RN:
leal EXT_PZRO,%a1 |answer is +/- zero
bsetb #z_bit,FPSR_CC(%a6)
bra uset_sign |now go set the sign
uEXT_RZ:
leal EXT_PZRO,%a1 |answer is +/- zero
bsetb #z_bit,FPSR_CC(%a6)
bra uset_sign |now go set the sign
uEXT_RM:
tstb LOCAL_SGN(%a0) |if negative underflow
beqs ue_rm_pos
ue_rm_neg:
leal EXT_PSML,%a1 |answer is negative smallest denorm
bsetb #neg_bit,FPSR_CC(%a6)
bra end_unfr
ue_rm_pos:
leal EXT_PZRO,%a1 |answer is positive zero
bsetb #z_bit,FPSR_CC(%a6)
bra end_unfr
uEXT_RP:
tstb LOCAL_SGN(%a0) |if negative underflow
beqs ue_rp_pos
ue_rp_neg:
leal EXT_PZRO,%a1 |answer is negative zero
oril #negz_mask,USER_FPSR(%a6)
bra end_unfr
ue_rp_pos:
leal EXT_PSML,%a1 |answer is positive smallest denorm
bra end_unfr
|
|case DEST_FMT = DBL
|
uDBL_RN:
leal DBL_PZRO,%a1 |answer is +/- zero
bsetb #z_bit,FPSR_CC(%a6)
bra uset_sign
uDBL_RZ:
leal DBL_PZRO,%a1 |answer is +/- zero
bsetb #z_bit,FPSR_CC(%a6)
bra uset_sign |now go set the sign
uDBL_RM:
tstb LOCAL_SGN(%a0) |if negative overflow
beqs ud_rm_pos
ud_rm_neg:
leal DBL_PSML,%a1 |answer is smallest denormalized negative
bsetb #neg_bit,FPSR_CC(%a6)
bra end_unfr
ud_rm_pos:
leal DBL_PZRO,%a1 |answer is positive zero
bsetb #z_bit,FPSR_CC(%a6)
bra end_unfr
uDBL_RP:
tstb LOCAL_SGN(%a0) |if negative overflow
beqs ud_rp_pos
ud_rp_neg:
leal DBL_PZRO,%a1 |answer is negative zero
oril #negz_mask,USER_FPSR(%a6)
bra end_unfr
ud_rp_pos:
leal DBL_PSML,%a1 |answer is smallest denormalized negative
bra end_unfr
|
|case DEST_FMT = SGL
|
uSGL_RN:
leal SGL_PZRO,%a1 |answer is +/- zero
bsetb #z_bit,FPSR_CC(%a6)
bras uset_sign
uSGL_RZ:
leal SGL_PZRO,%a1 |answer is +/- zero
bsetb #z_bit,FPSR_CC(%a6)
bras uset_sign
uSGL_RM:
tstb LOCAL_SGN(%a0) |if negative overflow
beqs us_rm_pos
us_rm_neg:
leal SGL_PSML,%a1 |answer is smallest denormalized negative
bsetb #neg_bit,FPSR_CC(%a6)
bras end_unfr
us_rm_pos:
leal SGL_PZRO,%a1 |answer is positive zero
bsetb #z_bit,FPSR_CC(%a6)
bras end_unfr
uSGL_RP:
tstb LOCAL_SGN(%a0) |if negative overflow
beqs us_rp_pos
us_rp_neg:
leal SGL_PZRO,%a1 |answer is negative zero
oril #negz_mask,USER_FPSR(%a6)
bras end_unfr
us_rp_pos:
leal SGL_PSML,%a1 |answer is smallest denormalized positive
bras end_unfr
uset_sign:
tstb LOCAL_SGN(%a0) |if negative overflow
beqs end_unfr
uneg_sign:
bsetb #neg_bit,FPSR_CC(%a6)
end_unfr:
movew LOCAL_EX(%a1),LOCAL_EX(%a0) |be careful not to overwrite sign
movel LOCAL_HI(%a1),LOCAL_HI(%a0)
movel LOCAL_LO(%a1),LOCAL_LO(%a0)
rts
|
| reg_dest --- write byte, word, or long data to Dn
|
|
| Input:
| L_SCR1: Data
| d1: data size and dest register number formatted as:
|
| 32 5 4 3 2 1 0
| -----------------------------------------------
| | 0 | Size | Dest Reg # |
| -----------------------------------------------
|
| Size is:
| 0 - Byte
| 1 - Word
| 2 - Long/Single
|
pregdst:
.long byte_d0
.long byte_d1
.long byte_d2
.long byte_d3
.long byte_d4
.long byte_d5
.long byte_d6
.long byte_d7
.long word_d0
.long word_d1
.long word_d2
.long word_d3
.long word_d4
.long word_d5
.long word_d6
.long word_d7
.long long_d0
.long long_d1
.long long_d2
.long long_d3
.long long_d4
.long long_d5
.long long_d6
.long long_d7
reg_dest:
leal pregdst,%a0
movel %a0@(%d1:l:4),%a0
jmp (%a0)
byte_d0:
moveb L_SCR1(%a6),USER_D0+3(%a6)
rts
byte_d1:
moveb L_SCR1(%a6),USER_D1+3(%a6)
rts
byte_d2:
moveb L_SCR1(%a6),%d2
rts
byte_d3:
moveb L_SCR1(%a6),%d3
rts
byte_d4:
moveb L_SCR1(%a6),%d4
rts
byte_d5:
moveb L_SCR1(%a6),%d5
rts
byte_d6:
moveb L_SCR1(%a6),%d6
rts
byte_d7:
moveb L_SCR1(%a6),%d7
rts
word_d0:
movew L_SCR1(%a6),USER_D0+2(%a6)
rts
word_d1:
movew L_SCR1(%a6),USER_D1+2(%a6)
rts
word_d2:
movew L_SCR1(%a6),%d2
rts
word_d3:
movew L_SCR1(%a6),%d3
rts
word_d4:
movew L_SCR1(%a6),%d4
rts
word_d5:
movew L_SCR1(%a6),%d5
rts
word_d6:
movew L_SCR1(%a6),%d6
rts
word_d7:
movew L_SCR1(%a6),%d7
rts
long_d0:
movel L_SCR1(%a6),USER_D0(%a6)
rts
long_d1:
movel L_SCR1(%a6),USER_D1(%a6)
rts
long_d2:
movel L_SCR1(%a6),%d2
rts
long_d3:
movel L_SCR1(%a6),%d3
rts
long_d4:
movel L_SCR1(%a6),%d4
rts
long_d5:
movel L_SCR1(%a6),%d5
rts
long_d6:
movel L_SCR1(%a6),%d6
rts
long_d7:
movel L_SCR1(%a6),%d7
rts
|end
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