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Ensure calculations happen with desired rounding mode in y1lf128

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math/test-float128-y1 fails on x86_64 and ppc64el with gcc 12 and -O3,
because code inside a block guarded by SET_RESTORE_ROUNDL is being moved
after the rounding mode has been restored. Use math_force_eval to
prevent this (and insert some math_opt_barrier calls to prevent code
from being moved before the rounding mode is set).

Fixes #29463

Reviewed-By: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
This commit is contained in:
Michael Hudson-Doyle 2022-08-12 11:29:31 +12:00
parent 1d78299911
commit 2b274fd8c9
1 changed files with 3 additions and 0 deletions
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3
sysdeps/ieee754/ldbl-128/e_j1l.c
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@ -869,10 +869,13 @@ __ieee754_y1l (_Float128 x)
{
/* 0 <= x <= 2 */
SET_RESTORE_ROUNDL (FE_TONEAREST);
xx = math_opt_barrier (xx);
x = math_opt_barrier (x);
z = xx * xx;
p = xx * neval (z, Y0_2N, NY0_2N) / deval (z, Y0_2D, NY0_2D);
p = -TWOOPI / xx + p;
p = TWOOPI * __ieee754_logl (x) * __ieee754_j1l (x) + p;
math_force_eval (p);
return p;
}