[turbofan] Recognize rotate right.

Extended the rotate left detection code.

BUG=

Review URL: https://codereview.chromium.org/760523004

Cr-Commit-Position: refs/heads/master@{#25517}

diff --git a/src/compiler/machine-operator-reducer.cc b/src/compiler/machine-operator-reducer.cc
index 470e71d..652b269 100644 (file)
--- a/src/compiler/machine-operator-reducer.cc
+++ b/src/compiler/machine-operator-reducer.cc
@@ -152,68 +152,8 @@ Reduction MachineOperatorReducer::Reduce(Node* node) {
       }
       break;
     }
-    case IrOpcode::kWord32Or: {
-      Int32BinopMatcher m(node);
-      if (m.right().Is(0)) return Replace(m.left().node());    // x | 0  => x
-      if (m.right().Is(-1)) return Replace(m.right().node());  // x | -1 => -1
-      if (m.IsFoldable()) {                                    // K | K  => K
-        return ReplaceInt32(m.left().Value() | m.right().Value());
-      }
-      if (m.LeftEqualsRight()) return Replace(m.left().node());  // x | x => x
-      if (m.left().IsWord32Shl() && m.right().IsWord32Shr()) {
-        Int32BinopMatcher mleft(m.left().node());
-        Int32BinopMatcher mright(m.right().node());
-        if (mleft.left().node() == mright.left().node()) {
-          // TODO(turbofan): here we are matching rotate left, shall we add
-          // support for rotate right?
-          // (x << y) | (x >>> (32 - y)) => x ror (32 - y)
-          if (mright.right().IsInt32Sub()) {
-            Int32BinopMatcher mrightright(mright.right().node());
-            if (mrightright.left().Is(32) &&
-                mrightright.right().node() == mleft.right().node()) {
-              node->set_op(machine()->Word32Ror());
-              node->ReplaceInput(0, mleft.left().node());
-              node->ReplaceInput(1, mright.right().node());
-              return Changed(node);
-            }
-          }
-          // (x << K) | (x >>> (32 - K)) => x ror (32 - K)
-          if (mleft.right().IsInRange(0, 31) &&
-              mright.right().Is(32 - mleft.right().Value())) {
-            node->set_op(machine()->Word32Ror());
-            node->ReplaceInput(0, mleft.left().node());
-            node->ReplaceInput(1, mright.right().node());
-            return Changed(node);
-          }
-        }
-      }
-      if (m.left().IsWord32Shr() && m.right().IsWord32Shl()) {
-        // (x >>> (32 - y)) | (x << y)  => x ror (32 -y)
-        Int32BinopMatcher mleft(m.left().node());
-        Int32BinopMatcher mright(m.right().node());
-        if (mleft.left().node() == mright.left().node()) {
-          if (mleft.right().IsInt32Sub()) {
-            Int32BinopMatcher mleftright(mleft.right().node());
-            if (mleftright.left().Is(32) &&
-                mleftright.right().node() == mright.right().node()) {
-              node->set_op(machine()->Word32Ror());
-              node->ReplaceInput(0, mright.left().node());
-              node->ReplaceInput(1, mleft.right().node());
-              return Changed(node);
-            }
-          }
-          // (x >>> (32 - K)) | (x << K) => x ror (32 - K)
-          if (mright.right().IsInRange(0, 31) &&
-              mleft.right().Is(32 - mright.right().Value())) {
-            node->set_op(machine()->Word32Ror());
-            node->ReplaceInput(0, mright.left().node());
-            node->ReplaceInput(1, mleft.right().node());
-            return Changed(node);
-          }
-        }
-      }
-      break;
-    }
+    case IrOpcode::kWord32Or:
+      return ReduceWord32Or(node);
     case IrOpcode::kWord32Xor: {
       Int32BinopMatcher m(node);
       if (m.right().Is(0)) return Replace(m.left().node());  // x ^ 0 => x
@@ -841,6 +781,64 @@ Reduction MachineOperatorReducer::ReduceWord32Shifts(Node* node) {
 }
 
