Fix frexp (NaN) (bug 20250).

Various implementations of frexp functions return sNaN for sNaN
input.  This patch fixes them to add such arguments to themselves so
that qNaN is returned.

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #20250]
	* sysdeps/i386/fpu/s_frexpl.S (__frexpl): Add non-finite input to
	itself.
	* sysdeps/ieee754/dbl-64/s_frexp.c (__frexp): Add non-finite or
	zero input to itself.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c (__frexp):
	Likewise.
	* sysdeps/ieee754/flt-32/s_frexpf.c (__frexpf): Likewise.
	* sysdeps/ieee754/ldbl-128/s_frexpl.c (__frexpl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_frexpl.c (__frexpl): Likewise.
	* sysdeps/ieee754/ldbl-96/s_frexpl.c (__frexpl): Likewise.
	* math/libm-test.inc (frexp_test_data): Add sNaN tests.

diff --git a/ChangeLog b/ChangeLog
index 84e6720fa40b1c845464fa2845d4051dbde02004..49fc9e7800b161e3814de0f774fbe89f9914ae5a 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,18 @@
+2016-06-13  Joseph Myers  <joseph@codesourcery.com>
+
+       [BZ #20250]
+       * sysdeps/i386/fpu/s_frexpl.S (__frexpl): Add non-finite input to
+       itself.
+       * sysdeps/ieee754/dbl-64/s_frexp.c (__frexp): Add non-finite or
+       zero input to itself.
+       * sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c (__frexp):
+       Likewise.
+       * sysdeps/ieee754/flt-32/s_frexpf.c (__frexpf): Likewise.
+       * sysdeps/ieee754/ldbl-128/s_frexpl.c (__frexpl): Likewise.
+       * sysdeps/ieee754/ldbl-128ibm/s_frexpl.c (__frexpl): Likewise.
+       * sysdeps/ieee754/ldbl-96/s_frexpl.c (__frexpl): Likewise.
+       * math/libm-test.inc (frexp_test_data): Add sNaN tests.
+
 2016-06-13  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
 
        * nptl/Makefile (test): Add tst-cancel4_1 and tst-cancel4_2.

diff --git a/math/libm-test.inc b/math/libm-test.inc
index 3d901ae96a5ac3cf9099e9ae6d760b91eec3cd09..81ca89662668de737c8eb368b855aba93c72ff28 100644 (file)
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -7760,6 +7760,8 @@ static const struct test_f_f1_data frexp_test_data[] =
     TEST_fI_f1 (frexp, minus_infty, minus_infty, IGNORE, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_fI_f1 (frexp, qnan_value, qnan_value, IGNORE, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_fI_f1 (frexp, -qnan_value, qnan_value, IGNORE, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
+    TEST_fI_f1 (frexp, snan_value, qnan_value, IGNORE, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
+    TEST_fI_f1 (frexp, -snan_value, qnan_value, IGNORE, NO_INEXACT_EXCEPTION|INVALID_EXCEPTION),
 
     TEST_fI_f1 (frexp, 0.0, 0.0, 0.0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),
     TEST_fI_f1 (frexp, minus_zero, minus_zero, 0.0, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED),

diff --git a/sysdeps/i386/fpu/s_frexpl.S b/sysdeps/i386/fpu/s_frexpl.S
index f687ab3c2edb03a22821e417b945790a31583cf7..b33a8a85738202a0fc3cd9477344e0639fdacf47 100644 (file)
--- a/sysdeps/i386/fpu/s_frexpl.S
+++ b/sysdeps/i386/fpu/s_frexpl.S
@@ -50,7 +50,7 @@ ENTRY (__frexpl)
        jz      1f
        xorl    %ecx, %ecx
        cmpl    $0x7fff, %eax
-       je      1f
+       je      3f
 
        cmpl    $0, %eax
        jne     2f
@@ -81,5 +81,12 @@ ENTRY (__frexpl)
        movl    %ecx, (%eax)
 
        ret
+
+       /* Infinity or NaN; ensure signaling NaNs are quieted.  */
+3:     movl    EXPP(%esp), %eax
+       fldt    VAL0(%esp)
+       fadd    %st
+       movl    %ecx, (%eax)
+       ret
 END (__frexpl)
 weak_alias (__frexpl, frexpl)

diff --git a/sysdeps/ieee754/dbl-64/s_frexp.c b/sysdeps/ieee754/dbl-64/s_frexp.c
index 1b8d8500ba89909319c05556ba79ce14593b1e28..874214ec7c8a746313afb72d2cc79a93b029fdb7 100644 (file)
--- a/sysdeps/ieee754/dbl-64/s_frexp.c
+++ b/sysdeps/ieee754/dbl-64/s_frexp.c
@@ -38,7 +38,7 @@ __frexp (double x, int *eptr)
   ix = 0x7fffffff & hx;
   *eptr = 0;
   if (ix >= 0x7ff00000 || ((ix | lx) == 0))
-    return x;                                           /* 0,inf,nan */
+    return x + x;                                           /* 0,inf,nan */
   if (ix < 0x00100000)                  /* subnormal */
     {
       x *= two54;

diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c
index 42068f8187ffdfd6382308c33f37fcf7049c34f6..4b075b720052ddec1d1fa4b939bff1c463ddddbf 100644 (file)
--- a/sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c
+++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c
@@ -55,6 +55,9 @@ __frexp (double x, int *eptr)
       ix = (ix & INT64_C (0x800fffffffffffff)) | INT64_C (0x3fe0000000000000);
       INSERT_WORDS64 (x, ix);
     }
+  else
+    /* Quiet signaling NaNs.  */
+    x += x;
 
   *eptr = e;
   return x;

diff --git a/sysdeps/ieee754/flt-32/s_frexpf.c b/sysdeps/ieee754/flt-32/s_frexpf.c
index 67a28d3603693844a8c9fc9315c94af2c3b6d2d1..005367cf585d96733880fa83e856de7dc3b33851 100644 (file)
--- a/sysdeps/ieee754/flt-32/s_frexpf.c
+++ b/sysdeps/ieee754/flt-32/s_frexpf.c
@@ -29,7 +29,7 @@ float __frexpf(float x, int *eptr)
        GET_FLOAT_WORD(hx,x);
        ix = 0x7fffffff&hx;
        *eptr = 0;
-       if(ix>=0x7f800000||(ix==0)) return x;   /* 0,inf,nan */
+       if(ix>=0x7f800000||(ix==0)) return x + x;       /* 0,inf,nan */
        if (ix<0x00800000) {            /* subnormal */
            x *= two25;
            GET_FLOAT_WORD(hx,x);

diff --git a/sysdeps/ieee754/ldbl-128/s_frexpl.c b/sysdeps/ieee754/ldbl-128/s_frexpl.c
index d61dddaaaa73daef69435888afe3df173c16acc0..70b2d3ae190dc366e9f3d63bd114c89400aadf55 100644 (file)
--- a/sysdeps/ieee754/ldbl-128/s_frexpl.c
+++ b/sysdeps/ieee754/ldbl-128/s_frexpl.c
@@ -39,7 +39,7 @@ long double __frexpl(long double x, int *eptr)
        GET_LDOUBLE_WORDS64(hx,lx,x);
        ix = 0x7fffffffffffffffULL&hx;
        *eptr = 0;
-       if(ix>=0x7fff000000000000ULL||((ix|lx)==0)) return x;   /* 0,inf,nan */
+       if(ix>=0x7fff000000000000ULL||((ix|lx)==0)) return x + x;/* 0,inf,nan */
        if (ix<0x0001000000000000ULL) {         /* subnormal */
            x *= two114;
            GET_LDOUBLE_MSW64(hx,x);

diff --git a/sysdeps/ieee754/ldbl-128ibm/s_frexpl.c b/sysdeps/ieee754/ldbl-128ibm/s_frexpl.c
index 52d2d3ea900c1922796cc49cf09d4525df5db3f1..210c5d2ed4fba9a8f25cfc7af927252dee323461 100644 (file)
--- a/sysdeps/ieee754/ldbl-128ibm/s_frexpl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_frexpl.c
@@ -47,7 +47,7 @@ long double __frexpl(long double x, int *eptr)
     {
       /* 0,inf,nan.  */
       *eptr = expon;
-      return x;
+      return x + x;
     }
   expon = ix >> 52;
   if (expon == 0)

diff --git a/sysdeps/ieee754/ldbl-96/s_frexpl.c b/sysdeps/ieee754/ldbl-96/s_frexpl.c
index ab217a659b624278f36ba295575c106db517d7b5..799880f37389c7b0e4d24e2b5782f1561c7b810e 100644 (file)
--- a/sysdeps/ieee754/ldbl-96/s_frexpl.c
+++ b/sysdeps/ieee754/ldbl-96/s_frexpl.c
@@ -46,7 +46,7 @@ long double __frexpl(long double x, int *eptr)
        GET_LDOUBLE_WORDS(se,hx,lx,x);
        ix = 0x7fff&se;
        *eptr = 0;
-       if(ix==0x7fff||((ix|hx|lx)==0)) return x;       /* 0,inf,nan */
+       if(ix==0x7fff||((ix|hx|lx)==0)) return x + x;   /* 0,inf,nan */
        if (ix==0x0000) {               /* subnormal */
            x *= two65;
            GET_LDOUBLE_EXP(se,x);