c2000ware-core-sdk/libraries/math/IQmath/c28/source/IQNexp.asm
2023-12-13 16:46:16 +05:30

369 lines
9.2 KiB
NASM

;;###########################################################################
;;
;; FILE: IQNexp.asm
;;
;; TITLE: C Callable IQ Exponent Math Function
;;
;;###########################################################################
;;
;; Ver | Date | Who | Description of changes
;; =====|=============|=======|==============================================
;; 1.0 | 11 Jul 2002 | A. T. | Original Release.
;; -----|-------------|-------|----------------------------------------------
;; 1.1 | 10 Mar 2005 | A. T. | Fixed Bug #1. "LSL ACC,T" instruction
;; | | | should have been "LSLL ACC,T".
;; -----|-------------|-------|----------------------------------------------
;; | | |
;;
;;###########################################################################
;;#############################################################################
;;!
;;! Copyright: Copyright (C) 2023 Texas Instruments Incorporated -
;;! All rights reserved not granted herein.
;;! Limited License.
;;!
;;! Texas Instruments Incorporated grants a world-wide, royalty-free,
;;! non-exclusive license under copyrights and patents it now or hereafter
;;! owns or controls to make, have made, use, import, offer to sell and sell
;;! ("Utilize") this software subject to the terms herein. With respect to the
;;! foregoing patent license, such license is granted solely to the extent that
;;! any such patent is necessary to Utilize the software alone. The patent
;;! license shall not apply to any combinations which include this software,
;;! other than combinations with devices manufactured by or for TI
;;! ("TI Devices").
;;! No hardware patent is licensed hereunder.
;;!
;;! Redistributions must preserve existing copyright notices and reproduce this
;;! license (including the above copyright notice and the disclaimer and
;;! (if applicable) source code license limitations below) in the documentation
;;! and/or other materials provided with the distribution.
;;!
;;! Redistribution and use in binary form, without modification, are permitted
;;! provided that the following conditions are met:
;;!
;;! * No reverse engineering, decompilation, or disassembly of this software is
;;! permitted with respect to any software provided in binary form.
;;! * Any redistribution and use are licensed by TI for use only
;;! with TI Devices.
;;! * Nothing shall obligate TI to provide you with source code for the
;;! software licensed and provided to you in object code.
;;!
;;! If software source code is provided to you, modification and redistribution
;;! of the source code are permitted provided that the following conditions
;;! are met:
;;!
;;! * any redistribution and use of the source code, including any resulting
;;! derivative works, are licensed by TI for use only with TI Devices.
;;! * any redistribution and use of any object code compiled from the source
;;! code and any resulting derivative works, are licensed by TI for use
;;! only with TI Devices.
;;!
;;! Neither the name of Texas Instruments Incorporated nor the names of its
;;! suppliers may be used to endorse or promote products derived from this
;;! software without specific prior written permission.
;;#############################################################################
;;===========================================================================
;; Function: _IQNexp
;;===========================================================================
;;
;; C Usage: extern long _IQNexp(long X); // Saturated
;;
;;---------------------------------------------------------------------------
;;
;; On Entry: ACC = X in IQ format
;;
;; Regs Used: XAR7, XAR6, XAR5, XAR4, XAR3
;; XT, P
;;
;; On Exit: ACC = exp(X) result in IQ format
;;
;; Q range: 29 to 1
;;
;;---------------------------------------------------------------------------
;; Algorithm: The procedure for calculating "Y = exp(X)" is as follows:
;;
;; Step 1) Saturate input to avoid overflow.
;;
;; Step 2) Normalize Input:
;;
;; X' = X * 2^n -1.0 <= X' < 1.0
;;
;; Step 3) Obtain Y' = exp(X') using taylor series expansion:
;;
;; Y' = 1 + X' + X'^2/2! + .... + X^11/11!
;;
;; Step 4) Denormalize value to get output Y:
;;
;; if( n == 0 ) Y = Y'
;; if( n == 1 ) Y = Y'^2
;; if( n == 2 ) Y = Y'^4
;; if( n == 3 ) Y = Y'^8
;; if( n == 4 ) Y = Y'^16
;;
;;---------------------------------------------------------------------------
;; Benchmark:
;;
;; Assumptions:
;; * Code executes from 0-wait SARAM block.
;; * _IQexp Tables located in seperate 0-wait SARAM or 1-wait ROM block.
;; * Stack located in seperate SARAM block.
;; * Includes LCR/LRETR.
