X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fmath%2F__fpclassifyl.c;h=e41781b689af7f7db420fc437cc4a72e4dd00c33;hb=c5f4b2dfea320356f69445dc1adf8f73596a3c36;hp=c274229716bcbed3c94e9077961b2905191619d3;hpb=0539e6dad39c1b3b204a14c403da68b587b1b3da;p=musl

diff --git a/src/math/__fpclassifyl.c b/src/math/__fpclassifyl.c
index c2742297..e41781b6 100644
--- a/src/math/__fpclassifyl.c
+++ b/src/math/__fpclassifyl.c
@@ -13,10 +13,18 @@ int __fpclassifyl(long double x)
 	int msb = u.i.m>>63;
 	if (!e && !msb)
 		return u.i.m ? FP_SUBNORMAL : FP_ZERO;
+	if (e == 0x7fff) {
+		/* The x86 variant of 80-bit extended precision only admits
+		 * one representation of each infinity, with the mantissa msb
+		 * necessarily set. The version with it clear is invalid/nan.
+		 * The m68k variant, however, allows either, and tooling uses
+		 * the version with it clear. */
+		if (__BYTE_ORDER == __LITTLE_ENDIAN && !msb)
+			return FP_NAN;
+		return u.i.m << 1 ? FP_NAN : FP_INFINITE;
+	}
 	if (!msb)
 		return FP_NAN;
-	if (e == 0x7fff)
-		return u.i.m << 1 ? FP_NAN : FP_INFINITE;
 	return FP_NORMAL;
 }
 #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
@@ -24,12 +32,11 @@ int __fpclassifyl(long double x)
 {
 	union ldshape u = {x};
 	int e = u.i.se & 0x7fff;
+	u.i.se = 0;
 	if (!e)
 		return u.i2.lo | u.i2.hi ? FP_SUBNORMAL : FP_ZERO;
-	if (e == 0x7fff) {
-		u.i.se = 0;
+	if (e == 0x7fff)
 		return u.i2.lo | u.i2.hi ? FP_NAN : FP_INFINITE;
-	}
 	return FP_NORMAL;
 }
 #endif