This is one more follow-up to PR https://github.com/llvm/llvm-project/pull/157517 that cleans up the usage of libc_errno in math unit-tests (non-smoke). It follows the same rule: * if you use libc_errno in code literally, include src/__support/libc_errno.h * if you only rely on errno constants, include hdr/errno_macros.h Several tests for exp/log still retain the direct libc_errno usage, since in some cases they skip doing any validation if the error was raised. But the direct usage of libc_errno is removed from all other cases.
https://github.com/llvm/llvm-project/issues/149993
This is the first step in preparation for: https://discourse.llvm.org/t/rfc-make-clang-builtin-math-functions-constexpr-with-llvm-libc-to-support-c-23-constexpr-math-functions/86450
Adds more FP test macros for the upcoming test adds for #61092 and the
issues opened from it: #88768, #88769, #88770, #88771, #88772.
Fix bug in `{EXPECT,ASSERT}_FP_EXCEPTION`. `EXPECT_FP_EXCEPTION(0)`
seems to be used to test that an exception did not happen, but it always
does `EXPECT_GE(... & 0, 0)` which never fails.
Update and refactor tests that break after the above bug fix. An
interesting way things broke after the above change is that
`ForceRoundingMode` and `quick_get_round()` were raising the inexact
exception, breaking a lot of the `atan*` tests.
The changes for all files other than `FPMatcher.h` and
`libc/test/src/math/smoke/RoundToIntegerTest.h` should have the same
semantics as before. For `RoundToIntegerTest.h`, lines 56-58 before the
changes do not always hold since this test is used for functions with
different exception and errno behavior like `lrint` and `lround`. I've
deleted those lines for now, but tests for those cases should be added
for the different nearest int functions to account for this.
Adding @nickdesaulniers for review.
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`.
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.
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; ```
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.
Having libc_errno outside of the namespace causes versioning issues when trying to link the tests against LLVM-libc. Most of this patch is just moving libc_errno inside the namespace in tests. This isn't necessary in the function implementations since those are already inside the namespace.