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Update CPU's getLong() and setLong() interfaces

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This commit is contained in:
Jeff Parsons 2015-01-25 15:07:58 -08:00 • committed by jeffpar
commit 7fb26846f9
4 changed files with 62 additions and 34 deletions
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50
modules/pcjs/lib/memory.js
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@ -80,14 +80,14 @@ if (typeof module !== 'undefined') {
* Because Memory blocks now allow us to have a "sparse" address space, we could choose to
* take the memory hit of allocating 4K arrays per block, where each element stores only one byte,
* instead of the more frugal but slightly slower approach of allocating arrays of 32-bit dwords
* (DWORDARRAYS) and shifting/masking bytes/words to/from dwords; in theory, byte accesses would
* (LONGARRAYS) and shifting/masking bytes/words to/from dwords; in theory, byte accesses would
* be faster and word accesses somewhat less faster.
*
* However, preliminary testing of that feature (FATARRAYS) did not yield significantly faster
* performance, so it is OFF by default to minimize our memory consumption. Using TYPEDARRAYS
* would seem best, but as discussed in defines.js, it's off by default, because it doesn't perform
* as well as DWORDARRAYS; the other advantage of TYPEDARRAYS is that it should theoretically use
* about 1/2 the memory of DWORDARRAYS (32-bit elements vs 64-bit numbers), but I value speed over
* as well as LONGARRAYS; the other advantage of TYPEDARRAYS is that it should theoretically use
* about 1/2 the memory of LONGARRAYS (32-bit elements vs 64-bit numbers), but I value speed over
* size at this point. Also, not all JavaScript implementations support TYPEDARRAYS (IE9 is probably
* the only real outlier: it lacks typed arrays but otherwise has all the necessary HTML5 support).
*
@ -288,12 +288,12 @@ Memory.readLongMemory = function readLongMemory(off)
}
var idw = off >> 2;
var nShift = (off & 0x3) << 3;
var dw = this.adw[idw];
var l = this.adw[idw];
if (nShift) {
dw >>>= nShift;
dw |= this.adw[idw + 1] << (32 - nShift);
l >>>= nShift;
l |= this.adw[idw + 1] << (32 - nShift);
}
return dw;
return l;
};
/**
@ -344,29 +344,29 @@ Memory.writeWordMemory = function writeWordMemory(off, w)
};
/**
* writeLongMemory(off, dw)
* writeLongMemory(off, l)
*
* @this {Memory}
* @param {number} off
* @param {number} dw
* @param {number} l
*/
Memory.writeLongMemory = function writeLongMemory(off, dw)
Memory.writeLongMemory = function writeLongMemory(off, l)
{
Component.assert(off >= 0 && off < this.cb - 3);
if (FATARRAYS) {
this.ab[off] = (dw & 0xff);
this.ab[off + 1] = (dw >> 8) & 0xff;
this.ab[off + 2] = (dw >> 16) & 0xff;
this.ab[off + 3] = (dw >> 24) & 0xff;
this.ab[off] = (l & 0xff);
this.ab[off + 1] = (l >> 8) & 0xff;
this.ab[off + 2] = (l >> 16) & 0xff;
this.ab[off + 3] = (l >> 24) & 0xff;
} else {
var idw = off >> 2;
var nShift = (off & 0x3) << 3;
if (!nShift) {
this.adw[idw] = dw;
this.adw[idw] = l;
} else {
this.adw[idw] = (this.adw[idw] & ~(0xffffffff << nShift)) | (dw << nShift);
this.adw[idw] = (this.adw[idw] & ~(0xffffffff << nShift)) | (l << nShift);
idw++;
this.adw[idw] = (this.adw[idw] & (0xffffffff << nShift)) | (dw >>> (32 - nShift));
this.adw[idw] = (this.adw[idw] & (0xffffffff << nShift)) | (l >>> (32 - nShift));
}
}
this.fDirty = true;
@ -449,13 +449,13 @@ Memory.writeWordChecked = function writeWordChecked(off, w)
};
/**
* writeLongChecked(off, dw)
* writeLongChecked(off, l)
*
* @this {Memory}
* @param {number} off
* @param {number} dw
* @param {number} l
*/
Memory.writeLongChecked = function writeLongChecked(off, dw)
Memory.writeLongChecked = function writeLongChecked(off, l)
{
if (DEBUGGER) {
this.dbg.checkMemoryWrite(this.addr + off) ||
@ -463,7 +463,7 @@ Memory.writeLongChecked = function writeLongChecked(off, dw)
this.dbg.checkMemoryWrite(this.addr + off + 2) ||
this.dbg.checkMemoryWrite(this.addr + off + 3)
}
this.writeLongDirect(off, dw);
this.writeLongDirect(off, l);
};
/**
@ -534,16 +534,16 @@ Memory.writeWordTypedArray = function writeWordTypedArray(off, w)
};
/**
* writeLongTypedArray(off, dw)
* writeLongTypedArray(off, l)
*
* @this {Memory}
* @param {number} off
* @param {number} dw
* @param {number} l
*/
Memory.writeLongTypedArray = function writeLongTypedArray(off, dw)
Memory.writeLongTypedArray = function writeLongTypedArray(off, l)
{
Component.assert(off >= 0 && off < this.cb - 3);
this.dv.setInt32(off, dw, true);
this.dv.setInt32(off, l, true);
this.fDirty = true;
};