[libc-commits] [libc] [libc][math][c23] Add hypotf16 function (PR #131991)

[via libc-commits]

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@@ -0,0 +1,58 @@
+//===-- Exhaustive test for hypotf16 --------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "exhaustive_test.h"
+#include "src/__support/FPUtil/FPBits.h"
+#include "src/__support/FPUtil/Hypot.h"
+#include "src/math/hypotf16.h"
+#include "test/UnitTest/FPMatcher.h"
+#include "utils/MPFRWrapper/MPFRUtils.h"
+
+namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
+
+// Range of both inputs: [0, inf]
+static constexpr uint16_t START = 0x0000U;
+static constexpr uint16_t STOP = 0x7C00U;
+
+struct Hypotf16Checker : public virtual LIBC_NAMESPACE::testing::Test {
+  using FloatType = float16;
+  using FPBits = LIBC_NAMESPACE::fputil::FPBits<float16>;
+  using StorageType = typename FPBits::StorageType;
+
+  uint64_t check(uint16_t start, uint16_t stop, mpfr::RoundingMode rounding) {
+    mpfr::ForceRoundingMode r(rounding);
+    if (!r.success)
+      return true;
+    uint16_t xbits = start;
+    uint64_t failed = 0;
+    do {
+      float16 x = FPBits(xbits).get_val();
+      uint16_t ybits = xbits;
+      do {
+        float16 y = FPBits(ybits).get_val();
+        bool correct = TEST_FP_EQ(LIBC_NAMESPACE::fputil::hypot(x, y),
+                                  LIBC_NAMESPACE::hypotf16(x, y));
+        // Using MPFR will be much slower.
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lntue wrote:

I don't think your test fully utilize the multithread/core capability.  You should take start and stop as `uint32_t`, split the high 16-bit as `x`, low 16-bit as `y`, and skip it when `x` or `y` is NaN.  Then test for everything from `0x0000'0000U` to `0x7FFF'FFFFU`.  Try and see if it's faster?

https://github.com/llvm/llvm-project/pull/131991