1 files changed, 34 insertions, 0 deletions
diff --git a/libc-bottom-half/sources/math/fmin-fmax.c b/libc-bottom-half/sources/math/fmin-fmax.c
new file mode 100644
index 0000000..9293798
--- /dev/null
+++ b/libc-bottom-half/sources/math/fmin-fmax.c
@@ -0,0 +1,34 @@
+// Wasm's `min` and `max` operators implement the IEEE 754-2019
+// `minimum` and `maximum` operations, meaning that given a choice
+// between NaN and a number, they return NaN. This differs from
+// the C standard library's `fmin` and `fmax` functions, which
+// return the number. However, we can still use wasm's builtins
+// by handling the NaN cases explicitly, and it still turns out
+// to be faster than doing the whole operation in
+// target-independent C. And, it's smaller.
+
+#include <math.h>
+
+float fminf(float x, float y) {
+    if (isnan(x)) return y;
+    if (isnan(y)) return x;
+    return __builtin_wasm_min_f32(x, y);
+}
+
+float fmaxf(float x, float y) {
+    if (isnan(x)) return y;
+    if (isnan(y)) return x;
+    return __builtin_wasm_max_f32(x, y);
+}
+
+double fmin(double x, double y) {
+    if (isnan(x)) return y;
+    if (isnan(y)) return x;
+    return __builtin_wasm_min_f64(x, y);
+}
+
+double fmax(double x, double y) {
+    if (isnan(x)) return y;
+    if (isnan(y)) return x;
+    return __builtin_wasm_max_f64(x, y);
+}