diff options
Diffstat (limited to 'libquadmath/math/cosq_kernel.c')
| -rw-r--r-- | libquadmath/math/cosq_kernel.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/libquadmath/math/cosq_kernel.c b/libquadmath/math/cosq_kernel.c index 86f39551c32..42d29adfd8c 100644 --- a/libquadmath/math/cosq_kernel.c +++ b/libquadmath/math/cosq_kernel.c @@ -99,13 +99,17 @@ __quadmath_kernel_cosq (__float128 x, __float128 y) { /* So that we don't have to use too large polynomial, we find l and h such that x = l + h, where fabsl(l) <= 1.0/256 with 83 - possible values for h. We look up cosl(h) and sinl(h) in - pre-computed tables, compute cosl(l) and sinl(l) using a + possible values for h. We look up cosq(h) and sinq(h) in + pre-computed tables, compute cosq(l) and sinq(l) using a Chebyshev polynomial of degree 10(11) and compute - cosl(h+l) = cosl(h)cosl(l) - sinl(h)sinl(l). */ + cosq(h+l) = cosq(h)cosq(l) - sinq(h)sinq(l). */ index = 0x3ffe - (tix >> 16); hix = (tix + (0x200 << index)) & (0xfffffc00 << index); - x = fabsq (x); + if (signbitq (x)) + { + x = -x; + y = -y; + } switch (index) { case 0: index = ((45 << 10) + hix - 0x3ffe0000) >> 8; break; |