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

2017-11-17  Tamar Christina  <tamar.christina@arm.com>

	PR target/82641
	* config/arm/arm.c (arm_valid_target_attribute_rec):
	Parse "arch=" and "+<ext>".
	(arm_valid_target_attribute_tree): Re-init global options.
	(arm_option_override): Make non-static.
	(arm_options_perform_arch_sanity_checks): Make errors fatal.
	* gcc/config/arm/arm-c.c (__ARM_FEATURE_CMSE): Support undef.
	(__ARM_FEATURE_CRC32): Support undef.
	* config/arm/arm_acle.h (__ARM_FEATURE_CRC32): Replace with pragma.
	* doc/extend.texi (ARM Function Attributes): Add pragma and target.

gcc/testsuite/
2017-11-17  Tamar Christina  <tamar.christina@arm.com>

	PR target/82641
	* gcc.target/arm/pragma_arch_attribute.c: New.

From-SVN: r254878

6 files changed, 139 insertions, 5 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 8a186a1..a7954d2 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,16 @@
+2017-11-17  Tamar Christina  <tamar.christina@arm.com>
+
+	PR target/82641
+	* config/arm/arm.c (arm_valid_target_attribute_rec):
+	Parse "arch=" and "+<ext>".
+	(arm_valid_target_attribute_tree): Re-init global options.
+	(arm_option_override): Make non-static.
+	(arm_options_perform_arch_sanity_checks): Make errors fatal.
+	* gcc/config/arm/arm-c.c (__ARM_FEATURE_CMSE): Support undef.
+	(__ARM_FEATURE_CRC32): Support undef.
+	* config/arm/arm_acle.h (__ARM_FEATURE_CRC32): Replace with pragma.
+	* doc/extend.texi (ARM Function Attributes): Add pragma and target.
+
 2017-11-17  David Malcolm  <dmalcolm@redhat.com>
 
 	* gdbinit.in (break-on-diagnostic): New command.
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 106e3ed..1c2f8fa 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -3297,6 +3297,7 @@ arm_configure_build_target (struct arm_build_target *target,
   target->tune_flags = tune_data->tune_flags;
   target->tune = tune_data->tune;
   target->tune_core = tune_data->scheduler;
+  arm_option_reconfigure_globals ();
 }
 
 /* Fix up any incompatible options that the user has specified.  */
@@ -30653,7 +30654,7 @@ arm_valid_target_attribute_rec (tree args, struct gcc_options *opts)
 	  if (! opt_enum_arg_to_value (OPT_mfpu_, q+4,
 				       &fpu_index, CL_TARGET))
 	    {
-	      error ("invalid fpu for attribute(target(\"%s\"))", q);
+	      error ("invalid fpu for target attribute or pragma %qs", q);
 	      return false;
 	    }
 	  if (fpu_index == TARGET_FPU_auto)
@@ -30666,9 +30667,29 @@ arm_valid_target_attribute_rec (tree args, struct gcc_options *opts)
 	    }
 	  opts->x_arm_fpu_index = (enum fpu_type) fpu_index;
 	}
+      else if (!strncmp (q, "arch=", 5))
+	{
+	  char* arch = q+5;
+	  const arch_option *arm_selected_arch
+	     = arm_parse_arch_option_name (all_architectures, "arch", arch);
+
+	  if (!arm_selected_arch)
+	    {
+	      error ("invalid architecture for target attribute or pragma %qs",
+		     q);
+	      return false;
+	    }
+
+	  opts->x_arm_arch_string = xstrndup (arch, strlen (arch));
+	}
+      else if (q[0] == '+')
+	{
+	  opts->x_arm_arch_string
+	    = xasprintf ("%s%s", opts->x_arm_arch_string, q);
+	}
       else
 	{
-	  error ("attribute(target(\"%s\")) is unknown", q);
+	  error ("unknown target attribute or pragma %qs", q);
 	  return false;
 	}
     }
@@ -30690,7 +30711,10 @@ arm_valid_target_attribute_tree (tree args, struct gcc_options *opts,
   cl_target_option_save (&cl_opts, opts);
   arm_configure_build_target (&arm_active_target, &cl_opts, opts_set, false);
   arm_option_check_internal (opts);
-  /* Do any overrides, such as global options arch=xxx.  */
+  /* Do any overrides, such as global options arch=xxx.
+     We do this since arm_active_target was overridden.  */
+  arm_option_reconfigure_globals ();
+  arm_options_perform_arch_sanity_checks ();
   arm_option_override_internal (opts, opts_set);
 
   return build_target_option_node (opts);
diff --git a/gcc/config/arm/arm_acle.h b/gcc/config/arm/arm_acle.h
index 972e28e..ad28a45 100644
--- a/gcc/config/arm/arm_acle.h
+++ b/gcc/config/arm/arm_acle.h
@@ -173,7 +173,10 @@ __arm_mrrc2 (const unsigned int __coproc, const unsigned int __opc1,
 #endif /*  __ARM_ARCH >= 5.  */
 #endif /* (!__thumb__ || __thumb2__) &&  __ARM_ARCH >= 4.  */
 
