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Better bitfiddling with the intel 63 normalize bit
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cvt_num16_num10 clears now bit 63
cvt_num10_num16 tries to shift-copy the mantissa ignoring this bit

Test precision regex seems to be stable now.
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Reini Urban committed Sep 11, 2012
1 parent b3b7395 commit 8f65204
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Showing 3 changed files with 54 additions and 48 deletions.
82 changes: 44 additions & 38 deletions src/packfile/pf_items.c
View file
Expand Up @@ -427,7 +427,7 @@ static opcode_t fetch_op_le_8(ARGIN(const unsigned char *b))
* Floattype 3 = IEEE-754 4 byte float (binary32)
* Floattype 4 = PowerPC 16 byte double-double (-mlong-double-128)
* not yet:
* Floattype 4 = IEEE-754 2 byte half-precision float (binary16)
* Floattype 5 = IEEE-754 2 byte half-precision float (binary16)
* Floattype 6 = MIPS64 16 byte long double
* Floattype 7 = AIX 16 byte long double
*
Expand Down Expand Up @@ -460,18 +460,18 @@ cvt_num10_num8(ARGOUT(unsigned char *dest), ARGIN(const unsigned char *src))
padding + 10-byte double (80 bits):
unused 2 byte on i386, 6 byte on x86_84/ia64
sign 1 bit 79
exp 15 bits 78-64
exp 15 bits 78-64 bias 16383
man 64 bits 63-0
to 8-byte double (64 bits):
sign 1 bit 63
exp 11 bits 62-52
exp 11 bits 62-52 bias 1023
man 52 bits 51-0
+-------+-------+-------+-------+-------+-------+--...--+-------+
|src[11]|src[10]|src[9] |src[8] |src[7] |src[6] | ... |src[0] |
| unused |S| Exp | Fract |
| unused |S| Exp |i| Fract |
+-------+-------+-------+-------+-------+-------+--...--+-------+
|<-----16------>|1|<-----15---->|<-----------64 bits----------->|
|<-----16------>|1|<-----15---->|1|<---------63 bits----------->|
<-------------->|<----------------80 bits----------------------->
+-------+-------+-------+-------+-------+-------+-------+-------+
Expand Down Expand Up @@ -515,7 +515,7 @@ cvt_num10_num8(ARGOUT(unsigned char *dest), ARGIN(const unsigned char *src))
if (sign)
dest[7] |= 0x80;
/* long double frac 63 bits => 52 bits
src[7] &= 0x7f; reset integer bit */
src[7] &= 0x7f; reset integer bit 63 */
for (i = 0; i < 6; ++i) {
dest[i+1] |= (i==5 ? src[7] & 0x7f : src[i+2]) >> 3;
dest[i] |= (src[i+2] & 0x1f) << 5;
Expand Down Expand Up @@ -562,11 +562,11 @@ cvt_num16_num8(ARGOUT(unsigned char *dest), ARGIN(const unsigned char *src))
/*
16-byte quad double (128 bits):
sign 1 bit 127
exp 15 bits 126-112 16383
exp 15 bits 126-112 bias 16383
man 112 bits 111-0
to 8-byte double (64 bits):
sign 1 bit 63
exp 11 bits 62-52 1023
exp 11 bits 62-52 bias 1023
man 52 bits 51-0
+-------+-------+-------+-------+-------+-------+--...--+-------+
Expand Down Expand Up @@ -602,7 +602,7 @@ cvt_num16_num8(ARGOUT(unsigned char *dest), ARGIN(const unsigned char *src))
expo2 = expo - 16383;
expo = expo2;
# else
expo -= 16383; /* - same bias as with 12-byte */
expo -= 16383; /* - same bias as with 80-bit */
# endif
expo += 1023; /* + bias 8byte */

Expand Down Expand Up @@ -676,29 +676,29 @@ cvt_num16_num10(ARGOUT(unsigned char *dest), ARGIN(const unsigned char *src))
/*
16-byte double (128 bits):
sign 1 bit 127
exp 15 bits 126-112
exp 15 bits 126-112 bias 16383
man 112 bits 111-0
to 12-byte double (96 bits):
unused 16 bits 95-80
sign 1 bit 79
exp 15 bits 78-64
man 64 bits 63-0
exp 15 bits 78-64 bias 16383
man 64 bits 63-0 bit 63 should be 1
+-------+-------+-------+-------+-------+-------+--...--+-------+
|src[15]|src[14]|src[13]|src[12]|src[11]|src[10]| ... |src[0] |
S| E | F |
+-------+-------+-------+-------+-------+-------+--...--+-------+
1|<-----15----->|<----------------112 bits--------------------->|
<---------------------------128 bits---------------------------->
16-byte LONG DOUBLE FLOATING-POINT (IA64 or BE 64-bit)
16-byte QUAD DOUBLE FLOATING-POINT (__float128 or BE 64-bit)
+-------+-------+-------+-------+-------+-------+--...--+-------+
|dest[11]dest[10]dest[9]|dest[8]|dest[7]|dest[6]| ... |dest[0]|
| unused |S| Exp | Fract |
+-------+-------+-------+-------+-------+-------+--...--+-------+
|<-----16------>|1|<-----15---->|<-----------64 bits----------->|
<-------------->|<----------------80 bits----------------------->
12-byte LONG DOUBLE FLOATING-POINT (i386 special)
12-byte LONG DOUBLE FLOATING-POINT (intel special)
*/

memset(dest, 0, 12);
Expand All @@ -707,6 +707,7 @@ cvt_num16_num10(ARGOUT(unsigned char *dest), ARGIN(const unsigned char *src))
dest[9] = src[14];
/* and copy the rest */
memcpy(&dest[0], &src[0], 8);
dest[7] |= 0x80; /* set integer bit 63 */
}

