[libc-commits] [libc] [libc][math] Implement double precision sin correctly rounded to all rounding modes. (PR #95736)

[Nick Desaulniers via libc-commits]

================
@@ -12,22 +12,102 @@
 #include "test/UnitTest/Test.h"
 #include "utils/MPFRWrapper/MPFRUtils.h"
 
-#include "hdr/math_macros.h"
-
 using LlvmLibcSinTest = LIBC_NAMESPACE::testing::FPTest<double>;
 
 namespace mpfr = LIBC_NAMESPACE::testing::mpfr;
 
-TEST_F(LlvmLibcSinTest, Range) {
-  static constexpr double _2pi = 6.283185307179586;
-  constexpr StorageType COUNT = 100'000;
-  constexpr StorageType STEP = STORAGE_MAX / COUNT;
-  for (StorageType i = 0, v = 0; i <= COUNT; ++i, v += STEP) {
-    double x = FPBits(v).get_val();
-    // TODO: Expand the range of testing after range reduction is implemented.
-    if (isnan(x) || isinf(x) || x > _2pi || x < -_2pi)
-      continue;
-
-    ASSERT_MPFR_MATCH(mpfr::Operation::Sin, x, LIBC_NAMESPACE::sin(x), 1.0);
+using LIBC_NAMESPACE::testing::tlog;
+
+TEST_F(LlvmLibcSinTest, TrickyInputs) {
+  constexpr int N = 50;
+  constexpr double INPUTS[] = {
+      0x1.940c877fb7dacp-7,    0x1.fffffffffdb6p24,    0x1.fd4da4ef37075p29,
+      0x1.b951f1572eba5p+31,   0x1.55202aefde314p+31,  0x1.85fc0f04c0128p101,
+      0x1.7776c2343ba4ep101,   0x1.678309fa50d58p110,  0x1.fffffffffef4ep199,
+      -0x1.ab514bfc61c76p+7,   -0x1.f7898d5a756ddp+2,  -0x1.f42fb19b5b9b2p-6,
+      0x1.5f09cad750ab1p+3,    -0x1.14823229799c2p+7,  -0x1.0285070f9f1bcp-5,
+      0x1.23f40dccdef72p+0,    0x1.43cf16358c9d7p+0,   0x1.addf3b9722265p+0,
+      0x1.48ff1782ca91dp+8,    0x1.a211877de55dbp+4,   0x1.dcbfda0c7559ep+8,
+      0x1.1ffb509f3db15p+5,    0x1.2345d1e090529p+5,   0x1.ae945054939c2p+10,
+      0x1.2e566149bf5fdp+9,    0x1.be886d9c2324dp+6,   -0x1.119471e9216cdp+10,
+      -0x1.aaf85537ea4c7p+3,   0x1.cb996c60f437ep+9,   0x1.c96e28eb679f8p+5,
+      -0x1.a5eece87e8606p+4,   0x1.e31b55306f22cp+2,   0x1.ae78d360afa15p+0,
+      0x1.1685973506319p+3,    0x1.4f2b874135d27p+4,   0x1.ae945054939c2p+10,
+      0x1.3eec5912ea7cdp+331,  0x1.dcbfda0c7559ep+8,   0x1.a65d441ea6dcep+4,
+      0x1.e639103a05997p+2,    0x1.13114266f9764p+4,   -0x1.3eec5912ea7cdp+331,
+      0x1.08087e9aad90bp+887,  0x1.2b5fe88a9d8d5p+903, -0x1.a880417b7b119p+1023,
+      -0x1.6deb37da81129p+205, 0x1.08087e9aad90bp+887, 0x1.f6d7518808571p+1023,
+      -0x1.8bb5847d49973p+845, 0x1.f08b14e1c4d0fp+890,
+  };
----------------
nickdesaulniers wrote:

```suggestion
  constexpr double INPUTS[] = {
      0x1.940c877fb7dacp-7,    0x1.fffffffffdb6p24,    0x1.fd4da4ef37075p29,
      0x1.b951f1572eba5p+31,   0x1.55202aefde314p+31,  0x1.85fc0f04c0128p101,
      0x1.7776c2343ba4ep101,   0x1.678309fa50d58p110,  0x1.fffffffffef4ep199,
      -0x1.ab514bfc61c76p+7,   -0x1.f7898d5a756ddp+2,  -0x1.f42fb19b5b9b2p-6,
      0x1.5f09cad750ab1p+3,    -0x1.14823229799c2p+7,  -0x1.0285070f9f1bcp-5,
      0x1.23f40dccdef72p+0,    0x1.43cf16358c9d7p+0,   0x1.addf3b9722265p+0,
      0x1.48ff1782ca91dp+8,    0x1.a211877de55dbp+4,   0x1.dcbfda0c7559ep+8,
      0x1.1ffb509f3db15p+5,    0x1.2345d1e090529p+5,   0x1.ae945054939c2p+10,
      0x1.2e566149bf5fdp+9,    0x1.be886d9c2324dp+6,   -0x1.119471e9216cdp+10,
      -0x1.aaf85537ea4c7p+3,   0x1.cb996c60f437ep+9,   0x1.c96e28eb679f8p+5,
      -0x1.a5eece87e8606p+4,   0x1.e31b55306f22cp+2,   0x1.ae78d360afa15p+0,
      0x1.1685973506319p+3,    0x1.4f2b874135d27p+4,   0x1.ae945054939c2p+10,
      0x1.3eec5912ea7cdp+331,  0x1.dcbfda0c7559ep+8,   0x1.a65d441ea6dcep+4,
      0x1.e639103a05997p+2,    0x1.13114266f9764p+4,   -0x1.3eec5912ea7cdp+331,
      0x1.08087e9aad90bp+887,  0x1.2b5fe88a9d8d5p+903, -0x1.a880417b7b119p+1023,
      -0x1.6deb37da81129p+205, 0x1.08087e9aad90bp+887, 0x1.f6d7518808571p+1023,
      -0x1.8bb5847d49973p+845, 0x1.f08b14e1c4d0fp+890,
  };
  constexpr int N = sizeof(INPUTS) / sizeof(INPUTS[0]);
```

https://github.com/llvm/llvm-project/pull/95736