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[shims] Move bit masks to SwiftShims and include/swift/ABI. #12306

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Merged
merged 2 commits into from
Oct 6, 2017
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[shims] Move bit masks to SwiftShims and include/swift/ABI. #12306

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3d04fb5
[shims] Move bit masks to SwiftShims and include/swift/ABI.
milseman Oct 4, 2017
87a84d8
[stubs] Prefer __swift_uintptr_t over uintptr_t. NFC
milseman Oct 6, 2017
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127 changes: 4 additions & 123 deletions include/swift/ABI/System.h
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Original file line number Diff line number Diff line change
Expand Up @@ -14,128 +14,9 @@
//
//===----------------------------------------------------------------------===//

#ifndef SWIFT_ABI_SYSTEM_H
#define SWIFT_ABI_SYSTEM_H
#ifndef __SWIFT_ABI_SYSTEM_H__
#define __SWIFT_ABI_SYSTEM_H__

// In general, these macros are expected to expand to host-independent
// integer constant expressions. This allows the same data to feed
// both the compiler and runtime implementation.
#include "../../../stdlib/public/SwiftShims/System.h"

/******************************* Default Rules ********************************/

/// The least valid pointer value for an actual pointer (as opposed to
/// Objective-C pointers, which may be tagged pointers and are covered
/// separately). Values up to this are "extra inhabitants" of the
/// pointer representation, and payloaded enum types can take
/// advantage of that as they see fit.
///
/// By default, we assume that there's at least an unmapped page at
/// the bottom of the address space. 4K is a reasonably likely page
/// size.
///
/// The minimum possible value for this macro is 1; we always assume
/// that the null representation is available.
#define SWIFT_ABI_DEFAULT_LEAST_VALID_POINTER 4096

/// The bitmask of spare bits in a function pointer.
#define SWIFT_ABI_DEFAULT_FUNCTION_SPARE_BITS_MASK 0

/// The bitmask of spare bits in a Swift heap object pointer. A Swift
/// heap object allocation will never set any of these bits.
#define SWIFT_ABI_DEFAULT_SWIFT_SPARE_BITS_MASK 0

/// The bitmask of reserved bits in an Objective-C object pointer.
/// By default we assume the ObjC runtime doesn't use tagged pointers.
#define SWIFT_ABI_DEFAULT_OBJC_RESERVED_BITS_MASK 0

/// The number of low bits in an Objective-C object pointer that
/// are reserved by the Objective-C runtime.
#define SWIFT_ABI_DEFAULT_OBJC_NUM_RESERVED_LOW_BITS 0

/// The ObjC runtime will not use pointer values for which
/// ``pointer & SWIFT_ABI_XXX_OBJC_RESERVED_BITS_MASK == 0 &&
/// pointer & SWIFT_ABI_XXX_SWIFT_SPARE_BITS_MASK != 0``.

// Weak references use a marker to tell when they are controlled by
// the ObjC runtime and when they are controlled by the Swift runtime.
// Non-ObjC platforms don't use this marker.
#define SWIFT_ABI_DEFAULT_OBJC_WEAK_REFERENCE_MARKER_MASK 0
#define SWIFT_ABI_DEFAULT_OBJC_WEAK_REFERENCE_MARKER_VALUE 0

/*********************************** i386 *************************************/

// Heap objects are pointer-aligned, so the low two bits are unused.
#define SWIFT_ABI_I386_SWIFT_SPARE_BITS_MASK 0x00000003U

// ObjC weak reference discriminator is the LSB.
#define SWIFT_ABI_I386_OBJC_WEAK_REFERENCE_MARKER_MASK \
(SWIFT_ABI_DEFAULT_OBJC_RESERVED_BITS_MASK | \
1<<SWIFT_ABI_DEFAULT_OBJC_NUM_RESERVED_LOW_BITS)
#define SWIFT_ABI_I386_OBJC_WEAK_REFERENCE_MARKER_VALUE \
(1<<SWIFT_ABI_DEFAULT_OBJC_NUM_RESERVED_LOW_BITS)

/*********************************** arm **************************************/

// Heap objects are pointer-aligned, so the low two bits are unused.
#define SWIFT_ABI_ARM_SWIFT_SPARE_BITS_MASK 0x00000003U

// ObjC weak reference discriminator is the LSB.
#define SWIFT_ABI_ARM_OBJC_WEAK_REFERENCE_MARKER_MASK \
(SWIFT_ABI_DEFAULT_OBJC_RESERVED_BITS_MASK | \
1<<SWIFT_ABI_DEFAULT_OBJC_NUM_RESERVED_LOW_BITS)
#define SWIFT_ABI_ARM_OBJC_WEAK_REFERENCE_MARKER_VALUE \
(1<<SWIFT_ABI_DEFAULT_OBJC_NUM_RESERVED_LOW_BITS)

