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fix: return subnormal values in math/base/special/exp2 and exp10 #16268

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6781f0d
fix: return subnormal values in `math/base/special/exp2` and `exp10`
0PrashantYadav0 Oct 20, 2026
3998a1c
fix: return subnormal values for `-1075 < x < -1074` in `math/base/sp…
0PrashantYadav0 Oct 26, 2026
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2 changes: 1 addition & 1 deletion lib/node_modules/@stdlib/math/base/special/exp10/lib/main.js
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Original file line number Diff line number Diff line change
Expand Up @@ -38,7 +38,7 @@ var floor = require( '@stdlib/math/base/special/floor' );
var ldexp = require( '@stdlib/math/base/special/ldexp' );
var isnan = require( '@stdlib/math/base/assert/is-nan' );
var MAXL10 = require( '@stdlib/constants/float64/max-base10-exponent' );
var MINL10 = require( '@stdlib/constants/float64/min-base10-exponent' );
var MINL10 = require( '@stdlib/constants/float64/min-base10-exponent-subnormal' );
var PINF = require( '@stdlib/constants/float64/pinf' );
var polyvalP = require( './polyval_p.js' );
var polyvalQ = require( './polyval_q.js' );
Expand Down
6 changes: 3 additions & 3 deletions lib/node_modules/@stdlib/math/base/special/exp10/manifest.json
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Expand Up @@ -42,7 +42,7 @@
"@stdlib/constants/float64/pinf",
"@stdlib/math/base/special/floor",
"@stdlib/math/base/special/ldexp",
"@stdlib/constants/float64/min-base10-exponent",
"@stdlib/constants/float64/min-base10-exponent-subnormal",
"@stdlib/constants/float64/nan"
]
},
Expand All @@ -62,7 +62,7 @@
"@stdlib/constants/float64/pinf",
"@stdlib/math/base/special/floor",
"@stdlib/math/base/special/ldexp",
"@stdlib/constants/float64/min-base10-exponent",
"@stdlib/constants/float64/min-base10-exponent-subnormal",
"@stdlib/constants/float64/nan"
]
},
Expand All @@ -82,7 +82,7 @@
"@stdlib/constants/float64/pinf",
"@stdlib/math/base/special/floor",
"@stdlib/math/base/special/ldexp",
"@stdlib/constants/float64/min-base10-exponent",
"@stdlib/constants/float64/min-base10-exponent-subnormal",
"@stdlib/constants/float64/nan"
]
}
Expand Down
4 changes: 2 additions & 2 deletions lib/node_modules/@stdlib/math/base/special/exp10/src/main.c
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Expand Up @@ -35,7 +35,7 @@
#include "stdlib/math/base/special/ldexp.h"
#include "stdlib/math/base/assert/is_nan.h"
#include "stdlib/constants/float64/max_base10_exponent.h"
#include "stdlib/constants/float64/min_base10_exponent.h"
#include "stdlib/constants/float64/min_base10_exponent_subnormal.h"
#include "stdlib/constants/float64/pinf.h"
#include "stdlib/constants/float64/nan.h"
#include <stdint.h>
Expand Down Expand Up @@ -129,7 +129,7 @@ double stdlib_base_exp10( const double x ) {
if ( x > STDLIB_CONSTANT_FLOAT64_MAX_BASE10_EXPONENT ) {
return STDLIB_CONSTANT_FLOAT64_PINF;
}
if ( x < STDLIB_CONSTANT_FLOAT64_MIN_BASE10_EXPONENT ) {
if ( x < STDLIB_CONSTANT_FLOAT64_MIN_BASE10_EXPONENT_SUBNORMAL ) {
return 0.0;
}
// Express 10^x = 10^g 2^n = 10^g 10^( n log10(2) ) = 10^( g + n log10(2) )
Expand Down
21 changes: 21 additions & 0 deletions lib/node_modules/@stdlib/math/base/special/exp10/test/test.js
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Expand Up @@ -25,6 +25,7 @@ var isnan = require( '@stdlib/math/base/assert/is-nan' );
var PINF = require( '@stdlib/constants/float64/pinf' );
var NINF = require( '@stdlib/constants/float64/ninf' );
var isPositiveZero = require( '@stdlib/assert/is-positive-zero' );
var isAlmostSameValue = require( '@stdlib/assert/is-almost-same-value' );
var exp10 = require( './../lib' );


