Mercurial > hg > truffle
changeset 21317:15ec3912cffb
LifetimeAnalysis: use multiline comments.
| author | Josef Eisl <josef.eisl@jku.at> |
|---|---|
| date | Tue, 12 May 2015 10:07:09 +0200 |
| parents | fd18bffefcc1 |
| children | 88f8bbed600f |
| files | graal/com.oracle.graal.lir/src/com/oracle/graal/lir/alloc/lsra/LifetimeAnalysis.java |
| diffstat | 1 files changed, 64 insertions(+), 47 deletions(-) [+] |
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--- a/graal/com.oracle.graal.lir/src/com/oracle/graal/lir/alloc/lsra/LifetimeAnalysis.java Tue May 12 10:58:26 2015 +0200 +++ b/graal/com.oracle.graal.lir/src/com/oracle/graal/lir/alloc/lsra/LifetimeAnalysis.java Tue May 12 10:07:09 2015 +0200 @@ -179,9 +179,11 @@ } if (DetailedAsserts.getValue()) { - // fixed intervals are never live at block boundaries, so - // they need not be processed in live sets - // process them only in debug mode so that this can be checked + /* + * Fixed intervals are never live at block boundaries, so they need not be + * processed in live sets. Process them only in debug mode so that this can + * be checked + */ verifyTemp(liveKill, operand); } }; @@ -193,9 +195,10 @@ try (Indent indent2 = Debug.logAndIndent("handle op %d", op.id())) { op.visitEachInput(useConsumer); op.visitEachAlive(useConsumer); - // Add uses of live locals from interpreter's point of view for proper -// debug - // information generation + /* + * Add uses of live locals from interpreter's point of view for proper debug + * information generation. + */ op.visitEachState(stateConsumer); op.visitEachTemp(defConsumer); op.visitEachOutput(defConsumer); @@ -218,9 +221,10 @@ } private void verifyTemp(BitSet liveKill, Value operand) { - // fixed intervals are never live at block boundaries, so - // they need not be processed in live sets - // process them only in debug mode so that this can be checked + /* + * Fixed intervals are never live at block boundaries, so they need not be processed in live + * sets. Process them only in debug mode so that this can be checked + */ if (isRegister(operand)) { if (allocator.isProcessed(operand)) { liveKill.set(allocator.operandNumber(operand)); @@ -229,11 +233,11 @@ } private void verifyInput(AbstractBlockBase<?> block, BitSet liveKill, Value operand) { - // fixed intervals are never live at block boundaries, so - // they need not be processed in live sets. - // this is checked by these assertions to be sure about it. - // the entry block may have incoming - // values in registers, which is ok. + /* + * Fixed intervals are never live at block boundaries, so they need not be processed in live + * sets. This is checked by these assertions to be sure about it. The entry block may have + * incoming values in registers, which is ok. + */ if (isRegister(operand) && block != allocator.ir.getControlFlowGraph().getStartBlock()) { if (allocator.isProcessed(operand)) { assert liveKill.get(allocator.operandNumber(operand)) : "using fixed register that is not defined in this block"; @@ -253,9 +257,10 @@ int iterationCount = 0; BitSet liveOut = new BitSet(allocator.liveSetSize()); // scratch set for calculations - // Perform a backward dataflow analysis to compute liveOut and liveIn for each -// block. - // The loop is executed until a fixpoint is reached (no changes in an iteration) + /* + * Perform a backward dataflow analysis to compute liveOut and liveIn for each block. + * The loop is executed until a fixpoint is reached (no changes in an iteration). + */ do { changeOccurred = false; @@ -268,8 +273,7 @@ changeOccurredInBlock = false; - // liveOut(block) is the union of liveIn(sux), for successors sux of -// block + /* liveOut(block) is the union of liveIn(sux), for successors sux of block. */ int n = block.getSuccessorCount(); if (n > 0) { liveOut.clear(); @@ -281,8 +285,10 @@ } if (!blockSets.liveOut.equals(liveOut)) { - // A change occurred. Swap the old and new live out - // sets to avoid copying. + /* + * A change occurred. Swap the old and new live out sets to avoid + * copying. + */ BitSet temp = blockSets.liveOut; blockSets.liveOut = liveOut; liveOut = temp; @@ -293,11 +299,13 @@ } if (iterationCount == 0 || changeOccurredInBlock) { - // liveIn(block) is the union of liveGen(block) with (liveOut(block) -// & - // !liveKill(block)) - // note: liveIn has to be computed only in first iteration - // or if liveOut has changed! + /* + * liveIn(block) is the union of liveGen(block) with (liveOut(block) & + * !liveKill(block)). + * + * Note: liveIn has to be computed only in first iteration or if liveOut + * has changed! + */ BitSet liveIn = blockSets.liveIn; liveIn.clear(); liveIn.or(blockSets.liveOut); @@ -418,8 +426,10 @@ } private void verifyLiveness() { - // check that fixed intervals are not live at block boundaries - // (live set must be empty at fixed intervals) + /* + * Check that fixed intervals are not live at block boundaries (live set must be empty at + * fixed intervals). + */ for (AbstractBlockBase<?> block : allocator.sortedBlocks) { for (int j = 0; j <= allocator.maxRegisterNumber(); j++) { assert !allocator.blockData.get(block).liveIn.get(j) : "liveIn set of fixed register must be empty"; @@ -481,14 +491,17 @@ Range r = interval.first(); if (r.from <= defPos) { - // Update the starting point (when a range is first created for a use, its - // start is the beginning of the current block until a def is encountered.) + /* + * Update the starting point (when a range is first created for a use, its start is the + * beginning of the current block until a def is encountered). + */ r.from = defPos; interval.addUsePos(defPos, registerPriority); } else { - // Dead value - make vacuous interval - // also add register priority for dead intervals + /* + * Dead value - make vacuous interval also add register priority for dead intervals + */ interval.addRange(defPos, defPos + 1); interval.addUsePos(defPos, registerPriority); if (Debug.isLogEnabled()) { @@ -631,17 +644,20 @@ addUse(operand, blockFrom, blockTo + 2, RegisterPriority.None, LIRKind.Illegal); - // add special use positions for loop-end blocks when the - // interval is used anywhere inside this loop. It's possible - // that the block was part of a non-natural loop, so it might - // have an invalid loop index. + /* + * Add special use positions for loop-end blocks when the interval is used + * anywhere inside this loop. It's possible that the block was part of a + * non-natural loop, so it might have an invalid loop index. + */ if (block.isLoopEnd() && block.getLoop() != null && allocator.isIntervalInLoop(operandNum, block.getLoop().getIndex())) { allocator.intervalFor(operandNum).addUsePos(blockTo + 1, RegisterPriority.LiveAtLoopEnd); } } - // iterate all instructions of the block in reverse order. - // definitions of intervals are processed before uses + /* + * Iterate all instructions of the block in reverse order. definitions of + * intervals are processed before uses. + */ for (int j = instructions.size() - 1; j >= 0; j--) { final LIRInstruction op = instructions.get(j); final int opId = op.id(); @@ -666,13 +682,12 @@ op.visitEachAlive(aliveConsumer); op.visitEachInput(inputConsumer); - // Add uses of live locals from interpreter's point of view for -// proper - // debug information generation - // Treat these operands as temp values (if the live range is -// extended - // to a call site, the value would be in a register at - // the call otherwise) + /* + * Add uses of live locals from interpreter's point of view for proper + * debug information generation. Treat these operands as temp values (if + * the live range is extended to a call site, the value would be in a + * register at the call otherwise). + */ op.visitEachState(stateProc); // special steps for some instructions (especially moves) @@ -684,8 +699,10 @@ } } // end of block iteration - // add the range [0, 1] to all fixed intervals. - // the register allocator need not handle unhandled fixed intervals + /* + * Add the range [0, 1] to all fixed intervals. the register allocator need not handle + * unhandled fixed intervals. + */ for (Interval interval : allocator.intervals) { if (interval != null && isRegister(interval.operand)) { interval.addRange(0, 1);