Fix acos (-1) in round-downwards mode on x86 (bug 14034).

8 files changed, 618 insertions, 1 deletions

diff --git a/ChangeLog b/ChangeLog
index 7a65e6c5b5..f436af4083 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,22 @@
 2012-04-30  Joseph Myers  <joseph@codesourcery.com>
 
+	[BZ #14034]
+	* sysdeps/i386/fpu/e_acos.S (__ieee754_acos): Take absolute value
+	of square root.
+	* sysdeps/i386/fpu/e_acosf.S (__ieee754_acosf): Likewise.
+	* sysdeps/i386/fpu/e_acosl.c (__ieee754_acosl): Likewise.
+	* math/libm-test.inc (acos_test_tonearest): New function.
+	(acos_test_towardzero): Likewise.
+	(acos_test_downward): Likewise.
+	(acos_test_upward): Likewise.
+	(asin_test_tonearest): Likewise.
+	(asin_test_towardzero): Likewise.
+	(asin_test_downward): Likewise.
+	(asin_test_upward): Likewise.
+	(main): Call the new functions.
+	* sysdeps/i386/fpu/libm-test-ulps: Update.
+	* sysdeps/x86_64/fpu/libm-test-ulps: Update.
+
 	[BZ #13884]
 	[BZ #13924]
 	* math/e_exp10.c: Include <float.h>.
diff --git a/NEWS b/NEWS
index da9174eff8..4481ea43fc 100644
--- a/NEWS
+++ b/NEWS
@@ -22,7 +22,7 @@ Version 2.16
   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, 13963, 13967, 13970, 13973, 14027, 14033
+  13941, 13963, 13967, 13970, 13973, 14027, 14033, 14034
 
 * ISO C11 support:
 
diff --git a/math/libm-test.inc b/math/libm-test.inc
index cd627cd829..bedff09fea 100644
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -761,6 +761,126 @@ acos_test (void)
   END (acos);
 }
 
+
+static void
+acos_test_tonearest (void)
+{
+  int save_round_mode;
+  errno = 0;
+  FUNC(acos) (0);
+  if (errno == ENOSYS)
+    /* Function not implemented.  */
+    return;
+
+  START (acos_tonearest);
+
+  save_round_mode = fegetround ();
+
+  if (!fesetround (FE_TONEAREST))
+    {
+      TEST_f_f (acos, 0, M_PI_2l);
+      TEST_f_f (acos, minus_zero, M_PI_2l);
+      TEST_f_f (acos, 1, 0);
+      TEST_f_f (acos, -1, M_PIl);
+      TEST_f_f (acos, 0.5, M_PI_6l*2.0);
+      TEST_f_f (acos, -0.5, M_PI_6l*4.0);
+    }
+
+  fesetround (save_round_mode);
+
+  END (acos_tonearest);
+}
+
+
+static void
+acos_test_towardzero (void)
+{
+  int save_round_mode;
+  errno = 0;
+  FUNC(acos) (0);
+  if (errno == ENOSYS)
+    /* Function not implemented.  */
+    return;
+
+  START (acos_towardzero);
+
+  save_round_mode = fegetround ();
+
+  if (!fesetround (FE_TOWARDZERO))
+    {
+      TEST_f_f (acos, 0, M_PI_2l);
+      TEST_f_f (acos, minus_zero, M_PI_2l);
+      TEST_f_f (acos, 1, 0);
+      TEST_f_f (acos, -1, M_PIl);
+      TEST_f_f (acos, 0.5, M_PI_6l*2.0);
+      TEST_f_f (acos, -0.5, M_PI_6l*4.0);
+    }
+
+  fesetround (save_round_mode);
+
+  END (acos_towardzero);
+}
+
+
+static void
+acos_test_downward (void)
+{
+  int save_round_mode;
+  errno = 0;
+  FUNC(acos) (0);
+  if (errno == ENOSYS)
+    /* Function not implemented.  */
+    return;
+
+  START (acos_downward);
+
+  save_round_mode = fegetround ();
+
+  if (!fesetround (FE_DOWNWARD))
+    {
+      TEST_f_f (acos, 0, M_PI_2l);
+      TEST_f_f (acos, minus_zero, M_PI_2l);
+      TEST_f_f (acos, 1, 0);
+      TEST_f_f (acos, -1, M_PIl);
+      TEST_f_f (acos, 0.5, M_PI_6l*2.0);
+      TEST_f_f (acos, -0.5, M_PI_6l*4.0);
+    }
+
+  fesetround (save_round_mode);
+
+  END (acos_downward);
+}
+
+
+static void
+acos_test_upward (void)
+{
+  int save_round_mode;
+  errno = 0;
+  FUNC(acos) (0);
+  if (errno == ENOSYS)
+    /* Function not implemented.  */
+    return;
+
+  START (acos_upward);
+
+  save_round_mode = fegetround ();
+
+  if (!fesetround (FE_UPWARD))
+    {
+      TEST_f_f (acos, 0, M_PI_2l);
+      TEST_f_f (acos, minus_zero, M_PI_2l);
+      TEST_f_f (acos, 1, 0);
+      TEST_f_f (acos, -1, M_PIl);
+      TEST_f_f (acos, 0.5, M_PI_6l*2.0);
+      TEST_f_f (acos, -0.5, M_PI_6l*4.0);
+    }
+
+  fesetround (save_round_mode);
+
+  END (acos_upward);
+}
+
 static void
 acosh_test (void)
 {
@@ -817,6 +937,126 @@ asin_test (void)
   END (asin);
 }
 
