Enable integrated assembler for Android™ 13 and onwards only

Since Android™ 13, the underlying NDK has deprecated system assembler
and favors integrated assembler instead

Please also see https://github.com/android/ndk/wiki/Changelog-r23

Resolves COMPMID-5410

Signed-off-by: SiCong Li <sicong.li@arm.com>
Change-Id: Ib9fa8a22f6cdb5cb4f0095e15bf332484f709630
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/7956
Benchmark: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Gunes Bayir <gunes.bayir@arm.com>
Reviewed-by: Ramy Elgammal <ramy.elgammal@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>

2 files changed, 39 insertions, 6 deletions

diff --git a/SConstruct b/SConstruct
index 7f0ebc1a0b..9e046161ac 100644
--- a/SConstruct
+++ b/SConstruct
@@ -426,12 +426,21 @@ if not GetOption("help"):
         if not version_at_least(compiler_ver, '7.0.0') and env['os'] == 'bare_metal':
             env.Append(LINKFLAGS = ['-fstack-protector-strong'])
 
-    # For NDK >= r21, clang 9 or above is used
-    if env['os'] == 'android' and version_at_least(compiler_ver, '9.0.0'):
-        env['ndk_above_r21'] = True
-
-        if env['openmp']:
-            env.Append(LINKFLAGS = ['-static-openmp'])
+    # Add Android NDK toolchain specific flags
+    if 'clang++' in cpp_compiler and env['os'] == 'android':
+        # For NDK >= r21, clang 9 or above is used
+        if version_at_least(compiler_ver, '9.0.0'):
+            env['ndk_above_r21'] = True
+
+            if env['openmp']:
+                env.Append(LINKFLAGS = ['-static-openmp'])
+
+        # For NDK >= r23, clang 12 or above is used. This condition detects NDK < r23
+        if not version_at_least(compiler_ver, '12.0.0'):
+            # System assembler is deprecated and integrated assembler is preferred since r23.
+            # However integrated assembler has always been suppressed for NDK < r23.
+            # Thus for backward compatibility, we include this flag only for NDK < r23
+            env.Append(CXXFLAGS = ['-no-integrated-as'])
 
 if env['high_priority'] and env['build_config']:
     print("The high priority library cannot be built in conjunction with a user-specified build configuration")
diff --git a/scripts/arm_compute_library_nn_driver.go b/scripts/arm_compute_library_nn_driver.go
index cbbe7a71e0..e00140294b 100644
--- a/scripts/arm_compute_library_nn_driver.go
+++ b/scripts/arm_compute_library_nn_driver.go
@@ -11,6 +11,24 @@ import (
     "strings"
 )
 
+func isVersionAtLeast(version_name string, target_version int) []bool {
+    name_map := map[string]int {
+    "L": 5, "5": 5,
+    "M": 6, "6": 6,
+    "N": 7, "7": 7,
+    "O": 8, "8": 8,
+    "P": 9, "9": 9,
+    "Q": 10, "10": 10,
+    "R": 11, "11": 11,
+    "S": 12, "12": 12,
+    "T": 13, "13": 13,
+    }
+    if ! name_map[version_name] {
+        return false
+    }
+    return name_map[version_name] >= target_version
+}
+
 func globalFlags(ctx android.BaseContext) []string {
     var cppflags []string
 
@@ -30,6 +48,12 @@ func globalFlags(ctx android.BaseContext) []string {
       }
     }
 
+    // Since Android T, the underlying NDK stops supporting system assembler like GAS, in favor of integrated assembler
+    // However for Android < Android T we still want to suppress integrated assembler for backward compatibility
+    if ! isVersionAtLeast(ctx.AConfig().PlatformVersionName(), 13) {
+        cppflags = append(cppflags, "-no-integrated-as")
+    }
+
     data_types := strings.Split(ctx.AConfig().GetenvWithDefault("COMPUTE_LIB_DATA_TYPE", "ALL"), ",")
 
     for _, x := range data_types {