Deduplicate phi just after Ir building
- Sccp can generate duplicate Phi, deduplicate them only on block
where it could be needed.
Change-Id: I5ec08d2c8696eea18b0a9d156ee685eee792501f
diff --git a/src/main/java/com/android/tools/r8/ir/code/BasicBlock.java b/src/main/java/com/android/tools/r8/ir/code/BasicBlock.java
index 3e685a2..fc74be1 100644
--- a/src/main/java/com/android/tools/r8/ir/code/BasicBlock.java
+++ b/src/main/java/com/android/tools/r8/ir/code/BasicBlock.java
@@ -14,6 +14,8 @@
import com.android.tools.r8.utils.ListUtils;
import com.android.tools.r8.utils.StringUtils;
import com.android.tools.r8.utils.StringUtils.BraceType;
+import com.google.common.base.Equivalence;
+import com.google.common.base.Equivalence.Wrapper;
import com.google.common.collect.ImmutableList;
import it.unimi.dsi.fastutil.ints.Int2ReferenceMap;
import java.util.ArrayDeque;
@@ -21,6 +23,7 @@
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
+import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.ListIterator;
@@ -1398,4 +1401,46 @@
return false;
}
+
+ private static class PhiEquivalence extends Equivalence<Phi> {
+ @Override
+ protected boolean doEquivalent(Phi a, Phi b) {
+ assert a.getBlock() == b.getBlock();
+ for (int i = 0; i < a.getOperands().size(); i++) {
+ if (a.getOperand(i) != b.getOperand(i)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ @Override
+ protected int doHash(Phi phi) {
+ int hash = 0;
+ for (Value value : phi.getOperands()) {
+ hash = hash * 13 + value.hashCode();
+ }
+ return hash;
+ }
+ }
+
+ public void deduplicatePhis() {
+ PhiEquivalence equivalence = new PhiEquivalence();
+ HashMap<Wrapper<Phi>, Phi> wrapper2phi = new HashMap<>();
+ Iterator<Phi> phiIt = phis.iterator();
+ while (phiIt.hasNext()) {
+ Phi phi = phiIt.next();
+ Wrapper<Phi> key = equivalence.wrap(phi);
+ Phi replacement = wrapper2phi.get(key);
+ if (replacement != null) {
+ phi.replaceUsers(replacement);
+ for (Value operand : phi.getOperands()) {
+ operand.removePhiUser(phi);
+ }
+ phiIt.remove();
+ } else {
+ wrapper2phi.put(key, phi);
+ }
+ }
+ }
}