 
+Reduction MachineOperatorReducer::ReduceWord32Or(Node* node) {
+  DCHECK(node->opcode() == IrOpcode::kWord32Or);
+
+  Int32BinopMatcher m(node);
+  if (m.right().Is(0)) return Replace(m.left().node());    // x | 0  => x
+  if (m.right().Is(-1)) return Replace(m.right().node());  // x | -1 => -1
+  if (m.IsFoldable()) {                                    // K | K  => K
+    return ReplaceInt32(m.left().Value() | m.right().Value());
+  }
+  if (m.LeftEqualsRight()) return Replace(m.left().node());  // x | x => x
+
+  Node* shl = NULL;
+  Node* shr = NULL;
+  // Recognize rotation, we are matching either:
+  //  * x << y | x >>> (32 - y) => x ror (32 - y), i.e  x rol y
+  //  * x << (32 - y) | x >>> y => x ror y
+  // as well as their commuted form.
+  if (m.left().IsWord32Shl() && m.right().IsWord32Shr()) {
+    shl = m.left().node();
+    shr = m.right().node();
+  } else if (m.left().IsWord32Shr() && m.right().IsWord32Shl()) {
+    shl = m.right().node();
+    shr = m.left().node();
+  } else {
+    return NoChange();
+  }
+
+  Int32BinopMatcher mshl(shl);
+  Int32BinopMatcher mshr(shr);
+  if (mshl.left().node() != mshr.left().node()) return NoChange();
+
+  if (mshl.right().HasValue() && mshr.right().HasValue()) {
+    // Case where y is a constant.
+    if (mshl.right().Value() + mshr.right().Value() != 32) return NoChange();
+  } else {
+    Node* sub = NULL;
+    Node* y = NULL;
+    if (mshl.right().IsInt32Sub()) {
+      sub = mshl.right().node();
+      y = mshr.right().node();
+    } else if (mshr.right().IsInt32Sub()) {
+      sub = mshr.right().node();
+      y = mshl.right().node();
+    } else {
+      return NoChange();
+    }
+
+    Int32BinopMatcher msub(sub);
+    if (!msub.left().Is(32) || msub.right().node() != y) return NoChange();
+  }
+
+  node->set_op(machine()->Word32Ror());
+  node->ReplaceInput(0, mshl.left().node());
+  node->ReplaceInput(1, mshr.right().node());
+  return Changed(node);
+}
+
+
 CommonOperatorBuilder* MachineOperatorReducer::common() const {
   return jsgraph()->common();
 }

diff --git a/src/compiler/machine-operator-reducer.h b/src/compiler/machine-operator-reducer.h
index 2973ab5..1f065c6 100644 (file)
--- a/src/compiler/machine-operator-reducer.h
+++ b/src/compiler/machine-operator-reducer.h
@@ -69,6 +69,7 @@ class MachineOperatorReducer FINAL : public Reducer {
   Reduction ReduceStore(Node* node);
   Reduction ReduceProjection(size_t index, Node* node);
   Reduction ReduceWord32Shifts(Node* node);
+  Reduction ReduceWord32Or(Node* node);
 
   Graph* graph() const;
   JSGraph* jsgraph() const { return jsgraph_; }

diff --git a/test/mjsunit/asm/word32ror.js b/test/mjsunit/asm/word32ror.js
index d385eac..9535bde 100644 (file)
--- a/test/mjsunit/asm/word32ror.js
+++ b/test/mjsunit/asm/word32ror.js
@@ -20,3 +20,18 @@ assertEquals(10, rol(10, 0));
 assertEquals(2, rol(1, 1));
 assertEquals(0x40000000, rol(1, 30));
 assertEquals(-0x80000000, rol(1, 31));
+
+var ror = (function Module(stdlib, foreign, heap) {
+  "use asm";
+  function ror(x, y) {
+    x = x | 0;
+    y = y | 0;
+    return (x << (32 - y)) | (x >>> y);
+  }
+  return { ror: ror };
+})(stdlib, foreign, heap).ror;
+
+assertEquals(10, ror(10, 0));
+assertEquals(-0x80000000, ror(1, 1));
+assertEquals(0x40000000, ror(1, 2));
+assertEquals(2, ror(1, 31));

