Fix atanhl missing underflows (bug 16352).

Similar to various other bugs in this area, some atanh implementations do not raise the underflow exception for subnormal arguments, when the result is tiny and inexact. This patch forces the exception in a similar way to previous fixes. (No change in this regard is needed for the i386 implementation; special handling to force underflows in these cases will only be needed there when the spurious underflows, bug 18049, get fixed.) Tested for x86_64, x86, powerpc and mips64. [BZ #16352] * sysdeps/i386/fpu/e_atanh.S (dbl_min): New object. (__ieee754_atanh): Force underflow exception for results with small absolute value. * sysdeps/i386/fpu/e_atanhf.S (flt_min): New object. (__ieee754_atanhf): Force underflow exception for results with small absolute value. * sysdeps/ieee754/dbl-64/e_atanh.c: Include <float.h>. (__ieee754_atanh): Force underflow exception for results with small absolute value. * sysdeps/ieee754/flt-32/e_atanhf.c: Include <float.h>. (__ieee754_atanhf): Force underflow exception for results with small absolute value. * sysdeps/ieee754/ldbl-128/e_atanhl.c: Include <float.h>. (__ieee754_atanhl): Force underflow exception for results with small absolute value. * sysdeps/ieee754/ldbl-128ibm/e_atanhl.c: Include <float.h>. (__ieee754_atanhl): Force underflow exception for results with small absolute value. * sysdeps/ieee754/ldbl-96/e_atanhl.c: Include <float.h>. (__ieee754_atanhl): Force underflow exception for results with small absolute value. * math/auto-libm-test-in: Do not allow missing underflow exceptions from atanh. * math/auto-libm-test-out: Regenerated.
git-mirror · May 15, 2015 · 8020a80 · 8020a80
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diff --git a/ChangeLog b/ChangeLog
@@ -1,5 +1,31 @@
 2015-05-15  Joseph Myers  <joseph@codesourcery.com>
 
+	[BZ #16352]
+	* sysdeps/i386/fpu/e_atanh.S (dbl_min): New object.
+	(__ieee754_atanh): Force underflow exception for results with
+	small absolute value.
+	* sysdeps/i386/fpu/e_atanhf.S (flt_min): New object.
+	(__ieee754_atanhf): Force underflow exception for results with
+	small absolute value.
+	* sysdeps/ieee754/dbl-64/e_atanh.c: Include <float.h>.
+	(__ieee754_atanh): Force underflow exception for results with
+	small absolute value.
+	* sysdeps/ieee754/flt-32/e_atanhf.c: Include <float.h>.
+	(__ieee754_atanhf): Force underflow exception for results with
+	small absolute value.
+	* sysdeps/ieee754/ldbl-128/e_atanhl.c: Include <float.h>.
+	(__ieee754_atanhl): Force underflow exception for results with
+	small absolute value.
+	* sysdeps/ieee754/ldbl-128ibm/e_atanhl.c: Include <float.h>.
+	(__ieee754_atanhl): Force underflow exception for results with
+	small absolute value.
+	* sysdeps/ieee754/ldbl-96/e_atanhl.c: Include <float.h>.
+	(__ieee754_atanhl): Force underflow exception for results with
+	small absolute value.
+	* math/auto-libm-test-in: Do not allow missing underflow
+	exceptions from atanh.
+	* math/auto-libm-test-out: Regenerated.
+
 	[BZ #18221]
 	* sysdeps/ieee754/flt-32/k_tanf.c (__kernel_tanf): Use 2**-13 not
 	2**-28 as threshold for returning x or +/- 1/x.

diff --git a/NEWS b/NEWS
@@ -10,14 +10,15 @@ Version 2.22
 * The following bugs are resolved with this release:
 
