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2025-03-11[libc] Provide more fine-grained control of FMA instruction for ARM targets. ↵lntue
(#130700)
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.
2024-04-01[libc][math] Implement atan2f correctly rounded to all rounding modes. (#86716)lntue
We compute atan2f(y, x) in 2 stages: - Fast step: perform computations in double precision , with relative errors < 2^-50 - Accurate step: if the result from the Fast step fails Ziv's rounding test, then we perform computations in double-double precision, with relative errors < 2^-100. On Ryzen 5900X, worst-case latency is ~ 200 clocks, compared to average latency ~ 60 clocks, and average reciprocal throughput ~ 20 clocks.
2024-03-20[libc][NFC] Move `Sign` type to separate header (#85930)Guillaume Chatelet
2024-03-19[libc] Prevent constant propagation for atanf(+-Inf) in gcc. (#85733)lntue
gcc bot failures with `atanf(+-Inf)`: https://lab.llvm.org/buildbot/#/builders/250/builds/20331/steps/8/logs/stdio
2024-03-18[libc][math] Improve atanf performance. (#85463)lntue
Simplify the range reduction logic and computations. Performance test using `perf.sh` from CORE-MATH project on Ryzen 5900X: Before: ``` $ ./perf.sh atanf --rdtsc --path1 LIBC-location: /home/lnt/experiment/llvm-project/build/projects/libc/lib/libllvmlibc.a GNU libc version: 2.35 GNU libc release: stable -- CORE-MATH reciprocal throughput -- [####################] 100 % Ntrial = 20 ; Min = 14.369 + 0.556 clc/call; Median-Min = 0.613 clc/call; Max = 15.061 clc/call; -- System LIBC reciprocal throughput -- [####################] 100 % Ntrial = 20 ; Min = 26.180 + 0.015 clc/call; Median-Min = 0.014 clc/call; Max = 26.260 clc/call; -- LIBC reciprocal throughput -- [####################] 100 % Ntrial = 20 ; Min = 21.237 + 0.022 clc/call; Median-Min = 0.020 clc/call; Max = 21.272 clc/call; $ ./perf.sh atanf --rdtsc --path1 --latency LIBC-location: /home/lnt/experiment/llvm-project/build/projects/libc/lib/libllvmlibc.a GNU libc version: 2.35 GNU libc release: stable -- CORE-MATH latency -- [####################] 100 % Ntrial = 20 ; Min = 50.505 + 0.045 clc/call; Median-Min = 0.037 clc/call; Max = 50.579 clc/call; -- System LIBC latency -- [####################] 100 % Ntrial = 20 ; Min = 62.438 + 0.836 clc/call; Median-Min = 0.049 clc/call; Max = 64.498 clc/call; -- LIBC latency -- [####################] 100 % Ntrial = 20 ; Min = 67.781 + 0.546 clc/call; Median-Min = 0.028 clc/call; Max = 68.844 clc/call; ``` After: ``` $ ./perf.sh atanf --rdtsc --path2 LIBC-location: /home/lnt/experiment/llvm/llvm-project/build/projects/libc/lib/libllvmlibc.a GNU libc version: 2.35 GNU libc release: stable -- CORE-MATH reciprocal throughput -- [####################] 100 % Ntrial = 20 ; Min = 14.400 + 0.353 clc/call; Median-Min = 0.404 clc/call; Max = 14.863 clc/call; -- System LIBC reciprocal throughput -- [####################] 100 % Ntrial = 20 ; Min = 25.247 + 0.783 clc/call; Median-Min = 0.714 clc/call; Max = 26.238 clc/call; -- LIBC reciprocal throughput -- [####################] 100 % Ntrial = 20 ; Min = 13.751 + 0.158 clc/call; Median-Min = 0.140 clc/call; Max = 14.006 clc/call; $ ./perf.sh atanf --rdtsc --path2 --latency LIBC-location: /home/lnt/experiment/llvm/llvm-project/build/projects/libc/lib/libllvmlibc.a GNU libc version: 2.35 GNU libc release: stable -- CORE-MATH latency -- [####################] 100 % Ntrial = 20 ; Min = 51.837 + 0.073 clc/call; Median-Min = 0.058 clc/call; Max = 52.000 clc/call; -- System LIBC latency -- [####################] 100 % Ntrial = 20 ; Min = 62.487 + 1.878 clc/call; Median-Min = 1.965 clc/call; Max = 64.569 clc/call; OK -- LIBC latency -- [####################] 100 % Ntrial = 20 ; Min = 55.414 + 1.312 clc/call; Median-Min = 0.345 clc/call; Max = 58.362 clc/call; ```
2024-01-18[libc][NFC] Introduce a Sign type for FPBits (#78500)Guillaume Chatelet
Another patch is needed to cover `DyadicFloat` and `NormalFloat` constructors.
2023-09-26[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
2023-09-07[libc][math] Fix signed zeros for acosf, acoshf, and atanf in FE_DOWNWARD mode.Tue Ly
Fix signed zeros for acosf, acoshf, and atanf in FE_DOWNWARD mode. Reviewed By: sivachandra Differential Revision: https://reviews.llvm.org/D159476
2023-06-12[libc] Add platform independent floating point rounding mode checks.Tue Ly
Many math functions need to check for floating point rounding modes to return correct values. Currently most of them use the internal implementation of `fegetround`, which is platform-dependent and blocking math functions to be enabled on platforms with unimplemented `fegetround`. In this change, we add platform independent rounding mode checks and switching math functions to use them instead. https://github.com/llvm/llvm-project/issues/63016 Reviewed By: sivachandra Differential Revision: https://reviews.llvm.org/D152280
2023-03-23[libc] Fix some math conversion warningsAlex Brachet
Differential Revision: https://reviews.llvm.org/D146738
2023-02-10[libc] Move likely/unlikely to the optimization headerGuillaume Chatelet
2023-02-07[libc][NFC] Move attributes from common to macros folderGuillaume Chatelet
2022-10-06[libc] Resolve NaN/implementation-defined behavior of floating-point testsDominic Chen
Differential Revision: https://reviews.llvm.org/D134917
2022-08-30[libc][math] Added atanf function.Kirill Okhotnikov
Performance by core-math (core-math/glibc 2.31/current llvm-14): 28.879/20.843/20.15 Differential Revision: https://reviews.llvm.org/D132842
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