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.
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 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
