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Enhance block normalization #1138

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3d60232
Enhance block normalization.
PaulSandoz Aug 7, 2026
d605a70
Merge branch 'code-reflection' into cfg-norm-block
PaulSandoz Aug 18, 2026
849ebb1
Simplify branching of lowered match op
PaulSandoz Aug 18, 2026
18d8129
Ensure conditional block args/params are unused are removed
PaulSandoz Aug 18, 2026
5ebd5fc
Follow explicit constant boolean branching
PaulSandoz Aug 18, 2026
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86 changes: 78 additions & 8 deletions ...ubator.code/share/classes/jdk/incubator/code/dialect/core/NormalizeBlocksTransformer.java
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Original file line number Diff line number Diff line change
Expand Up @@ -81,11 +81,12 @@ case CoreOp.BranchOp bop when isPureConditionalDispatchingBlock(bop.branch().tar
&& or.op() instanceof CoreOp.ConstantOp cop -> {
// Skip intermediate conditional branch with constant boolean argument and re-target
// directly to the true or false branch, based on the constant value.
CoreOp.ConditionalBranchOp cbo = (CoreOp.ConditionalBranchOp)bop.branch().targetBlock().terminatingOp();
Block.Reference br = (Boolean)cop.value() ? cbo.trueBranch() : cbo.falseBranch();
CoreOp.ConditionalBranchOp cbo = (CoreOp.ConditionalBranchOp) bop.branch().targetBlock().terminatingOp();
Block.Reference br = (boolean) cop.value() ? cbo.trueBranch() : cbo.falseBranch();
// Remove the conditional dispatching block if all predecessor reference args are constants
if (bop.branch().targetBlock().predecessorReferences().stream()
.allMatch(r -> r.arguments().getFirst() instanceof Op.Result orr && orr.op() instanceof CoreOp.ConstantOp)) {
.allMatch(r -> r.arguments().getFirst() instanceof Op.Result orr &&
orr.op() instanceof CoreOp.ConstantOp)) {
mergedBlocks.add(bop.branch().targetBlock());
if (br.targetBlock().predecessors().size() == 1) {
// Merge the successor's target block with this block
Expand All @@ -95,17 +96,21 @@ case CoreOp.BranchOp bop when isPureConditionalDispatchingBlock(bop.branch().tar
}
b.add(CoreOp.branch(b.context().getReferenceOrCreate(br)));
}
case CoreOp.ConditionalBranchOp cbo -> {
if (!replaceConditionalBranchTarget(b, cbo, cbo.trueBranch())) {
removeUnusedBlockParameters(b, cbo.trueBranch());
}
if (!replaceConditionalBranchTarget(b, cbo, cbo.falseBranch())) {
removeUnusedBlockParameters(b, cbo.falseBranch());
}
b.add(op);
}
case CoreOp.BranchOp bop when bop.branch().targetBlock().predecessors().size() == 1 -> {
// Merge the successor's target block with this block, and so on
// The terminal branch operation is replaced with the operations in the
// successor's target block
mergeBlock(b, bop);
}
case CoreOp.ConstantOp cop when cop.resultType().equals(JavaType.BOOLEAN)
&& cop.result().uses().stream().allMatch(cr -> cr.op() instanceof CoreOp.BranchOp bop
&& isPureConditionalDispatchingBlock(bop.branch().targetBlock())) -> {
// Remove boolean ConstantOp used purelly as BranchOp successor arguments to a conditional dispatching block
}
case JavaOp.ExceptionRegionEnter ere -> {
// Cannot remove block parameters from exception handlers
removeUnusedBlockParameters(b, ere.startReference());
Expand All @@ -129,6 +134,71 @@ && isPureConditionalDispatchingBlock(bop.branch().targetBlock())) -> {
return b;
}

private boolean replaceConditionalBranchTarget(Block.Builder b,
CoreOp.ConditionalBranchOp cbo,
Block.Reference successor) {
assert cbo.successors().contains(successor);

Block target = successor.targetBlock();
if (isPureConditionalDispatchingBlock(target)) {
if (successor.arguments().getFirst() == cbo.predicateOperand()) {
/*
func @"m" (%0 : java.type:"boolean")java.type:"void" -> {
cbranch %0 ^block_1 ^block_2(%0);
->
cbranch %0 ^block_1 ^block_3;

^block_1:
branch ^block_3;

^block_2(%1 : java.type:"boolean"):
cbranch %1 ^block_3 ^block_4;

