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Get rid of strict aliasing rule violations from libm (#3069)

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JerryScript-DCO-1.0-Signed-off-by: Csaba Osztrogonác oszi@inf.u-szeged.hu
This commit is contained in:
Csaba Osztrogonác
2019-10-01 14:37:18 +02:00
committed by Robert Fancsik
parent f7391a94ae
commit 3763ac8371
16 changed files with 246 additions and 197 deletions
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jerry-libm/trig.c
+53 -48
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@@ -475,7 +475,8 @@ static const int npio2_hw[] =
static int
__ieee754_rem_pio2 (double x, double *y)
{
double z, w, t, r, fn;
double_accessor z;
double w, t, r, fn;
double tx[3];
int e0, i, j, nx, n, ix, hx;
@@ -491,33 +492,33 @@ __ieee754_rem_pio2 (double x, double *y)
{
if (hx > 0)
{
z = x - pio2_1;
z.dbl = x - pio2_1;
if (ix != 0x3ff921fb) /* 33 + 53 bit pi is good enough */
{
y[0] = z - pio2_1t;
y[1] = (z - y[0]) - pio2_1t;
y[0] = z.dbl - pio2_1t;
y[1] = (z.dbl - y[0]) - pio2_1t;
}
else /* near pi/2, use 33 + 33 + 53 bit pi */
{
z -= pio2_2;
y[0] = z - pio2_2t;
y[1] = (z - y[0]) - pio2_2t;
z.dbl -= pio2_2;
y[0] = z.dbl - pio2_2t;
y[1] = (z.dbl - y[0]) - pio2_2t;
}
return 1;
}
else /* negative x */
{
z = x + pio2_1;
z.dbl = x + pio2_1;
if (ix != 0x3ff921fb) /* 33 + 53 bit pi is good enough */
{
y[0] = z + pio2_1t;
y[1] = (z - y[0]) + pio2_1t;
y[0] = z.dbl + pio2_1t;
y[1] = (z.dbl - y[0]) + pio2_1t;
}
else /* near pi/2, use 33 + 33 + 53 bit pi */
{
z += pio2_2;
y[0] = z + pio2_2t;
y[1] = (z - y[0]) + pio2_2t;
z.dbl += pio2_2;
y[0] = z.dbl + pio2_2t;
y[1] = (z.dbl - y[0]) + pio2_2t;
}
return -1;
}
@@ -577,15 +578,15 @@ __ieee754_rem_pio2 (double x, double *y)
return 0;
}
/* set z = scalbn(|x|, ilogb(x) - 23) */
__LO (z) = __LO (x);
z.as_int.lo = __LO (x);
e0 = (ix >> 20) - 1046; /* e0 = ilogb(z) - 23; */
__HI (z) = ix - (e0 << 20);
z.as_int.hi = ix - (e0 << 20);
for (i = 0; i < 2; i++)
{
tx[i] = (double) ((int) (z));
z = (z - tx[i]) * two24;
tx[i] = (double) ((int) (z.dbl));
z.dbl = (z.dbl - tx[i]) * two24;
}
tx[2] = z;
tx[2] = z.dbl;
nx = 3;
while (tx[nx - 1] == zero) /* skip zero term */
{
@@ -708,7 +709,7 @@ __kernel_sin (double x, double y, int iy)
static double
__kernel_cos (double x, double y)
{
double a, hz, z, r, qx;
double a, hz, z, r;
int ix;
ix = __HI (x) & 0x7fffffff; /* ix = |x|'s high word */
@@ -727,17 +728,18 @@ __kernel_cos (double x, double y)
}
else
{
double_accessor qx;
if (ix > 0x3fe90000) /* x > 0.78125 */
{
qx = 0.28125;
qx.dbl = 0.28125;
}
else
{
__HI (qx) = ix - 0x00200000; /* x / 4 */
__LO (qx) = 0;
qx.as_int.hi = ix - 0x00200000; /* x / 4 */
qx.as_int.lo = 0;
}
hz = 0.5 * z - qx;
a = one - qx;
hz = 0.5 * z - qx.dbl;
a = one - qx.dbl;
return a - (hz - (z * r - x * y));
}
} /* __kernel_cos */
@@ -794,7 +796,8 @@ __kernel_cos (double x, double y)
static double
__kernel_tan (double x, double y, int iy)
{
double z, r, v, w, s;
double_accessor z;
double r, v, w, s;
int ix, hx;
hx = __HI (x); /* high word of x */
@@ -815,15 +818,16 @@ __kernel_tan (double x, double y, int iy)
}
else /* compute -1 / (x + y) carefully */
{
double a, t;
double a;
double_accessor t;
z = w = x + y;
__LO (z) = 0;
v = y - (z - x);
t = a = -one / w;
__LO (t) = 0;
s = one + t * z;
return t + a * (s + t * v);
z.dbl = w = x + y;
z.as_int.lo = 0;
v = y - (z.dbl - x);
t.dbl = a = -one / w;
t.as_int.lo = 0;
s = one + t.dbl * z.dbl;
return t.dbl + a * (s + t.dbl * v);
}
}
}
@@ -835,22 +839,22 @@ __kernel_tan (double x, double y, int iy)
x = -x;
y = -y;
}
z = pio4 - x;
z.dbl = pio4 - x;
w = pio4lo - y;
x = z + w;
x = z.dbl + w;
y = 0.0;
}
z = x * x;
w = z * z;
z.dbl = x * x;
w = z.dbl * z.dbl;
/*
* Break x^5 * (T[1] + x^2 * T[2] + ...) into
* x^5 (T[1] + x^4 * T[3] + ... + x^20 * T[11]) +
* x^5 (x^2 * (T[2] + x^4 * T[4] + ... + x^22 * [T12]))
*/
r = T1 + w * (T3 + w * (T5 + w * (T7 + w * (T9 + w * T11))));
v = z * (T2 + w * (T4 + w * (T6 + w * (T8 + w * (T10 + w * T12)))));
s = z * x;
r = y + z * (s * (r + v) + y);
v = z.dbl * (T2 + w * (T4 + w * (T6 + w * (T8 + w * (T10 + w * T12)))));
s = z.dbl * x;
r = y + z.dbl * (s * (r + v) + y);
r += T0 * s;
w = x + r;
if (ix >= 0x3FE59428)
@@ -869,15 +873,16 @@ __kernel_tan (double x, double y, int iy)
* -1.0 / (x + r) here
*/
/* compute -1.0 / (x + r) accurately */
double a, t;
double a;
double_accessor t;
z = w;
__LO (z) = 0;
v = r - (z - x); /* z + v = r + x */
t = a = -1.0 / w; /* a = -1.0 / w */
__LO (t) = 0;
s = 1.0 + t * z;
return t + a * (s + t * v);
z.dbl = w;
z.as_int.lo = 0;
v = r - (z.dbl - x); /* z + v = r + x */
t.dbl = a = -1.0 / w; /* a = -1.0 / w */
t.as_int.lo = 0;
s = 1.0 + t.dbl * z.dbl;
return t.dbl + a * (s + t.dbl * v);
}
} /* __kernel_tan */