flags.h: Declare flag_finite_math_only.

2002-07-30  Toon Moene  <toon@moene.indiv.nluug.nl>

	* flags.h: Declare flag_finite_math_only.
	Use it in definition of HONOR_NANS and
	HONOR_INFINITIES.
	* c-common.c (cb_register_builtins): Emit
	__FINITE_MATH_ONLY__ when flag_finite_math_only
	is set.
	* combine.c (simplify_if_then_else): If
	flag_finite_math_only is set, a == b has a
	definite value.
	* toplev.c: Initialize flag_finite_math_only.
	(set_flags_fast_math): Set it on -ffast-math.
	(flag_fast_math_set_p): Test it.
doc:
	* invoke.texi: Document -ffinite-math-only.
f:
	* com.c (ffe_init_options): Set
	flag_finite_math_only.
	* invoke.texi: Document -fno-finite-math-only.

From-SVN: r55887

gcc/ChangeLog

+2002-07-30  Toon Moene  <toon@moene.indiv.nluug.nl>
+
+	* flags.h: Declare flag_finite_math_only.
+	Use it in definition of HONOR_NANS and
+	HONOR_INFINITIES.
+	* c-common.c (cb_register_builtins): Emit
+	__FINITE_MATH_ONLY__ when flag_finite_math_only
+	is set.
+	* combine.c (simplify_if_then_else): If
+	flag_finite_math_only is set, a == b has a
+	definite value.
+	* toplev.c: Initialize flag_finite_math_only.
+	(set_flags_fast_math): Set it on -ffast-math.
+	(flag_fast_math_set_p): Test it.
+	* doc/invoke.texi: Document -ffinite-math-only.
+
 2002-07-30  Richard Henderson  <rth@redhat.com>
 
 	* ifcvt.c (noce_get_alt_condition): Use reg_overlap_mentioned_p.

gcc/c-common.c

@@ -4385,6 +4385,8 @@ cb_register_builtins (pfile)
     cpp_define (pfile, "__NO_INLINE__");
   if (flag_signaling_nans)
     cpp_define (pfile, "__SUPPORT_SNAN__");
+  if (flag_finite_math_only)
+    cpp_define (pfile, "__FINITE_MATH_ONLY__");
 
   if (flag_iso)
     cpp_define (pfile, "__STRICT_ANSI__");

gcc/combine.c

@@ -4775,12 +4775,12 @@ simplify_if_then_else (x)
 
   /* Convert a == b ? b : a to "a".  */
   if (true_code == EQ && ! side_effects_p (cond)
-      && (! FLOAT_MODE_P (mode) || flag_unsafe_math_optimizations)
+      && (!FLOAT_MODE_P (mode) || !HONOR_NANS (mode))
       && rtx_equal_p (XEXP (cond, 0), false_rtx)
       && rtx_equal_p (XEXP (cond, 1), true_rtx))
     return false_rtx;
   else if (true_code == NE && ! side_effects_p (cond)
-	   && (! FLOAT_MODE_P (mode) || flag_unsafe_math_optimizations)
+	   && (!FLOAT_MODE_P (mode) || !HONOR_NANS (mode))
 	   && rtx_equal_p (XEXP (cond, 0), true_rtx)
 	   && rtx_equal_p (XEXP (cond, 1), false_rtx))
     return true_rtx;

gcc/doc/invoke.texi

@@ -273,7 +273,7 @@ in the following sections.
 -fmove-all-movables  -fnew-ra -fno-default-inline  -fno-defer-pop @gol
 -fno-function-cse  -fno-guess-branch-probability @gol
 -fno-inline  -fno-math-errno  -fno-peephole  -fno-peephole2 @gol
--funsafe-math-optimizations -fno-trapping-math @gol
+-funsafe-math-optimizations -ffinite-math-only -fno-trapping-math @gol
 -fno-zero-initialized-in-bss @gol
 -fomit-frame-pointer  -foptimize-register-move @gol
 -foptimize-sibling-calls  -fprefetch-loop-arrays @gol
@@ -3408,7 +3408,8 @@ performed when this option is not used.
 @item -ffast-math
 @opindex ffast-math
 Sets @option{-fno-math-errno}, @option{-funsafe-math-optimizations}, @*
-@option{-fno-trapping-math} and @option{-fno-signaling-nans}.
+@option{-fno-trapping-math}, @option{-ffinite-math-only} and @*
+@option{-fno-signaling-nans}.
 
 This option causes the preprocessor macro @code{__FAST_MATH__} to be defined.
 
@@ -3446,6 +3447,17 @@ math functions.
 
 The default is @option{-fno-unsafe-math-optimizations}.
 
