Fix nexttoward bugs (bugs 2550, 2570).

12 files changed, 121 insertions, 82 deletions

diff --git a/ChangeLog b/ChangeLog
index 55e17eb..74b4c0b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,24 @@
+2012-05-01  Joseph Myers  <joseph@codesourcery.com>
+
+	[BZ #2550]
+	[BZ #2570]
+	* math/s_nexttowardf.c (__nexttowardf): Use floating-point
+	comparisons to determine direction to adjust input.
+	* sysdeps/i386/fpu/s_nexttoward.c (__nexttoward): Likewise.
+	* sysdeps/i386/fpu/s_nexttowardf.c(__nexttowardf): Likewise.
+	* sysdeps/ieee754/ldbl-128/s_nexttoward.c (__nexttoward):
+	Likewise.
+	* sysdeps/ieee754/ldbl-128/s_nexttowardf.c (__nexttowardf):
+	Likewise.
+	* sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c (__nexttowardf):
+	Likewise.
+	* sysdeps/ieee754/ldbl-96/s_nexttoward.c (__nexttoward): Likewise.
+	* sysdeps/ieee754/ldbl-96/s_nexttowardf.c (__nexttowardf):
+	Likewise.
+	* sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c (__nldbl_nexttowardf):
+	Likewise.
+	* math/libm-test.inc (nexttoward_test): Add more tests.
+
 2012-05-01  Andreas Schwab  <schwab@linux-m68k.org>
 
 	[BZ #14040]
diff --git a/NEWS b/NEWS
index fdf3621..e429cef 100644
--- a/NEWS
+++ b/NEWS
@@ -9,20 +9,21 @@ Version 2.16
 
 * The following bugs are resolved with this release:
 
-  174, 350, 369, 411, 706, 887, 2074, 2541, 2547, 2548, 2551, 2552, 2553,
-  2554, 2562, 2563, 2565, 2566, 2576, 2636, 2678, 3335, 3768, 3866, 3868,
-  3976, 3992, 4026, 4108, 4596, 4822, 5077, 5461, 5805, 5993, 6471, 6486,
-  6578, 6649, 6730, 6770, 6794, 6884, 6890, 6894, 6895, 6907, 6911, 7064,
-  9739, 9902, 10110, 10135, 10140, 10153, 10210, 10254, 10346, 10545, 10716,
-  11174, 11322, 11365, 11451, 11494, 11521, 11959, 12047, 12340, 13058,
-  13525, 13526, 13527, 13528, 13529, 13530, 13531, 13532, 13533, 13547,
-  13551, 13552, 13553, 13555, 13559, 13566, 13583, 13592, 13618, 13637,
-  13656, 13658, 13673, 13691, 13695, 13704, 13705, 13706, 13726, 13738,
-  13739, 13758, 13760, 13761, 13786, 13792, 13806, 13824, 13840, 13841,
-  13844, 13846, 13851, 13852, 13854, 13871, 13872, 13873, 13879, 13883,
-  13886, 13892, 13895, 13908, 13910, 13911, 13912, 13913, 13915, 13916,
-  13917, 13918, 13919, 13920, 13921, 13924, 13926, 13927, 13928, 13938,
-  13941, 13942, 13963, 13967, 13970, 13973, 14027, 14033, 14034, 14040
+  174, 350, 369, 411, 706, 887, 2074, 2541, 2547, 2548, 2550, 2551, 2552,
+  2553, 2554, 2562, 2563, 2565, 2566, 2570, 2576, 2636, 2678, 3335, 3768,
+  3866, 3868, 3976, 3992, 4026, 4108, 4596, 4822, 5077, 5461, 5805, 5993,
+  6471, 6486, 6578, 6649, 6730, 6770, 6794, 6884, 6890, 6894, 6895, 6907,
+  6911, 7064, 9739, 9902, 10110, 10135, 10140, 10153, 10210, 10254, 10346,
