Revision: 24580
Author:   [email protected]
Date:     Tue Oct 14 08:34:20 2014 UTC
Log: [turbofan] Use register for instruction operands when SameAsFirst is specified.

As the register allocator cannot reuse spill slots, SameAsFirst
constraint means that we would have to do an expensive move to a
differen spill slot if we choose to spill. Forcing the operand
to a register is cheaper.

In zlib, we get >10% speed-up for ia32, >25% for x64.

BUG=
[email protected]

Review URL: https://codereview.chromium.org/650083003
https://code.google.com/p/v8/source/detail?r=24580

Modified:
 /branches/bleeding_edge/src/compiler/ia32/instruction-selector-ia32.cc
 /branches/bleeding_edge/src/compiler/instruction-selector-impl.h
 /branches/bleeding_edge/src/compiler/x64/instruction-selector-x64.cc

=======================================
--- /branches/bleeding_edge/src/compiler/ia32/instruction-selector-ia32.cc Mon Oct 13 08:15:03 2014 UTC +++ /branches/bleeding_edge/src/compiler/ia32/instruction-selector-ia32.cc Tue Oct 14 08:34:20 2014 UTC
@@ -260,7 +260,7 @@

   // TODO(turbofan): match complex addressing modes.
   if (g.CanBeImmediate(right)) {
-    inputs[input_count++] = g.Use(left);
+    inputs[input_count++] = g.UseRegister(left);
     inputs[input_count++] = g.UseImmediate(right);
   } else {
     if (node->op()->HasProperty(Operator::kCommutative) &&
@@ -315,7 +315,7 @@
   IA32OperandGenerator g(this);
   Int32BinopMatcher m(node);
   if (m.right().Is(-1)) {
-    Emit(kIA32Not, g.DefineSameAsFirst(node), g.Use(m.left().node()));
+ Emit(kIA32Not, g.DefineSameAsFirst(node), g.UseRegister(m.left().node()));
   } else {
     VisitBinop(this, node, kIA32Xor);
   }
@@ -330,7 +330,7 @@
   Node* right = node->InputAt(1);

   if (g.CanBeImmediate(right)) {
-    selector->Emit(opcode, g.DefineSameAsFirst(node), g.Use(left),
+    selector->Emit(opcode, g.DefineSameAsFirst(node), g.UseRegister(left),
                    g.UseImmediate(right));
   } else {
     Int32BinopMatcher m(node);
@@ -340,7 +340,7 @@
         right = mright.left().node();
       }
     }
-    selector->Emit(opcode, g.DefineSameAsFirst(node), g.Use(left),
+    selector->Emit(opcode, g.DefineSameAsFirst(node), g.UseRegister(left),
                    g.UseFixed(right, ecx));
   }
 }
=======================================
--- /branches/bleeding_edge/src/compiler/instruction-selector-impl.h Mon Oct 13 08:09:27 2014 UTC +++ /branches/bleeding_edge/src/compiler/instruction-selector-impl.h Tue Oct 14 08:34:20 2014 UTC
@@ -55,9 +55,9 @@
   }

   InstructionOperand* Use(Node* node) {
-    return Use(node,
-               new (zone()) UnallocatedOperand(
- UnallocatedOperand::ANY, UnallocatedOperand::USED_AT_START));
+    return Use(
+        node, new (zone()) UnallocatedOperand(
+ UnallocatedOperand::NONE, UnallocatedOperand::USED_AT_START));
   }

   InstructionOperand* UseRegister(Node* node) {
@@ -69,7 +69,7 @@
// Use register or operand for the node. If a register is chosen, it won't
   // alias any temporary or output registers.
   InstructionOperand* UseUnique(Node* node) {
- return Use(node, new (zone()) UnallocatedOperand(UnallocatedOperand::ANY)); + return Use(node, new (zone()) UnallocatedOperand(UnallocatedOperand::NONE));
   }

