|
  |	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
  |