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Bug 1409295 part 5 - Use memcpy on little endian platforms. r=luke

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--HG--
extra : rebase_source : 2e2bd1267a7d84d8458d6ec7cafef795ee5b6295
This commit is contained in:
Jan de Mooij 2017-10-19 13:53:30 +01:00
parent 890dd39ca8
commit 228ba6907b
1 changed files with 36 additions and 2 deletions
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38
js/src/jsopcode.h
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@ -12,6 +12,7 @@
*/
#include "mozilla/Attributes.h"
#include "mozilla/EndianUtils.h"
#include "jsbytecode.h"
#include "jstypes.h"
@ -136,14 +137,24 @@ UINT16_LO(uint16_t i)
static MOZ_ALWAYS_INLINE uint16_t
GET_UINT16(const jsbytecode* pc)
{
#if MOZ_LITTLE_ENDIAN
uint16_t result;
memcpy(&result, pc + 1, sizeof(result));
return result;
#else
return uint16_t((pc[2] << 8) | pc[1]);
#endif
}
static MOZ_ALWAYS_INLINE void
SET_UINT16(jsbytecode* pc, uint16_t i)
{
#if MOZ_LITTLE_ENDIAN
memcpy(pc + 1, &i, sizeof(i));
#else
pc[1] = UINT16_LO(i);
pc[2] = UINT16_HI(i);
#endif
}
static const unsigned UINT16_LIMIT = 1 << 16;
@ -153,19 +164,32 @@ static const unsigned JUMP_OFFSET_LEN = 4;
static const int32_t JUMP_OFFSET_MIN = INT32_MIN;
static const int32_t JUMP_OFFSET_MAX = INT32_MAX;
static MOZ_ALWAYS_INLINE unsigned
static MOZ_ALWAYS_INLINE uint32_t
GET_UINT24(const jsbytecode* pc)
{
#if MOZ_LITTLE_ENDIAN
// Do a single 32-bit load (for opcode and operand), then shift off the
// opcode.
uint32_t result;
memcpy(&result, pc, 4);
return result >> 8;
#else
return unsigned((pc[3] << 16) | (pc[2] << 8) | pc[1]);
#endif
}
static MOZ_ALWAYS_INLINE void
SET_UINT24(jsbytecode* pc, unsigned i)
SET_UINT24(jsbytecode* pc, uint32_t i)
{
MOZ_ASSERT(i < (1 << 24));
#if MOZ_LITTLE_ENDIAN
memcpy(pc + 1, &i, 3);
#else
pc[1] = jsbytecode(i);
pc[2] = jsbytecode(i >> 8);
pc[3] = jsbytecode(i >> 16);
#endif
}
static MOZ_ALWAYS_INLINE int8_t
@ -177,19 +201,29 @@ GET_INT8(const jsbytecode* pc)
static MOZ_ALWAYS_INLINE uint32_t
GET_UINT32(const jsbytecode* pc)
{
#if MOZ_LITTLE_ENDIAN
uint32_t result;
memcpy(&result, pc + 1, sizeof(result));
return result;
#else
return (uint32_t(pc[4]) << 24) |
(uint32_t(pc[3]) << 16) |
(uint32_t(pc[2]) << 8) |
uint32_t(pc[1]);
#endif
}
static MOZ_ALWAYS_INLINE void
SET_UINT32(jsbytecode* pc, uint32_t u)
{
#if MOZ_LITTLE_ENDIAN
memcpy(pc + 1, &u, sizeof(u));
#else
pc[1] = jsbytecode(u);
pc[2] = jsbytecode(u >> 8);
pc[3] = jsbytecode(u >> 16);
pc[4] = jsbytecode(u >> 24);
#endif
}
static MOZ_ALWAYS_INLINE int32_t