elf.h: add ELFCOMPRESS_ZSTD

[musl] / src / math / __fpclassifyl.c

diff --git a/src/math/__fpclassifyl.c b/src/math/__fpclassifyl.c
index 6365c58..e41781b 100644 (file)
--- a/src/math/__fpclassifyl.c
+++ b/src/math/__fpclassifyl.c
@@ -1,17 +1,30 @@
 #include "libm.h"
 
 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
-
+int __fpclassifyl(long double x)
+{
+       return __fpclassify(x);
+}
 #elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384
-/* invalid representations (top bit of u.i.m is wrong) are not handled */
 int __fpclassifyl(long double x)
 {
        union ldshape u = {x};
        int e = u.i.se & 0x7fff;
-       if (!e)
+       int msb = u.i.m>>63;
+       if (!e && !msb)
                return u.i.m ? FP_SUBNORMAL : FP_ZERO;
-       if (e == 0x7fff)
+       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;
        return FP_NORMAL;
 }
 #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384
@@ -19,12 +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