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-rw-r--r--src/math/tanhf.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/src/math/tanhf.c b/src/math/tanhf.c
index 8099ec30..10636fbd 100644
--- a/src/math/tanhf.c
+++ b/src/math/tanhf.c
@@ -17,7 +17,7 @@ float tanhf(float x)
/* |x| > log(3)/2 ~= 0.5493 or nan */
if (w > 0x41200000) {
/* |x| > 10 */
- t = 1 + 0/(x + 0x1p-120f);
+ t = 1 + 0/x;
} else {
t = expm1f(2*x);
t = 1 - 2/(t+2);
@@ -26,10 +26,14 @@ float tanhf(float x)
/* |x| > log(5/3)/2 ~= 0.2554 */
t = expm1f(2*x);
t = t/(t+2);
- } else {
- /* |x| is small */
+ } else if (w >= 0x00800000) {
+ /* |x| >= 0x1p-126 */
t = expm1f(-2*x);
t = -t/(t+2);
+ } else {
+ /* |x| is subnormal */
+ FORCE_EVAL(x*x);
+ t = x;
}
return sign ? -t : t;
}