-#ifdef __ARM_FEATURE_CRC32
+#pragma GCC push_options
+#if __ARM_ARCH >= 8
+#pragma GCC target ("arch=armv8-a+crc")
+
 __extension__ static __inline uint32_t __attribute__ ((__always_inline__))
 __crc32b (uint32_t __a, uint8_t __b)
 {
@@ -232,7 +235,8 @@ __crc32cd (uint32_t __a, uint64_t __b)
 }
 #endif
 
-#endif
+#endif /* __ARM_ARCH >= 8.  */
+#pragma GCC pop_options
 
 #ifdef __cplusplus
 }
diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
index 711264c..50bda91 100644
--- a/gcc/doc/extend.texi
+++ b/gcc/doc/extend.texi
@@ -3858,6 +3858,40 @@ Specifies the fpu for which to tune the performance of this function.
 The behavior and permissible arguments are the same as for the @option{-mfpu=}
 command-line option.
 
+@item arch=
+@cindex @code{arch=} function attribute, ARM
+Specifies the architecture version and architectural extensions to use
+for this function.  The behavior and permissible arguments are the same as
+for the @option{-march=} command-line option.
+
+The above target attributes can be specified as follows:
+
+@smallexample
+__attribute__((target("arch=armv8-a+crc")))
+int
+f (int a)
+@{
+  return a + 5;
+@}
+@end smallexample
+
+Additionally, the architectural extension string may be specified on its
+own.  This can be used to turn on and off particular architectural extensions
+without having to specify a particular architecture version or core.  Example:
+
+@smallexample
+__attribute__((target("+crc+nocrypto")))
+int
+foo (int a)
+@{
+  return a + 5;
+@}
+@end smallexample
+
+In this example @code{target("+crc+nocrypto")} enables the @code{crc}
+extension and disables the @code{crypto} extension for the function @code{foo}
+without modifying an existing @option{-march=} or @option{-mcpu} option.
+
 @end table
 
 @end table
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index d98ba98..eed45d2 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-11-17  Tamar Christina  <tamar.christina@arm.com>
+
+	PR target/82641
+	* gcc.target/arm/pragma_arch_attribute.c: New.
+
 2017-11-17  Segher Boessenkool  <segher@kernel.crashing.org>
 
 	* gcc.target/powerpc/altivec-macros.c: Include "-:" in the messages
diff --git a/gcc/testsuite/gcc.target/arm/pragma_arch_attribute.c b/gcc/testsuite/gcc.target/arm/pragma_arch_attribute.c
new file mode 100644
index 0000000..a06dbf0
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/pragma_arch_attribute.c
@@ -0,0 +1,54 @@
+/* Test for #pragma target macros.  */
+/* { dg-do compile } */
+/* { dg-require-effective-target arm_arch_v8a_ok } */
+/* { dg-add-options arm_arch_v8a } */
+
+#include <arm_acle.h>
+
+#ifdef __ARM_FEATURE_CRC32
+# error "__ARM_FEATURE_CRC32 is already defined."
+#endif
+
+#pragma GCC push_options
+#pragma GCC target ("arch=armv8-a+crc")
+#ifndef __ARM_FEATURE_CRC32
+# error "__ARM_FEATURE_CRC32 is not defined in push 1."
+#endif
+#pragma GCC pop_options
+
+#ifdef __ARM_FEATURE_CRC32
+# error "__ARM_FEATURE_CRC32 is defined after pop 1."
+#endif
+
+#pragma GCC push_options
+#pragma GCC target ("+crc")
+#ifndef __ARM_FEATURE_CRC32
+# error "__ARM_FEATURE_CRC32 is not defined in push 2."
+#endif
+#pragma GCC pop_options
+
+#ifdef __ARM_FEATURE_CRC32
+# error "__ARM_FEATURE_CRC32 is defined after pop 2."
+#endif
+
+__attribute__((target("+crc")))
+void test_crc_unknown_ok_attr_1 ()
+{
+	__crc32b (0, 0);
+}
+
+#ifdef __ARM_FEATURE_CRC32
+# error "__ARM_FEATURE_CRC32 is defined after attribute set 1."
+#endif
+
+__attribute__((target("arch=armv8-a+crc")))
+void test_crc_unknown_ok_attr_2 ()
+{
+	__crc32b (0, 0);
+}
+
+#ifdef __ARM_FEATURE_CRC32
+# error "__ARM_FEATURE_CRC32 is defined after attribute set 2."
+#endif
+
+#pragma GCC reset_options
\ No newline at end of file