+  10545, 10716, 11174, 11322, 11365, 11451, 11494, 11521, 11959, 12047,
+  12340, 13058, 13525, 13526, 13527, 13528, 13529, 13530, 13531, 13532,
+  13533, 13547, 13551, 13552, 13553, 13555, 13559, 13566, 13583, 13592,
+  13618, 13637, 13656, 13658, 13673, 13691, 13695, 13704, 13705, 13706,
+  13726, 13738, 13739, 13758, 13760, 13761, 13786, 13792, 13806, 13824,
+  13840, 13841, 13844, 13846, 13851, 13852, 13854, 13871, 13872, 13873,
+  13879, 13883, 13886, 13892, 13895, 13908, 13910, 13911, 13912, 13913,
+  13915, 13916, 13917, 13918, 13919, 13920, 13921, 13924, 13926, 13927,
+  13928, 13938, 13941, 13942, 13963, 13967, 13970, 13973, 14027, 14033,
+  14034, 14040
 
 * ISO C11 support:
 
diff --git a/math/libm-test.inc b/math/libm-test.inc
index d643bad..0875e2c 100644
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -5743,8 +5743,73 @@ nexttoward_test (void)
   TEST_ff_f (nexttoward, 1.1L, nan_value, nan_value);
   TEST_ff_f (nexttoward, nan_value, nan_value, nan_value);
 
-  /* XXX We need the hexadecimal FP number representation here for further
-     tests.  */
+#ifdef TEST_FLOAT
+  TEST_ff_f (nexttoward, 1.0, 1.1L, 0x1.000002p0);
+  TEST_ff_f (nexttoward, 1.0, LDBL_MAX, 0x1.000002p0);
+  TEST_ff_f (nexttoward, 1.0, 0x1.0000000000001p0, 0x1.000002p0);
+  TEST_ff_f (nexttoward, 1.0, 0.9L, 0x0.ffffffp0);
+  TEST_ff_f (nexttoward, 1.0, -LDBL_MAX, 0x0.ffffffp0);
+  TEST_ff_f (nexttoward, 1.0, 0x0.fffffffffffff8p0, 0x0.ffffffp0);
+  TEST_ff_f (nexttoward, -1.0, -1.1L, -0x1.000002p0);
+  TEST_ff_f (nexttoward, -1.0, -LDBL_MAX, -0x1.000002p0);
+  TEST_ff_f (nexttoward, -1.0, -0x1.0000000000001p0, -0x1.000002p0);
+  TEST_ff_f (nexttoward, -1.0, -0.9L, -0x0.ffffffp0);
+  TEST_ff_f (nexttoward, -1.0, LDBL_MAX, -0x0.ffffffp0);
+  TEST_ff_f (nexttoward, -1.0, -0x0.fffffffffffff8p0, -0x0.ffffffp0);
+  TEST_ff_f (nexttoward, -0x1.3p-145, -0xap-148L, -0x1.4p-145);
+# if LDBL_MANT_DIG >= 64
+  TEST_ff_f (nexttoward, 1.0, 0x1.000000000000002p0L, 0x1.000002p0);
+  TEST_ff_f (nexttoward, 1.0, 0x0.ffffffffffffffffp0L, 0x0.ffffffp0);
+  TEST_ff_f (nexttoward, -1.0, -0x1.000000000000002p0L, -0x1.000002p0);
+  TEST_ff_f (nexttoward, -1.0, -0x0.ffffffffffffffffp0L, -0x0.ffffffp0);
+# endif
+# if LDBL_MANT_DIG >= 106
+  TEST_ff_f (nexttoward, 1.0, 0x1.000000000000000000000000008p0L, 0x1.000002p0);
+  TEST_ff_f (nexttoward, 1.0, 0x0.ffffffffffffffffffffffffffcp0L, 0x0.ffffffp0);
+  TEST_ff_f (nexttoward, -1.0, -0x1.000000000000000000000000008p0L, -0x1.000002p0);
+  TEST_ff_f (nexttoward, -1.0, -0x0.ffffffffffffffffffffffffffcp0L, -0x0.ffffffp0);
+# endif
+# if LDBL_MANT_DIG >= 113
+  TEST_ff_f (nexttoward, 1.0, 0x1.0000000000000000000000000001p0L, 0x1.000002p0);
+  TEST_ff_f (nexttoward, 1.0, 0x0.ffffffffffffffffffffffffffff8p0L, 0x0.ffffffp0);