+@item -ffinite-math-only
+@opindex ffinite-math-only
+Allow optimizations for floating-point arithmetic that assume
+that arguments and results are not NaNs or +-Infs.
+
+This option should never be turned on by any @option{-O} option since
+it can result in incorrect output for programs which depend on
+an exact implementation of IEEE or ISO rules/specifications.
+
+The default is @option{-fno-finite-math-only}.
+
 @item -fno-trapping-math
 @opindex fno-trapping-math
 Compile code assuming that floating-point operations cannot generate

gcc/f/ChangeLog

+2002-07-30  Toon Moene  <toon@moene.indiv.nluug.nl>
+
+	* com.c (ffe_init_options): Set
+	flag_finite_math_only.
+	* invoke.texi: Document -fno-finite-math-only.
+
 Mon Jul 29 22:05:35 2002  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	* com.c (read_name_map): Use concat in lieu of xmalloc/strcpy.

gcc/f/com.c

@@ -14176,6 +14176,7 @@ ffe_init_options ()
   flag_reduce_all_givs = 1;
   flag_argument_noalias = 2;
   flag_merge_constants = 2;
+  flag_finite_math_only = 1;
   flag_errno_math = 0;
   flag_complex_divide_method = 1;
 }

gcc/f/invoke.texi

@@ -182,7 +182,7 @@ by type.  Explanations are in the following sections.
 -malign-double @gol
 -ffloat-store  -fforce-mem  -fforce-addr  -fno-inline @gol
 -ffast-math  -fstrength-reduce  -frerun-cse-after-loop @gol
--funsafe-math-optimizations -fno-trapping-math @gol
+-funsafe-math-optimizations -fno-finite-math-only -fno-trapping-math @gol
 -fexpensive-optimizations  -fdelayed-branch @gol
 -fschedule-insns  -fschedule-insn2  -fcaller-saves @gol
 -funroll-loops  -funroll-all-loops @gol
@@ -1551,6 +1551,16 @@ Sets @option{-funsafe-math-optimizations}, and
 Allow optimizations that may be give incorrect results
 for certain IEEE inputs.
 
+@cindex -fno-finite-math-only option
+@cindex options, -fno-finite-math-only
+@item -fno-finite-math-only
+Fortran specifies all arithmetic that can result in a NaN or an
+infinity as "giving undefined results", therefore the compiler
+by default operates in a way that assumes no NaNs or +-Inf can
+be generated.  If you want to use a NaN or an Inf produced by
+means other than Fortran, use this option to compile your
+Fortran program.
+
 @cindex -fno-trapping-math option
 @cindex options, -fno-trapping-math
 @item -fno-trapping-math

gcc/flags.h

@@ -359,6 +359,10 @@ extern int flag_errno_math;
 
 extern int flag_unsafe_math_optimizations;
 
+/* Nonzero means that no NaNs or +-Infs are expected.  */
+
+extern int flag_finite_math_only;
+
 /* Zero means that floating-point math operations cannot generate a
    (user-visible) trap.  This is the case, for example, in nonstop
    IEEE 754 arithmetic.  */
@@ -672,7 +676,7 @@ extern int flag_signaling_nans;
    disabled for modes with NaNs.  The user can ask for them to be
    done anyway using the -funsafe-math-optimizations switch.  */
 #define HONOR_NANS(MODE) \
-  (MODE_HAS_NANS (MODE) && !flag_unsafe_math_optimizations)
+  (MODE_HAS_NANS (MODE) && !flag_finite_math_only)
 
 /* Like HONOR_NANs, but true if we honor signaling NaNs (or sNaNs).  */
 #define HONOR_SNANS(MODE) (flag_signaling_nans && HONOR_NANS (MODE))
@@ -680,7 +684,7 @@ extern int flag_signaling_nans;
 /* As for HONOR_NANS, but true if the mode can represent infinity and
    the treatment of infinite values is important.  */
 #define HONOR_INFINITIES(MODE) \
-  (MODE_HAS_INFINITIES (MODE) && !flag_unsafe_math_optimizations)
+  (MODE_HAS_INFINITIES (MODE) && !flag_finite_math_only)
 
 /* Like HONOR_NANS, but true if the given mode distinguishes between
    postive and negative zero, and the sign of zero is important.  */

gcc/toplev.c

@@ -575,6 +575,10 @@ int flag_errno_math = 1;
 
 int flag_unsafe_math_optimizations = 0;
 
+/* Nonzero means that no NaNs or +-Infs are expected.  */
+
+int flag_finite_math_only = 0;
+
 /* Zero means that floating-point math operations cannot generate a
    (user-visible) trap.  This is the case, for example, in nonstop
    IEEE 754 arithmetic.  Trapping conditions include division by zero,
@@ -1170,6 +1174,8 @@ static const lang_independent_options f_options[] =
    N_("Process #ident directives") },
   { "peephole2", &flag_peephole2, 1,
    N_("Enables an rtl peephole pass run before sched2") },
+  {"finite-math-only", &flag_finite_math_only, 1,
+   N_("Assume no NaNs or +-Infs are generated") },
   { "guess-branch-probability", &flag_guess_branch_prob, 1,
    N_("Enables guessing of branch probabilities") },
   {"math-errno", &flag_errno_math, 1,
@@ -1575,6 +1581,7 @@ set_fast_math_flags (set)
 {
   flag_trapping_math = !set;
   flag_unsafe_math_optimizations = set;
+  flag_finite_math_only = set;
   flag_errno_math = !set;
   if (set)
     flag_signaling_nans = 0;
@@ -1586,6 +1593,7 @@ fast_math_flags_set_p ()
 {
   return (!flag_trapping_math
 	  && flag_unsafe_math_optimizations
+	  && flag_finite_math_only
 	  && !flag_errno_math);
 }