diff options
Diffstat (limited to 'math/math-narrow.h')
| -rw-r--r-- | math/math-narrow.h | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/math/math-narrow.h b/math/math-narrow.h index 0194f8c97e..fee00f12df 100644 --- a/math/math-narrow.h +++ b/math/math-narrow.h @@ -342,4 +342,57 @@ } \ while (0) +/* Check for error conditions from a narrowing fused multiply-add + function returning RET with arguments X, Y and Z and set errno as + needed. Checking for error conditions for fma (either narrowing or + not) and setting errno is not currently implemented. See bug + 6801. */ +#define CHECK_NARROW_FMA(RET, X, Y, Z) \ + do \ + { \ + } \ + while (0) + +/* Implement narrowing fused multiply-add using round-to-odd. The + arguments are X, Y and Z, the return type is TYPE and UNION, + MANTISSA, SUFFIX and CLEAR_UNDERFLOW are as for ROUND_TO_ODD. */ +#define NARROW_FMA_ROUND_TO_ODD(X, Y, Z, TYPE, UNION, SUFFIX, MANTISSA, \ + CLEAR_UNDERFLOW) \ + do \ + { \ + typeof (X) tmp; \ + TYPE ret; \ + \ + tmp = ROUND_TO_ODD (fma ## SUFFIX (math_opt_barrier (X), (Y), \ + (Z)), \ + UNION, SUFFIX, MANTISSA, CLEAR_UNDERFLOW); \ + /* If the round-to-odd result is zero, the result is an exact \ + zero and must be recomputed in the original rounding mode. */ \ + if (tmp == 0) \ + ret = (TYPE) (math_opt_barrier (X) * (Y) + (Z)); \ + else \ + ret = (TYPE) tmp; \ + \ + CHECK_NARROW_FMA (ret, (X), (Y), (Z)); \ + return ret; \ + } \ + while (0) + +/* Implement a narrowing fused multiply-add function where no attempt + is made to be correctly rounding (this only applies to IBM long + double; the case where the function is not actually narrowing is + handled by aliasing other fma functions in libm, not using this + macro). The arguments are X, Y and Z and the return type is + TYPE. */ +#define NARROW_FMA_TRIVIAL(X, Y, Z, TYPE, SUFFIX) \ + do \ + { \ + TYPE ret; \ + \ + ret = (TYPE) (fma ## SUFFIX ((X), (Y), (Z))); \ + CHECK_NARROW_FMA (ret, (X), (Y), (Z)); \ + return ret; \ + } \ + while (0) + #endif /* math-narrow.h. */ |