Context: https://github.com/llvm/llvm-project/pull/87017
- Add proxy header `libc/hdr/math_macros.h` that will:
- include `<math.h>` in overlay mode,
- include `"include/llvm-libc-macros/math-macros.h"` in full build mode.
- Its corresponding CMake target `libc.hdr.math_macros` will only depend
on `libc.include.math` and `libc.include.llvm-libc-macros.math_macros`
in full build mode.
- Replace all `#include "include/llvm-libc-macros/math-macros.h"` with
`#include "hdr/math_macros.h"`.
- Add dependency to `libc.hdr.math_macros` CMake target when using
`add_fp_unittest`.
- Update the remaining dependency.
- Update bazel overlay: add `libc:hdr_math_macros` target, and replacing
all dependency on `libc:llvm_libc_macros_math_macros` with
`libc:hdr_math_macros`.
Reland of #84991
A downstream overlay mode user ran into issues with the isnan macro not
working in our sources with a specific libc configuration. This patch
replaces the last direct includes of math.h with our internal
math_macros.h, along with the necessary build system changes.
This one might be a bit controversial since the terminology has been
introduced from the start but I think `FRACTION_LEN` is a better name
here. AFAICT it really is "the number of bits after the decimal dot when
the number is in normal form."
`MANTISSA_WIDTH` is less precise as it's unclear whether we take the
leading bit into account.
This patch also renames most of the properties to use the `_LEN` suffix
and fixes useless casts or variables.
MPFR has a minimum precision of 2, but the strtofloat fuzz sometimes
would request a precision of 1 for the case of the minimum subnormal.
This patch tells the fuzzer to ignore any case where the precision would
go below 2.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D155130
Subnormal floating point numbers have a lower effective precision than
normal floating point numbers. This can cause issues for the fuzz test
since the MPFR floats have a constant precision regardless of the
exponent, and the precision must match exactly or else create rounding
errors. To solve this problem, the precision of the MPFR floats is
dynamically calculated.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D154909
The accuracy for the MPFR numbers in the strtofloat fuzz test was set
too high, causing rounding issues when rounding to a smaller final
result.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D154150
The previous string to float tests didn't check correctness, but due to
the atof differential test proving unreliable the strtofloat fuzz test
has been changed to use MPFR for correctness checking. Some minor bugs
have been found and fixed as well.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D150905
The differential fuzzer for atof found a bug in glibc's handling of
hexadecimal rounding. Since we can't easily update glibc and we want to
avoid false positives when running the fuzzer, I've added an exception
to skip all hexadecimal subnormal cases.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D149359
The string to integer and string to float standalone fuzz targets just
ran the functions and didn't do anything with the output. This was
intentional, since they are intended to be used with sanitizers to
detect buffer overflow bugs. Not using the variables was causing compile
warnings, so this patch adds trivial checks to use the variables.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D144208
Fuzzing the string to integer and float functions without relying on the
system libc allows for tests to be run in a wider variety of places.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D143616
The string to integer conversion functions are well suited to
differential fuzzing, and this patch adds a target to enable just that.
It also fixes a bug in the fuzzing comparison logic and changes atoi
slightly to match the behavior described in the C standard.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D140178
