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Fixed zeroMemory() to properly zero any block(s) that originally underlaid the IOPAGE block(s), rather than trying to zero the IOPAGE block itself (which would be a bad idea)

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Jeff 2016-11-03 15:36:37 -07:00 • committed by Jeff Parsons
commit 97de321daa
4 changed files with 105 additions and 99 deletions
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13
modules/pdp11/lib/memory.js
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@ -174,10 +174,9 @@ function MemoryPDP11(bus, addr, used, size, type, controller)
a = this.ab = new Array(this.size);
} else {
/*
* NOTE: This is the default mode of operation (!TYPEDARRAYS && !BYTEARRAYS), because it
* seems to provide the best performance; and although in theory, that performance might
* come at twice the overhead of TYPEDARRAYS, it's increasingly likely that the JavaScript
* runtime will notice that all we ever store are 32-bit values, and optimize accordingly.
* NOTE: This used to be the default mode of operation (!TYPEDARRAYS && !BYTEARRAYS), because
* it seemed to provide the best performance; however, that was then, and this is now. TYPEDARRAYS
* is more efficient.
*/
a = this.adw = new Array(this.size >> 2);
}
@ -389,8 +388,8 @@ MemoryPDP11.prototype = {
* zero(off, len)
*
* Zeros the block. Supporting off and len parameters is probably overkill, and makes more
* work in the non-TYPEDARRAY, non-BYTEARRAY case, because there all we have is an array of DWORDs,
* but that's not the typical case.
* work in the non-TYPEDARRAY, non-BYTEARRAY case, but that's not the typical case. The other
* exception is controller-based blocks, which may not have any array backing at all.
*
* @this {MemoryPDP11}
* @param {number} [off] (optional starting byte offset within block)
@ -404,7 +403,7 @@ MemoryPDP11.prototype = {
*/
if (len === undefined) len = this.size;
Component.assert(off >= 0 && off < this.size);
if (TYPEDARRAYS || BYTEARRAYS) {
if ((TYPEDARRAYS || BYTEARRAYS) && this.ab) {
for (i = off; len-- && i < this.ab.length; i++) this.ab[i] = 0;
} else {
for (i = off; len-- && i < this.size; i++) this.writeByteDirect(off, 0, this.addr + off);