+  TEST_ff_f (nexttoward, -1.0, -0x1.0000000000000000000000000001p0L, -0x1.000002p0);
+  TEST_ff_f (nexttoward, -1.0, -0x0.ffffffffffffffffffffffffffff8p0L, -0x0.ffffffp0);
+# endif
+#endif
+#ifdef TEST_DOUBLE
+  TEST_ff_f (nexttoward, 1.0, 1.1L, 0x1.0000000000001p0);
+  TEST_ff_f (nexttoward, 1.0, LDBL_MAX, 0x1.0000000000001p0);
+  TEST_ff_f (nexttoward, 1.0, 0x1.0000000000001p0, 0x1.0000000000001p0);
+  TEST_ff_f (nexttoward, 1.0, 0.9L, 0x0.fffffffffffff8p0);
+  TEST_ff_f (nexttoward, 1.0, -LDBL_MAX, 0x0.fffffffffffff8p0);
+  TEST_ff_f (nexttoward, 1.0, 0x0.fffffffffffff8p0, 0x0.fffffffffffff8p0);
+  TEST_ff_f (nexttoward, -1.0, -1.1L, -0x1.0000000000001p0);
+  TEST_ff_f (nexttoward, -1.0, -LDBL_MAX, -0x1.0000000000001p0);
+  TEST_ff_f (nexttoward, -1.0, -0x1.0000000000001p0, -0x1.0000000000001p0);
+  TEST_ff_f (nexttoward, -1.0, -0.9L, -0x0.fffffffffffff8p0);
+  TEST_ff_f (nexttoward, -1.0, LDBL_MAX, -0x0.fffffffffffff8p0);
+  TEST_ff_f (nexttoward, -1.0, -0x0.fffffffffffff8p0, -0x0.fffffffffffff8p0);
+  TEST_ff_f (nexttoward, -1.0, -0x8.00346dc5d6388p-3L, -0x1.0000000000001p0);
+  TEST_ff_f (nexttoward, 0x1p-1074, 0x1p-1073L, 0x1p-1073);
+# if LDBL_MANT_DIG >= 64
+  TEST_ff_f (nexttoward, 1.0, 0x1.000000000000002p0L, 0x1.0000000000001p0);
+  TEST_ff_f (nexttoward, 1.0, 0x0.ffffffffffffffffp0L, 0x0.fffffffffffff8p0);
+  TEST_ff_f (nexttoward, -1.0, -0x1.000000000000002p0L, -0x1.0000000000001p0);
+  TEST_ff_f (nexttoward, -1.0, -0x0.ffffffffffffffffp0L, -0x0.fffffffffffff8p0);
+# endif
+# if LDBL_MANT_DIG >= 106
+  TEST_ff_f (nexttoward, 1.0, 0x1.000000000000000000000000008p0L, 0x1.0000000000001p0);
+  TEST_ff_f (nexttoward, 1.0, 0x0.ffffffffffffffffffffffffffcp0L, 0x0.fffffffffffff8p0);
+  TEST_ff_f (nexttoward, -1.0, -0x1.000000000000000000000000008p0L, -0x1.0000000000001p0);
+  TEST_ff_f (nexttoward, -1.0, -0x0.ffffffffffffffffffffffffffcp0L, -0x0.fffffffffffff8p0);
+# endif
+# if LDBL_MANT_DIG >= 113
+  TEST_ff_f (nexttoward, 1.0, 0x1.0000000000000000000000000001p0L, 0x1.0000000000001p0);
+  TEST_ff_f (nexttoward, 1.0, 0x0.ffffffffffffffffffffffffffff8p0L, 0x0.fffffffffffff8p0);
+  TEST_ff_f (nexttoward, -1.0, -0x1.0000000000000000000000000001p0L, -0x1.0000000000001p0);
+  TEST_ff_f (nexttoward, -1.0, -0x0.ffffffffffffffffffffffffffff8p0L, -0x0.fffffffffffff8p0);
+# endif
+#endif
 
   END (nexttoward);
 }
diff --git a/math/s_nexttowardf.c b/math/s_nexttowardf.c
index fb008d5..e8c4dd1 100644
--- a/math/s_nexttowardf.c
+++ b/math/s_nexttowardf.c
@@ -47,16 +47,12 @@ float __nexttowardf(float x, long double y)
 	    return x;
 	}
 	if(hx>=0) {				/* x > 0 */
-	    if(hy<0||(ix>>23)>(iy>>20)-0x380
-	       || ((ix>>23)==(iy>>20)-0x380
-		   && (ix&0x7fffff)>(((hy<<3)|(ly>>29))&0x7fffff)))	/* x > y, x -= ulp */
