2 files changed, 103 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);
+}
diff --git a/libc-bottom-half/sources/math/math-builtins.c b/libc-bottom-half/sources/math/math-builtins.c
new file mode 100644
index 0000000..a5eb7cd
--- /dev/null
+++ b/libc-bottom-half/sources/math/math-builtins.c
@@ -0,0 +1,69 @@
+// Each of the following math functions can be implemented with a single
+// wasm instruction, so use that implementation rather than the portable
+// one in libm.
+
+#include <math.h>
+
+float fabsf(float x) {
+    return __builtin_fabsf(x);
+}
+
+double fabs(double x) {
+    return __builtin_fabs(x);
+}
+
+float sqrtf(float x) {
+    return __builtin_sqrtf(x);
+}
+
+double sqrt(double x) {
+    return __builtin_sqrt(x);
+}
+
+float copysignf(float x, float y) {
+    return __builtin_copysignf(x, y);
+}
+
+double copysign(double x, double y) {
+    return __builtin_copysign(x, y);
+}
+
+float ceilf(float x) {
+    return __builtin_ceilf(x);
+}
+
+double ceil(double x) {
+    return __builtin_ceil(x);
+}
+
+float floorf(float x) {
+    return __builtin_floorf(x);
+}
+
+double floor(double x) {
+    return __builtin_floor(x);
+}
+
+float truncf(float x) {
+    return __builtin_truncf(x);
+}
+
+double trunc(double x) {
+    return __builtin_trunc(x);
+}
+
+float nearbyintf(float x) {
+    return __builtin_nearbyintf(x);
+}
+
+double nearbyint(double x) {
+    return __builtin_nearbyint(x);
+}
+
+float rintf(float x) {
+    return __builtin_rintf(x);
+}
+
+double rint(double x) {
+    return __builtin_rint(x);
+}