* i386.c (ix86_fp_comparison_arithmetics_cost,
ix86_fp_comparison_fcomi_cost, ix86_fp_comparison_sahf_cost,
ix86_fp_comparison_cost): New functions.
(ix86_expand_fp_compare): Use the costs to choose best bethod; add
two new parameters SECOND_TEST and BYPASS_TEST; allow generating
two-branch sequences; make static.
(ix86_use_fcomi_compare): Do decision according to the costs.
(split_fp_branch): New.
* i386.md (compare-and-branch patterns): Use split_fp_branch.
* i386-protos.h (ix86_expand_fp_compare): Remove
(ix86_split_fp_branch): Declare.
* i386.h (PREDICATE_CODES): Update codes from fcmov_comparison_operand
and ix86_comparison_operator.
* i386.c (ix86_prepare_fp_compare_args): Try to rearange the comparison
to make it cheaper.
* i386.c (put_condition_code): Output properly the unordered/ordered
compares in fp case.
(ix86_expand_fp_movcc): Use ix86_expand_compare infrastructure.
* tm.texi (REVERSE_CONDITION): Document.
* i386.c (ix86_fp_compare_mode): Simplify; return always CCFPmode
in -ffast-math mode.
* i386.h (REVERSE_CONDITION, REVERSIBLE_CC_MODE): New macro.
From-SVN: r38979