+
+static void
+asin_test_tonearest (void)
+{
+  int save_round_mode;
+  errno = 0;
+  FUNC(asin) (0);
+  if (errno == ENOSYS)
+    /* Function not implemented.  */
+    return;
+
+  START (asin_tonearest);
+
+  save_round_mode = fegetround ();
+
+  if (!fesetround (FE_TONEAREST))
+    {
+      TEST_f_f (asin, 0, 0);
+      TEST_f_f (asin, minus_zero, minus_zero);
+      TEST_f_f (asin, 0.5, M_PI_6l);
+      TEST_f_f (asin, -0.5, -M_PI_6l);
+      TEST_f_f (asin, 1.0, M_PI_2l);
+      TEST_f_f (asin, -1.0, -M_PI_2l);
+    }
+
+  fesetround (save_round_mode);
+
+  END (asin_tonearest);
+}
+
+
+static void
+asin_test_towardzero (void)
+{
+  int save_round_mode;
+  errno = 0;
+  FUNC(asin) (0);
+  if (errno == ENOSYS)
+    /* Function not implemented.  */
+    return;
+
+  START (asin_towardzero);
+
+  save_round_mode = fegetround ();
+
+  if (!fesetround (FE_TOWARDZERO))
+    {
+      TEST_f_f (asin, 0, 0);
+      TEST_f_f (asin, minus_zero, minus_zero);
+      TEST_f_f (asin, 0.5, M_PI_6l);
+      TEST_f_f (asin, -0.5, -M_PI_6l);
+      TEST_f_f (asin, 1.0, M_PI_2l);
+      TEST_f_f (asin, -1.0, -M_PI_2l);
+    }
+
+  fesetround (save_round_mode);
+
+  END (asin_towardzero);
+}
+
+
+static void
+asin_test_downward (void)
+{
+  int save_round_mode;
+  errno = 0;
+  FUNC(asin) (0);
+  if (errno == ENOSYS)
+    /* Function not implemented.  */
+    return;
+
+  START (asin_downward);
+
+  save_round_mode = fegetround ();
+
+  if (!fesetround (FE_DOWNWARD))
+    {
+      TEST_f_f (asin, 0, 0);
+      TEST_f_f (asin, minus_zero, minus_zero);
+      TEST_f_f (asin, 0.5, M_PI_6l);
+      TEST_f_f (asin, -0.5, -M_PI_6l);
+      TEST_f_f (asin, 1.0, M_PI_2l);
+      TEST_f_f (asin, -1.0, -M_PI_2l);
+    }
+
+  fesetround (save_round_mode);
+
+  END (asin_downward);
+}
+
+
+static void
+asin_test_upward (void)
+{
+  int save_round_mode;
+  errno = 0;
+  FUNC(asin) (0);
+  if (errno == ENOSYS)
+    /* Function not implemented.  */
+    return;
+
+  START (asin_upward);
+
+  save_round_mode = fegetround ();
+
+  if (!fesetround (FE_UPWARD))
+    {
+      TEST_f_f (asin, 0, 0);
+      TEST_f_f (asin, minus_zero, minus_zero);
+      TEST_f_f (asin, 0.5, M_PI_6l);
+      TEST_f_f (asin, -0.5, -M_PI_6l);
+      TEST_f_f (asin, 1.0, M_PI_2l);
+      TEST_f_f (asin, -1.0, -M_PI_2l);
+    }
+
+  fesetround (save_round_mode);
+
+  END (asin_upward);
+}
+
 static void
 asinh_test (void)
 {
@@ -8194,7 +8434,15 @@ main (int argc, char **argv)
 
