Merge pull request #52 from aiuto/arms

Add cortex-r52 r82 cpus

cpu/BUILD

@@ -13,6 +13,24 @@ filegroup(
 # To add a new constraint_value see https://github.com/bazelbuild/platforms.
 constraint_setting(name = "cpu")
 
+# New cpu values should refer to specific, highly available CPU implementations,
+# not broad architectures.  It should be possible to select the right compiler
+# options by just by knowing the cpu. This can be a difficult evaluation for
+# ARM variations, where there are many possibilities for customization within
+# an architecture.
+#
+# 1. No private names are be allowed. If you build your own custom ARM chips,
+#    then define them locally within your organization.
+# 2. All CPU values must be clear that they are for a 32 or a 64 bit
+#    implementation. For example, cortex-r52 is a 32 bit processor, and
+#    cortex-r82 is a 64 bit processor, but both are armv8-r architecture.
+#    We use the specific processor names because armv8-r is insufficient to
+#    select proper compiler options.
+#
+# Many of the name here are legacy values and probably violate these conditions.
+# We'll try to clean those up over time.
+
+
 # TODO(b/136237408): Remove this generic CPU name and replace with a specific one.
 alias(
     name = "aarch64",
@@ -55,12 +73,6 @@ constraint_value(
     constraint_setting = ":cpu",
 )
 
-# Cortex-R52
-constraint_value(
-    name = "armv8-r",
-    constraint_setting = ":cpu",
-)
-
 constraint_value(
     name = "arm64_32",
     constraint_setting = ":cpu",
@@ -86,6 +98,16 @@ constraint_value(
     constraint_setting = ":cpu",
 )
 
+constraint_value(
+    name = "cortex-r52",
+    constraint_setting = ":cpu",
+)
+
+constraint_value(
+    name = "cortex-r82",
+    constraint_setting = ":cpu",
+)
+
 constraint_value(
     name = "i386",
     constraint_setting = ":cpu",