Fix low-part sign handling in sin/cos for ldbl-128 and ldbl-128ibm.

3 files changed, 11 insertions, 3 deletions

diff --git a/sysdeps/ieee754/ldbl-128ibm/k_cosl.c b/sysdeps/ieee754/ldbl-128ibm/k_cosl.c
index 52414319a6..fc01374688 100644
--- a/sysdeps/ieee754/ldbl-128ibm/k_cosl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/k_cosl.c
@@ -123,7 +123,11 @@ __kernel_cosl(long double x, long double y)
     
       index = 0x3fe - (tix >> 20);
       hix = (tix + (0x200 << index)) & (0xfffffc00 << index);
-      x = fabsl (x);
+      if (signbit (x))
+	{
+	  x = -x;
+	  y = -y;
+	}
       switch (index)
 	{
 	case 0: index = ((45 << 14) + hix - 0x3fe00000) >> 12; break;
diff --git a/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c b/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c
index f3dd954887..98fe07d7a7 100644
--- a/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/k_sincosl.c
@@ -151,7 +151,11 @@ __kernel_sincosl(long double x, long double y, long double *sinx, long double *c
 
       index = 0x3fe - (tix >> 20);
       hix = (tix + (0x2000 << index)) & (0xffffc000 << index);
-      x = fabsl (x);
+      if (signbit (x))
+	{
+	  x = -x;
+	  y = -y;
+	}
       switch (index)
 	{
 	case 0: index = ((45 << 14) + hix - 0x3fe00000) >> 12; break;
diff --git a/sysdeps/ieee754/ldbl-128ibm/k_sinl.c b/sysdeps/ieee754/ldbl-128ibm/k_sinl.c
index 484b65fc8e..94aba0b62d 100644
--- a/sysdeps/ieee754/ldbl-128ibm/k_sinl.c
+++ b/sysdeps/ieee754/ldbl-128ibm/k_sinl.c
@@ -134,7 +134,7 @@ __kernel_sinl(long double x, long double y, int iy)
 */
       SET_LDOUBLE_WORDS64(h, ((u_int64_t)hix) << 32, 0);
       if (iy)
-	l = y - (h - x);
+	l = (ix < 0 ? -y : y) - (h - x);
       else
 	l = x - h;
       z = l * l;