Mercurial > hg > index.cgi
changeset 86:de42b8f77bc2
Fix problems related to parsing numbers (exponent, integers)
| author | William Astle <lost@l-w.ca> |
|---|---|
| date | Mon, 16 Oct 2023 00:52:50 -0600 |
| parents | 663d8e77b579 |
| children | 3bfd978ddb39 |
| files | src/number.s |
| diffstat | 1 files changed, 22 insertions(+), 22 deletions(-) [+] |
line wrap: on
line diff
--- a/src/number.s Sun Oct 15 22:15:36 2023 -0600 +++ b/src/number.s Mon Oct 16 00:52:50 2023 -0600 @@ -127,11 +127,11 @@ ; 4b. Set the exponent correctly then normalize the result to val0 val_parsenum lbeq SNERROR ; brif no numberr to parse ldd zero ; zero out digit accumulator - stx fpa0+fpa.sig - stx fpa0+fpa.sig+2 - stx fpa0+fpa.sig+4 - stx fpa0+fpa.sig+6 - stx fpa0+fpa.sig+8 + std fpa0+fpa.sig + std fpa0+fpa.sig+2 + std fpa0+fpa.sig+4 + std fpa0+fpa.sig+6 + std fpa0+fpa.sig+8 sta fpa0+fpa.sign ; set number sign to positive std fpaextra+4 ; clear out decimal exponent and sign std fpaextra ; set digit count and decimal flag to zero and no decimal @@ -173,7 +173,7 @@ stb fpaextra+2 bra val_parsenum2 ; go handle another digit or whatever val_parsenum5 cmpa #'. ; decimal? - bne val_parsenum3 ; brif not + bne val_parsenum6 ; brif not com fpaextra ; flag decimal seen lbeq SNERROR ; brif already seen a decimal point - syntax error bra val_parsenum2 ; go parse more digits @@ -211,13 +211,13 @@ ; By ensuring there were no leading zeroes converted, the result is already pre-normalized without losing precision due ; to an aribtrary number of leading zeroes. cmpb fpaextra ; is the exponent less than the number of digits? - blt val_parsenum13 ; brif so - return floating point (signed comparison!) + bgt val_parsenum13 ; brif so - return floating point (signed comparison!) cmpb #10 ; is exponent in the range for a binary integer? bgt val_parsenum13 ; brif not - return floating point ; Compare with 2147483648, the maximum *negative* value; note that this is a floating point comparison because we ; already normalized everything above and it handles exponents properly - lda fpa0+fpa.exp ; compare exponents (unbiased) - cmpa #9 + lda fpa0+fpa.exp ; compare exponents (unbiased), exponent adjusted for above code + cmpa #10 bne val_parsenum12 ldx fpa0+fpa.sig ; compare top of significand cmpx #0x2147 @@ -233,14 +233,14 @@ bpl val_parsenum14 ; brif not - doesn't fit in integer val_parsenum13 lda #valtype_float ; set return value to floating point sta val0+val.type - lda fpa0+fpa.exp ; put the bias into the exponent - adda #64 + lda fpa0+fpa.exp ; put the bias into the exponent but subtract one for leading digit + adda #63 sta fpa0+fpa.exp ldy #val0+val.value ; normalize/round and return the result jmp fps_normalize val_parsenum14 lda #valtype_int ; set value type to integer sta val0+val.type - ldb #9 ; exponent needed for decimal point to the right of significand + ldb #10 ; exponent needed for decimal point to the right of significand subb fpa0+fpa.exp ; number of digit shifts needed to denormalize beq val_parsenum16 ; brif already denormalized lslb ; do 4 shifts per digit @@ -253,17 +253,17 @@ decb ; done all shifts? bne val_parsenum15 ; Now convert BCD digit sequence in fpa0 significand to binary value in val0 -val_parsenum16 ldb #40 ; 40 bit shifts needed for whole significand +val_parsenum16 ldb #32 ; 40 bit shifts needed for whole significand stb fpa0+fpa.extra ; use extra precision byte as counter -val_parsenum17 lsl fpa0+fpa.sig+4 ; shift a bit into the binary result - rol fpa0+fpa.sig+3 - rol fpa0+fpa.sig+2 - rol fpa0+fpa.sig+1 - rol fpa0+fpa.sig - rol val0+val.int+3 - rol val0+val.int+2 - rol val0+val.int+1 - rol val0+val.int +val_parsenum17 lsr fpa0+fpa.sig ; shift a bit into the binary result + ror fpa0+fpa.sig+1 + ror fpa0+fpa.sig+2 + ror fpa0+fpa.sig+3 + ror fpa0+fpa.sig+4 + ror val0+val.int + ror val0+val.int+1 + ror val0+val.int+2 + ror val0+val.int+3 ldx #fpa0+fpa.sig ; point to BCD digits val_parsenum18 lda ,x ; get byte to check beq val_parsenum20 ; short circuit check if digits are 0