From e2c631384a1f9795514d8a7303838070ea81e2ec Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Thu, 18 Feb 2016 22:42:06 +0000 Subject: Fix ldbl-128ibm fmodl handling of subnormal results (bug 19595). The ldbl-128ibm implementation of fmodl has completely bogus logic for subnormal results (in this context, that means results for which the result is in the subnormal range for double, not results with absolute value below LDBL_MIN), based on code used for ldbl-128 that is correct in that case but incorrect in the ldbl-128ibm use. This patch fixes it to convert the mantissa into the correct form expected by ldbl_insert_mantissa, removing the other cases of the code that were incorrect and in one case unreachable for ldbl-128ibm. A correct exponent value is then passed to ldbl_insert_mantissa to reflect the shifted result. Tested for powerpc. [BZ #19595] * sysdeps/ieee754/ldbl-128ibm/e_fmodl.c (__ieee754_fmodl): Use common logic for all cases of shifting subnormal results. Do not insert sign bit in shifted mantissa. Always pass -1023 as biased exponent to ldbl_insert_mantissa in subnormal case. --- ChangeLog | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'ChangeLog') diff --git a/ChangeLog b/ChangeLog index f9c3118def..48d800c885 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,11 @@ 2016-02-18 Joseph Myers + [BZ #19595] + * sysdeps/ieee754/ldbl-128ibm/e_fmodl.c (__ieee754_fmodl): Use + common logic for all cases of shifting subnormal results. Do not + insert sign bit in shifted mantissa. Always pass -1023 as biased + exponent to ldbl_insert_mantissa in subnormal case. + [BZ #19594] * sysdeps/ieee754/ldbl-128ibm/s_roundl.c (__roundl): Use __round on high and low parts then adjust result and use -- cgit 1.4.1