;;
;; Cycles = 168 to 215
;;
;;===========================================================================
IQNexp .macro q_value
PUSH XAR3
; Step 1: Saturate input to avoid overflow:
MOVL XAR7,#(_IQexpTableMinMax + (q_value - 1)*4)
MINL ACC,*+XAR7[0] ; Saturate Input To Max Value
MAXL ACC,*+XAR7[2] ; Saturate Input To Min Value
MOVL XAR6,@ACC ; XAR6 = X (QG)
; Step 2: Normalize Input:
CSB ACC
MOVB AL,#(31 - q_value)
SUB AL,@T
MOVB @AL,#0,LT
MOVZ AR3,@AL ; AR3 = n
MOV T,@AL
MOVL ACC,@XAR6
ASR64 ACC:P,T ; ACC = X' (QG)
.if (q_value <= 29)
MOV @T,#(29 - q_value)
LSLL ACC,T ; (Fixed Bug #1) ACC = X' (Q29)
.endif
MOVL XAR6,@ACC ; XAR6 = X' (Q29)
; Step 3: Repeat 10 Times: ACC = X*(1 + ACC/Coeff)
MOV @PH,#(1 << 12)
MOV @PL,#0
MOVL XAR5,@P ; XAR5 = 1.0 (Q28)
MOVL XAR7,#_IQexpTableCoeff ; XAR7 -> 1/10 Coeff (Q31)
MOVB XAR4,#9
IQNexpLoop1:
MOVL XT,@ACC ; XT = ACC (Q29)
QMPYL ACC,XT,*XAR7++ ; ACC = ACC/Coeff (Q28)
ADDL ACC,@XAR5 ; ACC = 1 + ACC/Coeff (Q28)
MOVL XT,@XAR6 ; XT = X (Q29)
IMPYL P,XT,@ACC
QMPYL ACC,XT,@ACC ; ACC:P = X(1 + ACC/Coeff) (Q57)
LSL64 ACC:P,#4 ; ACC = X(1 + ACC/Coeff) (Q29)
BANZ IQNexpLoop1,AR4--
ADDL ACC,@XAR5
ADDL ACC,@XAR5
.if (q_value <= 29)
MOV @T,#(29 - q_value)
ASR64 ACC:P,T ; ACC = 1 + ACC = exp(X) (QG)
.endif
; Step 4: Denormalize result:
MOVB XAR6,#0
BAR IQNexpExit,AR3,AR6,EQ ;if( n == 0 ) Y = ACC
SUBB XAR3,#1
IQNexpLoop2:
MOVL XT,@ACC
IMPYL P,XT,@ACC
QMPYL ACC,XT,@ACC
MOV @T,#(32 - q_value)
LSL64 ACC:P,T ; ACC = ACC*ACC (QG)
BANZ IQNexpLoop2,AR3-- ; Loop until n == 0
IQNexpExit:
POP XAR3
LRETR
.endm
;; The value "GLOBAL_Q" needs to be supplied by the assembler
;; using the "-dGLOBAL_Q=q_value" directive:
.sect "IQmath"
.ref _IQexpTableMinMax
.ref _IQexpTableCoeff
.if GLOBAL_Q == 30
.def __IQ30exp
__IQ30exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 29
.def __IQ29exp
__IQ29exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 28
.def __IQ28exp
__IQ28exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 27
.def __IQ27exp
__IQ27exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 26
.def __IQ26exp
__IQ26exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 25
.def __IQ25exp
__IQ25exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 24
.def __IQ24exp
__IQ24exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 23
.def __IQ23exp
__IQ23exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 22
.def __IQ22exp
__IQ22exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 21
.def __IQ21exp
__IQ21exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 20
.def __IQ20exp
__IQ20exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 19
.def __IQ19exp
__IQ19exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 18
.def __IQ18exp
__IQ18exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 17
.def __IQ17exp
__IQ17exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 16
.def __IQ16exp
__IQ16exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 15
.def __IQ15exp
__IQ15exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 14
.def __IQ14exp
__IQ14exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 13
.def __IQ13exp
__IQ13exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 12
.def __IQ12exp
__IQ12exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 11
.def __IQ11exp
__IQ11exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 10
.def __IQ10exp
__IQ10exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 9
.def __IQ9exp
__IQ9exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 8
.def __IQ8exp
__IQ8exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 7
.def __IQ7exp
__IQ7exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 6
.def __IQ6exp
__IQ6exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 5
.def __IQ5exp
__IQ5exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 4
.def __IQ4exp
__IQ4exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 3
.def __IQ3exp
__IQ3exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 2
.def __IQ2exp
__IQ2exp:
IQNexp GLOBAL_Q
.endif
.if GLOBAL_Q == 1
.def __IQ1exp
__IQ1exp:
IQNexp GLOBAL_Q
.endif
;;###########################################################################
;; No More.
;;###########################################################################