z3-z3-4.12.6.src.util.tptr.h Maven / Gradle / Ivy
/*++
Copyright (c) 2006 Microsoft Corporation
Module Name:
tptr.h
Abstract:
Support for tagged pointers and other low level pointer manipulation macros.
Author:
Leonardo de Moura (leonardo) 2006-09-13.
Revision History:
--*/
#pragma once
#include
#include "util/machine.h"
#include "util/debug.h"
#define TAG_SHIFT PTR_ALIGNMENT
#define ALIGNMENT_VALUE (1 << PTR_ALIGNMENT)
#define TAG_MASK (ALIGNMENT_VALUE - 1)
#define PTR_MASK (~TAG_MASK)
#define ALIGN(T, PTR) reinterpret_cast(((reinterpret_cast(PTR) >> PTR_ALIGNMENT) + \
static_cast((reinterpret_cast(PTR) & TAG_MASK) != 0)) << PTR_ALIGNMENT)
#define UNTAG(T, PTR) reinterpret_cast(reinterpret_cast(PTR) & PTR_MASK)
#define TAG(T, PTR, TAG_VAL) reinterpret_cast(reinterpret_cast(PTR) | static_cast(TAG_VAL))
#define GET_TAG(PTR) (reinterpret_cast(PTR) & TAG_MASK)
#define BOXINT(T, VAL) reinterpret_cast(static_cast(VAL) << PTR_ALIGNMENT)
#define BOXTAGINT(T, VAL, TAG_VAL) reinterpret_cast((static_cast(VAL) << PTR_ALIGNMENT) | static_cast(TAG_VAL))
#define UNBOXINT(PTR) static_cast(reinterpret_cast(PTR) >> PTR_ALIGNMENT)
template
U unbox(T* ptr) {
return static_cast(reinterpret_cast(ptr) >> PTR_ALIGNMENT);
}
template
unsigned get_tag(T* ptr) {
return reinterpret_cast(ptr) & TAG_MASK;
}
template
T* box(U val, std::uintptr_t tag = 0) {
static_assert( sizeof(T*) >= sizeof(U) + PTR_ALIGNMENT );
SASSERT_EQ(tag & PTR_MASK, 0);
T* ptr = reinterpret_cast((static_cast(val) << PTR_ALIGNMENT) | tag);
SASSERT_EQ(val, unbox(ptr)); // roundtrip of conversion integer -> pointer -> integer is not actually guaranteed by the C++ standard (but seems fine in practice, as indicated by previous usage of BOXINT/UNBOXINT)
SASSERT_EQ(tag, get_tag(ptr));
return ptr;
}