 
ô >FPAssemble version 1.01R ô > ;ô >Program Copyright © Stewart Brodie - 7 February 1991 (: 2Eô This software may be freely distributed provided that the above <Hô credit is not altered, and the instructions below are not changed. FDô If you make any changes, please mail the new version to me at: P: Zô "snb90@uk.ac.soton.ecs" d nGô This is a library procedure which should by loaded by the LIBRARY xKô command from a BASIC program when the user wishes to use the floating ‚Kô point instruction set from BASICs assembler.  To use a floating point ŒIô instruction, use the mnemonics documented in the RISC OS PRM vol IV –Dô under Floating Point Emulator: The instruction set (Page 1701)  =ô Call the function by assembling an instruction such as: ھ ´'ô   EQUD FN_FP("LDFE F0,[R1,#44]!") ¾ ب=ô Call PROC_list_FP_commands to see the opcodes available ز ـAôEMBER to prefix the register numbers with F or R (default F) و.ôEMBER that rounding defualts to 'closest' ً=ôEMBER that precision should be specified (defaults to S) ْEô Unfortunately, you cannot use BASIC variables as register names<ô or constants.  Maybe somebody else will do that later."ô Case is unimportant,.ô PC,LR,SP can be used for R15,R14 and R136@0ô We start with some of the support routinesJT*ف ¤_get_FP_register(ّ F$,max_register)^ê P$,reg,Q$,reg2h*ç ہF$,2)="PC" Œ reg=15:F$="R15"+ءF$,3)r*ç ہF$,2)="LR" Œ reg=15:F$="R14"+ءF$,3)|*ç ہF$,2)="SP" Œ reg=15:F$="R13"+ءF$,3)†P$=ہF$,1)گç P$="F" „ P$="R" Œڑ  Q$=P$¤  F$=ءF$,2)®  P$=ہF$,1)¸حآreg=—(P$)-48جç Q$="R" € reg=1 Œض  reg2=10+—(ءF$,2))-48à-  ç reg2>9 € reg2<16 Œ F$=ءF$,2):reg=reg2êحô3ç reg>max_register Œ … &A0001,"Bad register"+E$‏@ç Q$="F" € max_register=15 Œ … &A0007,"Need ARM register"+E$?ç Q$="R" € max_register=7  Œ … &A0008,"Need FP register"+E$F$=ءF$,2)=reg&0ف ¤_FP_upper_case(F$):ê G$,G%Dم G%=1 ¸ ©F$N#  ç—ءF$,G%)>96 € —ءF$,G%)<123 ŒX    G$+=½(—ءF$,G%)-32)b   جl    G$+=½(—ءF$,G%))v  ح€يٹ=G$”‍¨ف ¤_get_FP_constant(F$)²	ê reg¼reg=»F$ئبژ reg تذ  ة 0.0:=0ع  ة 1.0:=1ن  ة 2.0:=2î  ة 3.0:=3ّ  ة 4.0:=4  ة 5.0:=5  ة 0.5:=6  ة 10.0:=7  **  … &A0005,"Bad immediate constant"+E$4ث>=0HRف ٍ_FP_strip_spaces(ّ I$)\ب• —I$=32:I$=ءI$,2):خfلpzف ٍ_list_FP_commands„ê I$,I%ژ'ٌ "Floating point instruction set:"کê ـ¢÷ +0¬َ I$,I%¶ب• I$<>"END"ہ
  ٌ I$ت  َ I$,I%شخقلèٍHô This routine provides the decoding for Floating Point instructionsüف ¤_FP(instr$)Iê I%,I$,X,Y,P$,cond%,roundX,roundY,round%,prec%,Fd,Rn,Fm,Fn,Rm,const%6ê E$,index,wb,offset,sign,K$,Rd,binop,instruction%$"instr$=¤_FP_upper_case(instr$).#E$=" in "+instr$+" instruction"8I%=0Bê ـL÷ +0V`'ـ LDF,%1100000100000000000100000000j'ـ STF,%1100000000000000000100000000tـ ADF,0~ـ MUF,2ˆـ SUF,4’ـ RSF,6œـ DVF,8¦ـ RDF,10°ـ POW,12؛ـ RPW,14ؤـ RMF,16خـ FML,18طـ FDV,20âـ FRD,22ىـ POL,24ِـ MVF,1 ـ MNF,3
ـ ABS,5ـ RND,7ـ SQT,9(ـ LOG,112ـ LGN,13<ـ EXP,15Fـ SIN,17Pـ COS,19Zـ TAN,21dـ ASN,23nـ ACS,25xـ ATN,27‚ـ FLT,0Œـ FIX,1–ـ WFS,2 ـ RFS,3ھـ WFC,4´ـ RFC,5¾ـ CMFE,6بـ CNFE,7زـ CMF,4ــ CNF,5وـ END,0ًْَ I$,opcode%instruction%=0ب• I$<>"END"";  ç (ہinstr$,5)="CMFEQ" „ ہinstr$,5)="CNFEQ") € ©I$=4 Œ,    I$="NotCompare"6  ح@  ç ہinstr$,©I$)=I$ ŒJ    J$=I$T    I$=ءinstr$,1+©I$)^9    cond%=§"EQNECSCCMIPLVSVCHILSGELTGTLEALNV",ہI$,2))h    ç cond%=0 „ cond%ƒ2=0 Œr      cond%=&E|
