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Bug 1304191 - Part 11: Fold jsval_layout into JS::Value. r=jwalden

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This commit is contained in:
Tooru Fujisawa 2016-10-18 16:46:01 +09:00
parent 934d8428a6
commit 4777efc768
1 changed files with 95 additions and 122 deletions
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217
js/public/Value.h
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@ -33,7 +33,7 @@ namespace JS { class Value; }
# define JSVAL_TAG_SHIFT 47
#endif
// Use enums so that printing a jsval_layout in the debugger shows nice
// Use enums so that printing a JS::Value in the debugger shows nice
// symbolic type tags.
#if defined(_MSC_VER)
@ -219,104 +219,6 @@ typedef enum JSWhyMagic
JS_WHY_MAGIC_COUNT
} JSWhyMagic;
#if MOZ_LITTLE_ENDIAN
# if defined(JS_NUNBOX32)
union MOZ_NON_PARAM alignas(8) jsval_layout
{
uint64_t asBits;
struct {
union {
int32_t i32;
uint32_t u32;
uint32_t boo; // Don't use |bool| -- it must be four bytes.
JSString* str;
JS::Symbol* sym;
JSObject* obj;
js::gc::Cell* cell;
void* ptr;
JSWhyMagic why;
size_t word;
uintptr_t uintptr;
} payload;
JSValueTag tag;
} s;
double asDouble;
void* asPtr;
};
# elif defined(JS_PUNBOX64)
union MOZ_NON_PARAM alignas(8) jsval_layout
{
uint64_t asBits;
#if !defined(_WIN64)
/* MSVC does not pack these correctly :-( */
struct {
uint64_t payload47 : 47;
JSValueTag tag : 17;
} debugView;
#endif
struct {
union {
int32_t i32;
uint32_t u32;
JSWhyMagic why;
} payload;
} s;
double asDouble;
void* asPtr;
size_t asWord;
uintptr_t asUIntPtr;
};
# endif /* JS_PUNBOX64 */
#else /* MOZ_LITTLE_ENDIAN */
# if defined(JS_NUNBOX32)
union MOZ_NON_PARAM alignas(8) jsval_layout
{
uint64_t asBits;
struct {
JSValueTag tag;
union {
int32_t i32;
uint32_t u32;
uint32_t boo; // Don't use |bool| -- it must be four bytes.
JSString* str;
JS::Symbol* sym;
JSObject* obj;
js::gc::Cell* cell;
void* ptr;
JSWhyMagic why;
size_t word;
uintptr_t uintptr;
} payload;
} s;
double asDouble;
void* asPtr;
};
# elif defined(JS_PUNBOX64)
union MOZ_NON_PARAM alignas(8) jsval_layout
{
uint64_t asBits;
struct {
JSValueTag tag : 17;
uint64_t payload47 : 47;
} debugView;
struct {
uint32_t padding;
union {
int32_t i32;
uint32_t u32;
JSWhyMagic why;
} payload;
} s;
double asDouble;
void* asPtr;
size_t asWord;
uintptr_t asUIntPtr;
};
# endif /* JS_PUNBOX64 */
#endif /* MOZ_LITTLE_ENDIAN */
JS_STATIC_ASSERT(sizeof(jsval_layout) == 8);
/*
* For codesize purposes on some platforms, it's important that the
* compiler know that JS::Values constructed from constant values can be
@ -417,7 +319,7 @@ CanonicalizeNaN(double d)
* 32-bit user code should avoid copying jsval/JS::Value as much as possible,
* preferring to pass by const Value&.
*/
class Value
class MOZ_NON_PARAM alignas(8) Value
{
public:
#if defined(JS_NUNBOX32)
@ -936,7 +838,97 @@ class Value
private:
#endif
jsval_layout data;
#if MOZ_LITTLE_ENDIAN
# if defined(JS_NUNBOX32)
union {
uint64_t asBits;
struct {
union {
int32_t i32;
uint32_t u32;
uint32_t boo; // Don't use |bool| -- it must be four bytes.
JSString* str;
JS::Symbol* sym;
JSObject* obj;
js::gc::Cell* cell;
void* ptr;
JSWhyMagic why;
size_t word;
uintptr_t uintptr;
} payload;
JSValueTag tag;
} s;
double asDouble;
void* asPtr;
} data;
# elif defined(JS_PUNBOX64)
union {
uint64_t asBits;
#if !defined(_WIN64)
/* MSVC does not pack these correctly :-( */
struct {
uint64_t payload47 : 47;
JSValueTag tag : 17;
} debugView;
#endif
struct {
union {
int32_t i32;
uint32_t u32;
JSWhyMagic why;
} payload;
} s;
double asDouble;
void* asPtr;
size_t asWord;
uintptr_t asUIntPtr;
} data;
# endif /* JS_PUNBOX64 */
#else /* MOZ_LITTLE_ENDIAN */
# if defined(JS_NUNBOX32)
union {
uint64_t asBits;
struct {
JSValueTag tag;
union {
int32_t i32;
uint32_t u32;
uint32_t boo; // Don't use |bool| -- it must be four bytes.
JSString* str;
JS::Symbol* sym;
JSObject* obj;
js::gc::Cell* cell;
void* ptr;
JSWhyMagic why;
size_t word;
uintptr_t uintptr;
} payload;
} s;
double asDouble;
void* asPtr;
} data;
# elif defined(JS_PUNBOX64)
union {
uint64_t asBits;
struct {
JSValueTag tag : 17;
uint64_t payload47 : 47;
} debugView;
struct {
uint32_t padding;
union {
int32_t i32;
uint32_t u32;
JSWhyMagic why;
} payload;
} s;
double asDouble;
void* asPtr;
size_t asWord;
uintptr_t asUIntPtr;
} data;
# endif /* JS_PUNBOX64 */
#endif /* MOZ_LITTLE_ENDIAN */
private:
#if defined(JS_VALUE_IS_CONSTEXPR)
@ -998,6 +990,8 @@ class Value
}
} JS_HAZ_GC_POINTER;
static_assert(sizeof(Value) == 8, "Value size must leave three tag bits, be a binary power, and is ubiquitously depended upon everywhere");
inline bool
IsOptimizedPlaceholderMagicValue(const Value& v)
{
@ -1515,27 +1509,6 @@ template <class S, bool v> struct BoolDefaultAdaptor { static bool defaultValue(
} // namespace js
namespace JS {
#ifdef JS_DEBUG
namespace detail {
struct ValueAlignmentTester { char c; JS::Value v; };
static_assert(sizeof(ValueAlignmentTester) == 16,
"JS::Value must be 16-byte-aligned");
struct LayoutAlignmentTester { char c; jsval_layout l; };
static_assert(sizeof(LayoutAlignmentTester) == 16,
"jsval_layout must be 16-byte-aligned");
} // namespace detail
#endif /* JS_DEBUG */
} // namespace JS
static_assert(sizeof(jsval_layout) == sizeof(JS::Value),
"jsval_layout and JS::Value must have identical layouts");
/************************************************************************/
namespace JS {