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rust: Reworked the unwrap helpers by effectively hiding the crime of memcpy()'ing into a non-POD type from the compiler

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There is still the possibility that this can explode horribly, but the result should be the same codegen and fixes the warning

This also makes the helpers `inline` so they'll usually be compiled out for a nice speed boost
This commit is contained in:
dragonmux 2024-01-03 15:07:22 +00:00 committed by myrtle
parent cfeb588d32
commit 3e46fbc655
1 changed files with 24 additions and 21 deletions
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45
rust/rust.cc
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@ -16,6 +16,7 @@
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <array>
#include <numeric>
#include "log.h"
#include "nextpnr.h"
@ -33,28 +34,30 @@ namespace {
memcpy(&b, &thing, sizeof(T));
return b;
}
BelId unwrap_bel(uint64_t bel) {
static_assert(sizeof(BelId) <= 8, "T is too big for FFI");
auto b = BelId();
memcpy(&b, &bel, sizeof(BelId));
return b;
}
PipId unwrap_pip(uint64_t pip) {
static_assert(sizeof(PipId) <= 8, "T is too big for FFI");
auto p = PipId();
memcpy(&p, &pip, sizeof(PipId));
return p;
}
WireId unwrap_wire(uint64_t wire) {
static_assert(sizeof(WireId) <= 8, "T is too big for FFI");
auto w = WireId();
memcpy(&w, &wire, sizeof(WireId));
return w;
}
#pragma GCC diagnostic pop
template<typename T> static inline T unwrap(const std::array<uint8_t, 8> &value) noexcept {
static_assert(sizeof(T) <= 8, "T is too big for FFI");
T result{};
memcpy(&result, value.data(), sizeof(result));
return result;
}
template<typename T> static inline T unwrap(const uint64_t value) noexcept {
std::array<uint8_t, 8> data{};
static_assert(sizeof(value) >= data.size(), "uint64_t is not an appropriate size");
memcpy(data.data(), &value, data.size());
return unwrap<T>(data);
}
static inline BelId unwrap_bel(const uint64_t bel) noexcept
{ return unwrap<BelId>(bel); }
static inline PipId unwrap_pip(const uint64_t pip) noexcept
{ return unwrap<PipId>(pip); }
static inline WireId unwrap_wire(const uint64_t wire) noexcept
{ return unwrap<WireId>(wire); }
}
using DownhillIter = decltype(Context(ArchArgs()).getPipsDownhill(WireId()).begin());