Merge "Increase usages of 2Addr instructions"
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 d6a64a4..52653a7 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
@@ -8,6 +8,7 @@
import com.android.tools.r8.graph.DebugLocalInfo;
import com.android.tools.r8.ir.code.Add;
import com.android.tools.r8.ir.code.And;
+import com.android.tools.r8.ir.code.ArithmeticBinop;
import com.android.tools.r8.ir.code.BasicBlock;
import com.android.tools.r8.ir.code.DebugLocalsChange;
import com.android.tools.r8.ir.code.IRCode;
@@ -811,6 +812,9 @@
// Go through each unhandled live interval and find a register for it.
while (!unhandled.isEmpty()) {
LiveIntervals unhandledInterval = unhandled.poll();
+
+ setHintToPromote2AddrInstruction(unhandledInterval);
+
// If this interval value is the src of an argument move. Fix the registers for the
// consecutive arguments now and add hints to the move sources. This looks forward
// and propagate hints backwards to avoid many moves in connection with ranged invokes.
@@ -862,6 +866,31 @@
return true;
}
+ /*
+ * This method tries to promote arithmetic binary instruction to use the 2Addr form.
+ * To achieve this goal the output interval of the binary instruction is set with an hint
+ * that is the left interval or the right interval if possible when intervals do not overlap.
+ */
+ private void setHintToPromote2AddrInstruction(LiveIntervals unhandledInterval) {
+ if (unhandledInterval.getHint() == null &&
+ unhandledInterval.getValue().definition instanceof ArithmeticBinop) {
+ ArithmeticBinop binOp = unhandledInterval.getValue().definition.asArithmeticBinop();
+ Value left = binOp.leftValue();
+ assert left != null;
+ if (left.getLiveIntervals() != null &&
+ !left.getLiveIntervals().overlaps(unhandledInterval)) {
+ unhandledInterval.setHint(left.getLiveIntervals());
+ } else {
+ Value right = binOp.rightValue();
+ assert right != null;
+ if (binOp.isCommutative() && right.getLiveIntervals() != null &&
+ !right.getLiveIntervals().overlaps(unhandledInterval)) {
+ unhandledInterval.setHint(right.getLiveIntervals());
+ }
+ }
+ }
+ }
+
/**
* Perform look-ahead and allocate registers for linked argument chains that have the argument
* interval as an argument move source.
diff --git a/src/test/java/com/android/tools/r8/smali/OutlineTest.java b/src/test/java/com/android/tools/r8/smali/OutlineTest.java
index d0e3ade..c64e39c 100644
--- a/src/test/java/com/android/tools/r8/smali/OutlineTest.java
+++ b/src/test/java/com/android/tools/r8/smali/OutlineTest.java
@@ -12,6 +12,7 @@
import com.android.tools.r8.code.ConstWide;
import com.android.tools.r8.code.ConstWideHigh16;
import com.android.tools.r8.code.DivInt;
+import com.android.tools.r8.code.DivInt2Addr;
import com.android.tools.r8.code.InvokeStatic;
import com.android.tools.r8.code.InvokeVirtual;
import com.android.tools.r8.code.MoveResult;
@@ -1176,7 +1177,7 @@
assertTrue(code.instructions[0] instanceof DivInt);
assertTrue(code.instructions[1] instanceof InvokeStatic);
assertTrue(code.instructions[2] instanceof MoveResult);
- assertTrue(code.instructions[3] instanceof DivInt);
+ assertTrue(code.instructions[3] instanceof DivInt2Addr);
assertTrue(code.instructions[4] instanceof Return);
assertTrue(code.instructions[5] instanceof Const4);
assertTrue(code.instructions[6] instanceof Return);
