mirror of
https://github.com/ziglang/zig.git
synced 2025-12-06 14:23:09 +00:00
78902db68b
Before, Sema for comptime `@bitCast` would return the same Value but change the Type. This gave invalid results because, for example, an integer Value when the Type is a float would be interpreted numerically, but `@bitCast` needs it to reinterpret how they would be stored in memory. This requires a mechanism to serialize a Value to a byte buffer and deserialize a Value from a byte buffer. Not done yet, but needs to happen: comptime dereferencing a pointer to a Decl needs to perform a comptime bitcast on the loaded value. Currently the value is silently wrong in the same way that `@bitCast` was silently wrong before this commit. The logic in Value for handling readFromMemory for large integers is only correct for small integers. It needs to be fleshed out for proper big integers. As part of this change: * std.math.big.Int: initial implementations of readTwosComplement and writeTwosComplement. They only support bit_count <= 128 so far and panic otherwise. * compiler-rt: move the compareXf2 exports over to the stage2 section. Even with the improvements in this commit, I'm still seeing test failures in the widening behavior tests; more investigation is needed.