Expand Down Expand Up @@ -167,3 +168,23 @@ tape( 'the function returns `NaN` if provided `NaN`', function test( t ) {
t.strictEqual( isnan( val ), true, 'equals NaN' );
t.end();
});

tape( 'the function returns subnormal values for `x` in the subnormal range', function test( t ) {
var expected;
var x;
var v;
var i;

x = [ -308.5, -310.0, -320.0, -323.5 ];
expected = [
3.16227766016838e-309,
1e-310,
1e-320,
5e-324
];
for ( i = 0; i < x.length; i++ ) {
v = exp10( x[ i ] );
t.strictEqual( isAlmostSameValue( v, expected[ i ], 1 ), true, 'returns expected value' );
}
t.end();
});
20 changes: 20 additions & 0 deletions lib/node_modules/@stdlib/math/base/special/exp10/test/test.native.js
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Expand Up @@ -181,3 +181,23 @@ tape( 'the function returns `NaN` if provided `NaN`', opts, function test( t ) {
t.strictEqual( isnan( val ), true, 'equals NaN' );
t.end();
});

tape( 'the function returns subnormal values for `x` in the subnormal range', opts, function test( t ) {
var expected;
var x;
var v;
var i;

x = [ -308.5, -310.0, -320.0, -323.5 ];
expected = [
3.16227766016838e-309,
1e-310,
1e-320,
5e-324
];
for ( i = 0; i < x.length; i++ ) {
v = exp10( x[ i ] );
t.strictEqual( isAlmostSameValue( v, expected[ i ], 1 ), true, 'returns expected value' );
}
t.end();
});
5 changes: 3 additions & 2 deletions lib/node_modules/@stdlib/math/base/special/exp2/lib/main.js
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Expand Up @@ -32,12 +32,12 @@

'use strict';

// TODO: replace with TOMS (Openlibm) algo (updating license header and long comment)

Check warning on line 35 in lib/node_modules/@stdlib/math/base/special/exp2/lib/main.js

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Unexpected 'todo' comment: 'TODO: replace with TOMS (Openlibm) algo...'

// MODULES //

var FLOAT64_MAX_BASE2_EXPONENT = require( '@stdlib/constants/float64/max-base2-exponent' ); // eslint-disable-line id-length
var FLOAT64_MIN_BASE2_EXPONENT = require( '@stdlib/constants/float64/min-base2-exponent' ); // eslint-disable-line id-length
var FLOAT64_MIN_BASE2_EXPONENT_SUBNORMAL = require( '@stdlib/constants/float64/min-base2-exponent-subnormal' ); // eslint-disable-line id-length
var round = require( '@stdlib/math/base/special/round' );
var ldexp = require( '@stdlib/math/base/special/ldexp' );
var isnan = require( '@stdlib/math/base/assert/is-nan' );
Expand Down Expand Up @@ -104,7 +104,8 @@
if ( x > FLOAT64_MAX_BASE2_EXPONENT ) {
return PINF;
}
if ( x < FLOAT64_MIN_BASE2_EXPONENT ) {
// Note: values on the interval `(-1075, -1074)` round to the smallest subnormal...
if ( x <= FLOAT64_MIN_BASE2_EXPONENT_SUBNORMAL-1 ) {
return 0.0;
}
// Separate into integer and fractional parts...
Expand Down
8 changes: 4 additions & 4 deletions lib/node_modules/@stdlib/math/base/special/exp2/manifest.json
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Expand Up @@ -44,7 +44,7 @@
"@stdlib/constants/float64/pinf",
"@stdlib/math/base/special/round",
"@stdlib/math/base/special/ldexp",
"@stdlib/constants/float64/min-base2-exponent"
"@stdlib/constants/float64/min-base2-exponent-subnormal"
]
},
{
Expand All @@ -64,7 +64,7 @@
"@stdlib/constants/float64/pinf",
"@stdlib/math/base/special/round",
"@stdlib/math/base/special/ldexp",
"@stdlib/constants/float64/min-base2-exponent"
"@stdlib/constants/float64/min-base2-exponent-subnormal"
]
},
{
Expand All @@ -84,7 +84,7 @@
"@stdlib/constants/float64/pinf",
"@stdlib/math/base/special/round",
"@stdlib/math/base/special/ldexp",
"@stdlib/constants/float64/min-base2-exponent"
"@stdlib/constants/float64/min-base2-exponent-subnormal"
]
},
{
Expand All @@ -104,7 +104,7 @@
"@stdlib/constants/float64/pinf",
"@stdlib/math/base/special/round",
"@stdlib/math/base/special/ldexp",
"@stdlib/constants/float64/min-base2-exponent"
"@stdlib/constants/float64/min-base2-exponent-subnormal"
]
}
]
Expand Down
5 changes: 3 additions & 2 deletions lib/node_modules/@stdlib/math/base/special/exp2/src/main.c
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Expand Up @@ -32,7 +32,7 @@

