|
| fpsp.h 3.3 3.3
|
| 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.
| fpsp.h --- stack frame offsets during FPSP exception handling
|
| These equates are used to access the exception frame, the fsave
| frame and any local variables needed by the FPSP package.
|
| All FPSP handlers begin by executing:
|
| link a6,#-LOCAL_SIZE
| fsave -(a7)
| movem.l d0-d1/a0-a1,USER_DA(a6)
| fmovem.x fp0-fp3,USER_FP0(a6)
| fmove.l fpsr/fpcr/fpiar,USER_FPSR(a6)
|
| After initialization, the stack looks like this:
|
| A7 ---> +-------------------------------+
| | |
| | FPU fsave area |
| | |
| +-------------------------------+
| | |
| | FPSP Local Variables |
| | including |
| | saved registers |
| | |
| +-------------------------------+
| A6 ---> | Saved A6 |
| +-------------------------------+
| | |
| | Exception Frame |
| | |
| | |
|
| Positive offsets from A6 refer to the exception frame. Negative
| offsets refer to the Local Variable area and the fsave area.
| The fsave frame is also accessible from the top via A7.
|
| On exit, the handlers execute:
|
| movem.l USER_DA(a6),d0-d1/a0-a1
| fmovem.x USER_FP0(a6),fp0-fp3
| fmove.l USER_FPSR(a6),fpsr/fpcr/fpiar
| frestore (a7)+
| unlk a6
|
| and then either "bra fpsp_done" if the exception was completely
| handled by the package, or "bra real_xxxx" which is an external
| label to a routine that will process a real exception of the
| type that was generated. Some handlers may omit the "frestore"
| if the FPU state after the exception is idle.
|
| Sometimes the exception handler will transform the fsave area
| because it needs to report an exception back to the user. This
| can happen if the package is entered for an unimplemented float
| instruction that generates (say) an underflow. Alternatively,
| a second fsave frame can be pushed onto the stack and the
| handler exit code will reload the new frame and discard the old.
|
| The registers d0, d1, a0, a1 and fp0-fp3 are always saved and
| restored from the "local variable" area and can be used as
| temporaries. If a routine needs to change any
| of these registers, it should modify the saved copy and let
| the handler exit code restore the value.
|
|----------------------------------------------------------------------
|
| Local Variables on the stack
|
.set LOCAL_SIZE,192 | bytes needed for local variables
.set LV,-LOCAL_SIZE | convenient base value
|
.set USER_DA,LV+0 | save space for D0-D1,A0-A1
.set USER_D0,LV+0 | saved user D0
.set USER_D1,LV+4 | saved user D1
.set USER_A0,LV+8 | saved user A0
.set USER_A1,LV+12 | saved user A1
.set USER_FP0,LV+16 | saved user FP0
.set USER_FP1,LV+28 | saved user FP1
.set USER_FP2,LV+40 | saved user FP2
.set USER_FP3,LV+52 | saved user FP3
.set USER_FPCR,LV+64 | saved user FPCR
.set FPCR_ENABLE,USER_FPCR+2 | FPCR exception enable
.set FPCR_MODE,USER_FPCR+3 | FPCR rounding mode control
.set USER_FPSR,LV+68 | saved user FPSR
.set FPSR_CC,USER_FPSR+0 | FPSR condition code
.set FPSR_QBYTE,USER_FPSR+1 | FPSR quotient
.set FPSR_EXCEPT,USER_FPSR+2 | FPSR exception
.set FPSR_AEXCEPT,USER_FPSR+3 | FPSR accrued exception
.set USER_FPIAR,LV+72 | saved user FPIAR
.set FP_SCR1,LV+76 | room for a temporary float value
.set FP_SCR2,LV+92 | room for a temporary float value
.set L_SCR1,LV+108 | room for a temporary long value
.set L_SCR2,LV+112 | room for a temporary long value
.set STORE_FLG,LV+116
.set BINDEC_FLG,LV+117 | used in bindec
.set DNRM_FLG,LV+118 | used in res_func
.set RES_FLG,LV+119 | used in res_func
.set DY_MO_FLG,LV+120 | dyadic/monadic flag
.set UFLG_TMP,LV+121 | temporary for uflag errata
.set CU_ONLY,LV+122 | cu-only flag
.set VER_TMP,LV+123 | temp holding for version number
.set L_SCR3,LV+124 | room for a temporary long value
.set FP_SCR3,LV+128 | room for a temporary float value
.set FP_SCR4,LV+144 | room for a temporary float value
.set FP_SCR5,LV+160 | room for a temporary float value
.set FP_SCR6,LV+176
|
|NEXT equ LV+192 ;need to increase LOCAL_SIZE
|
|--------------------------------------------------------------------------
|
| fsave offsets and bit definitions
|
| Offsets are defined from the end of an fsave because the last 10
| words of a busy frame are the same as the unimplemented frame.