/*********************************** x86-64 ***********************************/

/// Darwin reserves the low 4GB of address space.
#define SWIFT_ABI_DARWIN_X86_64_LEAST_VALID_POINTER (4ULL*1024*1024*1024)

// Only the bottom 56 bits are used, and heap objects are eight-byte-aligned.
#define SWIFT_ABI_X86_64_SWIFT_SPARE_BITS_MASK 0xFF00000000000007ULL

// Objective-C reserves the high and low bits for tagged pointers.
// Systems exist which use either bit.
#define SWIFT_ABI_X86_64_OBJC_RESERVED_BITS_MASK 0x8000000000000001ULL
#define SWIFT_ABI_X86_64_OBJC_NUM_RESERVED_LOW_BITS 1

// ObjC weak reference discriminator is the two bits
// reserved for ObjC tagged pointers plus one more low bit.
#define SWIFT_ABI_X86_64_OBJC_WEAK_REFERENCE_MARKER_MASK \
(SWIFT_ABI_X86_64_OBJC_RESERVED_BITS_MASK | \
1<<SWIFT_ABI_X86_64_OBJC_NUM_RESERVED_LOW_BITS)
#define SWIFT_ABI_X86_64_OBJC_WEAK_REFERENCE_MARKER_VALUE \
(1<<SWIFT_ABI_X86_64_OBJC_NUM_RESERVED_LOW_BITS)

/*********************************** arm64 ************************************/

/// Darwin reserves the low 4GB of address space.
#define SWIFT_ABI_DARWIN_ARM64_LEAST_VALID_POINTER (4ULL*1024*1024*1024)

// TBI guarantees the top byte of pointers is unused.
// Heap objects are eight-byte aligned.
#define SWIFT_ABI_ARM64_SWIFT_SPARE_BITS_MASK 0xFF00000000000007ULL

// Objective-C reserves just the high bit for tagged pointers.
#define SWIFT_ABI_ARM64_OBJC_RESERVED_BITS_MASK 0x8000000000000000ULL
#define SWIFT_ABI_ARM64_OBJC_NUM_RESERVED_LOW_BITS 0

// ObjC weak reference discriminator is the high bit
// reserved for ObjC tagged pointers plus the LSB.
#define SWIFT_ABI_ARM64_OBJC_WEAK_REFERENCE_MARKER_MASK \
(SWIFT_ABI_ARM64_OBJC_RESERVED_BITS_MASK | \
1<<SWIFT_ABI_ARM64_OBJC_NUM_RESERVED_LOW_BITS)
#define SWIFT_ABI_ARM64_OBJC_WEAK_REFERENCE_MARKER_VALUE \
(1<<SWIFT_ABI_ARM64_OBJC_NUM_RESERVED_LOW_BITS)

/*********************************** powerpc64 ********************************/

// Heap objects are pointer-aligned, so the low three bits are unused.
#define SWIFT_ABI_POWERPC64_SWIFT_SPARE_BITS_MASK 0x0000000000000007ULL

/*********************************** s390x ************************************/

// Top byte of pointers is unused, and heap objects are eight-byte aligned.
#define SWIFT_ABI_S390X_SWIFT_SPARE_BITS_MASK 0x0000000000000007ULL

#endif /* SWIFT_ABI_SYSTEM_H */
#endif // __SWIFT_ABI_SYSTEM_H__
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Missing newline at end of file

80 changes: 0 additions & 80 deletions include/swift/Runtime/Metadata.h
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Original file line number Diff line number Diff line change
Expand Up @@ -719,87 +719,7 @@ namespace {
using type = R;
};
}

namespace heap_object_abi {

// The extra inhabitants and spare bits of heap object pointers.
// These must align with the values in IRGen's SwiftTargetInfo.cpp.
#if defined(__x86_64__)

# ifdef __APPLE__
static const uintptr_t LeastValidPointerValue =
SWIFT_ABI_DARWIN_X86_64_LEAST_VALID_POINTER;
# else
static const uintptr_t LeastValidPointerValue =
SWIFT_ABI_DEFAULT_LEAST_VALID_POINTER;
# endif
static const uintptr_t SwiftSpareBitsMask =
SWIFT_ABI_X86_64_SWIFT_SPARE_BITS_MASK;
static const uintptr_t ObjCReservedBitsMask =
SWIFT_ABI_X86_64_OBJC_RESERVED_BITS_MASK;
static const unsigned ObjCReservedLowBits =
SWIFT_ABI_X86_64_OBJC_NUM_RESERVED_LOW_BITS;

#elif defined(__arm64__)

