Add implementations for fmin, fminf, and fminl. Testing infrastructure update is splitted to https://reviews.llvm.org/D83931.

2 files changed, 20 insertions, 0 deletions

diff --git a/libc/utils/FPUtil/BasicOperations.h b/libc/utils/FPUtil/BasicOperations.h
index 70c0bb5..2f86ddf 100644
--- a/libc/utils/FPUtil/BasicOperations.h
+++ b/libc/utils/FPUtil/BasicOperations.h
@@ -24,6 +24,25 @@ static inline T abs(T x) {
   return T(bits);
 }
 
+template <typename T,
+          cpp::EnableIfType<cpp::IsFloatingPointType<T>::Value, int> = 0>
+static inline T fmin(T x, T y) {
+  FPBits<T> bitx(x), bity(y);
+
+  if (bitx.isNaN()) {
+    return y;
+  } else if (bity.isNaN()) {
+    return x;
+  } else if (bitx.sign != bity.sign) {
+    // To make sure that fmin(+0, -0) == -0 == fmin(-0, +0), whenever x and
+    // y has different signs and both are not NaNs, we return the number
+    // with negative sign.
+    return (bitx.sign ? x : y);
+  } else {
+    return (x < y ? x : y);
+  }
+}
+
 } // namespace fputil
 } // namespace __llvm_libc
 
diff --git a/libc/utils/FPUtil/CMakeLists.txt b/libc/utils/FPUtil/CMakeLists.txt
index 682db93..e611372 100644
--- a/libc/utils/FPUtil/CMakeLists.txt
+++ b/libc/utils/FPUtil/CMakeLists.txt
@@ -14,6 +14,7 @@ add_header_library(
     FloatOperations.h
     FloatProperties.h
     FPBits.h
+    BasicOperations.h
     ManipulationFunctions.h
     NearestIntegerOperations.h
   DEPENDS