   /* Trigonometric functions:  */
   acos_test ();
+  acos_test_tonearest ();
+  acos_test_towardzero ();
+  acos_test_downward ();
+  acos_test_upward ();
   asin_test ();
+  asin_test_tonearest ();
+  asin_test_towardzero ();
+  asin_test_downward ();
+  asin_test_upward ();
   atan_test ();
   atan2_test ();
   cos_test ();
diff --git a/sysdeps/i386/fpu/e_acos.S b/sysdeps/i386/fpu/e_acos.S
index d3505baf07..d10a054b9c 100644
--- a/sysdeps/i386/fpu/e_acos.S
+++ b/sysdeps/i386/fpu/e_acos.S
@@ -15,6 +15,7 @@ ENTRY(__ieee754_acos)
 	fld1				/* 1 : x^2 : x */
 	fsubp				/* 1 - x^2 : x */
 	fsqrt				/* sqrt (1 - x^2) : x */
+	fabs
 	fxch	%st(1)			/* x : sqrt (1 - x^2) */
 	fpatan				/* atan (sqrt(1 - x^2) / x) */
 	ret
diff --git a/sysdeps/i386/fpu/e_acosf.S b/sysdeps/i386/fpu/e_acosf.S
index 6a843a51dd..54930af8b2 100644
--- a/sysdeps/i386/fpu/e_acosf.S
+++ b/sysdeps/i386/fpu/e_acosf.S
@@ -16,6 +16,7 @@ ENTRY(__ieee754_acosf)
 	fld1
 	fsubp				/* 1 - x^2 */
 	fsqrt				/* sqrt (1 - x^2) */
+	fabs
 	fxch	%st(1)
 	fpatan
 	ret
diff --git a/sysdeps/i386/fpu/e_acosl.c b/sysdeps/i386/fpu/e_acosl.c
index ec516ffca9..d249d5a956 100644
--- a/sysdeps/i386/fpu/e_acosl.c
+++ b/sysdeps/i386/fpu/e_acosl.c
@@ -18,6 +18,7 @@ __ieee754_acosl (long double x)
 	"fld1\n"
 	"fsubp\n"			/* 1 - x^2 */
 	"fsqrt\n"			/* sqrtl (1 - x^2) */
+	"fabs\n"
 	"fxch	%%st(1)\n"
 	"fpatan"
 	: "=t" (res) : "0" (x) : "st(1)");
diff --git a/sysdeps/i386/fpu/libm-test-ulps b/sysdeps/i386/fpu/libm-test-ulps
index c3a3ce0da2..fdaff3525d 100644
--- a/sysdeps/i386/fpu/libm-test-ulps
+++ b/sysdeps/i386/fpu/libm-test-ulps
@@ -5,6 +5,77 @@ Test "acos (0.75) == 0.722734247813415611178377352641333362":
 ildouble: 1
 ldouble: 1
 