     ج†      cond%=cond%پ2گ      I$=ءI$,3)ڑ	    ح¤L    cond%=cond%<<28      : ô Stick the condition code in the right place®¸    بژ J$ تآ$      ة "WFS","RFS","WFC","RFC":ج        X=0:Y=0ض        roundX=0à        roundY=0ê     :ô      P$=ہI$,1)‏      بژ P$ ت        ة "S":X=0:Y=0=        ة "D":X=1:Y=0              : ô Evaluate precision        ة "E":X=0:Y=1&        ة "P":X=1:Y=10       :        X=0D        Y=0N0        ôERROR &A0000,"Missing precision"+E$X      ثbl      I$=ءI$,2)v      بژ J$ ت€        ة "LDF","STF":ٹ?          round%=0            :ô Now evaluate rounding mode”          roundX=0‍          roundY=0¨        ²          P$=ہI$,1)¼          بژ P$ تئ'            ة "P":roundX=1:roundY=0ذ'            ة "M":roundX=1:roundY=0ع'            ة "Z":roundX=1:roundY=1ن           :î            roundX=0ّ            roundY=0            I$=" "+I$          ث          I$=ءI$,2)       ث*4	    ث>H    ٍ_FP_strip_spaces(I$)R\f"    round%=roundX*64+roundY*32p    prec%=(1<<19)*Y+128*Xz„    بژ J$ تژ      ة "LDF","STF":ک        index=1<<24¢        wb=0¬!        prec%=(Y<<22)+(X<<15)¶,        Fd=(¤_get_FP_register(I$,7))<<12ہ!        ٍ_FP_strip_spaces(I$)ت7        ç ہI$,2)<>",[" Œ … &A0002,"Syntax error"+E$ش        I$=ءI$,3)ق-        Rn=(¤_get_FP_register(I$,15))<<16è!        ٍ_FP_strip_spaces(I$)ٍ        ç ہI$,1)="]" Œü          I$=ءI$,2)	#          ٍ_FP_strip_spaces(I$)	          wb=1<<21	          index=0	$          ç ©I$=0 Œ	.            offset=0	8            sign=0	B            index=0	L&          ح : ô Used to be an ELSE	V         ج	`           K$=ءI$,1+§I$,"]"))	j#          ٍ_FP_strip_spaces(K$)	t%          ç ہK$,1)="!" Œ wb=1<<21	~           I$=ہI$,§I$,"]")-1)	ˆ        ح	’        ç ہI$,2)=",#" Œ	œ          I$=ءI$,3)	¦         ج	°(          … &A0003,"Syntax error"+E$	؛        ح	ؤ        offset=»(I$)	خ4        ç ´(offset)=-1 Œ sign=1:offset=”(offset)	ط@        ç(offset)ƒ4<>0Œ … &A0004,"Not on a word boundary"+E$	â        offset=offset پ 4	ى?        ç offset>255 Œ … &A0005,"Bad immediate constant"+E$	ِ        sign=(1-sign)<<23
 h        instruction%=cond% „ round% „ prec% „ index „ wb „ Fd „ Rn „ offset „ sign „ index „ opcode%

      ة "FLT":
4        Fn=((¤_get_FP_register(I$,7))<<16) „ 272
        I$=ءI$,2)
(-        Rd=(¤_get_FP_register(I$,15))<<12
2'        opcode%=(opcode% „ 224)<<20
<C        instruction%=cond% „ opcode% „ prec% „ round% „ Fn „ Rd
F      ة "FIX":
P5        Rd=((¤_get_FP_register(I$,15))<<12) „ 272
Z        I$=ءI$,2)
d(        Fm=(¤_get_FP_register(I$,7))
n'        opcode%=(opcode% „ 224)<<20
xC        instruction%=round% „ prec% „ opcode% „ Fm „ Rd „ cond%
‚$      ة "WFS","RFS","WFC","RFC":
Œ'        opcode%=(opcode% „ 224)<<20
–5        Rd=((¤_get_FP_register(I$,15))<<12) „ 280
 >        instruction%=cond% „ opcode% „ Rd „ prec% „ round%
ھ&      ة "CMF","CNF","CMFE","CNFE":
´G        opcode%=((opcode%*2+1)<<20) „ (&F1<<8) „ 16 „ cond% „ prec%
¾        ç ہI$,1)="#" Œ
ب          I$=ءI$,2)
ز*          Fm=8 „ ¤_get_FP_constant(I$)
ـ           I$=ءI$,1+§I$,","))
و         ج
ً(          Fm=¤_get_FP_register(I$,7)
ْ          I$=ءI$,2)        ح        ç ہI$,1)="#" ŒA          ç (Fm € 8) Œ … &A0008,"Can't have two constants"+E$"          Fn=Fm<<16,          I$=ءI$,2)6*          Fm=¤_get_FP_constant(I$) „ 8@         جJ.          Fn=(¤_get_FP_register(I$,7))<<16T        ح^N        instruction%=round% „ Fn „ Fm „ opcode% „ (&E<<24) „ cond% „ prec%h      r        binop=(opcode%ƒ2)=0|G        opcode%=(((opcode%پ2)+&E0)<<20) „ ((opcode%ƒ2)<<15) „ cond%†,        Fd=(¤_get_FP_register(I$,7))<<12گ        I$=ءI$,2)ڑ        ç binop Œ¤.          Fn=(¤_get_FP_register(I$,7))<<16®          I$=ءI$,2)¸         جآ          Fn=0ج        حض        ç ہI$,1)="#" Œà          I$=ءI$,2)ê*          Fm=8 „ ¤_get_FP_constant(I$)ô         ج‏(          Fm=¤_get_FP_register(I$,7)        حF        instruction%=opcode% „ Fm „ Fn „ Fd „ prec% „ round% „ 256	    ث&  ح0  ç instruction%<>0 Œ ÷ +0:  َ I$,opcode%DخNXـ END,0bl6ç instruction%=0 Œ … &A0006,"Unknown FP opcode"+E$v€=instruction%ے