Magic-Mirror/gecko-dev
1
0
Fork 0
mirror of https://github.com/mozilla/gecko-dev.git synced 2024-10-13 21:35:39 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Removal of 32K restriction on the length of the maximum jump offset.

Browse Source 
Now interpreter uses UintMap to store jump targets spanning more then 32K
of bytecode.
This commit is contained in:
igor%mir2.org 2004-05-17 21:36:47 +00:00
parent 542e90f394
commit 351dcb728c
2 changed files with 28 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
js/rhino/src/org/mozilla/javascript/Interpreter.java
View File

@ -510,10 +510,8 @@ public class Interpreter
Node defaultNode = (Node) switchNode.getProp(Node.DEFAULT_PROP);
if (defaultNode != null) {
Node.Target defaultTarget = new Node.Target();
defaultNode.getFirstChild().
addChildToFront(defaultTarget);
iCodeTop = addGoto(defaultTarget, Token.GOTO,
iCodeTop);
defaultNode.getFirstChild().addChildToFront(defaultTarget);
iCodeTop = addGoto(defaultTarget, Token.GOTO, iCodeTop);
}
Node.Target breakTarget = switchNode.target;
@ -1259,11 +1257,10 @@ public class Interpreter
} else {
iCodeTop = addToken(gotoOp, iCodeTop);
}
int jumpSite = iCodeTop;
iCodeTop = addShort(0, iCodeTop);
if (targetPC != -1) {
recordJumpOffset(jumpSite, targetPC - gotoPC);
recordJump(gotoPC, targetPC);
} else {
int top = itsFixupTableTop;
if (itsFixupTable == null || top == itsFixupTable.length) {
@ -1276,31 +1273,23 @@ public class Interpreter
}
}
itsFixupTableTop = top + 1;
itsFixupTable[top] = ((long)label << 32) | jumpSite;
itsFixupTable[top] = ((long)label << 32) | gotoPC;
}
return iCodeTop;
}
private void fixLabelGotos()
{
byte[] codeBuffer = itsData.itsICode;
for (int i = 0; i < itsFixupTableTop; i++) {
long fixup = itsFixupTable[i];
int label = (int)(fixup >> 32);
int fixupSite = (int)fixup;
int jumpSource = (int)fixup;
int pc = itsLabelTable[label];
if (pc == -1) {
// Unlocated label
throw new RuntimeException();
throw Kit.codeBug();
}
// -1 to get delta from instruction start
int offset = pc - (fixupSite - 1);
if ((short)offset != offset) {
throw new RuntimeException
("Program too complex: too big jump offset");
}
codeBuffer[fixupSite] = (byte)(offset >> 8);
codeBuffer[fixupSite + 1] = (byte)offset;
recordJump(jumpSource, pc);
}
itsFixupTableTop = 0;
}
@ -1315,18 +1304,23 @@ public class Interpreter
private void resolveForwardGoto(int jumpStart, int iCodeTop)
{
if (jumpStart + 3 > iCodeTop) Kit.codeBug();
int offset = iCodeTop - jumpStart;
// +1 to write after jump icode
recordJumpOffset(jumpStart + 1, offset);
recordJump(jumpStart, iCodeTop);
}
private void recordJumpOffset(int pos, int offset)
private void recordJump(int jumpSource, int jumpDestination)
{
if (jumpSource == jumpDestination) throw Kit.codeBug();
int offsetSite = jumpSource + 1;
int offset = jumpDestination - jumpSource;
if (offset != (short)offset) {
throw Context.reportRuntimeError0("msg.too.big.jump");
if (itsData.longJumps == null) {
itsData.longJumps = new UintMap();
}
itsData.longJumps.put(offsetSite, jumpDestination);
offset = 0;
}
itsData.itsICode[pos] = (byte)(offset >> 8);
itsData.itsICode[pos + 1] = (byte)offset;
itsData.itsICode[offsetSite] = (byte)(offset >> 8);
itsData.itsICode[offsetSite + 1] = (byte)offset;
}
private int addByte(int value, int iCodeTop)
@ -3046,9 +3040,13 @@ public class Interpreter
instructionCount = 0;
}
}
// -1 accounts to the fact that pc points to one byte past
// instruction
pc += getShort(iCode, pc) - 1;
int offset = getShort(iCode, pc);
if (offset != 0) {
// -1 accounts for pc pointing to jump opcode + 1
pc += offset - 1;
} else {
pc = idata.longJumps.getExistingInt(pc);
}
pcPrevBranch = pc;
continue Loop;

2
js/rhino/src/org/mozilla/javascript/InterpreterData.java
View File

@ -125,6 +125,8 @@ final class InterpreterData implements Serializable, DebuggableScript
Object[] literalIds;
UintMap longJumps;
InterpreterData parentData;
public boolean isTopLevel()