#include "stdlib/math/base/special/exp2.h"
#include "stdlib/constants/float64/max_base2_exponent.h"
#include "stdlib/constants/float64/min_base2_exponent.h"
#include "stdlib/constants/float64/min_base2_exponent_subnormal.h"
#include "stdlib/math/base/special/round.h"
#include "stdlib/math/base/special/ldexp.h"
#include "stdlib/math/base/assert/is_nan.h"
Expand Down Expand Up @@ -128,7 +128,8 @@ double stdlib_base_exp2( const double x ) {
if ( x > STDLIB_CONSTANT_FLOAT64_MAX_BASE2_EXPONENT ) {
return STDLIB_CONSTANT_FLOAT64_PINF;
}
if ( x < STDLIB_CONSTANT_FLOAT64_MIN_BASE2_EXPONENT ) {
// Note: values on the interval `(-1075, -1074)` round to the smallest subnormal...
if ( x <= STDLIB_CONSTANT_FLOAT64_MIN_BASE2_EXPONENT_SUBNORMAL-1 ) {
return 0.0;
}

Expand Down
20 changes: 20 additions & 0 deletions lib/node_modules/@stdlib/math/base/special/exp2/test/test.js
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Expand Up @@ -134,6 +134,7 @@ tape( 'the function returns `+infinity` for very large `x`', function test( t )
});

tape( 'the function returns `0.0` for negative large `x`', function test( t ) {
t.strictEqual( exp2( -1075.0 ), 0.0, 'equals 0' );
t.strictEqual( exp2( -1100.0 ), 0.0, 'equals 0' );
t.strictEqual( exp2( -1200.0 ), 0.0, 'equals 0' );
t.strictEqual( exp2( -1300.0 ), 0.0, 'equals 0' );
Expand Down Expand Up @@ -168,3 +169,22 @@ tape( 'the function returns `NaN` if provided `NaN`', function test( t ) {
t.strictEqual( isnan( val ), true, 'equals NaN' );
t.end();
});

tape( 'the function returns subnormal values for `x` in the subnormal range', function test( t ) {
var expected;
var x;
var v;
var i;

x = [ -1023.5, -1050.0, -1074.0 ];
expected = [
7.866824069956793e-309,
8.289046e-317,
5e-324
];
for ( i = 0; i < x.length; i++ ) {
v = exp2( x[ i ] );
t.strictEqual( isAlmostSameValue( v, expected[ i ], 1 ), true, 'returns expected value' );
}
t.end();
});
20 changes: 20 additions & 0 deletions lib/node_modules/@stdlib/math/base/special/exp2/test/test.native.js
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Original file line number Diff line number Diff line change
Expand Up @@ -143,6 +143,7 @@ tape( 'the function returns `+infinity` for very large `x`', opts, function test
});

tape( 'the function returns `0.0` for negative large `x`', opts, function test( t ) {
t.strictEqual( exp2( -1075.0 ), 0.0, 'equals 0' );
t.strictEqual( exp2( -1100.0 ), 0.0, 'equals 0' );
t.strictEqual( exp2( -1200.0 ), 0.0, 'equals 0' );
t.strictEqual( exp2( -1300.0 ), 0.0, 'equals 0' );
Expand Down Expand Up @@ -177,3 +178,22 @@ tape( 'the function returns `NaN` if provided `NaN`', opts, function test( t ) {
t.strictEqual( isnan( val ), true, 'equals NaN' );
t.end();
});

tape( 'the function returns subnormal values for `x` in the subnormal range', opts, function test( t ) {
var expected;
var x;
var v;
var i;

x = [ -1023.5, -1050.0, -1074.0 ];
expected = [
7.866824069956793e-309,
8.289046e-317,
5e-324
];
for ( i = 0; i < x.length; i++ ) {
v = exp2( x[ i ] );
t.strictEqual( isAlmostSameValue( v, expected[ i ], 1 ), true, 'returns expected value' );
}
t.end();
});
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