These are now supported enough that this example code hits the
limitations of the register allocator:
fn add(a: u32, b: u32) void {
const c = a + b; // 7
const d = a + c; // 10
const e = d + b; // 14
assert(e == 14);
}
// error: TODO implement copyToNewRegister
So now the next step is to implement register allocation as planned.
InfixOp is flattened out so that each operator is an independent AST
node tag. The two kinds of structs are now Catch and SimpleInfixOp.
Beginning implementation of supporting codegen for const locals.
Now that Big Sur does not have system libraries on the filesystem, zig can no longer read them and add them to the cache hash for the compiler id.
This changes it so that only the first library path returned by os_self_exe_shared_libs is added to the cache hash under Darwin. I looked into methods on getting the system version to keep parity with older versions, but @fengb reported that this works on Catalina (a version behind Big Sur)
Signed-off-by: Haze Booth <isnt@haze.cool>
ast.Node.Id => ast.Node.Tag, matching recent style conventions.
Now multiple different AST node tags can map to the same AST node data
structures. In this commit, simple prefix operators now all map top
SimplePrefixOp.
`ast.Node.castTag` is now preferred over `ast.Node.cast`.
Upcoming: InfixOp flattened out.
These AST nodes now have a flags field and then a bunch of optional
trailing objects. The end result is lower memory usage and consequently
better performance. This is part of an ongoing effort to reduce the
amount of memory parsed ASTs take up.
Running `zig fmt` on the std lib:
* cache-misses: 2,554,321 => 2,534,745
* instructions: 3,293,220,119 => 3,302,479,874
* peak memory: 74.0 MiB => 73.0 MiB
Holding the entire std lib AST in memory at the same time:
93.9 MiB => 88.5 MiB
This is useful for saving memory when allocating an object that has many
optional components. The optional objects are allocated sequentially in
memory, and a single integer is used to represent each optional object
and whether it is present based on each corresponding bit.
This is part of a larger effort to improve the memory layout of AST
nodes of the self-hosted parser to reduce wasted memory. Reduction of
wasted memory also translates to improved performance because of fewer
memory allocations, and fewer cache misses.
Compared to master, when running `zig fmt` on the std lib:
* cache-misses: 801,829 => 768,624
* instructions: 3,234,877,167 => 3,232,075,022
* peak memory: 81480 KB => 75964 KB
Also, check for overflow on incremented file descriptors. Previously,
we'd trigger a panic if we exceeded the `fd_t` resolution. Now, instead,
we throw an `error.Overflow` to signal that there can be no more
file descriptors available from the runtime. This way we give the user
the ability to still be able to check if their desired preopen exists
in the list or not.
