* Sema: implement comptime bitcast of f80 with integer-like types
bitwise rather than taking a round trip through memory layout.
* Type: introduce `isAbiInt`.
* Value: comptime memory write of f80 writes 0 bytes for padding
instead of leaving the memory uninitialized.
* Value: floatReadFromMemory has a more general implementation, checking
the endianness rather than checking for specific architectures.
This fixes behavior test failures occurring on MIPS.
These functions semantically benefit from being inline; it makes sense
that `isInf(x)` where `x` is comptime-known should have a
comptime-known result.
Rather than lowering float negation as `0.0 - x`.
* Add AIR instruction for float negation.
* Add compiler-rt functions for f128, f80 negation
closes#11853
Many of the Managed methods accepted by-val parameters which could
reference Limb slices that became invalid memory after any
ensureCapacity calls. Now, Managed methods accept `*const Managed`
parameters so that if the function allows aliasing and the
ensure-capacity call resizes the Limb slice, it also affects the
aliased parameters, avoiding use-after-free bugs.
This is a breaking change that reduces the requirement for callsites to
manually make the ensure-capacity changes prior to calling many of the
Managed methods.
Closes#11897
Since Zig provides @clz and not @ffs (find-first-set), log2 for comptime
integers needs to be computed algorithmically. To avoid hitting the
backward branch quota, this updates log2(x) to use a simple O(log N)
algorithm.
The reason for having `@tan` is that we already have `@sin` and `@cos`
because some targets have machine code instructions for them, but in the
case that the implementation needs to go into compiler-rt, sin, cos, and
tan all share a common dependency which includes a table of data. To
avoid duplicating this table of data, we promote tan to become a builtin
alongside sin and cos.
ZIR: The tag enum is at capacity so this commit moves
`field_call_bind_named` to be `extended`. I measured this as one of
the least used tags in the zig codebase.
Fix libc math suffix for `f32` being wrong in both stage1 and stage2.
stage1: add missing libc prefix for float functions.
* std.math.snan: fix compilation error. Also make it and nan inline.
* LLVM: use a proper enum type for float op instead of enum literal.
Also various cleanups.
* LLVM: use LLVMBuildVectorSplat for vector splat AIR instruction.
- also the bindings had parameter order wrong
* LLVM: additionally handle f16 lowering. For now all targets report OK
but I think we will need to add some exceptions to this list.
* unify the logic for exporting math functions from compiler-rt,
with the appropriate suffixes and prefixes.
- add all missing f128 and f80 exports. Functions with missing
implementations call other functions and have TODO comments.
- also add f16 functions
* move math functions from freestanding libc to compiler-rt (#7265)
* enable all the f128 and f80 code in the stage2 compiler and behavior
tests (#11161).
* update std lib to use builtins rather than `std.math`.
This also addresses a nit from #10133 where IntT might be a confusing
name because it might imply signed integer (iX, not uX). We settled on
TBits for math/float.zig so I've applied that change here too.
When I originally wrote ldexp() I copied the name from parse_hex_float.
Fixes#11353
The renderer treats comments and doc comments differently since doc
comments are parsed into the Ast. This commit adds a check after getting
the text for the doc comment and trims whitespace at the end before
rendering.
The `a = 0,` in the test is here to avoid a ParseError while parsing the
test.
* mul_add AIR instruction: use `pl_op` instead of `ty_pl`. The type is
always the same as the operand; no need to waste bytes redundantly
storing the type.
* AstGen: use coerced_ty for all the operands except for one which we
use to communicate the type.
* Sema: use the correct source location for requireRuntimeBlock in
handling of `@mulAdd`.
* native backends: handle liveness even for the functions that are
TODO.
* C backend: implement `@mulAdd`. It lowers to libc calls.
* LLVM backend: make `@mulAdd` handle all float types.
- improved fptrunc and fpext to handle f80 with compiler-rt calls.
* Value.mulAdd: handle all float types and use the `@mulAdd` builtin.
* behavior tests: revert the changes to testing `@mulAdd`. These
changes broke the test coverage, making it only tested at
compile-time.
Improved f80 support:
* std.math.fma handles f80
* move fma functions from freestanding libc to compiler-rt
- add __fmax and fmal
- make __fmax and fmaq only exported when they don't alias fmal.
- make their linkage weak just like the rest of compiler-rt symbols.
* removed `longDoubleIsF128` and replaced it with `longDoubleIs` which
takes a type as a parameter. The implementation is now more accurate
and handles more targets. Similarly, in stage2 the function
CTypes.sizeInBits is more accurate for long double for more targets.
Big-int functions were updated to respect the provided abi_size, rather
than inferring a potentially incorrect abi_size implicitly.
In combination with the convention that any required padding bits are
added on the MSB end, this means that exotic integers can potentially
have a well-defined memory layout.
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.
