PR target/52555: attribute optimize is overriding command line options

diff --git a/gcc/c-family/c-common.c b/gcc/c-family/c-common.c
index 1e6afaa..a1d47a6 100644
--- a/gcc/c-family/c-common.c
+++ b/gcc/c-family/c-common.c
@@ -8925,6 +8925,8 @@  handle_optimize_attribute (tree *node, tree name, tree args,
       DECL_FUNCTION_SPECIFIC_OPTIMIZATION (*node)
 	= build_optimization_node ();
 
+      save_optabs_if_changed (*node);
+
       /* Restore current options.  */
       cl_optimization_restore (&global_options, &cur_opts);
     }
diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index b203cdd..5e98485 100644
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -16313,7 +16313,26 @@  mips_set_mips16_mode (int mips16_p)
   if (mips16_p)
     {
       if (!mips16_globals)
-	mips16_globals = save_target_globals ();
+	{
+	  if (optimization_current_node != optimization_default_node)
+	    {
+	      tree opts = optimization_current_node;
+	      /* Temporarily switch to the default optimization node,
+		 so that *this_target_optabs is set to the default,
+		 not reflecting whatever the first mips16 function
+		 uses for the optimize attribute.  */
+	      optimization_current_node = optimization_default_node;
+	      cl_optimization_restore
+		(&global_options,
+		 TREE_OPTIMIZATION (optimization_default_node));
+	      mips16_globals = save_target_globals ();
+	      optimization_current_node = opts;
+	      cl_optimization_restore (&global_options,
+				       TREE_OPTIMIZATION (opts));
+	    }
+	  else
+	    mips16_globals = save_target_globals ();	  
+	}
       else
 	restore_target_globals (mips16_globals);
     }
diff --git a/gcc/expr.h b/gcc/expr.h
index f5063b4..15fcb47 100644
--- a/gcc/expr.h
+++ b/gcc/expr.h
@@ -718,7 +718,7 @@  extern bool split_comparison (enum rtx_code, enum machine_mode,
 /* Call this once to initialize the contents of the optabs
    appropriately for the current target machine.  */
 extern void init_optabs (void);
-extern void init_all_optabs (void);
+extern void init_all_optabs (struct target_optabs *);
 
 /* Call this to initialize an optab function entry.  */
 extern rtx init_one_libfunc (const char *);
diff --git a/gcc/function.c b/gcc/function.c
index 4ce2259..c87f62d 100644
--- a/gcc/function.c
+++ b/gcc/function.c
@@ -4400,6 +4400,27 @@  invoke_set_current_function_hook (tree fndecl)
 	}
 
       targetm.set_current_function (fndecl);
+
+      if (opts == optimization_default_node)
+	this_fn_optabs = this_target_optabs;
+      else
+	{
+	  struct function *fn = DECL_STRUCT_FUNCTION (fndecl);
+	  if (fn->optabs == NULL)
+	    {
+	      if (!SWITCHABLE_TARGET
+		  || this_target_optabs == &default_target_optabs)
+		fn->optabs = TREE_OPTIMIZATION_OPTABS (opts);
+	      else
+		{
+		  fn->optabs = (unsigned char *)
+		    ggc_alloc_atomic (sizeof (struct target_optabs));
+		  init_all_optabs ((struct target_optabs *) fn->optabs);
+		}
+	    }
+	  this_fn_optabs = fn->optabs ? (struct target_optabs *) fn->optabs
+	                              : this_target_optabs;
+	}
     }
 }
 
diff --git a/gcc/function.h b/gcc/function.h
index 89d71e5..53e28b7 100644
--- a/gcc/function.h
+++ b/gcc/function.h
@@ -580,6 +580,9 @@  struct GTY(()) function {
      a string describing the reason for failure.  */
   const char * GTY((skip)) cannot_be_copied_reason;
 
+  /* Optabs for this function.  This is of type `struct target_optabs *'.  */
+  unsigned char *GTY ((atomic)) optabs;
+
   /* Collected bit flags.  */
 
   /* Number of units of general registers that need saving in stdarg
diff --git a/gcc/genopinit.c b/gcc/genopinit.c
index 1bb2f77..fb80717 100644
--- a/gcc/genopinit.c
+++ b/gcc/genopinit.c
@@ -422,8 +422,8 @@  main (int argc, char **argv)
     fprintf (s_file, "  { %#08x, CODE_FOR_%s },\n", p->sort_num, p->name);
   fprintf (s_file, "};\n\n");
 
-  fprintf (s_file, "void\ninit_all_optabs (void)\n{\n");
-  fprintf (s_file, "  bool *ena = this_target_optabs->pat_enable;\n");
+  fprintf (s_file, "void\ninit_all_optabs (struct target_optabs *optabs)\n{\n");
+  fprintf (s_file, "  bool *ena = optabs->pat_enable;\n");
   for (i = 0; patterns.iterate (i, &p); ++i)
     fprintf (s_file, "  ena[%u] = HAVE_%s;\n", i, p->name);
   fprintf (s_file, "}\n\n");
@@ -456,7 +456,7 @@  main (int argc, char **argv)
 	   "raw_optab_handler (unsigned scode)\n"
 	   "{\n"
 	   "  int i = lookup_handler (scode);\n"
-	   "  return (i >= 0 && this_target_optabs->pat_enable[i]\n"
+	   "  return (i >= 0 && this_fn_optabs->pat_enable[i]\n"
 	   "          ? pats[i].icode : CODE_FOR_nothing);\n"
 	   "}\n\n");
 
