flag_complex_method: support optimize attribute

gcc/c-family/ChangeLog:

	* c-opts.c (c_common_init_options_struct): Set also
	  x_flag_default_complex_method.

gcc/ChangeLog:

	* common.opt: Add new variable flag_default_complex_method.
	* opts.c (finish_options): Handle flags related to
	  x_flag_complex_method.
	* toplev.c (process_options): Remove option handling related
	to flag_complex_method.

gcc/go/ChangeLog:

	* go-lang.c (go_langhook_init_options_struct): Set also
	  x_flag_default_complex_method.

gcc/lto/ChangeLog:

	* lto-lang.c (lto_init_options_struct): Set also
	  x_flag_default_complex_method.

gcc/testsuite/ChangeLog:

	* gcc.c-torture/compile/attr-complex-method-2.c: New test.
	* gcc.c-torture/compile/attr-complex-method.c: New test.

8 files changed, 38 insertions, 8 deletions

diff --git a/gcc/c-family/c-opts.c b/gcc/c-family/c-opts.c
index fdde082..3eaab5e 100644
--- a/gcc/c-family/c-opts.c
+++ b/gcc/c-family/c-opts.c
@@ -222,6 +222,7 @@ c_common_init_options_struct (struct gcc_options *opts)
 
   /* By default, C99-like requirements for complex multiply and divide.  */
   opts->x_flag_complex_method = 2;
+  opts->x_flag_default_complex_method = opts->x_flag_complex_method;
 }
 
 /* Common initialization before calling option handlers.  */
diff --git a/gcc/common.opt b/gcc/common.opt
index b921f5e..a9644ca 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -59,6 +59,9 @@ enum incremental_link flag_incremental_link = INCREMENTAL_LINK_NONE
 Variable
 int flag_complex_method = 1
 
+Variable
+int flag_default_complex_method = 1
+
 ; Language specific warning pass for unused results.
 Variable
 bool flag_warn_unused_result = false
diff --git a/gcc/go/go-lang.c b/gcc/go/go-lang.c
index a01db8d..c3ae6f0 100644
--- a/gcc/go/go-lang.c
+++ b/gcc/go/go-lang.c
@@ -174,6 +174,7 @@ go_langhook_init_options_struct (struct gcc_options *opts)
   /* Default to avoiding range issues for complex multiply and
      divide.  */
   opts->x_flag_complex_method = 2;
+  opts->x_flag_default_complex_method = opts->x_flag_complex_method;
 
   /* The builtin math functions should not set errno.  */
   opts->x_flag_errno_math = 0;
diff --git a/gcc/lto/lto-lang.c b/gcc/lto/lto-lang.c
index 92f4996..a014e58 100644
--- a/gcc/lto/lto-lang.c
+++ b/gcc/lto/lto-lang.c
@@ -813,6 +813,7 @@ lto_init_options_struct (struct gcc_options *opts)
      safe choice.  This will pessimize Fortran code with LTO unless
      people specify a complex method manually or use -ffast-math.  */
   opts->x_flag_complex_method = 2;
+  opts->x_flag_default_complex_method = opts->x_flag_complex_method;
 }
 
 /* Handle command-line option SCODE.  If the option takes an argument, it is
diff --git a/gcc/opts.c b/gcc/opts.c
index 1d2d22d..38b42db 100644
--- a/gcc/opts.c
+++ b/gcc/opts.c
@@ -1331,6 +1331,18 @@ finish_options (struct gcc_options *opts, struct gcc_options *opts_set,
       = (opts->x_flag_unroll_loops
          || opts->x_flag_peel_loops
          || opts->x_optimize >= 3);
+
+  /* With -fcx-limited-range, we do cheap and quick complex arithmetic.  */
+  if (opts->x_flag_cx_limited_range)
+    opts->x_flag_complex_method = 0;
+  else if (opts_set->x_flag_cx_limited_range)
+    opts->x_flag_complex_method = opts->x_flag_default_complex_method;
+
+  /* With -fcx-fortran-rules, we do something in-between cheap and C99.  */
+  if (opts->x_flag_cx_fortran_rules)
+    opts->x_flag_complex_method = 1;
+  else if (opts_set->x_flag_cx_fortran_rules)
+    opts->x_flag_complex_method = opts->x_flag_default_complex_method;
 }
 
 #define LEFT_COLUMN	27
diff --git a/gcc/testsuite/gcc.c-torture/compile/attr-complex-method-2.c b/gcc/testsuite/gcc.c-torture/compile/attr-complex-method-2.c
new file mode 100644
index 0000000..a3dc9c1
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/attr-complex-method-2.c
@@ -0,0 +1,10 @@
+/* { dg-additional-options "-fcx-limited-range -fdump-tree-optimized" } */
+
+#pragma GCC optimize "-fno-cx-limited-range"
+
+void do_div (_Complex double *a, _Complex double *b)
+{
+  *a = *b / (4.0 - 5.0fi);
+}
+
+/* { dg-final { scan-tree-dump "__divdc3" "optimized" } } */
diff --git a/gcc/testsuite/gcc.c-torture/compile/attr-complex-method.c b/gcc/testsuite/gcc.c-torture/compile/attr-complex-method.c
new file mode 100644
index 0000000..f08b72e
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/attr-complex-method.c
@@ -0,0 +1,10 @@
+/* { dg-additional-options "-fdump-tree-optimized" } */
+
+#pragma GCC optimize "-fcx-limited-range"
+
+void do_div (_Complex double *a, _Complex double *b)
+{
+  *a = *b / (4.0 - 5.0fi);
+}
+
+/* { dg-final { scan-tree-dump-not "__divdc3" "optimized" } } */
diff --git a/gcc/toplev.c b/gcc/toplev.c
index 14d1335..e1688aa 100644
--- a/gcc/toplev.c
+++ b/gcc/toplev.c
@@ -1695,14 +1695,6 @@ process_options (void)
       flag_stack_check = NO_STACK_CHECK;
     }
 
-  /* With -fcx-limited-range, we do cheap and quick complex arithmetic.  */
-  if (flag_cx_limited_range)
-    flag_complex_method = 0;
-
-  /* With -fcx-fortran-rules, we do something in-between cheap and C99.  */
-  if (flag_cx_fortran_rules)
-    flag_complex_method = 1;
-
   /* Targets must be able to place spill slots at lower addresses.  If the
      target already uses a soft frame pointer, the transition is trivial.  */
   if (!FRAME_GROWS_DOWNWARD && flag_stack_protect)