diff options
Diffstat (limited to 'sysdeps/ieee754/flt-32/k_rem_pio2f.c')
| -rw-r--r-- | sysdeps/ieee754/flt-32/k_rem_pio2f.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/sysdeps/ieee754/flt-32/k_rem_pio2f.c b/sysdeps/ieee754/flt-32/k_rem_pio2f.c index 392afdbb6c..ea4915b765 100644 --- a/sysdeps/ieee754/flt-32/k_rem_pio2f.c +++ b/sysdeps/ieee754/flt-32/k_rem_pio2f.c @@ -18,7 +18,9 @@ static char rcsid[] = "$NetBSD: k_rem_pio2f.c,v 1.4 1995/05/10 20:46:28 jtc Exp #endif #include <math.h> +#include <math-narrow-eval.h> #include <math_private.h> +#include <libc-diag.h> /* In the float version, the input parameter x contains 8 bit integers, not 24 bit integers. 113 bit precision is not supported. */ @@ -122,7 +124,16 @@ recompute: j = 0; for (i=jz-1;i>=jk;i--) 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_pio2f calls __kernel_rem_pio2f for normal + numbers and |x| ~> 2^7*(pi/2). 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] */ f[jx+i] = (float) ipio2[jv+i]; @@ -172,7 +183,17 @@ recompute: float fv = 0.0; 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; break; |