   4719, 6792, 13064, 14094, 14841, 14906, 15319, 15467, 15790, 15969, 16339,
-  16351, 16512, 16560, 16704, 16783, 16850, 17090, 17195, 17269, 17523,
-  17542, 17569, 17588, 17596, 17620, 17621, 17628, 17631, 17692, 17711,
-  17715, 17776, 17779, 17792, 17836, 17912, 17916, 17930, 17932, 17944,
-  17949, 17964, 17965, 17967, 17969, 17978, 17987, 17991, 17996, 17998,
-  17999, 18007, 18019, 18020, 18029, 18030, 18032, 18036, 18038, 18039,
-  18042, 18043, 18046, 18047, 18068, 18080, 18093, 18100, 18104, 18110,
-  18111, 18125, 18128, 18138, 18185, 18196, 18197, 18206, 18210, 18211,
-  18217, 18220, 18221, 18247, 18287, 18319, 18333, 18346, 18397, 18409.
+  16351, 16352, 16512, 16560, 16704, 16783, 16850, 17090, 17195, 17269,
+  17523, 17542, 17569, 17588, 17596, 17620, 17621, 17628, 17631, 17692,
+  17711, 17715, 17776, 17779, 17792, 17836, 17912, 17916, 17930, 17932,
+  17944, 17949, 17964, 17965, 17967, 17969, 17978, 17987, 17991, 17996,
+  17998, 17999, 18007, 18019, 18020, 18029, 18030, 18032, 18036, 18038,
+  18039, 18042, 18043, 18046, 18047, 18068, 18080, 18093, 18100, 18104,
+  18110, 18111, 18125, 18128, 18138, 18185, 18196, 18197, 18206, 18210,
+  18211, 18217, 18220, 18221, 18247, 18287, 18319, 18333, 18346, 18397,
+  18409.
 
 * Cache information can be queried via sysconf() function on s390 e.g. with
   _SC_LEVEL1_ICACHE_SIZE as argument.

diff --git a/math/auto-libm-test-in b/math/auto-libm-test-in
@@ -382,13 +382,12 @@ atanh 0x3.91d9f3c80c72d7acp-4
 atanh -0x2.6c52c26567198p-4
 atanh 0x3.a274ecp-4
 atanh -0x3.f0f519a687b64p-8
-# Bug 16352: underflow exception may be missing.
-atanh 0x1p-500 missing-underflow
-atanh 0x1p-5000 missing-underflow
-atanh min missing-underflow
-atanh -min missing-underflow
-atanh min_subnorm missing-underflow
-atanh -min_subnorm missing-underflow
+atanh 0x1p-500
+atanh 0x1p-5000
+atanh min
+atanh -min
+atanh min_subnorm
+atanh -min_subnorm
 
 # cabs (x,y) == cabs (y,x).
 cabs 0.75 12.390625

diff --git a/math/auto-libm-test-out b/math/auto-libm-test-out
diff --git a/sysdeps/i386/fpu/e_atanh.S b/sysdeps/i386/fpu/e_atanh.S
@@ -35,6 +35,13 @@ limit:	.double 0.29
 ln2_2:	.tfloat 0.3465735902799726547086160
 	ASM_SIZE_DIRECTIVE(ln2_2)
 
+	.section .rodata.cst8,"aM",@progbits,8
+
+	.p2align 3
+	.type dbl_min,@object
+dbl_min:	.byte 0, 0, 0, 0, 0, 0, 0x10, 0
+	ASM_SIZE_DIRECTIVE(dbl_min)
+
 #ifdef PIC
 #define MO(op) op##@GOTOFF(%edx)
 #else
@@ -81,7 +88,18 @@ ENTRY(__ieee754_atanh)
 	sahf
 	jae	4f
 	fyl2xp1			// 0.5*ln2*ld(1+2*|x|+(2*|x|^2)/(1-|x|))
-	jecxz	3f
+	fcoml	MO(dbl_min)
+	fnstsw
+	sahf
+	jae	8f
+	subl	$8, %esp
+	cfi_adjust_cfa_offset (8)
+	fld	%st(0)
+	fmul	%st(0)
+	fstpl	(%esp)
+	addl	$8, %esp
+	cfi_adjust_cfa_offset (-8)
+8:	jecxz	3f
 	fchs			// 0.5*ln2*ld(1+2*x+(2*x^2)/(1-x))
 3:	ret
 

diff --git a/sysdeps/i386/fpu/e_atanhf.S b/sysdeps/i386/fpu/e_atanhf.S
@@ -36,6 +36,13 @@ limit:	.double 0.29
 ln2_2:	.tfloat 0.3465735902799726547086160
 	ASM_SIZE_DIRECTIVE(ln2_2)
 