@@ -468,8 +468,8 @@  main (int argc, char **argv)
 	   "  int i = lookup_handler (scode);\n"
 	   "  if (i >= 0)\n"
 	   "    {\n"
-	   "      bool ret = this_target_optabs->pat_enable[i];\n"
-	   "      this_target_optabs->pat_enable[i] = set;\n"
+	   "      bool ret = this_fn_optabs->pat_enable[i];\n"
+	   "      this_fn_optabs->pat_enable[i] = set;\n"
 	   "      return ret;\n"
 	   "    }\n"
 	   "  else\n"
diff --git a/gcc/optabs.c b/gcc/optabs.c
index c1dacf4..c5778d1 100644
--- a/gcc/optabs.c
+++ b/gcc/optabs.c
@@ -44,6 +44,7 @@  along with GCC; see the file COPYING3.  If not see
 
 struct target_optabs default_target_optabs;
 struct target_libfuncs default_target_libfuncs;
+struct target_optabs *this_fn_optabs = &default_target_optabs;
 #if SWITCHABLE_TARGET
 struct target_optabs *this_target_optabs = &default_target_optabs;
 struct target_libfuncs *this_target_libfuncs = &default_target_libfuncs;
@@ -6150,7 +6151,7 @@  init_optabs (void)
     libfunc_hash = htab_create_ggc (10, hash_libfunc, eq_libfunc, NULL);
 
   /* Fill in the optabs with the insns we support.  */
-  init_all_optabs ();
+  init_all_optabs (this_fn_optabs);
 
   /* The ffs function operates on `int'.  Fall back on it if we do not
      have a libgcc2 function for that width.  */
@@ -6207,6 +6208,38 @@  init_optabs (void)
   targetm.init_libfuncs ();
 }
 
+/* Recompute the optabs and save them if they have changed.  */
+
+void
+save_optabs_if_changed (tree fndecl)
+{
+  /* ?? If this fails, we should temporarily restore the default
+     target first (set_cfun (NULL) ??), do the rest of this function,
+     and then restore it.  */
+  gcc_assert (this_target_optabs == &default_target_optabs);
+
+  struct target_optabs *tmp_optabs = (struct target_optabs *)
+    ggc_alloc_atomic (sizeof (struct target_optabs));
+  tree optnode = DECL_FUNCTION_SPECIFIC_OPTIMIZATION (fndecl);
+
+  /* Generate a new set of optabs into tmp_optabs.  */
+  init_all_optabs (tmp_optabs);
+
+  /* If the optabs changed, record it.  */
+  if (memcmp (tmp_optabs, this_target_optabs, sizeof (struct target_optabs)))
+    {
+      if (TREE_OPTIMIZATION_OPTABS (optnode))
+	ggc_free (TREE_OPTIMIZATION_OPTABS (optnode));
+
+      TREE_OPTIMIZATION_OPTABS (optnode) = (unsigned char *) tmp_optabs;
+    }
+  else
+    {
+      TREE_OPTIMIZATION_OPTABS (optnode) = NULL;
+      ggc_free (tmp_optabs);
+    }
+}
+
 /* A helper function for init_sync_libfuncs.  Using the basename BASE,
    install libfuncs into TAB for BASE_N for 1 <= N <= MAX.  */
 
diff --git a/gcc/optabs.h b/gcc/optabs.h
index c08adcf..4de4409 100644
--- a/gcc/optabs.h
+++ b/gcc/optabs.h
@@ -76,6 +76,7 @@  struct target_optabs {
 };
 
 extern struct target_optabs default_target_optabs;
+extern struct target_optabs *this_fn_optabs;
 #if SWITCHABLE_TARGET
 extern struct target_optabs *this_target_optabs;
 #else
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr52555.c b/gcc/testsuite/gcc.c-torture/compile/pr52555.c
new file mode 100644
index 0000000..7016834
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr52555.c
@@ -0,0 +1,10 @@ 
+/* { dg-options "-ffast-math" } */
+
+float farg;
+unsigned val;
+
+void __attribute__((optimize("O")))
+test()
+{
+  val = __builtin_ceilf(farg);
+}
diff --git a/gcc/tree.h b/gcc/tree.h
index c3c814c..740d438 100644
--- a/gcc/tree.h
+++ b/gcc/tree.h
@@ -3586,14 +3586,25 @@  struct GTY(()) tree_optimization_option {
 
   /* The optimization options used by the user.  */
   struct cl_optimization opts;
+
+  /* Target optabs for this set of optimization options.  This is of
+     type `struct target_optabs *'.  */
+  unsigned char *GTY ((atomic)) target_optabs;
 };
 
 #define TREE_OPTIMIZATION(NODE) \
   (&OPTIMIZATION_NODE_CHECK (NODE)->optimization.opts)
 
+#define TREE_OPTIMIZATION_OPTABS(NODE) \
+  (OPTIMIZATION_NODE_CHECK (NODE)->optimization.target_optabs)
+
 /* Return a tree node that encapsulates the current optimization options.  */
 extern tree build_optimization_node (void);
 
+/* Save a new set of target_optabs in a TREE_OPTIMIZATION node if the
+   current set of optabs has changed.  */
+extern void save_optabs_if_changed (tree);
+
 /* Target options used by a function.  */
 
 struct GTY(()) tree_target_option {