[PATCH][GCC 8] arm: Add support for Neoverse N2 CPU

[Alex Coplan via Gcc-patches]

This patch backports the AArch32 support for Arm's Neoverse N2 CPU to
GCC 8.

Testing:
 * Bootstrapped and regtested on arm-none-linux-gnueabihf.

OK for GCC 8 branch?

Thanks,
Alex

---

gcc/ChangeLog:

        * config/arm/arm-cpus.in (neoverse-n2): New.
        * config/arm/arm-tables.opt: Regenerate.
        * config/arm/arm-tune.md: Regenerate.
        * config/arm/driver-arm.c (arm_cpu_table): Add Neoverse N2.
        * doc/invoke.texi: Document support for Neoverse N2.

diff --git a/gcc/config/arm/arm-cpus.in b/gcc/config/arm/arm-cpus.in
index edfe5b378da..39a9e8b76ba 100644
--- a/gcc/config/arm/arm-cpus.in
+++ b/gcc/config/arm/arm-cpus.in
@@ -1588,6 +1588,17 @@ begin cpu neoverse-v1
 end cpu neoverse-v1
 
 
+# Armv8.5 A-profile Architecture Processors
+begin cpu neoverse-n2
+  cname neoversen2
+  tune for cortex-a57
+  tune flags LDSCHED
+  architecture armv8.4-a+fp16
+  option crypto add FP_ARMv8 CRYPTO
+  costs cortex_a57
+end cpu neoverse-n2
+
+
 # V8 M-profile implementations.
 begin cpu cortex-m23
  cname cortexm23
diff --git a/gcc/config/arm/arm-tables.opt b/gcc/config/arm/arm-tables.opt
index 36dba62003a..a0fb8323ee3 100644
--- a/gcc/config/arm/arm-tables.opt
+++ b/gcc/config/arm/arm-tables.opt
@@ -354,6 +354,9 @@ Enum(processor_type) String(cortex-a75.cortex-a55) Value( 
TARGET_CPU_cortexa75co
 EnumValue
 Enum(processor_type) String(neoverse-v1) Value( TARGET_CPU_neoversev1)
 
+EnumValue
+Enum(processor_type) String(neoverse-n2) Value( TARGET_CPU_neoversen2)
+
 EnumValue
 Enum(processor_type) String(cortex-m23) Value( TARGET_CPU_cortexm23)
 
diff --git a/gcc/config/arm/arm-tune.md b/gcc/config/arm/arm-tune.md
index c972ce55576..ea3dbcda43f 100644
--- a/gcc/config/arm/arm-tune.md
+++ b/gcc/config/arm/arm-tune.md
@@ -57,6 +57,6 @@
        cortexa73,exynosm1,xgene1,
        cortexa57cortexa53,cortexa72cortexa53,cortexa73cortexa35,
        cortexa73cortexa53,cortexa55,cortexa75,
-       cortexa75cortexa55,neoversev1,cortexm23,
-       cortexm33,cortexr52"
+       cortexa75cortexa55,neoversev1,neoversen2,
+       cortexm23,cortexm33,cortexr52"
        (const (symbol_ref "((enum attr_tune) arm_tune)")))
diff --git a/gcc/config/arm/driver-arm.c b/gcc/config/arm/driver-arm.c
index a53c2272864..45ad92ef0e0 100644
--- a/gcc/config/arm/driver-arm.c
+++ b/gcc/config/arm/driver-arm.c
@@ -56,6 +56,7 @@ static struct vendor_cpu arm_cpu_table[] = {
     {"0xd09", "armv8-a+crc", "cortex-a73"},
     {"0xd05", "armv8.2-a+fp16+dotprod", "cortex-a55"},
     {"0xd0a", "armv8.2-a+fp16+dotprod", "cortex-a75"},
+    {"0xd49", "armv8.4-a+fp16", "neoverse-n2"},
     {"0xc14", "armv7-r", "cortex-r4"},
     {"0xc15", "armv7-r", "cortex-r5"},
     {"0xc17", "armv7-r", "cortex-r7"},
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index b91366daafd..78ca7738df2 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -16334,8 +16334,8 @@ Permissible names are: @samp{arm2}, @samp{arm250},
 @samp{cortex-a9}, @samp{cortex-a12}, @samp{cortex-a15}, @samp{cortex-a17},
 @samp{cortex-a32}, @samp{cortex-a35}, @samp{cortex-a53}, @samp{cortex-a55},
 @samp{cortex-a57}, @samp{cortex-a72}, @samp{cortex-a73}, @samp{cortex-a75},
-@samp{neoverse-v1}, @samp{cortex-r4}, @samp{cortex-r4f}, @samp{cortex-r5},
-@samp{cortex-r7}, @samp{cortex-r8}, @samp{cortex-r52},
+@samp{neoverse-v1}, @samp{neoverse-n2}, @samp{cortex-r4}, @samp{cortex-r4f},
+@samp{cortex-r5}, @samp{cortex-r7}, @samp{cortex-r8}, @samp{cortex-r52},
 @samp{cortex-m33},
 @samp{cortex-m23},
 @samp{cortex-m7},