The semantics for casting can range from "bitcast" (same representation)
to "different representation", to "type promotion". Here we remove the
cast operator and force usage of `get_val` as the only function to get
the floating point value, making the intent clearer and more consistent.
fixes https://github.com/llvm/llvm-project/issues/78743
- For normal objects, the patch removes `RTTI` and exceptions in `fullbuild`
- For FP tests, the patch adds links to `stdc++` and `gcc_s` if `MPFR` is used.
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.
According to [wikipedia](https://en.wikipedia.org/wiki/Exponent_bias)
the "biased exponent" is the encoded form that is always positive
whereas the unbiased form is the actual "real" exponent that can be
positive or negative.
`FPBits` seems to be using `unbiased_exponent` to describe the encoded
form (unsigned). This patch simply use `biased` instead of `unbiased`.
`PlatformDefs.h` does not bring a lot of value as a separate file.
It is transitively included in `FloatProperties.h` and `FPBits.h`. This
patch sinks it into `FloatProperties.h` and removes the associated build
targets.
We compute `pow(x, y)` using the formula
```
pow(x, y) = x^y = 2^(y * log2(x))
```
We follow similar steps as in `log2f(x)` and `exp2f(x)`, by breaking
down into `hi + mid + lo` parts, in which `hi` parts are computed using
the exponent field directly, `mid` parts will use look-up tables, and
`lo` parts are approximated by polynomials.
We add some speedup for common use-cases:
```
pow(2, y) = exp2(y)
pow(10, y) = exp10(y)
pow(x, 2) = x * x
pow(x, 1/2) = sqrt(x)
pow(x, -1/2) = rsqrt(x) - to be added
```
Explicit braces were added to fix the "suggest explicit braces to avoid
ambiguous ‘else’" warning since the current solution (switch (0) case 0:
default:) doesn't work since gcc 7 (see
https://github.com/google/googletest/issues/1119)
gcc 13 generates about 5000 of these warnings when building libc without
this patch.
This patch fixes a couple of warnings when compiling with gcc 13:
* CPP/type_traits_test.cpp: 'apply' overrides a member function but is
not marked 'override'
* UnitTest/LibcTest.cpp:98: control reaches end of non-void function
* MPFRWrapper/MPFRUtils.cpp:75: control reaches end of non-void function
* smoke/FrexpTest.h:92: backslash-newline at end of file
* __support/float_to_string.h:118: comparison of unsigned expression in ‘>= 0’ is always true
* test/src/__support/CPP/bitset_test.cpp:197: comparison of unsigned expression in ‘>= 0’ is always true
---------
Signed-off-by: Mikhail R. Gadelha <mikhail@igalia.com>
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
Fixing an issue with LLVM libc's fenv.h defined rounding mode macros
differently from system libc, making get_round() return different values from
fegetround(). Also letting math tests to skip rounding modes that cannot be
set. This should allow math tests to be run on platforms in which fenv.h is not
implemented yet.
This allows us to re-enable hermatic floating point tests in
https://reviews.llvm.org/D151123 and reverting https://reviews.llvm.org/D152742.
Reviewed By: jhuber6
Differential Revision: https://reviews.llvm.org/D152873
This patch mimics the behavior of Google Test and allow users to log custom messages after all flavors of ASSERT_ / EXPECT_.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D152630
This patch mimics the behavior of Google Test and allow users to log custom messages after all flavors of ASSERT_ / EXPECT_.
Reviewed By: sivachandra, lntue
Differential Revision: https://reviews.llvm.org/D152630
str method of FPBits class is only used for pretty printing its objects
in tests. It brings cpp::string dependency to FPBits class, which is not ideal
for embedded use case. We move str method to a free function in test utils and
remove this dependency of FPBits class.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D152607
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
Unit tests for the str() method have also been added.
Previously, a separate test only helper function was being used by the
test matchers which has regressed over many cleanups. Moreover, being a
test only utility, it was not tested separately (and hence the
regression).
Reviewed By: michaelrj
Differential Revision: https://reviews.llvm.org/D150906
This function is used to add unit test and hermetic test framework libraries.
It avoids the duplicated code to add compile options to each every test
framework libraries.
