From 638a572eb0d9af9588bf79e14badc1efefe59d99 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Mon, 9 Jul 2012 11:06:34 +0000 Subject: Fix clog, clog10 spurious underflow exceptions (bug 14337). --- math/s_clog10f.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) (limited to 'math/s_clog10f.c') diff --git a/math/s_clog10f.c b/math/s_clog10f.c index 11bb0bb9ad..5a0c370de5 100644 --- a/math/s_clog10f.c +++ b/math/s_clog10f.c @@ -43,25 +43,30 @@ __clog10f (__complex__ float x) else if (__builtin_expect (rcls != FP_NAN && icls != FP_NAN, 1)) { /* Neither real nor imaginary part is NaN. */ + float absx = fabsf (__real__ x), absy = fabsf (__imag__ x); float d; int scale = 0; - if (fabsf (__real__ x) > FLT_MAX / 2.0f - || fabsf (__imag__ x) > FLT_MAX / 2.0f) + if (absx > FLT_MAX / 2.0f) { scale = -1; - __real__ x = __scalbnf (__real__ x, scale); - __imag__ x = __scalbnf (__imag__ x, scale); + absx = __scalbnf (absx, scale); + absy = (absy >= FLT_MIN * 2.0f ? __scalbnf (absy, scale) : 0.0f); } - else if (fabsf (__real__ x) < FLT_MIN - && fabsf (__imag__ x) < FLT_MIN) + else if (absy > FLT_MAX / 2.0f) + { + scale = -1; + absx = (absx >= FLT_MIN * 2.0f ? __scalbnf (absx, scale) : 0.0f); + absy = __scalbnf (absy, scale); + } + else if (absx < FLT_MIN && absy < FLT_MIN) { scale = FLT_MANT_DIG; - __real__ x = __scalbnf (__real__ x, scale); - __imag__ x = __scalbnf (__imag__ x, scale); + absx = __scalbnf (absx, scale); + absy = __scalbnf (absy, scale); } - d = __ieee754_hypotf (__real__ x, __imag__ x); + d = __ieee754_hypotf (absx, absy); __real__ result = __ieee754_log10f (d) - scale * M_LOG10_2f; __imag__ result = M_LOG10E * __ieee754_atan2f (__imag__ x, __real__ x); -- cgit v1.2.1