+	.section .rodata.cst4,"aM",@progbits,4
+
+	.p2align 2
+	.type flt_min,@object
+flt_min:	.byte 0, 0, 0x80, 0
+	ASM_SIZE_DIRECTIVE(flt_min)
+
 #ifdef PIC
 #define MO(op) op##@GOTOFF(%edx)
 #else
@@ -77,7 +84,18 @@ ENTRY(__ieee754_atanhf)
 	sahf
 	jae	4f
 	fyl2xp1			// 0.5*ln2*ld(1+2*|x|+(2*|x|^2)/(1-|x|))
-	jecxz	3f
+	fcoms	MO(flt_min)
+	fnstsw
+	sahf
+	jae	6f
+	subl	$4, %esp
+	cfi_adjust_cfa_offset (4)
+	fld	%st(0)
+	fmul	%st(0)
+	fstps	(%esp)
+	addl	$4, %esp
+	cfi_adjust_cfa_offset (-4)
+6:	jecxz	3f
 	fchs			// 0.5*ln2*ld(1+2*x+(2*x^2)/(1-x))
 3:	ret
 

diff --git a/sysdeps/ieee754/dbl-64/e_atanh.c b/sysdeps/ieee754/dbl-64/e_atanh.c
@@ -35,6 +35,7 @@
 
  */
 
+#include <float.h>
 #include <inttypes.h>
 #include <math.h>
 #include <math_private.h>
@@ -51,6 +52,11 @@ __ieee754_atanh (double x)
       if (__glibc_unlikely (xa < 0x1.0p-28))
 	{
 	  math_force_eval (huge + x);
+	  if (fabs (x) < DBL_MIN)
+	    {
+	      double force_underflow = x * x;
+	      math_force_eval (force_underflow);
+	    }
 	  return x;
 	}
 

diff --git a/sysdeps/ieee754/flt-32/e_atanhf.c b/sysdeps/ieee754/flt-32/e_atanhf.c
@@ -35,6 +35,7 @@
 
  */
 
+#include <float.h>
 #include <inttypes.h>
 #include <math.h>
 #include <math_private.h>
@@ -51,6 +52,11 @@ __ieee754_atanhf (float x)
       if (__glibc_unlikely (xa < 0x1.0p-28f))
 	{
 	  math_force_eval (huge + x);
+	  if (fabsf (x) < FLT_MIN)
+	    {
+	      float force_underflow = x * x;
+	      math_force_eval (force_underflow);
+	    }
 	  return x;
 	}
 

diff --git a/sysdeps/ieee754/ldbl-128/e_atanhl.c b/sysdeps/ieee754/ldbl-128/e_atanhl.c
@@ -32,6 +32,7 @@
  *
  */
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -57,7 +58,15 @@ __ieee754_atanhl(long double x)
 	    else
 	      return (x-x)/(x-x);
 	  }
-	if(ix<0x3fc60000 && (huge+x)>zero) return x;	/* x < 2^-57 */
+	if(ix<0x3fc60000 && (huge+x)>zero)	/* x < 2^-57 */
+	  {
+	    if (fabsl (x) < LDBL_MIN)
+	      {
+		long double force_underflow = x * x;
+		math_force_eval (force_underflow);
+	      }
+	    return x;
+	  }
 
 	if(ix<0x3ffe0000) {		/* x < 0.5 */
 	    t = u.value+u.value;

diff --git a/sysdeps/ieee754/ldbl-128ibm/e_atanhl.c b/sysdeps/ieee754/ldbl-128ibm/e_atanhl.c
@@ -28,6 +28,7 @@
  *
  */
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -54,7 +55,15 @@ __ieee754_atanhl(long double x)
 	    if (t == one)
 		return x/zero;
 	}
-	if(ix<0x3c70000000000000LL&&(huge+x)>zero) return x;	/* x<2**-56 */
+	if(ix<0x3c70000000000000LL&&(huge+x)>zero)	/* x<2**-56 */
+	  {
+	    if (fabsl (x) < LDBL_MIN)
+	      {
+		long double force_underflow = x * x;
+		math_force_eval (force_underflow);
+	      }
+	    return x;
+	  }
 	x = fabsl (x);
 	if(ix<0x3fe0000000000000LL) {		/* x < 0.5 */
 	    t = x+x;

diff --git a/sysdeps/ieee754/ldbl-96/e_atanhl.c b/sysdeps/ieee754/ldbl-96/e_atanhl.c
@@ -32,6 +32,7 @@
  *
  */
 
+#include <float.h>
 #include <math.h>
 #include <math_private.h>
 
@@ -54,6 +55,11 @@ __ieee754_atanhl(long double x)
 	    return x/zero;
 	if(ix<0x3fdf) {
 	    math_force_eval(huge+x);
+	    if (fabsl (x) < LDBL_MIN)
+	      {
+		long double force_underflow = x * x;
+		math_force_eval (force_underflow);
+	      }
 	    return x;	/* x<2**-32 */
 	}
 	SET_LDOUBLE_EXP(x,ix);