+	    if(x > y)				/* x -= ulp */
 		hx -= 1;
 	    else				/* x < y, x += ulp */
 		hx += 1;
 	} else {				/* x < 0 */
-	    if(hy>=0||(ix>>23)>(iy>>20)-0x380
-	       || ((ix>>23)==(iy>>20)-0x380
-		   && (ix&0x7fffff)>(((hy<<3)|(ly>>29))&0x7fffff)))	/* x < y, x -= ulp */
+	    if(x < y)				/* x -= ulp */
 		hx -= 1;
 	    else				/* x > y, x += ulp */
 		hx += 1;
diff --git a/sysdeps/i386/fpu/s_nexttoward.c b/sysdeps/i386/fpu/s_nexttoward.c
index e5f0164..74147c4 100644
--- a/sysdeps/i386/fpu/s_nexttoward.c
+++ b/sysdeps/i386/fpu/s_nexttoward.c
@@ -55,11 +55,7 @@ double __nexttoward(double x, long double y)
 	    return x;
 	}
 	if(hx>=0) {				/* x > 0 */
-	    if (esy>=0x8000||((ix>>20)&0x7ff)>iy-0x3c00
-		|| (((ix>>20)&0x7ff)==iy-0x3c00
-		    && (((hx<<11)|(lx>>21))>(hy&0x7fffffff)
-			|| (((hx<<11)|(lx>>21))==(hy&0x7fffffff)
-			    && (lx<<11)>ly)))) {	/* x > y, x -= ulp */
+	    if (x > y) {			/* x -= ulp */
 		if(lx==0) hx -= 1;
 		lx -= 1;
 	    } else {				/* x < y, x += ulp */
@@ -67,11 +63,7 @@ double __nexttoward(double x, long double y)
 		if(lx==0) hx += 1;
 	    }
 	} else {				/* x < 0 */
-	    if (esy<0x8000||((ix>>20)&0x7ff)>iy-0x3c00
-		|| (((ix>>20)&0x7ff)==iy-0x3c00
-		    && (((hx<<11)|(lx>>21))>(hy&0x7fffffff)
-			|| (((hx<<11)|(lx>>21))==(hy&0x7fffffff)
-			    && (lx<<11)>ly))))	{/* x < y, x -= ulp */
+	    if (x < y) {			/* x -= ulp */
 		if(lx==0) hx -= 1;
 		lx -= 1;
 	    } else {				/* x > y, x += ulp */
diff --git a/sysdeps/i386/fpu/s_nexttowardf.c b/sysdeps/i386/fpu/s_nexttowardf.c
index 89e8771..49651be 100644
--- a/sysdeps/i386/fpu/s_nexttowardf.c
+++ b/sysdeps/i386/fpu/s_nexttowardf.c
@@ -47,17 +47,13 @@ float __nexttowardf(float x, long double y)
 	    return x;
 	}
 	if(hx>=0) {				/* x > 0 */
-	    if(esy>=0x8000||((ix>>23)&0xff)>iy-0x3f80
-	       || (((ix>>23)&0xff)==iy-0x3f80
-		   && ((ix&0x7fffff)<<8)>(hy&0x7fffffff))) {/* x > y, x -= ulp */
+	    if(x > y) {				/* x -= ulp */
 		hx -= 1;
 	    } else {				/* x < y, x += ulp */
 		hx += 1;
 	    }
 	} else {				/* x < 0 */
-	    if(esy<0x8000||((ix>>23)&0xff)>iy-0x3f80
-	       || (((ix>>23)&0xff)==iy-0x3f80
-		   && ((ix&0x7fffff)<<8)>(hy&0x7fffffff))) {/* x < y, x -= ulp */
+	    if(x < y) {				/* x -= ulp */
 		hx -= 1;
 	    } else {				/* x > y, x += ulp */
 		hx += 1;
diff --git a/sysdeps/ieee754/ldbl-128/s_nexttoward.c b/sysdeps/ieee754/ldbl-128/s_nexttoward.c
index 87a9a6c..1ea0b64 100644
--- a/sysdeps/ieee754/ldbl-128/s_nexttoward.c
+++ b/sysdeps/ieee754/ldbl-128/s_nexttoward.c
@@ -55,11 +55,7 @@ double __nexttoward(double x, long double y)
 	    return x;
 	}
 	if(hx>=0) {				/* x > 0 */
-	    if (hy<0||(ix>>20)>(iy>>48)-0x3c00
-		|| ((ix>>20)==(iy>>48)-0x3c00
