Improve code generation for bounds checks.

src/x64/lithium-codegen-x64.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4122 matching lines @@
   ASSERT(ToRegister(instr->context()).is(rsi));
   ASSERT(ToRegister(instr->object()).is(rdx));
   ASSERT(ToRegister(instr->value()).is(rax));
 
   __ Move(rcx, instr->hydrogen()->name());
   Handle<Code> ic = StoreIC::initialize_stub(isolate(), instr->strict_mode());
   CallCode(ic, RelocInfo::CODE_TARGET, instr);
 }
 
 
-void LCodeGen::ApplyCheckIf(Condition cc, LBoundsCheck* check) {
-  if (FLAG_debug_code && check->hydrogen()->skip_check()) {
+void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
+  Representation representation = instr->hydrogen()->length()->representation();
+  ASSERT(representation.Equals(instr->hydrogen()->index()->representation()));
+  ASSERT(representation.IsSmiOrInteger32());
+
+  Condition cc = instr->hydrogen()->allow_equality() ? below : below_equal;
+  if (instr->length()->IsConstantOperand()) {
+    int32_t length = ToInteger32(LConstantOperand::cast(instr->length()));
+    Register index = ToRegister(instr->index());
+    if (representation.IsSmi()) {
+      __ Cmp(index, Smi::FromInt(length));
+    } else {
+      __ cmpl(index, Immediate(length));
+    }
+    cc = ReverseCondition(cc);
+  } else if (instr->index()->IsConstantOperand()) {
+    int32_t index = ToInteger32(LConstantOperand::cast(instr->index()));
+    if (instr->length()->IsRegister()) {
+      Register length = ToRegister(instr->length());
+      if (representation.IsSmi()) {
+        __ Cmp(length, Smi::FromInt(index));
+      } else {
+        __ cmpl(length, Immediate(index));
+      }
+    } else {
+      Operand length = ToOperand(instr->length());
+      if (representation.IsSmi()) {
+        __ Cmp(length, Smi::FromInt(index));
+      } else {
+        __ cmpl(length, Immediate(index));
+      }
+    }
+  } else {
+    Register index = ToRegister(instr->index());
+    if (instr->length()->IsRegister()) {
+      Register length = ToRegister(instr->length());
+      if (representation.IsSmi()) {
+        __ cmpp(length, index);
+      } else {
+        __ cmpl(length, index);
+      }
+    } else {
+      Operand length = ToOperand(instr->length());
+      if (representation.IsSmi()) {
+        __ cmpp(length, index);
+      } else {
+        __ cmpl(length, index);
+      }
+    }
+  }
+  if (FLAG_debug_code && instr->hydrogen()->skip_check()) {
     Label done;
     __ j(NegateCondition(cc), &done, Label::kNear);
     __ int3();
     __ bind(&done);
   } else {
-    DeoptimizeIf(cc, check->environment());
+    DeoptimizeIf(cc, instr->environment());
   }
 }
 
 
-void LCodeGen::DoBoundsCheck(LBoundsCheck* instr) {
-  HBoundsCheck* hinstr = instr->hydrogen();
-  if (hinstr->skip_check()) return;
-
-  Representation representation = hinstr->length()->representation();
-  ASSERT(representation.Equals(hinstr->index()->representation()));
-  ASSERT(representation.IsSmiOrInteger32());
-
-  if (instr->length()->IsRegister()) {
-    Register reg = ToRegister(instr->length());
-
-    if (instr->index()->IsConstantOperand()) {
-      int32_t constant_index =
-          ToInteger32(LConstantOperand::cast(instr->index()));
-      if (representation.IsSmi()) {
-        __ Cmp(reg, Smi::FromInt(constant_index));
-      } else {
-        __ cmpl(reg, Immediate(constant_index));
-      }
-    } else {
-      Register reg2 = ToRegister(instr->index());
-      if (representation.IsSmi()) {
-        __ cmpp(reg, reg2);
-      } else {
-        __ cmpl(reg, reg2);
-      }
-    }
-  } else {
-    Operand length = ToOperand(instr->length());
-    if (instr->index()->IsConstantOperand()) {
-      int32_t constant_index =
-          ToInteger32(LConstantOperand::cast(instr->index()));
-      if (representation.IsSmi()) {
-        __ Cmp(length, Smi::FromInt(constant_index));
-      } else {
-        __ cmpl(length, Immediate(constant_index));
-      }
-    } else {
-      if (representation.IsSmi()) {
-        __ cmpp(length, ToRegister(instr->index()));
-      } else {
-        __ cmpl(length, ToRegister(instr->index()));
-      }
-    }
-  }
-  Condition condition = hinstr->allow_equality() ? below : below_equal;
-  ApplyCheckIf(condition, instr);
-}
-
-
 void LCodeGen::DoStoreKeyedExternalArray(LStoreKeyed* instr) {
   ElementsKind elements_kind = instr->elements_kind();
   LOperand* key = instr->key();
   int base_offset = instr->is_fixed_typed_array()
     ? FixedTypedArrayBase::kDataOffset - kHeapObjectTag
     : 0;
   Operand operand(BuildFastArrayOperand(
       instr->elements(),
       key,
       elements_kind,
@@ skipping 1509 matching lines @@
   __ bind(deferred->exit());
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64