Instruction abs.[ds] is not generating correct result when working
with NaNs for revisions prior mips32r6 and mips64r6.
To generate a sequence which always produce a correct result, but also
to allow user more control on how his code is compiled, attribute
+abs2008 is added, so user can choose legacy or 2008.
By default legacy mode is used on revisions prior R6. Mips32r6 and
mips64r6 use abs2008 mode by default.
Differential Revision: https://reviews.llvm.org/D35983
llvm-svn: 352370
Summary:
They behave in accordance with the Has2008 and ABS2008 configuration bits of the processor which are used to select between the 1985 and 2008 versions of IEEE 754. In 1985 mode, these instructions are arithmetic (i.e. they raise invalid operation exceptions when given NaN), in 2008 mode they are non-arithmetic (i.e. they are copies).
nmadd.[ds], and nmsub.[ds] are still subject to -enable-no-nans-fp-math because the ISA spec does not explicitly state that they obey Has2008 and ABS2008.
Fixed the issue with the previous version of this patch (r205628). A pre-existing 'let Predicate =' statement was removing some predicates that were necessary for FP64 to behave correctly.
Reviewers: matheusalmeida
Reviewed By: matheusalmeida
Differential Revision: http://llvm-reviews.chandlerc.com/D3274
llvm-svn: 205844
Summary:
They behave in accordance with the Has2008 and ABS2008 configuration bits of the
processor which are used to select between the 1985 and 2008 versions of IEEE
754. In 1985 mode, these instructions are arithmetic (i.e. they raise invalid
operation exceptions when given NaN), in 2008 mode they are non-arithmetic
(i.e. they are copies).
nmadd.[ds], and nmsub.[ds] are still subject to -enable-no-nans-fp-math because
the ISA spec does not explicitly state that they obey Has2008 and ABS2008.
Reviewers: matheusalmeida
Reviewed By: matheusalmeida
Differential Revision: http://llvm-reviews.chandlerc.com/D3274
llvm-svn: 205628
Aleksandar Beserminji