+# acos_downward
+Test "acos_downward (-0) == pi/2":
+float: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+Test "acos_downward (-0.5) == M_PI_6l*4.0":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+Test "acos_downward (-1) == pi":
+float: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+Test "acos_downward (0) == pi/2":
+float: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+Test "acos_downward (0.5) == M_PI_6l*2.0":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+
+# acos_towardzero
+Test "acos_towardzero (-0) == pi/2":
+float: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+Test "acos_towardzero (-0.5) == M_PI_6l*4.0":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+Test "acos_towardzero (-1) == pi":
+float: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+Test "acos_towardzero (0) == pi/2":
+float: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+Test "acos_towardzero (0.5) == M_PI_6l*2.0":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+
+# acos_upward
+Test "acos_upward (-0) == pi/2":
+double: 1
+idouble: 1
+Test "acos_upward (-0.5) == M_PI_6l*4.0":
+ildouble: 1
+ldouble: 1
+Test "acos_upward (-1) == pi":
+double: 1
+idouble: 1
+Test "acos_upward (0) == pi/2":
+double: 1
+idouble: 1
+Test "acos_upward (0.5) == M_PI_6l*2.0":
+ildouble: 1
+ldouble: 1
+
 # asin
 Test "asin (-0.5) == -pi/6":
 ildouble: 1
@@ -22,6 +93,76 @@ Test "asin (1.0) == pi/2":
 ildouble: 1
 ldouble: 1
 
+# asin_downward
+Test "asin_downward (-0.5) == -pi/6":
+ildouble: 1
+ldouble: 1
+Test "asin_downward (-1.0) == -pi/2":
+double: 1
+idouble: 1
+ildouble: 1
+ldouble: 1
+Test "asin_downward (0.5) == pi/6":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+Test "asin_downward (1.0) == pi/2":
+float: 1
+ifloat: 1
+
+# asin_tonearest
+Test "asin_tonearest (-0.5) == -pi/6":
+ildouble: 1
+ldouble: 1
+Test "asin_tonearest (0.5) == pi/6":
+ildouble: 1
+ldouble: 1
+
+# asin_towardzero
+Test "asin_towardzero (-0.5) == -pi/6":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+Test "asin_towardzero (-1.0) == -pi/2":
+float: 1
+ifloat: 1
+Test "asin_towardzero (0.5) == pi/6":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+Test "asin_towardzero (1.0) == pi/2":
+float: 1
+ifloat: 1
+
+# asin_upward
+Test "asin_upward (-0.5) == -pi/6":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+Test "asin_upward (-1.0) == -pi/2":
+float: 1
+ifloat: 1
+Test "asin_upward (0.5) == pi/6":
+ildouble: 1
+ldouble: 1
+Test "asin_upward (1.0) == pi/2":
+double: 1
+idouble: 1
+ildouble: 1
+ldouble: 1
+
 # atanh
 Test "atanh (0.75) == 0.972955074527656652552676371721589865":
 ildouble: 2
@@ -2132,10 +2273,60 @@ Function: "acos":
 ildouble: 1
 ldouble: 1
 
+Function: "acos_downward":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+
+Function: "acos_towardzero":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+
+Function: "acos_upward":
+double: 1
+idouble: 1
+ildouble: 1
+ldouble: 1
+
 Function: "asin":
 ildouble: 1
 ldouble: 1
 
+Function: "asin_downward":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+
+Function: "asin_tonearest":
+ildouble: 1
+ldouble: 1
+
+Function: "asin_towardzero":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+
+Function: "asin_upward":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+
 Function: "atanh":
 ildouble: 2
 ldouble: 1
diff --git a/sysdeps/x86_64/fpu/libm-test-ulps b/sysdeps/x86_64/fpu/libm-test-ulps
index c700bdf74d..5068fe6952 100644
--- a/sysdeps/x86_64/fpu/libm-test-ulps
+++ b/sysdeps/x86_64/fpu/libm-test-ulps
@@ -5,6 +5,52 @@ Test "acos (0.75) == 0.722734247813415611178377352641333362":
 ildouble: 1
 ldouble: 1
 
