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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 13:54:38 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 13:54:38 +0000
commit8c1ab65c0f548d20b7f177bdb736daaf603340e1 (patch)
treedf55b7e75bf43f2bf500845b105afe3ac3a5157e /libc-bottom-half/sources/math/fmin-fmax.c
parentInitial commit. (diff)
downloadwasi-libc-b0f726bfa464c79fdf040fa7daed6094ddbffb4c.tar.xz
wasi-libc-b0f726bfa464c79fdf040fa7daed6094ddbffb4c.zip
Adding upstream version 0.0~git20221206.8b7148f.upstream/0.0_git20221206.8b7148f
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'libc-bottom-half/sources/math/fmin-fmax.c')
-rw-r--r--libc-bottom-half/sources/math/fmin-fmax.c34
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
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+++ b/libc-bottom-half/sources/math/fmin-fmax.c
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+// 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);
+}