|
.set CU_SAVEPC,LV-92 | micro-pc for CU (1 byte)
.set FPR_DIRTY_BITS,LV-91 | fpr dirty bits
|
.set WBTEMP,LV-76 | write back temp (12 bytes)
.set WBTEMP_EX,WBTEMP | wbtemp sign and exponent (2 bytes)
.set WBTEMP_HI,WBTEMP+4 | wbtemp mantissa [63:32] (4 bytes)
.set WBTEMP_LO,WBTEMP+8 | wbtemp mantissa [31:00] (4 bytes)
|
.set WBTEMP_SGN,WBTEMP+2 | used to store sign
|
.set FPSR_SHADOW,LV-64 | fpsr shadow reg
|
.set FPIARCU,LV-60 | Instr. addr. reg. for CU (4 bytes)
|
.set CMDREG2B,LV-52 | cmd reg for machine 2
.set CMDREG3B,LV-48 | cmd reg for E3 exceptions (2 bytes)
|
.set NMNEXC,LV-44 | NMNEXC (unsup,snan bits only)
.set nmn_unsup_bit,1 |
.set nmn_snan_bit,0 |
|
.set NMCEXC,LV-43 | NMNEXC & NMCEXC
.set nmn_operr_bit,7
.set nmn_ovfl_bit,6
.set nmn_unfl_bit,5
.set nmc_unsup_bit,4
.set nmc_snan_bit,3
.set nmc_operr_bit,2
.set nmc_ovfl_bit,1
.set nmc_unfl_bit,0
|
.set STAG,LV-40 | source tag (1 byte)
.set WBTEMP_GRS,LV-40 | alias wbtemp guard, round, sticky
.set guard_bit,1 | guard bit is bit number 1
.set round_bit,0 | round bit is bit number 0
.set stag_mask,0xE0 | upper 3 bits are source tag type
.set denorm_bit,7 | bit determines if denorm or unnorm
.set etemp15_bit,4 | etemp exponent bit #15
.set wbtemp66_bit,2 | wbtemp mantissa bit #66
.set wbtemp1_bit,1 | wbtemp mantissa bit #1
.set wbtemp0_bit,0 | wbtemp mantissa bit #0
|
.set STICKY,LV-39 | holds sticky bit
.set sticky_bit,7
|
.set CMDREG1B,LV-36 | cmd reg for E1 exceptions (2 bytes)
.set kfact_bit,12 | distinguishes static/dynamic k-factor
| ;on packed move outs. NOTE: this
| ;equate only works when CMDREG1B is in
| ;a register.
|
.set CMDWORD,LV-35 | command word in cmd1b
.set direction_bit,5 | bit 0 in opclass
.set size_bit2,12 | bit 2 in size field
|
.set DTAG,LV-32 | dest tag (1 byte)
.set dtag_mask,0xE0 | upper 3 bits are dest type tag
.set fptemp15_bit,4 | fptemp exponent bit #15
|
.set WB_BYTE,LV-31 | holds WBTE15 bit (1 byte)
.set wbtemp15_bit,4 | wbtemp exponent bit #15
|
.set E_BYTE,LV-28 | holds E1 and E3 bits (1 byte)
.set E1,2 | which bit is E1 flag
.set E3,1 | which bit is E3 flag
.set SFLAG,0 | which bit is S flag
|
.set T_BYTE,LV-27 | holds T and U bits (1 byte)
.set XFLAG,7 | which bit is X flag
.set UFLAG,5 | which bit is U flag
.set TFLAG,4 | which bit is T flag
|
.set FPTEMP,LV-24 | fptemp (12 bytes)
.set FPTEMP_EX,FPTEMP | fptemp sign and exponent (2 bytes)
.set FPTEMP_HI,FPTEMP+4 | fptemp mantissa [63:32] (4 bytes)
.set FPTEMP_LO,FPTEMP+8 | fptemp mantissa [31:00] (4 bytes)
|
.set FPTEMP_SGN,FPTEMP+2 | used to store sign
|
.set ETEMP,LV-12 | etemp (12 bytes)
.set ETEMP_EX,ETEMP | etemp sign and exponent (2 bytes)
.set ETEMP_HI,ETEMP+4 | etemp mantissa [63:32] (4 bytes)
.set ETEMP_LO,ETEMP+8 | etemp mantissa [31:00] (4 bytes)
|
.set ETEMP_SGN,ETEMP+2 | used to store sign
|
.set EXC_SR,4 | exception frame status register
.set EXC_PC,6 | exception frame program counter
.set EXC_VEC,10 | exception frame vector (format+vector#)
.set EXC_EA,12 | exception frame effective address
|
|--------------------------------------------------------------------------
|
| FPSR/FPCR bits
|
.set neg_bit,3 | negative result
.set z_bit,2 | zero result
.set inf_bit,1 | infinity result
.set nan_bit,0 | not-a-number result
|
.set q_sn_bit,7 | sign bit of quotient byte
|
.set bsun_bit,7 | branch on unordered
.set snan_bit,6 | signalling nan