diff --git a/test/unittests/compiler/machine-operator-reducer-unittest.cc b/test/unittests/compiler/machine-operator-reducer-unittest.cc
index 6e1b12f..9377f1f 100644 (file)
--- a/test/unittests/compiler/machine-operator-reducer-unittest.cc
+++ b/test/unittests/compiler/machine-operator-reducer-unittest.cc
@@ -591,23 +591,43 @@ TEST_F(MachineOperatorReducerTest, Word32XorWithWord32XorAndMinusOne) {
 TEST_F(MachineOperatorReducerTest, ReduceToWord32RorWithParameters) {
   Node* value = Parameter(0);
   Node* shift = Parameter(1);
-  Node* shl = graph()->NewNode(machine()->Word32Shl(), value, shift);
   Node* sub = graph()->NewNode(machine()->Int32Sub(), Int32Constant(32), shift);
-  Node* shr = graph()->NewNode(machine()->Word32Shr(), value, sub);
+
+  // Testing rotate left.
+  Node* shl_l = graph()->NewNode(machine()->Word32Shl(), value, shift);
+  Node* shr_l = graph()->NewNode(machine()->Word32Shr(), value, sub);
 
   // (x << y) | (x >>> (32 - y)) => x ror (32 - y)
-  Node* node1 = graph()->NewNode(machine()->Word32Or(), shl, shr);
+  Node* node1 = graph()->NewNode(machine()->Word32Or(), shl_l, shr_l);
   Reduction reduction1 = Reduce(node1);
   EXPECT_TRUE(reduction1.Changed());
   EXPECT_EQ(reduction1.replacement(), node1);
   EXPECT_THAT(reduction1.replacement(), IsWord32Ror(value, sub));
 
-  // (x >>> (32 - y)) | (x << y) => x ror y
-  Node* node2 = graph()->NewNode(machine()->Word32Or(), shr, shl);
+  // (x >>> (32 - y)) | (x << y) => x ror (32 - y)
+  Node* node2 = graph()->NewNode(machine()->Word32Or(), shr_l, shl_l);
   Reduction reduction2 = Reduce(node2);
   EXPECT_TRUE(reduction2.Changed());
   EXPECT_EQ(reduction2.replacement(), node2);
   EXPECT_THAT(reduction2.replacement(), IsWord32Ror(value, sub));
+
+  // Testing rotate right.
+  Node* shl_r = graph()->NewNode(machine()->Word32Shl(), value, sub);
+  Node* shr_r = graph()->NewNode(machine()->Word32Shr(), value, shift);
+
+  // (x << (32 - y)) | (x >>> y) => x ror y
+  Node* node3 = graph()->NewNode(machine()->Word32Or(), shl_r, shr_r);
+  Reduction reduction3 = Reduce(node3);
+  EXPECT_TRUE(reduction3.Changed());
+  EXPECT_EQ(reduction3.replacement(), node3);
+  EXPECT_THAT(reduction3.replacement(), IsWord32Ror(value, shift));
+
+  // (x >>> y) | (x << (32 - y)) => x ror y
+  Node* node4 = graph()->NewNode(machine()->Word32Or(), shr_r, shl_r);
+  Reduction reduction4 = Reduce(node4);
+  EXPECT_TRUE(reduction4.Changed());
+  EXPECT_EQ(reduction4.replacement(), node4);
+  EXPECT_THAT(reduction4.replacement(), IsWord32Ror(value, shift));
 }
 
 
@@ -627,7 +647,7 @@ TEST_F(MachineOperatorReducerTest, ReduceToWord32RorWithConstant) {
     EXPECT_THAT(reduction1.replacement(),
                 IsWord32Ror(value, IsInt32Constant(32 - k)));
 
-    // (x >>> (32 - K)) | (x << K) => x ror K
+    // (x >>> (32 - K)) | (x << K) => x ror (32 - K)
     Node* node2 = graph()->NewNode(machine()->Word32Or(), shr, shl);
     Reduction reduction2 = Reduce(node2);
     EXPECT_TRUE(reduction2.Changed());