Reviewed By: jhuber6
Differential Revision: https://reviews.llvm.org/D150727
This part of the effort to make all test related pieces into the `test`
directory. This helps is excluding test related pieces in a straight
forward manner if LLVM_INCLUDE_TESTS is OFF. Future patches will also move
the MPFR wrapper and testutils into the 'test' directory.
Adding `EXPECT_MPFR_MATCH_ROUNDING_SILENTLY` macro that does not call
`explainError` when the tests fail. This is useful to check the passing or
failing rates, such as hitting percentages of fast passes in math
implementations.
Reviewed By: michaelrj, sivachandra
Differential Revision: https://reviews.llvm.org/D136731
Implement exp10f function correctly rounded to all rounding modes.
Algorithm: perform range reduction to reduce
```
10^x = 2^(hi + mid) * 10^lo
```
where:
```
hi is an integer,
0 <= mid * 2^5 < 2^5
-log10(2) / 2^6 <= lo <= log10(2) / 2^6
```
Then `2^mid` is stored in a table of 32 entries and the product `2^hi * 2^mid` is
performed by adding `hi` into the exponent field of `2^mid`.
`10^lo` is then approximated by a degree-5 minimax polynomials generated by Sollya with:
```
> P = fpminimax((10^x - 1)/x, 4, [|D...|], [-log10(2)/64. log10(2)/64]);
```
Performance benchmark using perf tool from the CORE-MATH project on Ryzen 1700:
```
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh exp10f
GNU libc version: 2.35
GNU libc release: stable
CORE-MATH reciprocal throughput : 10.215
System LIBC reciprocal throughput : 7.944
LIBC reciprocal throughput : 38.538
LIBC reciprocal throughput : 12.175 (with `-msse4.2` flag)
LIBC reciprocal throughput : 9.862 (with `-mfma` flag)
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh exp10f --latency
GNU libc version: 2.35
GNU libc release: stable
CORE-MATH latency : 40.744
System LIBC latency : 37.546
BEFORE
LIBC latency : 48.989
LIBC latency : 44.486 (with `-msse4.2` flag)
LIBC latency : 40.221 (with `-mfma` flag)
```
This patch relies on https://reviews.llvm.org/D134002
Reviewed By: orex, zimmermann6
Differential Revision: https://reviews.llvm.org/D134104
Implement acosf function correctly rounded for all rounding modes.
We perform range reduction as follows:
- When `|x| < 2^(-10)`, we use cubic Taylor polynomial:
```
acos(x) = pi/2 - asin(x) ~ pi/2 - x - x^3 / 6.
```
- When `2^(-10) <= |x| <= 0.5`, we use the same approximation that is used for `asinf(x)` when `|x| <= 0.5`:
```
acos(x) = pi/2 - asin(x) ~ pi/2 - x - x^3 * P(x^2).
```
- When `0.5 < x <= 1`, we use the double angle formula: `cos(2y) = 1 - 2 * sin^2 (y)` to reduce to:
```
acos(x) = 2 * asin( sqrt( (1 - x)/2 ) )
```
- When `-1 <= x < -0.5`, we reduce to the positive case above using the formula:
```
acos(x) = pi - acos(-x)
```
Performance benchmark using perf tool from the CORE-MATH project on Ryzen 1700:
```
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh acosf
GNU libc version: 2.35
GNU libc release: stable
CORE-MATH reciprocal throughput : 28.613
System LIBC reciprocal throughput : 29.204
LIBC reciprocal throughput : 24.271
$ CORE_MATH_PERF_MODE="rdtsc" ./perf.sh asinf --latency
GNU libc version: 2.35
GNU libc release: stable
CORE-MATH latency : 55.554
System LIBC latency : 76.879
LIBC latency : 62.118
```
Reviewed By: orex, zimmermann6
Differential Revision: https://reviews.llvm.org/D133550
The libc.src.__support.FPUtil.fputil target encompassed many unrelated
files, and provided a lot of hidden dependencies. This patch splits out
all of these files into component parts and cleans up the cmake files
that used them. It does not touch any source files for simplicity, but
there may be changes made to them in future patches.
Reviewed By: lntue
Differential Revision: https://reviews.llvm.org/D132980
Performance by core-math (core-math/glibc 2.31/current llvm-14):
10.845/43.174/13.467
The review is done on top of D132809.
Differential Revision: https://reviews.llvm.org/D132811
