[interpreter] Bytecode register optimizer.

test/cctest/interpreter/bytecode_expectations/ForIn.golden

 #
 # Autogenerated by generate-bytecode-expectations.
 #
 
 ---
 pool type: mixed
 execute: yes
 wrap: yes
 
 ---
@@ skipping 47 matching lines @@
 handlers: [
 ]
 
 ---
 snippet: "
   var x = 'potatoes';
   for (var p in x) { return p; }
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 46
+bytecode array length: 44
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaConstant), U8(0),
                 B(Star), R(1),
-  /*   68 S> */ B(JumpIfUndefined), U8(39),
-                B(JumpIfNull), U8(37),
+  /*   68 S> */ B(JumpIfUndefined), U8(37),
+                B(JumpIfNull), U8(35),
                 B(ToObject),
+                B(ForInPrepare), R(4),
                 B(Star), R(3),
-                B(ForInPrepare), R(4),
                 B(LdaZero),
                 B(Star), R(7),
   /*   63 S> */ B(ForInDone), R(7), R(6),
-                B(JumpIfTrue), U8(24),
+                B(JumpIfTrue), U8(22),
                 B(ForInNext), R(3), R(7), R(4), U8(1),
-                B(JumpIfUndefined), U8(11),
+                B(JumpIfUndefined), U8(9),
                 B(Star), R(0),
   /*   54 E> */ B(StackCheck),
-                B(Ldar), R(0),
                 B(Star), R(2),
   /*   73 S> */ B(Nop),
   /*   85 S> */ B(Return),
                 B(ForInStep), R(7),
                 B(Star), R(7),
-                B(Jump), U8(-25),
+                B(Jump), U8(-23),
                 B(LdaUndefined),
   /*   85 S> */ B(Return),
 ]
 constant pool: [
   InstanceType::ONE_BYTE_INTERNALIZED_STRING_TYPE,
 ]
 handlers: [
 ]
 
 ---
 snippet: "
   var x = 0;
   for (var p in [1,2,3]) { x += p; }
 "
 frame size: 9
 parameter count: 1
-bytecode array length: 57
+bytecode array length: 55
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(LdaZero),
                 B(Star), R(1),
   /*   59 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(3),
-                B(JumpIfUndefined), U8(47),
-                B(JumpIfNull), U8(45),
+                B(JumpIfUndefined), U8(45),
+                B(JumpIfNull), U8(43),
                 B(ToObject),
+                B(ForInPrepare), R(4),
                 B(Star), R(3),
-                B(ForInPrepare), R(4),
                 B(LdaZero),
                 B(Star), R(7),
   /*   54 S> */ B(ForInDone), R(7), R(6),
-                B(JumpIfTrue), U8(32),
+                B(JumpIfTrue), U8(30),
                 B(ForInNext), R(3), R(7), R(4), U8(1),
-                B(JumpIfUndefined), U8(19),
+                B(JumpIfUndefined), U8(17),
                 B(Star), R(0),
   /*   45 E> */ B(StackCheck),
-                B(Ldar), R(0),
                 B(Star), R(2),
-  /*   70 S> */ B(Ldar), R(1),
-                B(Star), R(8),
-  /*   75 E> */ B(Ldar), R(2),
-                B(Add), R(8),
+  /*   70 S> */ B(Nop),
+  /*   75 E> */ B(Ldar), R(0),
+                B(Add), R(1),
+                B(Mov), R(1), R(8),
   /*   72 E> */ B(Star), R(1),
                 B(ForInStep), R(7),
                 B(Star), R(7),
-                B(Jump), U8(-33),
+                B(Jump), U8(-31),
                 B(LdaUndefined),
   /*   80 S> */ B(Return),
 ]
 constant pool: [
   InstanceType::FIXED_ARRAY_TYPE,
 ]
 handlers: [
 ]
 
