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.
Upstream LLVM fixes#8597, no longer need `-Dskip-debug` and others.
Additionally, due to the nature of drone.io server pool, it is
beneficial to know which aarch64 CPU brand is in use.
- drop `-Dskip-debug` and others
- invoke `lscpu` prior to build
- enable more testsuite consistent with ci azure
- remove workaround for (already closed) #6830closes#8597
Updates the Language Reference sections: Comments, Values, and Zig Test.
Zig Test section moved down with the goal "make sure it can be read top to
bottom sensibly" in mind (issue #1524).
Comments and Values section examples changed test declarations to a main
function and expect statement to print statements.
A print statement was added to the "String Literals and Unicode Code Point"
section's example to demonstrate the "u" format specifier.
Zig Test Section:
* Addresses the question: "How does the syntax work?".
* Partially answers the question: "What can I do with the zig test tool?" but
should be sufficient to understand the examples in all of this document.
* Addresses the question: "How does a top-level test block differ from a function definition?"
* Provides a example to run multiple test.
Lacks clear definitions of containers, top-level, order independence, lazy
analysis, resolve, reference.
GitHub Issues: #8221, #8234
This was an attempt to move saturating_arithmetic.zig to the "passing
for stage2" section, which did not pan out due to the discovery of 2
prerequisite items that need to be done, but I did make a bug fix along
the way of the calculation of max/min integers.
This commit also simplifies the saturating arithmetic behavior tests to
depend on less of the zig language that is not related to saturating
arithmetic.
This function can be used to initialize a big integer to either the upper
or lower limit of a 2s-complement integer. Note that the result is still
in sign-magnitude representation, though in order to convert it into twos
complement all one has to do is take the absolute value.
lladd is now implemented in terms of lladdcarry, which returns the carry limb.
Similarly, llsub is implemented using llsubcarry, which returns the borrow limb.
Decl names are now rendered fully qualified, so that e.g. "main" in two
different files does not conflict with each other.
Additionally, they are now mangled so as to not generate invalid C
identifier names.
Before, the system to replace a result location pointer with a
traditional break instruction did not notice the case when one of the
bodies was unreachable. Now, the emitted ZIR code is improved and
simplified in this case, resulting in a new passing behavior test.
