From a2a582413e5d0d67af69deb30a9f5924703dd875 Mon Sep 17 00:00:00 2001
From: Isaac Chen <ycchen@google.com>
Date: Wed, 23 Aug 2017 10:57:17 +0000
Subject: [PATCH] Revert "Revert "Build support for 32-bit armv8-a""

This reverts commit 80b27e4e2093309a72a15b9802212da47172f026.

Fixed CTS build issue by adding -march=armv7-a in cts/tests/tests/os/jni/Android.mk since the library built here needs/uses instruction (swp) obsolete in ARMv8.

Bug: 64964151
Test: lunch aosp_arm64-userdebug; make -j cts
      lunch aosp_x86-userdebug; make -j cts
      lunch aosp_sailfish-userdebug; make -j cts
      lunch aosp_bullhead-userdebug; make -j cts

Change-Id: I6ccafce043e101c769ad370a81ffa0eb62719b5e
---
 cc/config/arm_device.go | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/cc/config/arm_device.go b/cc/config/arm_device.go
index d50de2b4f..f093563fb 100644
--- a/cc/config/arm_device.go
+++ b/cc/config/arm_device.go
@@ -102,6 +102,11 @@ var (
 			"-mfloat-abi=softfp",
 			"-mfpu=neon",
 		},
+		"armv8-a": []string{
+			"-march=armv8-a",
+			"-mfloat-abi=softfp",
+			"-mfpu=neon-fp-armv8",
+		},
 	}
 
 	armCpuVariantCflags = map[string][]string{
@@ -174,6 +179,7 @@ func init() {
 		"armv5te",
 		"armv7-a",
 		"armv7-a-neon",
+		"armv8-a",
 		"cortex-a7",
 		"cortex-a8",
 		"cortex-a9",
@@ -188,12 +194,19 @@ func init() {
 		"denver")
 
 	android.RegisterArchVariantFeatures(android.Arm, "armv7-a-neon", "neon")
+	android.RegisterArchVariantFeatures(android.Arm, "armv8-a", "neon")
 
 	// Krait and Kryo targets are not supported by GCC, but are supported by Clang,
 	// so override the definitions when building modules with Clang.
 	replaceFirst(armClangCpuVariantCflags["krait"], "-mcpu=cortex-a15", "-mcpu=krait")
 	replaceFirst(armClangCpuVariantCflags["kryo"], "-mcpu=cortex-a15", "-mcpu=krait")
 
+	// The reason we use "-march=armv8-a+crc", instead of "-march=armv8-a", for
+	// gcc is the latter would conflict with any specified/supported -mcpu!
+	// All armv8-a cores supported by gcc 4.9 support crc, so it's safe
+	// to add +crc. Besides, the use of gcc is only for legacy code.
+	replaceFirst(armArchVariantCflags["armv8-a"], "-march=armv8-a", "-march=armv8-a+crc")
+
 	pctx.StaticVariable("armGccVersion", armGccVersion)
 
 	pctx.SourcePathVariable("ArmGccRoot",
@@ -215,6 +228,7 @@ func init() {
 	pctx.StaticVariable("ArmArmv5TECflags", strings.Join(armArchVariantCflags["armv5te"], " "))
 	pctx.StaticVariable("ArmArmv7ACflags", strings.Join(armArchVariantCflags["armv7-a"], " "))
 	pctx.StaticVariable("ArmArmv7ANeonCflags", strings.Join(armArchVariantCflags["armv7-a-neon"], " "))
+	pctx.StaticVariable("ArmArmv8ACflags", strings.Join(armArchVariantCflags["armv8-a"], " "))
 
 	// Cpu variant cflags
 	pctx.StaticVariable("ArmGenericCflags", strings.Join(armCpuVariantCflags[""], " "))
@@ -242,6 +256,8 @@ func init() {
 		strings.Join(armClangArchVariantCflags["armv7-a"], " "))
 	pctx.StaticVariable("ArmClangArmv7ANeonCflags",
 		strings.Join(armClangArchVariantCflags["armv7-a-neon"], " "))
+	pctx.StaticVariable("ArmClangArmv8ACflags",
+		strings.Join(armClangArchVariantCflags["armv8-a"], " "))
 
 	// Clang cpu variant cflags
 	pctx.StaticVariable("ArmClangGenericCflags",
@@ -265,6 +281,7 @@ var (
 		"armv5te":      "${config.ArmArmv5TECflags}",
 		"armv7-a":      "${config.ArmArmv7ACflags}",
 		"armv7-a-neon": "${config.ArmArmv7ANeonCflags}",
+		"armv8-a":      "${config.ArmArmv8ACflags}",
 	}
 
 	armCpuVariantCflagsVar = map[string]string{
@@ -286,6 +303,7 @@ var (
 		"armv5te":      "${config.ArmClangArmv5TECflags}",
 		"armv7-a":      "${config.ArmClangArmv7ACflags}",
 		"armv7-a-neon": "${config.ArmClangArmv7ANeonCflags}",
+		"armv8-a":      "${config.ArmClangArmv8ACflags}",
 	}
 
 	armClangCpuVariantCflagsVar = map[string]string{
@@ -402,6 +420,11 @@ func armToolchainFactory(arch android.Arch) Toolchain {
 	toolchainClangCflags[0] = "${config.ArmToolchainClangCflags}"
 	toolchainClangCflags[1] = armClangArchVariantCflagsVar[arch.ArchVariant]
 
+	toolchainCflags = append(toolchainCflags,
+		variantOrDefault(armCpuVariantCflagsVar, arch.CpuVariant))
+	toolchainClangCflags = append(toolchainClangCflags,
+		variantOrDefault(armClangCpuVariantCflagsVar, arch.CpuVariant))
+
 	switch arch.ArchVariant {
 	case "armv7-a-neon":
 		switch arch.CpuVariant {
@@ -411,15 +434,12 @@ func armToolchainFactory(arch android.Arch) Toolchain {
 		default:
 			fixCortexA8 = "-Wl,--no-fix-cortex-a8"
 		}
-
-		toolchainCflags = append(toolchainCflags,
-			variantOrDefault(armCpuVariantCflagsVar, arch.CpuVariant))
-		toolchainClangCflags = append(toolchainClangCflags,
-			variantOrDefault(armClangCpuVariantCflagsVar, arch.CpuVariant))
 	case "armv7-a":
 		fixCortexA8 = "-Wl,--fix-cortex-a8"
 	case "armv5te":
 		// Nothing extra for armv5te
+	case "armv8-a":
+		// Nothing extra for armv8-a
 	default:
 		panic(fmt.Sprintf("Unknown ARM architecture version: %q", arch.ArchVariant))
 	}