Fix spilling of argument live intervals
Bug: b/382220159
Change-Id: I17f15ff6783a567b625fdac9b82dfafa3271d6c0
diff --git a/src/main/java/com/android/tools/r8/ir/regalloc/LinearScanRegisterAllocator.java b/src/main/java/com/android/tools/r8/ir/regalloc/LinearScanRegisterAllocator.java
index 8e8cda3..7c8e08e 100644
--- a/src/main/java/com/android/tools/r8/ir/regalloc/LinearScanRegisterAllocator.java
+++ b/src/main/java/com/android/tools/r8/ir/regalloc/LinearScanRegisterAllocator.java
@@ -2901,17 +2901,20 @@
private void splitRangesForSpilledArgument(LiveIntervals spilled) {
assert spilled.isSpilled();
assert spilled.isArgumentInterval();
- // Argument intervals are spilled to the original argument register. We don't know what
- // that is yet, and therefore we split before the next use to make sure we get a usable
+ // Argument intervals are spilled to the original argument register. We don't know what that is
+ // yet, and therefore we split before the next constrained use to make sure we get a usable
// register at the next use.
- if (!spilled.getUses().isEmpty()) {
- LiveIntervals split = spilled.splitBefore(spilled.getUses().first().getPosition(), mode);
- if (split != spilled) {
- unhandled.add(split);
- } else {
- spilled.setRegister(spilled.getSplitParent().getRegister());
- }
+ LiveIntervalsUse firstUseWithConstraint = spilled.firstUseWithConstraint(mode);
+ if (firstUseWithConstraint == null
+ || (mode.is8BitRefinement()
+ && spilled.getSplitParent().getRegisterEnd() < numberOf4BitArgumentRegisters)) {
+ spilled.setRegister(spilled.getSplitParent().getRegister());
+ spilled.setSpilled(false);
+ return;
}
+ LiveIntervals splitOfSplit = spilled.splitBefore(firstUseWithConstraint.getPosition(), mode);
+ assert splitOfSplit != spilled;
+ unhandled.add(splitOfSplit);
}
private void splitRangesForSpilledInterval(LiveIntervals spilled) {
