X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fmath%2Filogbf.c;h=e23ba209ec4cd1c7648ca903e6b3aa948c6dc053;hb=03919b26ed41c31876db41f7cee076ced4513fad;hp=272cbdac0ccf36dc2bb9d2ede7116853cad1748f;hpb=b69f695acedd4ce2798ef9ea28d834ceccc789bd;p=musl

diff --git a/src/math/ilogbf.c b/src/math/ilogbf.c
index 272cbdac..e23ba209 100644
--- a/src/math/ilogbf.c
+++ b/src/math/ilogbf.c
@@ -3,18 +3,24 @@
 
 int ilogbf(float x)
 {
-	union fshape u = {x};
-	int e = u.bits>>23 & 0xff;
+	#pragma STDC FENV_ACCESS ON
+	union {float f; uint32_t i;} u = {x};
+	uint32_t i = u.i;
+	int e = i>>23 & 0xff;
 
 	if (!e) {
-		u.bits <<= 9;
-		if (u.bits == 0)
+		i <<= 9;
+		if (i == 0) {
+			FORCE_EVAL(0/0.0f);
 			return FP_ILOGB0;
+		}
 		/* subnormal x */
-		for (e = -0x7f; u.bits < (uint32_t)1<<31; e--, u.bits<<=1);
+		for (e = -0x7f; i>>31 == 0; e--, i<<=1);
 		return e;
 	}
-	if (e == 0xff)
-		return u.bits<<9 ? FP_ILOGBNAN : INT_MAX;
+	if (e == 0xff) {
+		FORCE_EVAL(0/0.0f);
+		return i<<9 ? FP_ILOGBNAN : INT_MAX;
+	}
 	return e - 0x7f;
 }