# HG changeset patch
# User Josef Eisl <josef.eisl@jku.at>
# Date 1430401151 -7200
# Node ID a2430e146460b728fde6ee7a66e1f7e4d43cf952
# Parent  bf5e055dbc9c9c50189ab9db2aa5e314f0288d20
SSALinearScan: add register hints to PHIs.

diff -r bf5e055dbc9c -r a2430e146460 graal/com.oracle.graal.lir/src/com/oracle/graal/lir/alloc/lsra/SSALinearScan.java
--- a/graal/com.oracle.graal.lir/src/com/oracle/graal/lir/alloc/lsra/SSALinearScan.java	Thu Apr 30 15:36:03 2015 +0200
+++ b/graal/com.oracle.graal.lir/src/com/oracle/graal/lir/alloc/lsra/SSALinearScan.java	Thu Apr 30 15:39:11 2015 +0200
@@ -32,9 +32,12 @@
 import com.oracle.graal.compiler.common.alloc.*;
 import com.oracle.graal.compiler.common.cfg.*;
 import com.oracle.graal.debug.*;
-import com.oracle.graal.debug.Debug.*;
+import com.oracle.graal.debug.Debug.Scope;
 import com.oracle.graal.lir.*;
-import com.oracle.graal.lir.StandardOp.*;
+import com.oracle.graal.lir.LIRInstruction.OperandFlag;
+import com.oracle.graal.lir.LIRInstruction.OperandMode;
+import com.oracle.graal.lir.StandardOp.LabelOp;
+import com.oracle.graal.lir.StandardOp.MoveOp;
 import com.oracle.graal.lir.gen.*;
 import com.oracle.graal.lir.gen.LIRGeneratorTool.SpillMoveFactory;
 import com.oracle.graal.lir.ssa.*;
@@ -130,6 +133,40 @@
         return false;
     }
 
+    @Override
+    void addRegisterHint(final LIRInstruction op, final Value targetValue, OperandMode mode, EnumSet<OperandFlag> flags, final boolean hintAtDef) {
+        super.addRegisterHint(op, targetValue, mode, flags, hintAtDef);
+
+        if (hintAtDef && op instanceof LabelOp) {
+            LabelOp label = (LabelOp) op;
+
+            Interval to = getOrCreateInterval((AllocatableValue) targetValue);
+
+            SSAUtils.forEachPhiRegisterHint(ir, blockForId(label.id()), label, targetValue, mode, (ValueConsumer) (registerHint, valueMode, valueFlags) -> {
+                if (isVariableOrRegister(registerHint)) {
+                    Interval from = getOrCreateInterval((AllocatableValue) registerHint);
+
+                    setHint(op, to, from);
+                    setHint(op, from, to);
+                }
+            });
+        }
+    }
+
+    private static void setHint(final LIRInstruction op, Interval target, Interval source) {
+        Interval currentHint = target.locationHint(false);
+        if (currentHint == null || currentHint.from() > target.from()) {
+            /*
+             * Update hint if there was none or if the hint interval starts after the hinted
+             * interval.
+             */
+            target.setLocationHint(source);
+            if (Debug.isLogEnabled()) {
+                Debug.log("operation at opId %d: added hint from interval %d to %d", op.id(), source.operandNumber, target.operandNumber);
+            }
+        }
+    }
+
     private boolean isPhiResolutionMove(AbstractBlockBase<?> block, MoveOp move, Interval toInterval) {
         if (!LinearScanPhase.SSA_LSRA.getValue()) {
             return false;
diff -r bf5e055dbc9c -r a2430e146460 graal/com.oracle.graal.lir/src/com/oracle/graal/lir/ssa/SSAUtils.java
--- a/graal/com.oracle.graal.lir/src/com/oracle/graal/lir/ssa/SSAUtils.java	Thu Apr 30 15:36:03 2015 +0200
+++ b/graal/com.oracle.graal.lir/src/com/oracle/graal/lir/ssa/SSAUtils.java	Thu Apr 30 15:39:11 2015 +0200
@@ -27,6 +27,7 @@
 import com.oracle.graal.api.meta.*;
 import com.oracle.graal.compiler.common.cfg.*;
 import com.oracle.graal.lir.*;
+import com.oracle.graal.lir.LIRInstruction.OperandMode;
 import com.oracle.graal.lir.StandardOp.BlockEndOp;
 import com.oracle.graal.lir.StandardOp.JumpOp;
 import com.oracle.graal.lir.StandardOp.LabelOp;
@@ -53,14 +54,14 @@
  *   v0|i = ...
  *   JUMP ~[v0|i, int[0|0x0]] destination: B0 -> B1
  * ________________________________________________
- *
+ * 
  * B2 -> B1
  *   ...
  *   v1|i = ...
  *   v2|i = ...
  *   JUMP ~[v1|i, v2|i] destination: B2 -> B1
  * ________________________________________________
- *
+ * 
  * B1 <- B0,B2
  *   [v3|i, v4|i] = LABEL
  *   ...
@@ -144,6 +145,31 @@
         }
     }
 
+    public static void forEachPhiRegisterHint(LIR lir, AbstractBlockBase<?> block, LabelOp label, Value targetValue, OperandMode mode, ValueConsumer valueConsumer) {
+        assert mode == OperandMode.DEF : "Wrong operand mode: " + mode;
+        assert lir.getLIRforBlock(block).get(0).equals(label) : String.format("Block %s and Label %s do not match!", block, label);
 
+        if (!label.isPhiIn()) {
+            return;
+        }
+        int idx = indexOfValue(label, targetValue);
+        assert idx >= 0 : String.format("Value %s not in label %s", targetValue, label);
+
+        for (AbstractBlockBase<?> pred : block.getPredecessors()) {
+            JumpOp jump = phiOut(lir, pred);
+            Value sourceValue = jump.getOutgoingValue(idx);
+            valueConsumer.visitValue(jump, sourceValue, null, null);
+        }
+
+    }
+
+    private static int indexOfValue(LabelOp label, Value value) {
+        for (int i = 0; i < label.getIncomingSize(); i++) {
+            if (label.getIncomingValue(i).equals(value)) {
+                return i;
+            }
+        }
+        return -1;
+    }
 
 }