* Makefile.in: rtlanal.o now depends upon real.h.
* flags.h [flag_signaling_nans]: New flag.
[HONOR_SNANS]: New macro.
* toplev.c [flag_signaling_nans]: Initialize to false.
(f_options): Add processing for "-fsignaling-nans".
(set_fast_math_flags): Clear flag_signaling_nans with -ffast-math.
(process_options): flag_signaling_nans implies flag_trapping_math.
* c-common.c (cb_register_builtins): Define __SUPPORT_SNAN__
when -fsignaling-nans. First step to implementing WG14's N965.
* fold-const.c (fold) [MULT_EXPR]: Conditionalize transforming
1.0 * x into x, and -1.0 * x into -x on !HONOR_SNANS.
[RDIV_EXPR]: Conditionalize x/1.0 into x on !HONOR_SNANS.
* simplify-rtx.c (simplify_relational_operation): Conditionalize
transforming abs(x) < 0.0 into false on !HONOR_SNANS.
* rtlanal.c: #include real.c for TARGET_FLOAT_FORMAT definitions
required by HONOR_SNANS. (may_trap_p): Floating point DIV, MOD,
UDIV, UMOD, GE, GT, LE, LT and COMPARE may always trap with
-fsignaling_nans. EQ and NE only trap for flag_signaling_nans
not flag_trapping_math (i.e. HONOR_SNANS but not HONOR_NANS).
* doc/invoke.texi: Document new -fsignaling-nans compiler option.
From-SVN: r55804
