Reviewers: Jarin,
Description:
[strong] Simplify (and sortof optimize) string addition for strong mode.
In strong mode, whenever either operand to an addition is a string, both
must be strings, so we can just use a simple string map check instead of
the STRING_ADD_LEFT / STRING_ADD_RIGHT machinery, which tries to do sloppy
and strict mode conversions before giving up.
[email protected]
Please review this at https://codereview.chromium.org/1287203002/
Base URL: https://chromium.googlesource.com/v8/v8.git@master
Affected files (+24, -40 lines):
M src/builtins.h
M src/hydrogen.cc
M src/runtime.js
Index: src/builtins.h
diff --git a/src/builtins.h b/src/builtins.h
index
212ad89e4fea882975a5ddfad2cc828d86c2d6eb..8ced3e3b93b71b6c3f4acd186a1f96252ae88ef5
100644
--- a/src/builtins.h
+++ b/src/builtins.h
@@ -186,9 +186,7 @@ enum BuiltinExtraArguments {
V(TO_STRING, 0) \
V(TO_NAME, 0) \
V(STRING_ADD_LEFT, 1) \
- V(STRING_ADD_LEFT_STRONG, 1) \
V(STRING_ADD_RIGHT, 1) \
- V(STRING_ADD_RIGHT_STRONG, 1) \
V(APPLY_PREPARE, 1) \
V(REFLECT_APPLY_PREPARE, 1) \
V(REFLECT_CONSTRUCT_PREPARE, 2) \
Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index
559eca6e5847eb8d3503a1f2426a74e60d5c8026..9354266d768c656bfe5db0e1acb89d9cb5aedd04
100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -10914,29 +10914,35 @@ HValue* HGraphBuilder::BuildBinaryOperation(
}
// Convert left argument as necessary.
- if (left_type->Is(Type::Number()) && !is_strong(strength)) {
+ if (!left_type->Is(Type::String())) {
DCHECK(right_type->Is(Type::String()));
- left = BuildNumberToString(left, left_type);
- } else if (!left_type->Is(Type::String())) {
- DCHECK(right_type->Is(Type::String()));
- HValue* function = AddLoadJSBuiltin(
- is_strong(strength) ? Builtins::STRING_ADD_RIGHT_STRONG
- : Builtins::STRING_ADD_RIGHT);
- Add<HPushArguments>(left, right);
- return AddUncasted<HInvokeFunction>(function, 2);
+ if (is_strong(strength)) {
+ // In strong mode, if the left hand side of an additition is a
string,
+ // the right hand side must be a string too.
+ left = BuildCheckString(left);
+ } else if (left_type->Is(Type::Number())) {
+ left = BuildNumberToString(left, left_type);
+ } else {
+ HValue* function = AddLoadJSBuiltin(Builtins::STRING_ADD_RIGHT);
+ Add<HPushArguments>(left, right);
+ return AddUncasted<HInvokeFunction>(function, 2);
+ }
}
// Convert right argument as necessary.
- if (right_type->Is(Type::Number()) && !is_strong(strength)) {
+ if (!right_type->Is(Type::String())) {
DCHECK(left_type->Is(Type::String()));
- right = BuildNumberToString(right, right_type);
- } else if (!right_type->Is(Type::String())) {
- DCHECK(left_type->Is(Type::String()));
- HValue* function = AddLoadJSBuiltin(is_strong(strength)
- ?
Builtins::STRING_ADD_LEFT_STRONG
- : Builtins::STRING_ADD_LEFT);
- Add<HPushArguments>(left, right);
- return AddUncasted<HInvokeFunction>(function, 2);
+ if (is_strong(strength)) {
+ // In strong mode, if the right hand side of an additition is a
string,
+ // the left hand side must be a string too.
+ right = BuildCheckString(right);
+ } else if (right_type->Is(Type::Number())) {
+ right = BuildNumberToString(right, right_type);
+ } else {
+ HValue* function = AddLoadJSBuiltin(Builtins::STRING_ADD_LEFT);
+ Add<HPushArguments>(left, right);
+ return AddUncasted<HInvokeFunction>(function, 2);
+ }
}
// Fast paths for empty constant strings.
Index: src/runtime.js
diff --git a/src/runtime.js b/src/runtime.js
index
a120d9648c494b1d586393a10d053912e09bd2d3..e82d25e3295c745af5ee701e1166f9fdc5935aea
100644
--- a/src/runtime.js
+++ b/src/runtime.js
@@ -23,9 +23,7 @@ var COMPARE_STRONG;
var ADD;
var ADD_STRONG;
var STRING_ADD_LEFT;
-var STRING_ADD_LEFT_STRONG;
var STRING_ADD_RIGHT;
-var STRING_ADD_RIGHT_STRONG;
var SUB;
var SUB_STRONG;
var MUL;
@@ -262,15 +260,6 @@ STRING_ADD_LEFT = function STRING_ADD_LEFT(y) {
}
-// Left operand (this) is already a string.
-STRING_ADD_LEFT_STRONG = function STRING_ADD_LEFT_STRONG(y) {
- if (IS_STRING(y)) {
- return %_StringAdd(this, y);
- }
- throw %MakeTypeError(kStrongImplicitConversion);
-}
-
-
// Right operand (y) is already a string.
STRING_ADD_RIGHT = function STRING_ADD_RIGHT(y) {
var x = this;
@@ -287,15 +276,6 @@ STRING_ADD_RIGHT = function STRING_ADD_RIGHT(y) {
}
-// Right operand (y) is already a string.
-STRING_ADD_RIGHT_STRONG = function STRING_ADD_RIGHT_STRONG(y) {
- if (IS_STRING(this)) {
- return %_StringAdd(this, y);
- }
- throw %MakeTypeError(kStrongImplicitConversion);
-}
-
-
// ECMA-262, section 11.6.2, page 50.
SUB = function SUB(y) {
var x = IS_NUMBER(this) ? this : %$nonNumberToNumber(this);
--
--
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