# ifdef __APPLE__
static const uintptr_t LeastValidPointerValue =
SWIFT_ABI_DARWIN_ARM64_LEAST_VALID_POINTER;
# else
static const uintptr_t LeastValidPointerValue =
SWIFT_ABI_DEFAULT_LEAST_VALID_POINTER;
# endif
static const uintptr_t SwiftSpareBitsMask =
SWIFT_ABI_ARM64_SWIFT_SPARE_BITS_MASK;
static const uintptr_t ObjCReservedBitsMask =
SWIFT_ABI_ARM64_OBJC_RESERVED_BITS_MASK;
static const unsigned ObjCReservedLowBits =
SWIFT_ABI_ARM64_OBJC_NUM_RESERVED_LOW_BITS;

#elif defined(__powerpc64__)

static const uintptr_t LeastValidPointerValue =
SWIFT_ABI_DEFAULT_LEAST_VALID_POINTER;
static const uintptr_t SwiftSpareBitsMask =
SWIFT_ABI_POWERPC64_SWIFT_SPARE_BITS_MASK;
static const uintptr_t ObjCReservedBitsMask =
SWIFT_ABI_DEFAULT_OBJC_RESERVED_BITS_MASK;
static const unsigned ObjCReservedLowBits =
SWIFT_ABI_DEFAULT_OBJC_NUM_RESERVED_LOW_BITS;

#elif defined(__s390x__)

static const uintptr_t LeastValidPointerValue =
SWIFT_ABI_DEFAULT_LEAST_VALID_POINTER;
static const uintptr_t SwiftSpareBitsMask =
SWIFT_ABI_S390X_SWIFT_SPARE_BITS_MASK;
static const uintptr_t ObjCReservedBitsMask =
SWIFT_ABI_DEFAULT_OBJC_RESERVED_BITS_MASK;
static const unsigned ObjCReservedLowBits =
SWIFT_ABI_DEFAULT_OBJC_NUM_RESERVED_LOW_BITS;

#else

static const uintptr_t LeastValidPointerValue =
SWIFT_ABI_DEFAULT_LEAST_VALID_POINTER;
static const uintptr_t SwiftSpareBitsMask =
# if __i386__
SWIFT_ABI_I386_SWIFT_SPARE_BITS_MASK
# elif __arm__
SWIFT_ABI_ARM_SWIFT_SPARE_BITS_MASK
# else
SWIFT_ABI_DEFAULT_SWIFT_SPARE_BITS_MASK
# endif
;
static const uintptr_t ObjCReservedBitsMask =
SWIFT_ABI_DEFAULT_OBJC_RESERVED_BITS_MASK;
static const unsigned ObjCReservedLowBits =
SWIFT_ABI_DEFAULT_OBJC_NUM_RESERVED_LOW_BITS;

#endif

}

template <typename Runtime> struct TargetNominalTypeDescriptor;
template <typename Runtime> struct TargetGenericMetadata;
template <typename Runtime> struct TargetClassMetadata;
Expand Down
1 change: 1 addition & 0 deletions stdlib/public/SwiftShims/CMakeLists.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,7 @@ set(sources
SwiftStdbool.h
SwiftStddef.h
SwiftStdint.h
System.h
UnicodeShims.h
Visibility.h

Expand Down
104 changes: 103 additions & 1 deletion stdlib/public/SwiftShims/HeapObject.h
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Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@
#define SWIFT_STDLIB_SHIMS_HEAPOBJECT_H

#include "RefCount.h"
#include "System.h"

#define SWIFT_ABI_HEAP_OBJECT_HEADER_SIZE_64 16
// TODO: Should be 8
Expand Down Expand Up @@ -53,7 +54,7 @@ struct HeapObject {
: metadata(newMetadata)
, refCounts(InlineRefCounts::Initialized)
{ }
#endif
#endif // __cplusplus
};

#ifdef __cplusplus
Expand Down Expand Up @@ -88,6 +89,107 @@ static_assert(alignof(HeapObject) == alignof(void*),
"HeapObject must be pointer-aligned");

} // end namespace swift
#endif // __cplusplus

/// Global bit masks

// TODO(<rdar://problem/34837179>): Convert each macro below to static consts
// when static consts are visible to SIL.

