Rather than using runtime to perform pointer arithmetic to set the stack offset as
a pointer into a local, we now store the offset as a WValue from the bottom of the stack.
This has the benefit of less instructions, few locals, and less performance impact when
we allocate a value on the virtual stack.
* pass more x64 behavior tests
* return with a TODO error when lowering a decl with no runtime bits
* insert some debug logs for tracing recursive descent down the
type-value tree when lowering types
* print `Decl`'s name when print debugging `decl_ref` value
This updates the test runner for stage2 to emit to stdout with the passed, skipped and failed tests
similar to the LLVM backend.
Another change to this is the start function, as it's now more in line with stage1's.
The stage2 test infrastructure for wasm/wasi has been updated to reflect this as well.
- approach by Hacker's Delight with wrapping subtraction
- performance expected to be similar to addo
- tests with all relevant combinations of min,max with -1,0,+1 and all
combinations of sequences +-1,2,4..,max
* pass air_tag instead of zir_tag
* also pass eval function so that the branch only happens once and the
body of zirUnaryMath is simplified
* Value.sqrt: update to handle f80 and f128 in the normalized way that
includes handling c_longdouble.
Semi-related change: fix incorrect sqrt builtin name for f80 in stage1.
Support for f128, comptime_float, and c_longdouble require improvements
to compiler_rt and will implemented in a later PR. Some of the code in
this commit could be made more generic, for instance `llvm.airSqrt`
could probably be `llvm.airUnaryMath`, but let's cross that
bridge when we get to it.
For large ranges, this is faster than having the caller call setValue() for
each index in the range. Masks wholly covered by the range can be set to
the new mask value in one go, and the two masks at either end that are
partially covered can each set the covered range of bits in one go.
- approach by Hacker's Delight with wrapping addition
- ca. 1.10x perf over the standard approach on my laptop
- tests with all combinations of min,max with -1,0,+1 and combinations of
sequences +-1,2,4..,max
* link: add a virtual function `lowerUnnamedConsts`, similar to
`updateFunc` or `updateDecl` which needs to be implemented by the
linker backend in order to be used with the `CodeGen` code
* elf: implement `lowerUnnamedConsts` specialization where we
lower unnamed constants to `.rodata` section. We keep track of the
atoms encompassing the lowered unnamed consts in a global table
indexed by parent `Decl`. When the `Decl` is updated or destroyed,
we clear the unnamed consts referenced within the `Decl`.
* macho: implement `lowerUnnamedConsts` specialization where we
lower unnamed constants to `__TEXT,__const` section. We keep track of the
atoms encompassing the lowered unnamed consts in a global table
indexed by parent `Decl`. When the `Decl` is updated or destroyed,
we clear the unnamed consts referenced within the `Decl`.
* x64: change `MCValue.linker_sym_index` into two `MCValue`s: `.got_load` and
`.direct_load`. The former signifies to the emitter that it should
emit a GOT load relocation, while the latter that it should emit
a direct load (`SIGNED`) relocation.
* x64: lower `struct` instantiations
In accordance with the requesting issue (#10750):
- `zig test` skips any tests that it cannot spawn, returning success
- `zig run` and `zig build` exit with failure, reporting the command the cannot be run
- `zig clang`, `zig ar`, etc. already punt directly to the appropriate clang/lld main(), even before this change
- Native `libc` Detection is not supported
Additionally, `exec()` and related Builder functions error at run-time, reporting the command that cannot be run
Currently Zig lowers `@intToFloat` for f80 incorrectly on non-x86
targets:
```
broken LLVM module found:
UIToFP result must be FP or FP vector
%62 = uitofp i64 %61 to i128
SIToFP result must be FP or FP vector
%66 = sitofp i64 %65 to i128
```
This happens because on such targets, we use i128 instead of x86_fp80 in
order to avoid "LLVM ERROR: Cannot select". `@intToFloat` must be
lowered differently to account for this difference as well.
We're going to remove the first parameter from this function in the
future. Stage2 already ignores the first parameter. So we put an `@as`
in here to make it work for both.
This adds a new path which avoids using compiler_rt generated div
udivmod instructions in the case that a divisor is less than half the
max usize value. Two half-limb divisions are performed instead which
ensures that non-emulated division instructions are actually used. This
does not improve the udivmod code which should still be reviewed
independently of this issue.
Notably this improves the performance of the toString implementation of
non-power-of-two bases considerably.
Division performance is improved ~1000% based on some coarse testing.
The following test code is used to provide a rough comparison between
the old vs. new method.