-		    && (((((int64_t)hx)<<28)|(lx>>4))>(hy&0x0000ffffffffffffLL)
-			|| (((((int64_t)hx)<<28)|(lx>>4))==(hy&0x0000ffffffffffffLL)
-			    && (lx&0xf)>(ly>>60))))) {	/* x > y, x -= ulp */
+	    if (x > y) {			/* x -= ulp */
 		if(lx==0) hx -= 1;
 		lx -= 1;
 	    } else {				/* x < y, x += ulp */
@@ -67,11 +63,7 @@ double __nexttoward(double x, long double y)
 		if(lx==0) hx += 1;
 	    }
 	} else {				/* x < 0 */
-	    if (hy>=0||(ix>>20)>(iy>>48)-0x3c00
-		|| ((ix>>20)==(iy>>48)-0x3c00
-		    && (((((int64_t)hx)<<28)|(lx>>4))>(hy&0x0000ffffffffffffLL)
-			|| (((((int64_t)hx)<<28)|(lx>>4))==(hy&0x0000ffffffffffffLL)
-			    && (lx&0xf)>(ly>>60))))) {	/* x < y, x -= ulp */
+	    if (x < y) {			/* x -= ulp */
 		if(lx==0) hx -= 1;
 		lx -= 1;
 	    } else {				/* x > y, x += ulp */
diff --git a/sysdeps/ieee754/ldbl-128/s_nexttowardf.c b/sysdeps/ieee754/ldbl-128/s_nexttowardf.c
index 371fa80..02a1407 100644
--- a/sysdeps/ieee754/ldbl-128/s_nexttowardf.c
+++ b/sysdeps/ieee754/ldbl-128/s_nexttowardf.c
@@ -46,17 +46,13 @@ float __nexttowardf(float x, long double y)
 	    return x;
 	}
 	if(hx>=0) {				/* x > 0 */
-	    if(hy<0||(ix>>23)>(iy>>48)-0x3f80
-	       || ((ix>>23)==(iy>>48)-0x3f80
-		   && (ix&0x7fffff)>((hy>>25)&0x7fffff))) {/* x > y, x -= ulp */
+	    if(x > y) {				/* x -= ulp */
 		hx -= 1;
 	    } else {				/* x < y, x += ulp */
 		hx += 1;
 	    }
 	} else {				/* x < 0 */
-	    if(hy>=0||(ix>>23)>(iy>>48)-0x3f80
-	       || ((ix>>23)==(iy>>48)-0x3f80
-		   && (ix&0x7fffff)>((hy>>25)&0x7fffff))) {/* x < y, x -= ulp */
+	    if(x < y) {				/* x < y, x -= ulp */
 		hx -= 1;
 	    } else {				/* x > y, x += ulp */
 		hx += 1;
diff --git a/sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c b/sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c
index a674583..b387a91 100644
--- a/sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c
+++ b/sysdeps/ieee754/ldbl-128ibm/s_nexttowardf.c
@@ -49,17 +49,13 @@ float __nexttowardf(float x, long double y)
 	    return x;
 	}
 	if(hx>=0) {				/* x > 0 */
-	    if(hy<0||(ix>>23)>(iy>>52)-0x380
-	       || ((ix>>23)==(iy>>52)-0x380
-		   && (ix&0x7fffff)>((hy>>29)&0x7fffff))) {/* x > y, x -= ulp */
+	    if(x > y) {				/* x -= ulp */
 		hx -= 1;
 	    } else {				/* x < y, x += ulp */
 		hx += 1;
 	    }
 	} else {				/* x < 0 */
-	    if(hy>=0||(ix>>23)>(iy>>52)-0x380
-	       || ((ix>>23)==(iy>>52)-0x380
-		   && (ix&0x7fffff)>((hy>>29)&0x7fffff))) {/* x < y, x -= ulp */
+	    if(x < y) {				/* x -= ulp */
 		hx -= 1;
 	    } else {				/* x > y, x += ulp */
 		hx += 1;
diff --git a/sysdeps/ieee754/ldbl-96/s_nexttoward.c b/sysdeps/ieee754/ldbl-96/s_nexttoward.c
index 9b93eca..f7a8b21 100644
--- a/sysdeps/ieee754/ldbl-96/s_nexttoward.c
