Re: [Valgrind-users] mysterious failures when using valgrind

[John R. <jr...@Bi...>]

>> The likely cause is __float128 operations being performed as "double precision"
>> of two __float80 by the Intel math library for x86_64.  Memcheck-3.8.1 implements
>> __float80 operations as __float64 (ordinary IEEE-754 'double'.)

> Thanks for analyzing this! I assume this means that a fix will be rather 
> complex?

Nearly every user whose programs utilize 80-bit x86 floating point
is disappointed by memcheck's 64-bit implementation of 80-bit operations.
This situation is many years old.  The fix requires a major effort
of design and implementation.

If all of your use of 80-bit operations on x86 is indirect as the result
of __float128, then perhaps you could run on s390, where memcheck has
good support for the 128-bit hardware floating point.

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