// The extra inhabitants and spare bits of heap object pointers.
// These must align with the values in IRGen's SwiftTargetInfo.cpp.
#if defined(__x86_64__)

#ifdef __APPLE__
#define _swift_abi_LeastValidPointerValue \
(__swift_uintptr_t) SWIFT_ABI_DARWIN_X86_64_LEAST_VALID_POINTER
#else
#define _swift_abi_LeastValidPointerValue \
(__swift_uintptr_t) SWIFT_ABI_DEFAULT_LEAST_VALID_POINTER
#endif
#define _swift_abi_SwiftSpareBitsMask \
(__swift_uintptr_t) SWIFT_ABI_X86_64_SWIFT_SPARE_BITS_MASK
#define _swift_abi_ObjCReservedBitsMask \
(__swift_uintptr_t) SWIFT_ABI_X86_64_OBJC_RESERVED_BITS_MASK
#define _swift_abi_ObjCReservedLowBits \
(unsigned) SWIFT_ABI_X86_64_OBJC_NUM_RESERVED_LOW_BITS

#elif defined(__arm64__)

#ifdef __APPLE__
#define _swift_abi_LeastValidPointerValue \
(__swift_uintptr_t) SWIFT_ABI_DARWIN_ARM64_LEAST_VALID_POINTER
#else
#define _swift_abi_LeastValidPointerValue \
(__swift_uintptr_t) SWIFT_ABI_DEFAULT_LEAST_VALID_POINTER
#endif
#define _swift_abi_SwiftSpareBitsMask \
(__swift_uintptr_t) SWIFT_ABI_ARM64_SWIFT_SPARE_BITS_MASK
#define _swift_abi_ObjCReservedBitsMask \
(__swift_uintptr_t) SWIFT_ABI_ARM64_OBJC_RESERVED_BITS_MASK
#define _swift_abi_ObjCReservedLowBits \
(unsigned) SWIFT_ABI_ARM64_OBJC_NUM_RESERVED_LOW_BITS

#elif defined(__powerpc64__)

#define _swift_abi_LeastValidPointerValue \
(__swift_uintptr_t) SWIFT_ABI_DEFAULT_LEAST_VALID_POINTER
#define _swift_abi_SwiftSpareBitsMask \
(__swift_uintptr_t) SWIFT_ABI_POWERPC64_SWIFT_SPARE_BITS_MASK
#define _swift_abi_ObjCReservedBitsMask \
(__swift_uintptr_t) SWIFT_ABI_DEFAULT_OBJC_RESERVED_BITS_MASK
#define _swift_abi_ObjCReservedLowBits \
(unsigned) SWIFT_ABI_DEFAULT_OBJC_NUM_RESERVED_LOW_BITS

#elif defined(__s390x__)

#define _swift_abi_LeastValidPointerValue \
(__swift_uintptr_t) SWIFT_ABI_DEFAULT_LEAST_VALID_POINTER
#define _swift_abi_SwiftSpareBitsMask \
(__swift_uintptr_t) SWIFT_ABI_S390X_SWIFT_SPARE_BITS_MASK
#define _swift_abi_ObjCReservedBitsMask \
(__swift_uintptr_t) SWIFT_ABI_DEFAULT_OBJC_RESERVED_BITS_MASK
#define _swift_abi_ObjCReservedLowBits \
(unsigned) SWIFT_ABI_DEFAULT_OBJC_NUM_RESERVED_LOW_BITS

#else

#define _swift_abi_LeastValidPointerValue \
(__swift_uintptr_t) SWIFT_ABI_DEFAULT_LEAST_VALID_POINTER

#if __i386__
#define _swift_abi_SwiftSpareBitsMask \
(__swift_uintptr_t) SWIFT_ABI_I386_SWIFT_SPARE_BITS_MASK
#elif __arm__
#define _swift_abi_SwiftSpareBitsMask \
(__swift_uintptr_t) SWIFT_ABI_ARM_SWIFT_SPARE_BITS_MASK
#else
#define _swift_abi_SwiftSpareBitsMask \
(__swift_uintptr_t) SWIFT_ABI_DEFAULT_SWIFT_SPARE_BITS_MASK
#endif

#define _swift_abi_ObjCReservedBitsMask \
(__swift_uintptr_t) SWIFT_ABI_DEFAULT_OBJC_RESERVED_BITS_MASK
#define _swift_abi_ObjCReservedLowBits \
(unsigned) SWIFT_ABI_DEFAULT_OBJC_NUM_RESERVED_LOW_BITS
#endif

/// Corresponding namespaced decls
#ifdef __cplusplus
namespace heap_object_abi {
static const __swift_uintptr_t LeastValidPointerValue =
_swift_abi_LeastValidPointerValue;
static const __swift_uintptr_t SwiftSpareBitsMask =
_swift_abi_SwiftSpareBitsMask;
static const __swift_uintptr_t ObjCReservedBitsMask =
_swift_abi_ObjCReservedBitsMask;
static const unsigned ObjCReservedLowBits = _swift_abi_ObjCReservedLowBits;
} // heap_object_abi
#endif // __cplusplus

/// BridgeObject masks

#define _swift_BridgeObject_TaggedPointerBits _swift_abi_ObjCReservedBitsMask


#endif // SWIFT_STDLIB_SHIMS_HEAPOBJECT_H
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