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math: Fix exp10 undefined left shift

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Left shift of ki is undefined when ki<0, copy the logic from exp,
which uses unsigned arithmetics, to fix it.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
This commit is contained in:
Szabolcs Nagy 2024-05-22 16:33:43 +01:00
parent d0106b6ae2
commit 2a9943b4a0
1 changed files with 3 additions and 3 deletions
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6
sysdeps/ieee754/dbl-64/e_exp10.c
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@ -38,7 +38,7 @@ special_case (uint64_t sbits, double_t tmp, uint64_t ki)
{ {
double_t scale, y; double_t scale, y;
if (ki - (1ull << 16) < 0x80000000) if ((ki & 0x80000000) == 0)
{ {
/* The exponent of scale might have overflowed by 1. */ /* The exponent of scale might have overflowed by 1. */
sbits -= 1ull << 52; sbits -= 1ull << 52;
@ -100,14 +100,14 @@ __exp10 (double x)
/* Reduce x: z = x * N / log10(2), k = round(z). */ /* Reduce x: z = x * N / log10(2), k = round(z). */
double_t z = __exp_data.invlog10_2N * x; double_t z = __exp_data.invlog10_2N * x;
double_t kd; double_t kd;
int64_t ki; uint64_t ki;
#if TOINT_INTRINSICS #if TOINT_INTRINSICS
kd = roundtoint (z); kd = roundtoint (z);
ki = converttoint (z); ki = converttoint (z);
#else #else
kd = math_narrow_eval (z + Shift); kd = math_narrow_eval (z + Shift);
ki = asuint64 (kd);
kd -= Shift; kd -= Shift;
ki = kd;
#endif #endif
/* r = x - k * log10(2), r in [-0.5, 0.5]. */ /* r = x - k * log10(2), r in [-0.5, 0.5]. */