.set operr_bit,5 | operand error
.set ovfl_bit,4 | overflow
.set unfl_bit,3 | underflow
.set dz_bit,2 | divide by zero
.set inex2_bit,1 | inexact result 2
.set inex1_bit,0 | inexact result 1
|
.set aiop_bit,7 | accrued illegal operation
.set aovfl_bit,6 | accrued overflow
.set aunfl_bit,5 | accrued underflow
.set adz_bit,4 | accrued divide by zero
.set ainex_bit,3 | accrued inexact
|
| FPSR individual bit masks
|
.set neg_mask,0x08000000
.set z_mask,0x04000000
.set inf_mask,0x02000000
.set nan_mask,0x01000000
|
.set bsun_mask,0x00008000 |
.set snan_mask,0x00004000
.set operr_mask,0x00002000
.set ovfl_mask,0x00001000
.set unfl_mask,0x00000800
.set dz_mask,0x00000400
.set inex2_mask,0x00000200
.set inex1_mask,0x00000100
|
.set aiop_mask,0x00000080 | accrued illegal operation
.set aovfl_mask,0x00000040 | accrued overflow
.set aunfl_mask,0x00000020 | accrued underflow
.set adz_mask,0x00000010 | accrued divide by zero
.set ainex_mask,0x00000008 | accrued inexact
|
| FPSR combinations used in the FPSP
|
.set dzinf_mask,inf_mask+dz_mask+adz_mask
.set opnan_mask,nan_mask+operr_mask+aiop_mask
.set nzi_mask,0x01ffffff | clears N, Z, and I
.set unfinx_mask,unfl_mask+inex2_mask+aunfl_mask+ainex_mask
.set unf2inx_mask,unfl_mask+inex2_mask+ainex_mask
.set ovfinx_mask,ovfl_mask+inex2_mask+aovfl_mask+ainex_mask
.set inx1a_mask,inex1_mask+ainex_mask
.set inx2a_mask,inex2_mask+ainex_mask
.set snaniop_mask,nan_mask+snan_mask+aiop_mask
.set naniop_mask,nan_mask+aiop_mask
.set neginf_mask,neg_mask+inf_mask
.set infaiop_mask,inf_mask+aiop_mask
.set negz_mask,neg_mask+z_mask
.set opaop_mask,operr_mask+aiop_mask
.set unfl_inx_mask,unfl_mask+aunfl_mask+ainex_mask
.set ovfl_inx_mask,ovfl_mask+aovfl_mask+ainex_mask
|
|--------------------------------------------------------------------------
|
| FPCR rounding modes
|
.set x_mode,0x00 | round to extended
.set s_mode,0x40 | round to single
.set d_mode,0x80 | round to double
|
.set rn_mode,0x00 | round nearest
.set rz_mode,0x10 | round to zero
.set rm_mode,0x20 | round to minus infinity
.set rp_mode,0x30 | round to plus infinity
|
|--------------------------------------------------------------------------
|
| Miscellaneous equates
|
.set signan_bit,6 | signalling nan bit in mantissa
.set sign_bit,7
|
.set rnd_stky_bit,29 | round/sticky bit of mantissa
| this can only be used if in a data register
.set sx_mask,0x01800000 | set s and x bits in word $48
|
.set LOCAL_EX,0
.set LOCAL_SGN,2
.set LOCAL_HI,4
.set LOCAL_LO,8
.set LOCAL_GRS,12 | valid ONLY for FP_SCR1, FP_SCR2
|
|
.set norm_tag,0x00 | tag bits in {7:5} position
.set zero_tag,0x20
.set inf_tag,0x40
.set nan_tag,0x60
.set dnrm_tag,0x80
|
| fsave sizes and formats
|
.set VER_4,0x40 | fpsp compatible version numbers
| are in the $40s {$40-$4f}
.set VER_40,0x40 | original version number
.set VER_41,0x41 | revision version number
|
.set BUSY_SIZE,100 | size of busy frame
.set BUSY_FRAME,LV-BUSY_SIZE | start of busy frame
|
.set UNIMP_40_SIZE,44 | size of orig unimp frame
.set UNIMP_41_SIZE,52 | size of rev unimp frame
|
.set IDLE_SIZE,4 | size of idle frame
.set IDLE_FRAME,LV-IDLE_SIZE | start of idle frame
|
| exception vectors
|
.set TRACE_VEC,0x2024 | trace trap
.set FLINE_VEC,0x002C | real F-line
.set UNIMP_VEC,0x202C | unimplemented
.set INEX_VEC,0x00C4
|
.set dbl_thresh,0x3C01
.set sgl_thresh,0x3F81
|
