ROM subroutines: print double

ROM subroutines

Print double

addr code mnemonic action comments
EE0...2B8 2176 6F00 ADDI $76, $6F, 0 $76 <== $6F store return address to $76
2BC 0273 7171 FUN $73, $71, $71 $73 <== [f($71)] check argument for NAN (1 if NAN, else - 0)
2C0 4273 0004 BZ $73, 0004 branch to 2D0, if $73=0 branch if correct value
2C4 9F6F 7030 GOI $6F, $70, 30 call subroutine $70 + 30, return - $6F print the following text
2C8 034E 414E #3 'NAN' 3 symbols: "NAN" text to print (length=3 - first byte)
2CC 9F76 7600 GOI $76, $76, 0 return using $76 (finish subroutine)
2D0 E375 0000 SETL $75, 0000 $75 <== 0 exponent for 0
2D4 4271 0017 BZ $71, 0017 branch to 330, if $71=0 to print, if argument = 0
2D8 3173 7100 CMPI $73, $71, 0 compare $71 with 0 and set $73 is argument negative?
2DC 4873 0004 BNN $73, 0004 brach to 2EC, if $73 >=0 no "-" sign
2E0 E373 002D SETL $73, 002D $73 <== 2D symbol '-'
2E4 0005 0273 TRAP 5/02, $73 (I/O) call system function: print symbol print char from $73
2E8 EC71 8000 ANDNH $71, 8000 $71 <== $71 AND (NOT 800...) = $71 AND 7FF... reset sign bit
2EC E074 4024 SETH $74, 4024 $74 <== 402400.. float value 10
2F0 E073 3FF0 SETH $73, 3FF0 $73 <== 3FF000.. float value 1
2F4 2175 7200 ADDI $75, $72, 0 $75 <== $72 D - number of decimal digits (input parameter) to exponent
2F8 1073 7374 FMUL $73, $73, $74 $73 <== $73 * $74 10^D is calculating in $73
2FC 2572 7201 SUBI $72, $72, 1 $72 <== $72 - 1 dec number of digits
300 4572 FFFE BPB $72, FFFE branch to 2F8, if $72 > 0 repeat cycle until 0
304 0172 7173 FCMP $72, $71, $73 compare $71 with $73 and set $72 compare argument with 10^D
308 4072 0004 BN $72, 0004 branch to 318, if $72 < 0 skip if argument < 10^D
30C 1471 7174 FDIV $71, $71, $74 $71 <== $71 / $74 argument / 10
310 2175 7501 ADDI $75, $75, 1 $75 <== $75 + 1 inc exponent
314 F1FF FFFC JMPB FFFFFC jump to 304 repeat cycle
318 1473 7374 FDIV $73, $73, $74 $73 <== $73 / $74 10^D-1 (const for normalization: first digit must be non-zero)
31C 0172 7173 FCMP $72, $71, $73 compare $71 with $73 and set $72 compare argument with const
320 4872 0004 BNN $72, 0004 branch to 330, if $72 >= 0 finish if normalized mantissa is set in integer part of $71
324 1071 7174 FMUL $71, $71, $74 $71 <== $71 * $74 * 10
328 2575 7501 SUBI $75, $75, 1 $75 <== $75 - 1 dec exponent
32C F1FF FFFC JMPB FFFFFC jump to 31C repeat cycle
330 E372 0030 SETL $72, 0030 $72 <== 30 symbol '0'
334 0005 0272 TRAP 5/02, $72 (I/O) call system function: print symbol print char from $72
338 E372 0030 SETL $72, 002E $72 <== 2E symbol '.'
33C 0005 0272 TRAP 5/02, $72 (I/O) call system function: print symbol print char from $72
340 1771 0071 FINT $71, 00, $71 $71 <== int ($71) mantissa
344 9F6F 7010 GOI $6F, $70, 10 call subroutine $70 + 10, return - $6F print INT64 from $71
348 E372 0065 SETL $72, 0065 $72 <== 65 symbol 'e'
34C 0005 0272 TRAP 5/02, $72 (I/O) call system function: print symbol print char from $72
350 2171 7500 ADDI $71, $75, 00 $71 <== $75 exponent
354 9F6F 7010 GOI $6F, $70, 10 call subroutine $70 + 10, return - $6F print INT64 from $71
358 9F76 7600 GOI $76, $76, 00 return using $76 (finish subroutine)

previous page next page

Related topics:

E-MMI software