Andrew Kelley 78902db68b stage2: fix comptime @bitCast ...

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.

2021-10-04 23:30:04 -07:00

..

int_test.zig

big ints: Fix tests for 32-bit architectures

2021-10-04 11:25:29 +02:00

int.zig

stage2: fix comptime @bitCast

2021-10-04 23:30:04 -07:00

rational.zig

remove redundant license headers from zig standard library

2021-08-24 12:25:09 -07:00