+# acos_downward
+Test "acos_downward (-0) == pi/2":
+ildouble: 1
+ldouble: 1
+Test "acos_downward (-0.5) == M_PI_6l*4.0":
+double: 1
+idouble: 1
+Test "acos_downward (-1) == pi":
+ildouble: 1
+ldouble: 1
+Test "acos_downward (0) == pi/2":
+ildouble: 1
+ldouble: 1
+Test "acos_downward (0.5) == M_PI_6l*2.0":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+
+# acos_towardzero
+Test "acos_towardzero (-0) == pi/2":
+ildouble: 1
+ldouble: 1
+Test "acos_towardzero (-0.5) == M_PI_6l*4.0":
+double: 1
+idouble: 1
+Test "acos_towardzero (-1) == pi":
+ildouble: 1
+ldouble: 1
+Test "acos_towardzero (0) == pi/2":
+ildouble: 1
+ldouble: 1
+Test "acos_towardzero (0.5) == M_PI_6l*2.0":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+
+# acos_upward
+Test "acos_upward (-0.5) == M_PI_6l*4.0":
+ildouble: 1
+ldouble: 1
+Test "acos_upward (0.5) == M_PI_6l*2.0":
+ildouble: 1
+ldouble: 1
+
 # asin
 Test "asin (-0.5) == -pi/6":
 ildouble: 1
@@ -22,6 +68,72 @@ Test "asin (1.0) == pi/2":
 ildouble: 1
 ldouble: 1
 
+# asin_downward
+Test "asin_downward (-0.5) == -pi/6":
+double: 1
+idouble: 1
+ildouble: 1
+ldouble: 1
+Test "asin_downward (0.5) == pi/6":
+double: 1
+idouble: 1
+ildouble: 1
+ldouble: 1
+Test "asin_downward (1.0) == pi/2":
+float: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+
+# asin_tonearest
+Test "asin_tonearest (-0.5) == -pi/6":
+ildouble: 1
+ldouble: 1
+Test "asin_tonearest (-1.0) == -pi/2":
+ildouble: 1
+ldouble: 1
+Test "asin_tonearest (0.5) == pi/6":
+ildouble: 1
+ldouble: 1
+Test "asin_tonearest (1.0) == pi/2":
+ildouble: 1
+ldouble: 1
+
+# asin_towardzero
+Test "asin_towardzero (-0.5) == -pi/6":
+double: 1
+idouble: 1
+ildouble: 1
+ldouble: 1
+Test "asin_towardzero (-1.0) == -pi/2":
+float: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+Test "asin_towardzero (0.5) == pi/6":
+double: 1
+idouble: 1
+ildouble: 1
+ldouble: 1
+Test "asin_towardzero (1.0) == pi/2":
+float: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+
+# asin_upward
+Test "asin_upward (-0.5) == -pi/6":
+ildouble: 1
+ldouble: 1
+Test "asin_upward (-1.0) == -pi/2":
+float: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+Test "asin_upward (0.5) == pi/6":
+ildouble: 1
+ldouble: 1
+
 # atan2
 Test "atan2 (-0.75, -1.0) == -2.49809154479650885165983415456218025":
 float: 1
@@ -2078,10 +2190,56 @@ Function: "acos":
 ildouble: 1
 ldouble: 1
 
+Function: "acos_downward":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+
+Function: "acos_towardzero":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+
+Function: "acos_upward":
+ildouble: 1
+ldouble: 1
+
 Function: "asin":
 ildouble: 1
 ldouble: 1
 
+Function: "asin_downward":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+
+Function: "asin_tonearest":
+ildouble: 1
+ldouble: 1
+
+Function: "asin_towardzero":
+double: 1
+float: 1
+idouble: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+
+Function: "asin_upward":
+float: 1
+ifloat: 1
+ildouble: 1
+ldouble: 1
+
 Function: "atan2":
 float: 1
 ifloat: 1