// Use a unique register for the node that does not alias any temporary or
=======================================
--- /branches/bleeding_edge/src/compiler/x64/instruction-selector-x64.cc Mon Oct 13 08:15:03 2014 UTC +++ /branches/bleeding_edge/src/compiler/x64/instruction-selector-x64.cc Tue Oct 14 08:34:20 2014 UTC
@@ -241,7 +241,7 @@

   // TODO(turbofan): match complex addressing modes.
   if (g.CanBeImmediate(right)) {
-    inputs[input_count++] = g.Use(left);
+    inputs[input_count++] = g.UseRegister(left);
     inputs[input_count++] = g.UseImmediate(right);
   } else {
     if (node->op()->HasProperty(Operator::kCommutative) &&
@@ -305,7 +305,7 @@
   X64OperandGenerator g(this);
   Uint32BinopMatcher m(node);
   if (m.right().Is(-1)) {
-    Emit(kX64Not32, g.DefineSameAsFirst(node), g.Use(m.left().node()));
+ Emit(kX64Not32, g.DefineSameAsFirst(node), g.UseRegister(m.left().node()));
   } else {
     VisitBinop(this, node, kX64Xor32);
   }
@@ -316,7 +316,7 @@
   X64OperandGenerator g(this);
   Uint64BinopMatcher m(node);
   if (m.right().Is(-1)) {
-    Emit(kX64Not, g.DefineSameAsFirst(node), g.Use(m.left().node()));
+ Emit(kX64Not, g.DefineSameAsFirst(node), g.UseRegister(m.left().node()));
   } else {
     VisitBinop(this, node, kX64Xor);
   }
@@ -332,7 +332,7 @@
   Node* right = node->InputAt(1);

   if (g.CanBeImmediate(right)) {
-    selector->Emit(opcode, g.DefineSameAsFirst(node), g.Use(left),
+    selector->Emit(opcode, g.DefineSameAsFirst(node), g.UseRegister(left),
                    g.UseImmediate(right));
   } else {
     Int32BinopMatcher m(node);
@@ -342,7 +342,7 @@
         right = mright.left().node();
       }
     }
-    selector->Emit(opcode, g.DefineSameAsFirst(node), g.Use(left),
+    selector->Emit(opcode, g.DefineSameAsFirst(node), g.UseRegister(left),
                    g.UseFixed(right, rcx));
   }
 }
@@ -357,7 +357,7 @@
   Node* right = node->InputAt(1);

   if (g.CanBeImmediate(right)) {
-    selector->Emit(opcode, g.DefineSameAsFirst(node), g.Use(left),
+    selector->Emit(opcode, g.DefineSameAsFirst(node), g.UseRegister(left),
                    g.UseImmediate(right));
   } else {
     Int64BinopMatcher m(node);
@@ -367,7 +367,7 @@
         right = mright.left().node();
       }
     }
-    selector->Emit(opcode, g.DefineSameAsFirst(node), g.Use(left),
+    selector->Emit(opcode, g.DefineSameAsFirst(node), g.UseRegister(left),
                    g.UseFixed(right, rcx));
   }
 }
@@ -472,7 +472,7 @@
   X64OperandGenerator g(this);
   Int32BinopMatcher m(node);
   if (m.left().Is(0)) {
-    Emit(kX64Neg32, g.DefineSameAsFirst(node), g.Use(m.right().node()));
+ Emit(kX64Neg32, g.DefineSameAsFirst(node), g.UseRegister(m.right().node()));
   } else {
     VisitBinop(this, node, kX64Sub32);
   }
@@ -483,7 +483,7 @@
   X64OperandGenerator g(this);
   Int64BinopMatcher m(node);
   if (m.left().Is(0)) {
-    Emit(kX64Neg, g.DefineSameAsFirst(node), g.Use(m.right().node()));
+ Emit(kX64Neg, g.DefineSameAsFirst(node), g.UseRegister(m.right().node()));
   } else {
     VisitBinop(this, node, kX64Sub);
   }

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