re PR target/82641 (Unable to enable crc32 for a certain function with target attribute on ARM (aarch32))

2017-12-07  Tamar Christina  <tamar.christina@arm.com>

	PR target/82641
	* config/arm/arm.c (INCLUDE_STRING): Define.
	(arm_last_printed_arch_string, arm_last_printed_fpu_string): New.
	(arm_declare_function_name): Conservatively emit .arch, .arch_extensions
	and .fpu.

gcc/testsuite/
2017-12-07  Tamar Christina  <tamar.christina@arm.com>

	PR target/82641
	* gcc.target/arm/pragma_arch_attribute_2.c: New.
	* gcc.target/arm/pragma_arch_attribute_2.c: New.
	* gcc.target/arm/pragma_arch_attribute_3.c: New.
	* gcc.target/arm/pragma_fpu_attribute.c: New.
	* gcc.target/arm/pragma_fpu_attribute_2.c: New.

From-SVN: r255468

1 files changed, 58 insertions, 4 deletions

diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 64dc8cd..b986377 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -21,6 +21,7 @@
    <http://www.gnu.org/licenses/>.  */
 
 #include "config.h"
+#define INCLUDE_STRING
 #include "system.h"
 #include "coretypes.h"
 #include "backend.h"
@@ -30956,9 +30957,57 @@ arm_identify_fpu_from_isa (sbitmap isa)
   gcc_unreachable ();
 }
 
+/* The last .arch and .fpu assembly strings that we printed.  */
+static std::string arm_last_printed_arch_string;
+static std::string arm_last_printed_fpu_string;
+
+/* Implement ASM_DECLARE_FUNCTION_NAME.  Output the ISA features used
+   by the function fndecl.  */
 void
 arm_declare_function_name (FILE *stream, const char *name, tree decl)
 {
+  tree target_parts = DECL_FUNCTION_SPECIFIC_TARGET (decl);
+
+  struct cl_target_option *targ_options;
+  if (target_parts)
+    targ_options = TREE_TARGET_OPTION (target_parts);
+  else
+    targ_options = TREE_TARGET_OPTION (target_option_current_node);
+  gcc_assert (targ_options);
+
+  /* Only update the assembler .arch string if it is distinct from the last
+     such string we printed.  */
+  std::string arch_to_print = targ_options->x_arm_arch_string;
+  if (arch_to_print != arm_last_printed_arch_string)
+    {
+      std::string arch_name
+	= arch_to_print.substr (0, arch_to_print.find ("+"));
+      asm_fprintf (asm_out_file, "\t.arch %s\n", arch_name.c_str ());
+      const arch_option *arch
+	= arm_parse_arch_option_name (all_architectures, "-march",
+				      targ_options->x_arm_arch_string);
+      auto_sbitmap opt_bits (isa_num_bits);
+
+      gcc_assert (arch);
+      if (arch->common.extensions)
+	{
+	  for (const struct cpu_arch_extension *opt = arch->common.extensions;
+	       opt->name != NULL;
+	       opt++)
+	    {
+	      if (!opt->remove)
+		{
+		  arm_initialize_isa (opt_bits, opt->isa_bits);
+		  if (bitmap_subset_p (opt_bits, arm_active_target.isa)
+		      && !bitmap_subset_p (opt_bits, isa_all_fpubits))
+		    asm_fprintf (asm_out_file, "\t.arch_extension %s\n",
+				 opt->name);
+		}
+	     }
+	}
+
+      arm_last_printed_arch_string = arch_to_print;
+    }
 
   fprintf (stream, "\t.syntax unified\n");
 
@@ -30976,10 +31025,15 @@ arm_declare_function_name (FILE *stream, const char *name, tree decl)
   else
     fprintf (stream, "\t.arm\n");
 
-  asm_fprintf (asm_out_file, "\t.fpu %s\n",
-	       (TARGET_SOFT_FLOAT
-		? "softvfp"
-		: arm_identify_fpu_from_isa (arm_active_target.isa)));
+  std::string fpu_to_print
+    = TARGET_SOFT_FLOAT
+	? "softvfp" : arm_identify_fpu_from_isa (arm_active_target.isa);
+
+  if (fpu_to_print != arm_last_printed_arch_string)
+    {
+      asm_fprintf (asm_out_file, "\t.fpu %s\n", fpu_to_print.c_str ());
+      arm_last_printed_fpu_string = fpu_to_print;
+    }
 
   if (TARGET_POKE_FUNCTION_NAME)
     arm_poke_function_name (stream, (const char *) name);