```
const std = @import("std");
const Managed = std.math.big.int.Managed;
const allocator = std.heap.c_allocator;
fn fib(a: *Managed, n: usize) !void {
var b = try Managed.initSet(allocator, 1);
defer b.deinit();
var c = try Managed.init(allocator);
defer c.deinit();
var i: usize = 0;
while (i < n) : (i += 1) {
try c.add(a.toConst(), b.toConst());
a.swap(&b);
b.swap(&c);
}
}
pub fn main() !void {
var a = try Managed.initSet(allocator, 0);
defer a.deinit();
try fib(&a, 1_000_000);
// Note: Next two lines (and printed digit count) omitted on no-print version.
const as = try a.toString(allocator, 10, .lower);
defer allocator.free(as);
std.debug.print("fib: digit count: {}, limb count: {}\n", .{ as.len, a.limbs.len });
}
```
```
==> time.no-print <==
limb count: 10849
________________________________________________________
Executed in 10.60 secs fish external
usr time 10.44 secs 0.00 millis 10.44 secs
sys time 0.02 secs 1.12 millis 0.02 secs
==> time.old <==
fib: digit count: 208988, limb count: 10849
________________________________________________________
Executed in 22.78 secs fish external
usr time 22.43 secs 1.01 millis 22.43 secs
sys time 0.03 secs 0.13 millis 0.03 secs
==> time.optimized <==
fib: digit count: 208988, limb count: 10849
________________________________________________________
Executed in 11.59 secs fish external
usr time 11.56 secs 1.03 millis 11.56 secs
sys time 0.03 secs 0.12 millis 0.03 secs
```
Perf data for non-optimized and optimized, verifying no udivmod is
generated by the new code.
```
$ perf report -i perf.data.old --stdio
- Total Lost Samples: 0
-
- Samples: 90K of event 'cycles:u'
- Event count (approx.): 71603695208
-
- Overhead Command Shared Object Symbol
- ........ ....... ................ ...........................................
-
52.97% t t [.] compiler_rt.udivmod.udivmod
45.97% t t [.] std.math.big.int.Mutable.addCarry
0.83% t t [.] main
0.08% t libc-2.33.so [.] __memmove_avx_unaligned_erms
0.08% t t [.] __udivti3
0.03% t [unknown] [k] 0xffffffff9a0010a7
0.02% t t [.] std.math.big.int.Managed.ensureCapacity
0.01% t libc-2.33.so [.] _int_malloc
0.00% t libc-2.33.so [.] __malloc_usable_size
0.00% t libc-2.33.so [.] _int_free
0.00% t t [.] 0x0000000000004a80
0.00% t t [.] std.heap.CAllocator.resize
0.00% t libc-2.33.so [.] _mid_memalign
0.00% t libc-2.33.so [.] sysmalloc
0.00% t libc-2.33.so [.] __posix_memalign
0.00% t t [.] std.heap.CAllocator.alloc
0.00% t ld-2.33.so [.] do_lookup_x
$ perf report -i perf.data.optimized --stdio
- Total Lost Samples: 0
-
- Samples: 46K of event 'cycles:u'
- Event count (approx.): 36790112336
-
- Overhead Command Shared Object Symbol
- ........ ....... ................ ...........................................
-
79.98% t t [.] std.math.big.int.Mutable.addCarry
15.14% t t [.] main
4.58% t t [.] std.math.big.int.Managed.ensureCapacity
0.21% t libc-2.33.so [.] __memmove_avx_unaligned_erms
0.05% t [unknown] [k] 0xffffffff9a0010a7
0.02% t libc-2.33.so [.] _int_malloc
0.01% t t [.] std.heap.CAllocator.alloc
0.01% t libc-2.33.so [.] __malloc_usable_size
0.00% t libc-2.33.so [.] systrim.constprop.0
0.00% t libc-2.33.so [.] _mid_memalign
0.00% t t [.] 0x0000000000000c7d
0.00% t libc-2.33.so [.] malloc
0.00% t ld-2.33.so [.] check_match
```
Closes#10630.
AstGen: Fixed bug where f80 types in source were triggering illegal
behavior.
Value: handle f80 in floating point arithmetic functions.
Value: implement floatRem and floatMod
This commit introduces dependencies on compiler-rt that are not
implemented. Those are a prerequisite to merging this branch.
When setting the break value in an if expression we must explicitly
check if a result location type coercion that needs to happen. This was
already done for switch expression, so let's just imitate that check
and fix for if expressions. To make this possible, we now also propagate
`rl_ty_inst` to sub scopes.
This was found on a user's machine when calling "git" as a child process from msys. Instead of getting BROKEN_PIPE on GetOverlappedREsult, it would occur on ReadFile which would then cause the function to hang because the async operation was never started.
For example, a situation like this is allowed
```zig
extern "c" var stderrp: c_int;
```
In this case, `Module.Var` wrapping `stderrp` will have `lib_name`
populated with the library name where this import is expected.
`ExternFn` will contain a maybe-lib-name if it was defined with
the `extern` keyword like so
```zig
extern "c" fn write(usize, usize, usize) usize;
```
`lib_name` will live as long as `ExternFn` decl does.
These options were removed in 5e63baae8 (CLI: remove --verbose-ast and
--verbose-tokenize, 2021-06-09) but some remainders were left in.
Signed-off-by: Johannes Löthberg <johannes@kyriasis.com>
