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Clarify roundValue() parameters

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This commit is contained in:
Jeff Parsons 2015-12-04 14:01:22 -08:00
commit b37f8f0918
1 changed files with 15 additions and 9 deletions
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24
modules/pcjs/lib/x86fpu.js
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@ -701,16 +701,19 @@ X86FPU.prototype.doSquareRoot = function(operand)
};
/**
* roundInteger(operand, max)
* roundValue(operand, max)
*
* NOTE: The max parameter is EXCLUSIVE, not inclusive (ie, the maximum positive integer is < max).
* NOTE: The max parameter is EXCLUSIVE, not inclusive (ie, the maximum positive value is < max).
*
* Also, callers that expect intTmpLR[] to be loaded with the result *must* also specify a max parameter;
* callers performing internal rounding and using just the return value may omit max to skip loading intTmpLR[].
*
* @this {X86FPU}
* @param {number|null} operand
* @param {number} [max] (ie, 0x8000, 0x80000000, or 0x8000000000000000)
* @return {number|null} (rounded result if intTmpLR was loaded, null if not)
* @return {number|null} (rounded result, or null if there was an unmasked exception)
*/
X86FPU.prototype.roundInteger = function(operand, max)
X86FPU.prototype.roundValue = function(operand, max)
{
if (operand == null) return null;
@ -842,7 +845,7 @@ X86FPU.prototype.setTags = function(n)
*/
X86FPU.prototype.getWI = function(i)
{
return this.roundInteger(this.getST(i), X86FPU.MAX_INT16) != null;
return this.roundValue(this.getST(i), X86FPU.MAX_INT16) != null;
};
/**
@ -856,7 +859,7 @@ X86FPU.prototype.getWI = function(i)
*/
X86FPU.prototype.getSI = function(i)
{
return this.roundInteger(this.getST(i), X86FPU.MAX_INT32) != null;
return this.roundValue(this.getST(i), X86FPU.MAX_INT32) != null;
};
/**
@ -870,7 +873,7 @@ X86FPU.prototype.getSI = function(i)
*/
X86FPU.prototype.getLI = function(i)
{
return this.roundInteger(this.getST(i), X86FPU.MAX_INT64) != null;
return this.roundValue(this.getST(i), X86FPU.MAX_INT64) != null;
};
/**
@ -1699,7 +1702,10 @@ X86FPU.FBLDpd = function()
*/
X86FPU.FBSTPpd = function()
{
var v = this.roundInteger(this.popValue());
/*
* TODO: Verify the operation of FBSTP (eg, does it signal an exception if abs(value) >= 1000000000000000000?)
*/
var v = this.roundValue(this.popValue());
if (v != null) {
/*
* intTmpTR[0] will contain the 8 least-significant BCD digits, intTmpTR[1] will contain the next 8,
@ -2734,7 +2740,7 @@ X86FPU.FRSTOR = function()
*/
X86FPU.FRNDINT = function()
{
this.setST(0, this.roundInteger(this.getST(0), X86FPU.MAX_INT64));
this.setST(0, this.roundValue(this.getST(0), X86FPU.MAX_INT64));
};
/**