^block_3:
branch ^block_5;
*/
CoreOp.ConditionalBranchOp targetCbo = (CoreOp.ConditionalBranchOp) target.terminatingOp();
Block.Reference replacementSuccessor = cbo.trueBranch() == successor
? targetCbo.trueBranch()
: targetCbo.falseBranch();
b.context().mapReference(successor,
b.context().getReferenceOrCreate(replacementSuccessor));
return true;
} else if (successor.arguments().getFirst() instanceof Op.Result or
&& or.op() instanceof CoreOp.ConstantOp cop) {
/*
func @"m" ()java.type:"void" -> {
%false : java.type:"boolean" = constant @false;
cbranch %0 ^block_1 ^block_2(%false);
->
cbranch %0 ^block_1 ^block_3;

^block_1:
branch ^block_3;

^block_2(%1 : java.type:"boolean"):
cbranch %1 ^block_3 ^block_4;

^block_3:
branch ^block_5;
*/

CoreOp.ConditionalBranchOp targetCbo = (CoreOp.ConditionalBranchOp) target.terminatingOp();
Block.Reference replacementSuccessor = (boolean) cop.value()
? targetCbo.trueBranch()
: targetCbo.falseBranch();
b.context().mapReference(successor,
b.context().getReferenceOrCreate(replacementSuccessor));
return true;
}
}
return false;
}

/*
^b(%pred : java.type:"boolean"):
cbranch %pred ^true ^false;
*/
private static boolean isPureConditionalDispatchingBlock(Block b) {
return b.parameters().size() == 1
&& b.parameters().getFirst().type().equals(JavaType.BOOLEAN)
Expand Down
50 changes: 22 additions & 28 deletions src/jdk.incubator.code/share/classes/jdk/incubator/code/dialect/java/JavaOp.java
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4597,6 +4597,9 @@ static Block.Builder lower(Block.Builder startBlock, BiFunction<Block.Builder, O
CodeType oprType = cop.result().type();
Block.Parameter arg = exit.parameter(oprType);
startBlock.context().mapValue(cop.result(), arg);
// Short circuit exit reference, with false for && and true for ||
Block.Reference shortCircuitRef = exit.reference(startBlock.add(constant(BOOLEAN,
cop instanceof ConditionalOrOp)));

// Transform bodies in reverse order
// This makes available the blocks to be referenced as successors in prior blocks
Expand All @@ -4621,9 +4624,9 @@ static Block.Builder lower(Block.Builder startBlock, BiFunction<Block.Builder, O
if (op instanceof CoreOp.YieldOp yop) {
Value p = block.context().getValue(yop.yieldValue());
if (cop instanceof ConditionalAndOp) {
block.add(conditionalBranch(p, nextPred.reference(), exit.reference(p)));
block.add(conditionalBranch(p, nextPred.reference(), shortCircuitRef));
} else {
block.add(conditionalBranch(p, exit.reference(p), nextPred.reference()));
block.add(conditionalBranch(p, shortCircuitRef, nextPred.reference()));
}
return block;
} else {
Expand Down Expand Up @@ -6138,34 +6141,25 @@ public Value targetOperand() {
}

@Override
public Block.Builder lower(Block.Builder b, BiFunction<Block.Builder, Op, Block.Builder> inherited) {
// No match block
Block.Builder endNoMatchBlock = b.block();
// Match block
Block.Builder endMatchBlock = b.block();
public Block.Builder lower(Block.Builder startBlock, BiFunction<Block.Builder, Op, Block.Builder> inherited) {
// End block
Block.Builder endBlock = b.block();
Block.Builder endBlock = startBlock.block();
Block.Parameter matchResult = endBlock.parameter(resultType());
// Map match operation result
b.context().mapValue(result(), matchResult);
startBlock.context().mapValue(result(), matchResult);
Block.Reference noMatchRef = endBlock.reference(startBlock.add(constant(BOOLEAN, false)));

List<Value> patternValues = new ArrayList<>();
Op patternYieldOp = patternBody.entryBlock().terminatingOp();
Op.Result rootPatternValue = (Op.Result) patternYieldOp.operands().get(0);
Block.Builder currentBlock = lower(endNoMatchBlock, b,
Block.Builder matchedBlock = lower(noMatchRef, startBlock,
patternValues,
rootPatternValue.op(),
b.context().getValue(targetOperand()));
currentBlock.add(branch(endMatchBlock.reference()));

