[AArch64 2/3 big.LITTLE] Allow tuning parameters without unique tuning targets.

[James Greenhalgh <james dot greenhalgh at arm dot com>]

Hi,

AArch64 imports the limitation from ARM that each entry in the CORE_IDENT
column in aarch64-cores.def must be unique (as this column is used to
generate enums). We would like to have different -mcpu values map to
the same scheduler description, so remove that limitation.

One oddity this enforces, the core named by SCHEDULER_IDENT
must appear at least once in the CORE_IDENT column, so we while we
wish to use the Cortex-A15 scheduler model for the Cortex-A57,
we must set the CORE_IDENT for "cortex-a57" to cortex15.

Checked for aarch64-none-elf and built for aarch64-none-linux-gnu
with no issues.

OK?

Thanks,
James

---
2013-12-18  James Greenhalgh  <james.greenhalgh@arm.com>

	* config/aarch64/aarch64-cores.def: Add new column for
	SCHEDULER_IDENT.
	* config/aarch64/aarch64-opts.h (AARCH64_CORE): Handle
	SCHEDULER_IDENT.
	* config/aarch64/aarch64.c (AARCH64_CORE): Handle
	SCHEDULER_IDENT.
	(aarch64_parse_cpu): mcpu implies a default value for mtune.
	* config/aarch64/aarch64.h (AARCH64_CORE): Handle
	SCHEDULER_IDENT.

diff --git a/gcc/config/aarch64/aarch64-cores.def b/gcc/config/aarch64/aarch64-cores.def
index b631dbe..1b4a49f 100644
--- a/gcc/config/aarch64/aarch64-cores.def
+++ b/gcc/config/aarch64/aarch64-cores.def
@@ -21,18 +21,18 @@
 
    Before using #include to read this file, define a macro:
 
-      AARCH64_CORE(CORE_NAME, CORE_IDENT, ARCH, FLAGS, COSTS)
+      AARCH64_CORE(CORE_NAME, CORE_IDENT, SCHEDULER_IDENT, ARCH, FLAGS, COSTS)
 
    The CORE_NAME is the name of the core, represented as a string constant.
    The CORE_IDENT is the name of the core, represented as an identifier.
+   The SCHEDULER_IDENT is the name of the core for which scheduling decisions
+   will be made, represented as an identifier.
    ARCH is the architecture revision implemented by the chip.
    FLAGS are the bitwise-or of the traits that apply to that core.
    This need not include flags implied by the architecture.
    COSTS is the name of the rtx_costs routine to use.  */
 
-/* V8 Architecture Processors.
-   This list currently contains example CPUs that implement AArch64, and
-   therefore serves as a template for adding more CPUs in the future.  */
+/* V8 Architecture Processors.  */
 
-AARCH64_CORE("cortex-a53",	  cortexa53,	     8,  AARCH64_FL_FPSIMD,    cortexa53)
-AARCH64_CORE("cortex-a57",	  cortexa15,	     8,  AARCH64_FL_FPSIMD,    generic)
+AARCH64_CORE("cortex-a53",  cortexa53, cortexa53, 8,  AARCH64_FL_FPSIMD, cortexa53)
+AARCH64_CORE("cortex-a57",  cortexa15, cortexa15, 8,  AARCH64_FL_FPSIMD, generic)
diff --git a/gcc/config/aarch64/aarch64-opts.h b/gcc/config/aarch64/aarch64-opts.h
index 31e105f..6275112 100644
--- a/gcc/config/aarch64/aarch64-opts.h
+++ b/gcc/config/aarch64/aarch64-opts.h
@@ -25,8 +25,8 @@
 /* The various cores that implement AArch64.  */
 enum aarch64_processor
 {
-#define AARCH64_CORE(NAME, IDENT, ARCH, FLAGS, COSTS) \
-  IDENT,
+#define AARCH64_CORE(NAME, INTERNAL_IDENT, IDENT, ARCH, FLAGS, COSTS) \
+  INTERNAL_IDENT,
 #include "aarch64-cores.def"
 #undef AARCH64_CORE
   /* Used to indicate that no processor has been specified.  */
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 0c53e64..e668088 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -246,7 +246,7 @@ struct processor
 /* Processor cores implementing AArch64.  */
 static const struct processor all_cores[] =
 {
-#define AARCH64_CORE(NAME, IDENT, ARCH, FLAGS, COSTS) \
+#define AARCH64_CORE(NAME, X, IDENT, ARCH, FLAGS, COSTS) \
   {NAME, IDENT, #ARCH, FLAGS | AARCH64_FL_FOR_ARCH##ARCH, &COSTS##_tunings},
 #include "aarch64-cores.def"
 #undef AARCH64_CORE
@@ -5119,6 +5119,7 @@ aarch64_parse_cpu (void)
       if (strlen (cpu->name) == len && strncmp (cpu->name, str, len) == 0)
 	{
 	  selected_cpu = cpu;
+	  selected_tune = cpu;
 	  aarch64_isa_flags = selected_cpu->flags;
 
 	  if (ext != NULL)
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index d89c09b..e3e4846 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -461,8 +461,8 @@ enum reg_class
 
 enum target_cpus
 {
-#define AARCH64_CORE(NAME, IDENT, ARCH, FLAGS, COSTS) \
-  TARGET_CPU_##IDENT,
+#define AARCH64_CORE(NAME, INTERNAL_IDENT, IDENT, ARCH, FLAGS, COSTS) \
+  TARGET_CPU_##INTERNAL_IDENT,
 #include "aarch64-cores.def"
 #undef AARCH64_CORE
   TARGET_CPU_generic