+++ b/sysdeps/ieee754/ldbl-96/s_nexttoward.c
@@ -52,11 +52,7 @@ double __nexttoward(double x, long double y)
 	    return x;
 	}
 	if(hx>=0) {				/* x > 0 */
-	    if (esy>=0x8000||((ix>>20)&0x7ff)>iy-0x3c00
-		|| (((ix>>20)&0x7ff)==iy-0x3c00
-		    && (((hx<<11)|(lx>>21))>(hy&0x7fffffff)
-			|| (((hx<<11)|(lx>>21))==(hy&0x7fffffff)
-			    && (lx<<11)>ly)))) {	/* x > y, x -= ulp */
+	    if (x > y) {			/* x -= ulp */
 		if(lx==0) hx -= 1;
 		lx -= 1;
 	    } else {				/* x < y, x += ulp */
@@ -64,11 +60,7 @@ double __nexttoward(double x, long double y)
 		if(lx==0) hx += 1;
 	    }
 	} else {				/* x < 0 */
-	    if (esy<0x8000||((ix>>20)&0x7ff)>iy-0x3c00
-		|| (((ix>>20)&0x7ff)==iy-0x3c00
-		    && (((hx<<11)|(lx>>21))>(hy&0x7fffffff)
-			|| (((hx<<11)|(lx>>21))==(hy&0x7fffffff)
-			    && (lx<<11)>ly))))	{/* x < y, x -= ulp */
+	    if (x < y) {			/* x -= ulp */
 		if(lx==0) hx -= 1;
 		lx -= 1;
 	    } else {				/* x > y, x += ulp */
diff --git a/sysdeps/ieee754/ldbl-96/s_nexttowardf.c b/sysdeps/ieee754/ldbl-96/s_nexttowardf.c
index aeb92b6..a96f9da 100644
--- a/sysdeps/ieee754/ldbl-96/s_nexttowardf.c
+++ b/sysdeps/ieee754/ldbl-96/s_nexttowardf.c
@@ -44,17 +44,13 @@ float __nexttowardf(float x, long double y)
 	    return x;
 	}
 	if(hx>=0) {				/* x > 0 */
-	    if(esy>=0x8000||((ix>>23)&0xff)>iy-0x3f80
-	       || (((ix>>23)&0xff)==iy-0x3f80
-		   && ((ix&0x7fffff)<<8)>(hy&0x7fffffff))) {/* x > y, x -= ulp */
+	    if(x > y) {				/* x -= ulp */
 		hx -= 1;
 	    } else {				/* x < y, x += ulp */
 		hx += 1;
 	    }
 	} else {				/* x < 0 */
-	    if(esy<0x8000||((ix>>23)&0xff)>iy-0x3f80
-	       || (((ix>>23)&0xff)==iy-0x3f80
-		   && ((ix&0x7fffff)<<8)>(hy&0x7fffffff))) {/* x < y, x -= ulp */
+	    if(x < y) {				/* x -= ulp */
 		hx -= 1;
 	    } else {				/* x > y, x += ulp */
 		hx += 1;
diff --git a/sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c b/sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c
index 68027f2..7eca121 100644
--- a/sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c
+++ b/sysdeps/ieee754/ldbl-opt/s_nexttowardfd.c
@@ -50,16 +50,12 @@ float __nldbl_nexttowardf(float x, double y)
 	    return x;
 	}
 	if(hx>=0) {				/* x > 0 */
-	    if(hy<0||(ix>>23)>(iy>>20)-0x380
-	       || ((ix>>23)==(iy>>20)-0x380
-		   && (ix&0x7fffff)>(((hy<<3)|(ly>>29))&0x7fffff)))	/* x > y, x -= ulp */
+	    if(x > y)				/* x -= ulp */
 		hx -= 1;
 	    else				/* x < y, x += ulp */
 		hx += 1;
 	} else {				/* x < 0 */
-	    if(hy>=0||(ix>>23)>(iy>>20)-0x380
-	       || ((ix>>23)==(iy>>20)-0x380
-		   && (ix&0x7fffff)>(((hy<<3)|(ly>>29))&0x7fffff)))	/* x < y, x -= ulp */
+	    if(x < y)				/* x -= ulp */
 		hx -= 1;
 	    else				/* x > y, x += ulp */
 		hx += 1;