squiid/rust
1
0
Fork 0
Code Issues Pull requests Projects Activity

rt: Move to a custom alignof since __alignof__ returns the "preferred" alignment rather than the one that gets used in structs

Browse source
This commit is contained in:
Patrick Walton 2011-08-29 15:27:01 -07:00
parent b16a9a984a
commit 0a4d43379e
2 changed files with 30 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
src/rt/rust_shape.cpp
View file

@ -199,7 +199,7 @@ size_of::compute_tag_size(tag_info &tinfo) {
tinfo.tag_sa.set(1, 1);
} else {
// Add in space for the tag.
tinfo.tag_sa.add(sizeof(uint32_t), ALIGNOF(uint32_t));
tinfo.tag_sa.add(sizeof(uint32_t), alignof<uint32_t>());
}
}
@ -259,7 +259,7 @@ private:
}
inline void cmp_two_pointers(bool align) {
if (align) dp = align_to(dp, ALIGNOF(uint8_t *) * 2);
if (align) dp = align_to(dp, alignof<uint8_t *>() * 2);
data_pair<uint8_t *> fst = bump_dp<uint8_t *>(dp);
data_pair<uint8_t *> snd = bump_dp<uint8_t *>(dp);
cmp_number(fst);
@ -268,7 +268,7 @@ private:
}
inline void cmp_pointer(bool align) {
if (align) dp = align_to(dp, ALIGNOF(uint8_t *));
if (align) dp = align_to(dp, alignof<uint8_t *>());
cmp_number(bump_dp<uint8_t *>(dp));
}

36
src/rt/rust_shape.h
View file

@ -6,12 +6,6 @@
#include "rust_internal.h"
#ifdef _MSC_VER
#define ALIGNOF __alignof
#else
#define ALIGNOF __alignof__
#endif
#define ARENA_SIZE 256
#define DPRINT(fmt,...) fprintf(stderr, fmt, ##__VA_ARGS__)
@ -86,6 +80,30 @@ public:
};
// Alignment inquiries
//
// We can't directly use __alignof__ everywhere because that returns the
// preferred alignment of the type, which is different from the ABI-mandated
// alignment of the type in some cases (e.g. doubles on x86). The latter is
// what actually gets used for struct elements.
template<typename T>
inline size_t
alignof() {
#ifdef _MSC_VER
return __alignof(T);
#else
return __alignof__(T);
#endif
}
template<>
inline size_t
alignof<double>() {
return 4;
}
// Utility classes
struct size_align {
@ -546,7 +564,7 @@ public:
}
template<typename T>
void walk_number(bool align) { sa.set(sizeof(T), ALIGNOF(T)); }
void walk_number(bool align) { sa.set(sizeof(T), alignof<T>()); }
void compute_tag_size(tag_info &tinfo);
@ -709,7 +727,7 @@ namespace shape {
// for methods that actually manipulate the data involved.
#define DATA_SIMPLE(ty, call) \
if (align) dp = align_to(dp, sizeof(ty)); \
if (align) dp = align_to(dp, alignof<ty>()); \
U end_dp = dp + sizeof(ty); \
static_cast<T *>(this)->call; \
dp = end_dp;
@ -847,7 +865,7 @@ data<T,U>::walk_tag(bool align, tag_info &tinfo) {
size_of::compute_tag_size(*this, tinfo);
if (tinfo.variant_count > 1 && align)
dp = align_to(dp, ALIGNOF(uint32_t));
dp = align_to(dp, alignof<uint32_t>());
U end_dp = dp + tinfo.tag_sa.size;