// No match block
// Pass false
endNoMatchBlock.add(branch(endBlock.reference(
endNoMatchBlock.add(constant(BOOLEAN, false)))));
startBlock.context().getValue(targetOperand()));

// Match block
// Lower match body and pass true
endMatchBlock.transformBody(matchBody, patternValues, loweringTransformer(inherited, (block, op) -> {
matchedBlock.transformBody(matchBody, patternValues, loweringTransformer(inherited, (block, op) -> {
if (op instanceof CoreOp.YieldOp) {
block.add(branch(endBlock.reference(
block.add(constant(BOOLEAN, true)))));
Expand All @@ -6178,18 +6172,18 @@ public Block.Builder lower(Block.Builder b, BiFunction<Block.Builder, Op, Block.
return endBlock;
}

static Block.Builder lower(Block.Builder endNoMatchBlock, Block.Builder currentBlock,
static Block.Builder lower(Block.Reference noMatchRef, Block.Builder currentBlock,
List<Value> bindings,
Op pattern, Value target) {
return switch (pattern) {
case RecordPatternOp rp -> lowerRecordPattern(endNoMatchBlock, currentBlock, bindings, rp, target);
case TypePatternOp tp -> lowerTypePattern(endNoMatchBlock, currentBlock, bindings, tp, target);
case MatchAllPatternOp map -> lowerMatchAllPattern(currentBlock);
case RecordPatternOp rp -> lowerRecordPattern(noMatchRef, currentBlock, bindings, rp, target);
case TypePatternOp tp -> lowerTypePattern(noMatchRef, currentBlock, bindings, tp, target);
case MatchAllPatternOp _ -> lowerMatchAllPattern(currentBlock);
case null, default -> throw new UnsupportedOperationException("Unknown pattern op: " + pattern);
};
}

static Block.Builder lowerRecordPattern(Block.Builder endNoMatchBlock, Block.Builder currentBlock,
static Block.Builder lowerRecordPattern(Block.Reference noMatchRef, Block.Builder currentBlock,
List<Value> bindings,
JavaOp.PatternOps.RecordPatternOp rpOp, Value target) {
CodeType targetType = rpOp.targetType();
Expand All @@ -6198,7 +6192,7 @@ static Block.Builder lowerRecordPattern(Block.Builder endNoMatchBlock, Block.Bui

// Check if instance of target type
Op.Result isInstance = currentBlock.add(instanceOf(targetType, target));
currentBlock.add(conditionalBranch(isInstance, nextBlock.reference(), endNoMatchBlock.reference()));
currentBlock.add(conditionalBranch(isInstance, nextBlock.reference(), noMatchRef));

currentBlock = nextBlock;

Expand All @@ -6209,15 +6203,15 @@ static Block.Builder lowerRecordPattern(Block.Builder endNoMatchBlock, Block.Bui
for (int i = 0; i < dArgs.size(); i++) {
Op.Result nestedPattern = (Op.Result) dArgs.get(i);
// @@@ Handle exceptions?
Value nestedTarget = currentBlock.add(invoke(rpOp.recordReference().methodForComponent(i), target));
Value nestedTarget = currentBlock.add(invoke(rpOp.recordReference().methodForComponent(i), target));

currentBlock = lower(endNoMatchBlock, currentBlock, bindings, nestedPattern.op(), nestedTarget);
currentBlock = lower(noMatchRef, currentBlock, bindings, nestedPattern.op(), nestedTarget);
}

return currentBlock;
}

static Block.Builder lowerTypePattern(Block.Builder endNoMatchBlock, Block.Builder currentBlock,
static Block.Builder lowerTypePattern(Block.Reference noMatchRef, Block.Builder currentBlock,
List<Value> bindings,
TypePatternOp tpOp, Value target) {
CodeType targetType = tpOp.targetType();
Expand Down Expand Up @@ -6276,7 +6270,7 @@ static Block.Builder lowerTypePattern(Block.Builder endNoMatchBlock, Block.Build
if (p != null) {
// p != null, we need to perform type check at runtime
Block.Builder nextBlock = currentBlock.block();
currentBlock.add(conditionalBranch(currentBlock.add(p), nextBlock.reference(), endNoMatchBlock.reference()));
currentBlock.add(conditionalBranch(currentBlock.add(p), nextBlock.reference(), noMatchRef));
currentBlock = nextBlock;
}
if (c != null) {
Expand Down
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