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-rw-r--r--lib/mlibc/options/ansi/musl-generic-math/trunc.c19
1 files changed, 19 insertions, 0 deletions
diff --git a/lib/mlibc/options/ansi/musl-generic-math/trunc.c b/lib/mlibc/options/ansi/musl-generic-math/trunc.c
new file mode 100644
index 0000000..d13711b
--- /dev/null
+++ b/lib/mlibc/options/ansi/musl-generic-math/trunc.c
@@ -0,0 +1,19 @@
+#include "libm.h"
+
+double trunc(double x)
+{
+ union {double f; uint64_t i;} u = {x};
+ int e = (int)(u.i >> 52 & 0x7ff) - 0x3ff + 12;
+ uint64_t m;
+
+ if (e >= 52 + 12)
+ return x;
+ if (e < 12)
+ e = 1;
+ m = -1ULL >> e;
+ if ((u.i & m) == 0)
+ return x;
+ FORCE_EVAL(x + 0x1p120f);
+ u.i &= ~m;
+ return u.f;
+}