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This commit is contained in:
Jeff Parsons 2017-02-15 11:54:16 -08:00 • committed by Jeff Parsons
commit 259dd7d66f
1 changed files with 10 additions and 6 deletions
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16
modules/shared/lib/int36.js
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@ -37,14 +37,18 @@ var DEBUG = true;
* @property {number|null} remainder * @property {number|null} remainder
* @property {number} error * @property {number} error
* *
* The 'value' property stores the 36-bit value as a two's complement integer. * The 'value' property stores the 36-bit value as a signed integer, meaning if the sign bit
* (bit 35) is set, we store the corresponding negative (two's complement) value. While there
* might be some slight benefits to always storing the 36-bit value as an unsigned quantity
* and negating it "on demand", I like having JavaScript's native representation match the
* emulated value.
* *
* The 'extended' property stores an additional 36 bits of data from a multiplication; * The 'extended' property stores an additional 36 bits of data from a multiplication;
* it must also be set prior to a division. Internally, it will be set to null whenever * it must also be set prior to a division. Internally, it will be set to null whenever the
* the current value is not extended. * current value is not extended.
* *
* The 'remainder' property stores the remainder from the last division. You should * The 'remainder' property stores the remainder from the last division. You should assume it
* assume that it will be set to null by any other operation. * will be set to null by any other operation.
* *
* The 'error' property records any error(s) from the last operation. * The 'error' property records any error(s) from the last operation.
*/ */
@ -481,7 +485,7 @@ class Int36 {
* 126 -126 -127 * 126 -126 -127
* 127 -127 -128 * 127 -127 -128
* *
* so you can see that, when performing two's complement, MINVAL and ZERO are not modified. * you can see that, when performing two's complement, MINVAL and ZERO are not modified.
* *
* However, in our happy little world, since JavaScript numbers CAN represent both positive and negative * However, in our happy little world, since JavaScript numbers CAN represent both positive and negative
* MINVAL values, we don't need to exclude MINVAL from the conversion. * MINVAL values, we don't need to exclude MINVAL from the conversion.