/*
Expand Down Expand Up @@ -763,9 +764,9 @@ cvt_num4_num10(ARGOUT(unsigned char *dest), ARGIN(const unsigned char *src))
=item C<static void cvt_num10_num16(unsigned char *dest, const unsigned char
*src)>
Converts i386 LE 10-byte long double to IEEE 754 LE 16-byte long double.
Converts i386 LE 10-byte long double to IEEE 754 LE 16-byte quad double.
Not tested yet.
Rounding errors.
=cut
Expand All @@ -780,18 +781,18 @@ cvt_num10_num16(ARGOUT(unsigned char *dest), ARGIN(const unsigned char *src))
12/16-byte double (80 bit):
unused padding 2-6 byte
sign 1 bit 79
exp 15 bits 78-64
man 64 bits 63-0
exp 15 bits 78-64 bias 16383
man 64 bits 63-0 bit 63 should be 1 (normalized)
to 16-byte double (__float128):
sign 1 bit 127
exp 15 bits 126-112
exp 15 bits 126-112 bias 16383
man 112 bits 111-0
+-------+-------+-------+-------+-------+-------+--...--+-------+
|src[11]|src[10]|src[9] |src[8] |src[7] |src[6] | ... |src[0] |
| unused |S| Exp | Fract |
| unused |S| Exp |i| Fract |
+-------+-------+-------+-------+-------+-------+--...--+-------+
|<------------->|1|<-----15---->|<-----------64 bits----------->|
|<------------->|1|<-----15---->|1|<---------63 bits----------->|
<-------------->|<----------------80 bits----------------------->
12/16-byte LONG DOUBLE FLOATING-POINT (intel special)
Expand All @@ -805,28 +806,33 @@ cvt_num10_num16(ARGOUT(unsigned char *dest), ARGIN(const unsigned char *src))
*/

FLOATVAL ld;
long double d;
int expo, i;
memset(dest, 0, 16);
/* simply copy over sign + exp */
/* sign + exp */
dest[15] = src[9];
dest[14] = src[8];
/* and copy the rest */
memcpy(&dest[0], &src[0], 8);
#if 0
/* TODO round on 15 digits */
memcpy(&ld, dest, 16);
# if 1
expo = ((src[9] & 0x7f)<< 8 | src[8]);
expo -= 16383;
/* On Intel expo 0 is allowed */
if (expo <= 0) /* underflow */
return;
if (expo > 0x7ff) /* overflow, inf/nan */
return;
/* shortcut 0 mantissa */
#if __WORDSIZE == 64
if (*(Parrot_UInt8*)src != 0x8000000000000000LU)
#else
if (*(Parrot_UInt4*)src || *(Parrot_UInt4*)&src[4] != 0x80000000U)
#endif
{
char buf[20];
sprintf(buf, "%.15g", ld);
d = atof(buf);
}
# else
d = (long double)ld;
# endif
memcpy(dest, &d, 16);
#if 0
memcpy(&dest[6], &src[0], 8);
#endif
for (i = 13; i > 5; i--) {
dest[i] |= ((i==13 ? src[7] & 0x7f : src[i-5]) << 1)
| (src[i-6] & 0x7f) >> 7;
}
}
}
#endif

Expand Down
20 changes: 10 additions & 10 deletions t/native_pbc/number.t
View file
Expand Up @@ -70,7 +70,7 @@ my $output = << 'END_OUTPUT';
16384
-65536
-262144
-10.48576
-10.48576\d*
4194304
16777216
67108864
Expand All @@ -81,7 +81,7 @@ my $output = << 'END_OUTPUT';
68719476736
274877906944
1099511627776
4.398046511104
4.39804651110\d*
17592186044416
70368744177664
281474976710656
Expand Down Expand Up @@ -112,14 +112,14 @@ sub test_pbc_number {
# required precision: 7 for float, 15 for double, ...
my $out = $output;
my $minprec = min_precision($id, $myprec);
# [GH #xxx] Looks like we cannot guarantee more then 15 digits
$minprec = 15 if $minprec > 15 and $id ne $arch;
$minprec--;
my $prec1 = $minprec - 1; # 4.398046511104 => 4.398046\d*
my $prec2 = $minprec - 2; # -10.48576 => -10.48576\*
$out =~ s/(^-?\d\d\.\d{$prec2,})\d*/$1\\d*/mg;
$out =~ s/(^-?\d\.\d{$prec1,})\d*/$1\\d*/mg;
$out =~ s/(^-?\d{$minprec,})\d*/$1\\d*/mg;
# [GH #xxx] Looks like we cannot guarantee more then 13 digits
$minprec = 13 if $minprec > 13 and $id ne $arch;
$minprec -= 2;
my $prec1 = $minprec - 2; # 4.398046511104 => 4.398046\d*
#my $prec2 = $minprec - 3; # -10.48576 => -10.48576\d*
#$out =~ s/^(-?\d\d\.\d{$prec2,})\d*/$1\\d*/mg;
$out =~ s/^(-?\d\.\d{$prec1,})\d+$/$1\\d*/mg;
$out =~ s/^(-?\d{$minprec,})\d+$/$1\\d*/mg;
my $qr = qr/$out/;

test_native_pbc($id, "number", $qr, $desc, $skip, $todo);
Expand Down
Binary file modified t/native_pbc/number_8_10_le.pbc
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