Comment out non-x86_64 architectures for now in codegen.zig, because
they all have compile errors for their codepaths anyway, and it was
bloating the compilation speed and memory usage when stage1 tried to
build self-hosted. Here's the panic message:
"Backend architectures that don't have good support yet are commented
out, to improve compilation performance. If you are interested in one
of these other backends feel free to uncomment them. Eventually these
will be completed, but stage1 is slow and a memory hog."
This is a workaround to lower the time it takes to build self-hosted
with stage1 as well as use less memory. It should fix the CI.
Additionally:
* Add `single_mut_pointer` support to `Type`
* Trivial implementation of stack allocation in codegen.zig. It does
not deal with freeing yet, and it's missing the stack pointer
adjustment prologue.
* Add the `alloc` IR instruction and semantic analysis for `alloc` ZIR
instruction.
This makes sense from an organizational point of view, as explained by
this new doc comment at the top of the new file:
//! Semantic analysis of ZIR instructions.
//! This file operates on a `Module` instance, transforming untyped ZIR
//! instructions into semantically-analyzed IR instructions. It does type
//! checking, comptime control flow, and safety-check generation. This is the
//! the heart of the Zig compiler.
//! When deciding if something goes into this file or into Module, here is a
//! guiding principle: if it has to do with (untyped) ZIR instructions, it goes
//! here. If the analysis operates on typed IR instructions, it goes in Module.
Before:
4009 src-self-hosted/Module.zig
After:
2776 src-self-hosted/Module.zig
1128 src-self-hosted/zir_sema.zig
This should be sufficient to avoid the situation we have in stage1 where
ir.cpp is 32,516 lines.
* AST: flatten ControlFlowExpression into Continue, Break, and Return.
* AST: unify identifiers and literals into the same AST type: OneToken
* AST: ControlFlowExpression uses TrailerFlags to optimize storage
space.
* astgen: support `var` as well as `const` locals, and support
explicitly typed locals. Corresponding Module and codegen code is not
implemented yet.
* astgen: support result locations.
* ZIR: add the following instructions (see the corresponding doc
comments for explanations of semantics):
- alloc
- alloc_inferred
- bitcast_result_ptr
- coerce_result_block_ptr
- coerce_result_ptr
- coerce_to_ptr_elem
- ensure_result_used
- ensure_result_non_error
- ret_ptr
- ret_type
- store
- param_type
* the skeleton structure for result locations is set up. It's looking
pretty clean so far.
* add compile error for unused result and compile error for discarding
errors.
* astgen: split builtin calls up to implemented manually, and implement
`@as`, `@bitCast` (and others) with respect to result locations.
* add CLI support for hex and raw object formats. They are not
supported by the self-hosted compiler yet, and emit errors.
* rename `--c` CLI to `-ofmt=[objectformat]` which can be any of the
object formats. Only ELF and C are supported so far. Also added missing
help to the help text.
* Remove hard tabs from C backend test cases. Shame on you Noam, you
are grounded, you should know better, etc. Bad boy.
* Delete C backend code and test case that relied on comptime_int
incorrectly making it all the way to codegen.
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
