diff options
Diffstat (limited to 'sysdeps/ieee754/dbl-64/k_rem_pio2.c')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/k_rem_pio2.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/sysdeps/ieee754/dbl-64/k_rem_pio2.c b/sysdeps/ieee754/dbl-64/k_rem_pio2.c index e58c9e854c..d8403dc345 100644 --- a/sysdeps/ieee754/dbl-64/k_rem_pio2.c +++ b/sysdeps/ieee754/dbl-64/k_rem_pio2.c @@ -131,7 +131,9 @@ static char rcsid[] = "$NetBSD: k_rem_pio2.c,v 1.7 1995/05/10 20:46:25 jtc Exp $ */ #include <math.h> +#include <math-narrow-eval.h> #include <math_private.h> +#include <libc-diag.h> static const int init_jk[] = {2,3,4,6}; /* initial value for jk */ @@ -251,8 +253,17 @@ recompute: j |= iq[i]; if (j == 0) /* need recomputation */ { + /* On s390x gcc 6.1 -O3 produces the warning "array subscript is below + array bounds [-Werror=array-bounds]". Only __ieee754_rem_pio2l + calls __kernel_rem_pio2 for normal numbers and |x| > pi/4 in case + of ldbl-96 and |x| > 3pi/4 in case of ldbl-128[ibm]. + Thus x can't be zero and ipio2 is not zero, too. Thus not all iq[] + values can't be zero. */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (6.1, "-Warray-bounds"); for (k = 1; iq[jk - k] == 0; k++) ; /* k = no. of terms needed */ + DIAG_POP_NEEDS_COMMENT; for (i = jz + 1; i <= jz + k; i++) /* add q[jz+1] to q[jz+k] */ { @@ -319,7 +330,16 @@ recompute: for (i = jz; i >= 0; i--) fv = math_narrow_eval (fv + fq[i]); y[0] = (ih == 0) ? fv : -fv; + /* GCC mainline (to be GCC 9), as of 2018-05-22 on i686, warns + that fq[0] may be used uninitialized. This is not possible + because jz is always nonnegative when the above loop + initializing fq is executed, because the result is never zero + to full precision (this function is not called for zero + arguments). */ + DIAG_PUSH_NEEDS_COMMENT; + DIAG_IGNORE_NEEDS_COMMENT (9, "-Wmaybe-uninitialized"); fv = math_narrow_eval (fq[0] - fv); + DIAG_POP_NEEDS_COMMENT; for (i = 1; i <= jz; i++) fv = math_narrow_eval (fv + fq[i]); y[1] = (ih == 0) ? fv : -fv; |