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2025-04-08[libc][math] Fix signaling NaN handling for math functions. (#133347)wldfngrs
Add tests for signaling NaNs, and fix function behavior for handling signaling NaN input. Fixes https://github.com/llvm/llvm-project/issues/124812
2025-03-11[libc][math] Skip checking for exceptional values when ↵lntue
LIBC_MATH_SKIP_ACCURATE_PASS is set. (#130811)
2024-07-12[libc] Migrate to using LIBC_NAMESPACE_DECL for namespace declaration (#98597)Petr Hosek
This is a part of #97655.
2024-07-12Revert "[libc] Migrate to using LIBC_NAMESPACE_DECL for namespace ↵Mehdi Amini
declaration" (#98593) Reverts llvm/llvm-project#98075 bots are broken
2024-07-11[libc] Migrate to using LIBC_NAMESPACE_DECL for namespace declaration (#98075)Petr Hosek
This is a part of #97655.
2024-07-05[libc][math] Fix signed zeros for erff. (#97742)lntue
The inexact exception flag was raised for the exact cases of signed zeros. This was reported by Paul Zimmermann using the CORE-MATH test suites.
2024-01-18[libc][NFC] Introduce a Sign type for FPBits (#78500)Guillaume Chatelet
Another patch is needed to cover `DyadicFloat` and `NormalFloat` constructors.
2023-12-15[libc][NFC] Rename `MANTISSA_WIDTH` in `FRACTION_LEN` (#75489)Guillaume Chatelet
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.
2023-12-13[reland][libc][NFC] Implement `FPBits` in terms of `FloatProperties` to ↵Guillaume Chatelet
reduce clutter (#75196) (#75318) Also make type naming consistent by using `UIntType` instead of `intU_t`. This patch is a reland of #75196 but does not include the "use `FPBits` instead of `FPBits_t`, `FPB`" part. This needs more work.
2023-12-13Revert "[libc][NFC] Implement `FPBits` in terms of `FloatProperties` to ↵Guillaume Chatelet
reduce clutter" (#75304) Reverts llvm/llvm-project#75196 GCC complains about change of meaning for `FPBits` ``` /home/llvm-libc-buildbot/buildbot-worker/libc-x86_64-debian-fullbuild/libc-x86_64-debian-gcc-fullbuild-dbg/llvm-project/libc/src/__support/FPUtil/generic/FMod.h:188:9: error: declaration of ‘using FPBits = struct __llvm_libc_18_0_0_git::fputil::FPBits<T>’ changes meaning of ‘FPBits’ [-fpermissive] 188 | using FPBits = FPBits<T>; | ^~~~~~ ``` I'll reland with a different name.
2023-12-13[libc][NFC] Implement `FPBits` in terms of `FloatProperties` to reduce ↵Guillaume Chatelet
clutter (#75196) Also make type naming consistent: - `UIntType` instead of `intU_t` - `FPBits` instead of `FPBits_t`, `FPB`
2023-09-26[libc] Mass replace enclosing namespace (#67032)Guillaume Chatelet
This is step 4 of https://discourse.llvm.org/t/rfc-customizable-namespace-to-allow-testing-the-libc-when-the-system-libc-is-also-llvms-libc/73079
2023-06-28[libc][math] Implement erff function correctly rounded to all rounding modes.Tue Ly
Implement correctly rounded `erff` functions. For `x >= 4`, `erff(x) = 1` for `FE_TONEAREST` or `FE_UPWARD`, `0x1.ffffep-1` for `FE_DOWNWARD` or `FE_TOWARDZERO`. For `0 <= x < 4`, we divide into 32 sub-intervals of length `1/8`, and use a degree-15 odd polynomial to approximate `erff(x)` in each sub-interval: ``` erff(x) ~ x * (c0 + c1 * x^2 + c2 * x^4 + ... + c7 * x^14). ``` For `x < 0`, we can use the same formula as above, since the odd part is factored out. Performance tested with `perf.sh` tool from the CORE-MATH project on AMD Ryzen 9 5900X: Reciprocal throughput (clock cycles / op) ``` $ ./perf.sh erff --path2 GNU libc version: 2.35 GNU libc release: stable -- CORE-MATH reciprocal throughput -- with -march=native (with FMA instructions) [####################] 100 % Ntrial = 20 ; Min = 11.790 + 0.182 clc/call; Median-Min = 0.154 clc/call; Max = 12.255 clc/call; -- CORE-MATH reciprocal throughput -- with -march=x86-64-v2 (without FMA instructions) [####################] 100 % Ntrial = 20 ; Min = 14.205 + 0.151 clc/call; Median-Min = 0.159 clc/call; Max = 15.893 clc/call; -- System LIBC reciprocal throughput -- [####################] 100 % Ntrial = 20 ; Min = 45.519 + 0.445 clc/call; Median-Min = 0.552 clc/call; Max = 46.345 clc/call; -- LIBC reciprocal throughput -- with -mavx2 -mfma (with FMA instructions) [####################] 100 % Ntrial = 20 ; Min = 9.595 + 0.214 clc/call; Median-Min = 0.220 clc/call; Max = 9.887 clc/call; -- LIBC reciprocal throughput -- with -msse4.2 (without FMA instructions) [####################] 100 % Ntrial = 20 ; Min = 10.223 + 0.190 clc/call; Median-Min = 0.222 clc/call; Max = 10.474 clc/call; ``` and latency (clock cycles / op): ``` $ ./perf.sh erff --path2 GNU libc version: 2.35 GNU libc release: stable -- CORE-MATH latency -- with -march=native (with FMA instructions) [####################] 100 % Ntrial = 20 ; Min = 38.566 + 0.391 clc/call; Median-Min = 0.503 clc/call; Max = 39.170 clc/call; -- CORE-MATH latency -- with -march=x86-64-v2 (without FMA instructions) [####################] 100 % Ntrial = 20 ; Min = 43.223 + 0.667 clc/call; Median-Min = 0.680 clc/call; Max = 43.913 clc/call; -- System LIBC latency -- [####################] 100 % Ntrial = 20 ; Min = 111.613 + 1.267 clc/call; Median-Min = 1.696 clc/call; Max = 113.444 clc/call; -- LIBC latency -- with -mavx2 -mfma (with FMA instructions) [####################] 100 % Ntrial = 20 ; Min = 40.138 + 0.410 clc/call; Median-Min = 0.536 clc/call; Max = 40.729 clc/call; -- LIBC latency -- with -msse4.2 (without FMA instructions) [####################] 100 % Ntrial = 20 ; Min = 44.858 + 0.872 clc/call; Median-Min = 0.814 clc/call; Max = 46.019 clc/call; ``` Reviewed By: michaelrj Differential Revision: https://reviews.llvm.org/D153683