[AArch64] Add support for Arm Cortex-A76

The Cortex-A76 is an Armv8.2-A processor with dotproduct and FP16 support.
It can be paired with the Cortex-A55 and hence the option
-mcpu/-mtune=cortex-a76.cortex-a55 is also introduced.

Bootstrapped and tested on aarch64-none-linux-gnu. 

	* config/aarch64/aarch64-cores.def (cortex-a76): New entry.
	(cortex-a76.cortex-a55): Likewise.
	* config/aarch64/aarch64-tune.md: Regenerate.
	* doc/invoke.texi (AArch64 Options): Document cortex-a76 and
	cortex-a76.cortex-a55.

From-SVN: r262186

gcc/ChangeLog

+2018-06-27  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* config/aarch64/aarch64-cores.def (cortex-a76): New entry.
+	(cortex-a76.cortex-a55): Likewise.
+	* config/aarch64/aarch64-tune.md: Regenerate.
+	* doc/invoke.texi (AArch64 Options): Document cortex-a76 and
+	cortex-a76.cortex-a55.
+
 2018-06-27  Jeff Law  <law@redhat.com>
 
 	* config/v850/t-v850 (MULTILIB_OPTIONS): Remove 8byte-align.

gcc/config/aarch64/aarch64-cores.def

@@ -85,6 +85,7 @@ AARCH64_CORE("thunderx2t99",  thunderx2t99,  thunderx2t99, 8_1A,  AARCH64_FL_FOR
 /* ARM ('A') cores. */
 AARCH64_CORE("cortex-a55",  cortexa55, cortexa53, 8_2A,  AARCH64_FL_FOR_ARCH8_2 | AARCH64_FL_F16 | AARCH64_FL_RCPC | AARCH64_FL_DOTPROD, cortexa53, 0x41, 0xd05, -1)
 AARCH64_CORE("cortex-a75",  cortexa75, cortexa57, 8_2A,  AARCH64_FL_FOR_ARCH8_2 | AARCH64_FL_F16 | AARCH64_FL_RCPC | AARCH64_FL_DOTPROD, cortexa73, 0x41, 0xd0a, -1)
+AARCH64_CORE("cortex-a76",  cortexa76, cortexa57, 8_2A,  AARCH64_FL_FOR_ARCH8_2 | AARCH64_FL_F16 | AARCH64_FL_RCPC | AARCH64_FL_DOTPROD, cortexa72, 0x41, 0xd0b, -1)
 
 /* ARMv8.4-A Architecture Processors.  */
 
@@ -101,5 +102,6 @@ AARCH64_CORE("cortex-a73.cortex-a53",  cortexa73cortexa53, cortexa53, 8A,  AARCH
 /* ARM DynamIQ big.LITTLE configurations.  */
 
 AARCH64_CORE("cortex-a75.cortex-a55",  cortexa75cortexa55, cortexa53, 8_2A,  AARCH64_FL_FOR_ARCH8_2 | AARCH64_FL_F16 | AARCH64_FL_RCPC | AARCH64_FL_DOTPROD, cortexa73, 0x41, AARCH64_BIG_LITTLE (0xd0a, 0xd05), -1)
+AARCH64_CORE("cortex-a76.cortex-a55",  cortexa76cortexa55, cortexa53, 8_2A,  AARCH64_FL_FOR_ARCH8_2 | AARCH64_FL_F16 | AARCH64_FL_RCPC | AARCH64_FL_DOTPROD, cortexa72, 0x41, AARCH64_BIG_LITTLE (0xd0b, 0xd05), -1)
 
 #undef AARCH64_CORE

gcc/config/aarch64/aarch64-tune.md

 ;; -*- buffer-read-only: t -*-
 ;; Generated automatically by gentune.sh from aarch64-cores.def
 (define_attr "tune"
-	"cortexa35,cortexa53,cortexa57,cortexa72,cortexa73,thunderx,thunderxt88p1,thunderxt88,thunderxt81,thunderxt83,xgene1,falkor,qdf24xx,exynosm1,thunderx2t99p1,vulcan,thunderx2t99,cortexa55,cortexa75,saphira,cortexa57cortexa53,cortexa72cortexa53,cortexa73cortexa35,cortexa73cortexa53,cortexa75cortexa55"
+	"cortexa35,cortexa53,cortexa57,cortexa72,cortexa73,thunderx,thunderxt88p1,thunderxt88,thunderxt81,thunderxt83,xgene1,falkor,qdf24xx,exynosm1,thunderx2t99p1,vulcan,thunderx2t99,cortexa55,cortexa75,cortexa76,saphira,cortexa57cortexa53,cortexa72cortexa53,cortexa73cortexa35,cortexa73cortexa53,cortexa75cortexa55,cortexa76cortexa55"
 	(const (symbol_ref "((enum attr_tune) aarch64_tune)")))

gcc/doc/invoke.texi

@@ -14665,18 +14665,19 @@ Specify the name of the target processor for which GCC should tune the
 performance of the code.  Permissible values for this option are:
 @samp{generic}, @samp{cortex-a35}, @samp{cortex-a53}, @samp{cortex-a55},
 @samp{cortex-a57}, @samp{cortex-a72}, @samp{cortex-a73}, @samp{cortex-a75},
-@samp{exynos-m1}, @samp{falkor}, @samp{qdf24xx}, @samp{saphira},
-@samp{xgene1}, @samp{vulcan}, @samp{thunderx},
+@samp{cortex-a76}, @samp{exynos-m1}, @samp{falkor}, @samp{qdf24xx},
+@samp{saphira}, @samp{xgene1}, @samp{vulcan}, @samp{thunderx},
 @samp{thunderxt88}, @samp{thunderxt88p1}, @samp{thunderxt81},
 @samp{thunderxt83}, @samp{thunderx2t99}, @samp{cortex-a57.cortex-a53},
 @samp{cortex-a72.cortex-a53}, @samp{cortex-a73.cortex-a35},
 @samp{cortex-a73.cortex-a53}, @samp{cortex-a75.cortex-a55},
+@samp{cortex-a76.cortex-a55}
 @samp{native}.
 
 The values @samp{cortex-a57.cortex-a53}, @samp{cortex-a72.cortex-a53},
 @samp{cortex-a73.cortex-a35}, @samp{cortex-a73.cortex-a53},
-@samp{cortex-a75.cortex-a55} specify that GCC should tune for a
-big.LITTLE system.
+@samp{cortex-a75.cortex-a55}, @samp{cortex-a76.cortex-a55} specify that GCC
+should tune for a big.LITTLE system.
 
 Additionally on native AArch64 GNU/Linux systems the value
 @samp{native} tunes performance to the host system.  This option has no effect