 ---
 snippet: "
   var x = { 'a': 1, 'b': 2 };
   for (x['a'] in [10, 20, 30]) {
     if (x['a'] == 10) continue;
     if (x['a'] == 20) break;
   }
 "
 frame size: 8
 parameter count: 1
-bytecode array length: 92
+bytecode array length: 82
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateObjectLiteral), U8(0), U8(0), U8(1),
                 B(Star), R(1),
                 B(Star), R(0),
   /*   77 S> */ B(CreateArrayLiteral), U8(1), U8(1), U8(3),
-                B(JumpIfUndefined), U8(77),
-                B(JumpIfNull), U8(75),
+                B(JumpIfUndefined), U8(67),
+                B(JumpIfNull), U8(65),
                 B(ToObject),
+                B(ForInPrepare), R(2),
                 B(Star), R(1),
-                B(ForInPrepare), R(2),
                 B(LdaZero),
                 B(Star), R(5),
   /*   68 S> */ B(ForInDone), R(5), R(4),
-                B(JumpIfTrue), U8(62),
+                B(JumpIfTrue), U8(52),
                 B(ForInNext), R(1), R(5), R(2), U8(9),
-                B(JumpIfUndefined), U8(49),
+                B(JumpIfUndefined), U8(39),
                 B(Star), R(6),
-  /*   67 E> */ B(Ldar), R(0),
-                B(Star), R(7),
-                B(Ldar), R(6),
-                B(StaNamedPropertySloppy), R(7), U8(2), U8(7),
+  /*   67 E> */ B(Ldar), R(6),
+                B(StaNamedPropertySloppy), R(0), U8(2), U8(7),
   /*   62 E> */ B(StackCheck),
-  /*   95 S> */ B(Ldar), R(0),
-                B(Star), R(6),
-  /*  100 E> */ B(LdrNamedProperty), R(6), U8(2), U8(3), R(7),
+  /*   95 S> */ B(Nop),
+  /*  100 E> */ B(LdrNamedProperty), R(0), U8(2), U8(3), R(7),
                 B(LdaSmi), U8(10),
   /*  106 E> */ B(TestEqual), R(7),
                 B(JumpIfFalse), U8(4),
-  /*  113 S> */ B(Jump), U8(19),
-  /*  125 S> */ B(Ldar), R(0),
-                B(Star), R(6),
-  /*  130 E> */ B(LdrNamedProperty), R(6), U8(2), U8(5), R(7),
+  /*  113 S> */ B(Jump), U8(16),
+  /*  125 S> */ B(Nop),
+  /*  130 E> */ B(LdrNamedProperty), R(0), U8(2), U8(5), R(7),
                 B(LdaSmi), U8(20),
   /*  136 E> */ B(TestEqual), R(7),
                 B(JumpIfFalse), U8(4),
   /*  143 S> */ B(Jump), U8(8),
                 B(ForInStep), R(5),
                 B(Star), R(5),
-                B(Jump), U8(-63),
+                B(Jump), U8(-53),
                 B(LdaUndefined),
   /*  152 S> */ B(Return),
 ]
 constant pool: [
   InstanceType::FIXED_ARRAY_TYPE,
   InstanceType::FIXED_ARRAY_TYPE,
   InstanceType::ONE_BYTE_INTERNALIZED_STRING_TYPE,
 ]
 handlers: [
 ]
 
 ---
 snippet: "
   var x = [ 10, 11, 12 ] ;
   for (x[0] in [1,2,3]) { return x[3]; }
 "
 frame size: 9
 parameter count: 1
-bytecode array length: 69
+bytecode array length: 62
 bytecodes: [
   /*   30 E> */ B(StackCheck),
   /*   42 S> */ B(CreateArrayLiteral), U8(0), U8(0), U8(3),
                 B(Star), R(0),
   /*   72 S> */ B(CreateArrayLiteral), U8(1), U8(1), U8(3),
-                B(JumpIfUndefined), U8(56),
-                B(JumpIfNull), U8(54),
+                B(JumpIfUndefined), U8(49),
+                B(JumpIfNull), U8(47),
                 B(ToObject),
+                B(ForInPrepare), R(2),
                 B(Star), R(1),
-                B(ForInPrepare), R(2),
                 B(LdaZero),
                 B(Star), R(5),
   /*   65 S> */ B(ForInDone), R(5), R(4),
-                B(JumpIfTrue), U8(41),
+                B(JumpIfTrue), U8(34),
                 B(ForInNext), R(1), R(5), R(2), U8(7),
-                B(JumpIfUndefined), U8(28),
+                B(JumpIfUndefined), U8(21),
                 B(Star), R(6),
-  /*   64 E> */ B(Ldar), R(0),
-                B(Star), R(7),
-                B(LdaZero),
+  /*   64 E> */ B(LdaZero),
                 B(Star), R(8),
                 B(Ldar), R(6),
-                B(StaKeyedPropertySloppy), R(7), R(8), U8(5),
+                B(StaKeyedPropertySloppy), R(0), R(8), U8(5),
   /*   59 E> */ B(StackCheck),
-  /*   83 S> */ B(Ldar), R(0),
-                B(Star), R(6),
+  /*   83 S> */ B(Nop),
   /*   91 E> */ B(LdaSmi), U8(3),
-                B(LdaKeyedProperty), R(6), U8(3),
+                B(LdaKeyedProperty), R(0), U8(3),
   /*   98 S> */ B(Return),
                 B(ForInStep), R(5),
                 B(Star), R(5),
-                B(Jump), U8(-42),
+                B(Jump), U8(-35),
                 B(LdaUndefined),
   /*   98 S> */ B(Return),
 ]
 constant pool: [
   InstanceType::FIXED_ARRAY_TYPE,
   InstanceType::FIXED_ARRAY_TYPE,
 ]
 handlers: [
 ]