Changes to enable FP16 in armv8a multi_isa

* This is the initial patch to start working on enabling fp16 in all
  multi_isa builds. More changes are required in the way we register
  the kernels using the macro REGISTER_FP16_NEON.

* In this patch we add the capability to build the fp16 files in listed in
  filelist.json with the correct arch option to enable FP16

* This patch is required towards building an universal multi_isa binary
  where fp16 is enable.

* Enable REGISTER_FP16_NEON macro for all builds by removing
  __ARM_FEATURE_FP16_VECTOR_ARITHMETIC guard from the macro definition.
  The macro has to be used across all types of builds.

Change-Id: I99f4c273f6ee04cad3c097e5e374200f48568fa9
Signed-off-by: Pablo Marquez Tello <pablo.tello@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/10682
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Jakub Sujak <jakub.sujak@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Benchmark: Arm Jenkins <bsgcomp@arm.com>

1 files changed, 12 insertions, 8 deletions

diff --git a/SConstruct b/SConstruct
index 68c518a4a0..3eee4c0561 100644
--- a/SConstruct
+++ b/SConstruct
@@ -62,8 +62,14 @@ def read_build_config_json(build_config):
 
 def update_data_type_layout_flags(env, data_types, data_layouts):
     # Manage data-types
-    if any(i in data_types for i in ['all', 'fp16']):
-        env.Append(CXXFLAGS = ['-DENABLE_FP16_KERNELS'])
+    if env['multi_isa']:
+        if  any(i in data_types for i in ['all', 'fp16']):
+            env.Append(CXXFLAGS = ['-DENABLE_FP16_KERNELS'])
+    else:
+            if not 'v8a' in env['arch'] and not 'v7a' in env['arch']:
+                if  any(i in data_types for i in ['all', 'fp16']):
+                    env.Append(CXXFLAGS = ['-DENABLE_FP16_KERNELS'])
+
     if any(i in data_types for i in ['all', 'fp32']):
         env.Append(CXXFLAGS = ['-DENABLE_FP32_KERNELS'])
     if any(i in data_types for i in ['all', 'qasymm8']):
@@ -112,7 +118,7 @@ vars.AddVariables(
     BoolVariable("exceptions", "Enable/disable C++ exception support", True),
     BoolVariable("high_priority", "Generate a library containing only the high priority operators", False),
     PathVariable("linker_script", "Use an external linker script", "", PathVariable.PathAccept),
-    PathVariable("external_tests_dir", """Add examples, benchmarks and tests to the tests suite from an external path. In order to use this option, the external tests directory must have the following structure: 
+    PathVariable("external_tests_dir", """Add examples, benchmarks and tests to the tests suite from an external path. In order to use this option, the external tests directory must have the following structure:
     EXTERNAL_TESTS_DIR:
     └── tests
         ├── benchmark
@@ -240,7 +246,6 @@ env.Append(CXXFLAGS = ['-DARCH_ARM',
 if not 'windows' in env['os']:
     env.Append(CXXFLAGS = ['-Wall','-std=c++14', '-pedantic' ])
 
-env.Append(CPPDEFINES = ['_GLIBCXX_USE_NANOSLEEP'])
 
 cpp_tool = {'linux': 'g++', 'android' : 'clang++',
              'tizen': 'g++', 'macos':'clang++',
@@ -312,8 +317,7 @@ if env['multi_isa']:
         Exit(1)
 
     if 'v8a' in env['arch']:
-        print("INFO: multi_isa armv8-a architecture build doesn't enable __ARM_FEATURE_FP16_VECTOR_ARITHMETIC. Use armv8.2-a or beyond to enable FP16 vector arithmetic support")
-        env.Append(CXXFLAGS = ['-march=armv8-a']) # note: this will disable fp16 extension __ARM_FEATURE_FP16_VECTOR_ARITHMETIC
+        env.Append(CXXFLAGS = ['-march=armv8-a'])
     else:
         if 'v8.6-a' in env['arch']:
             if "disable_mmla_fp" not in env['custom_options']:
@@ -536,7 +540,7 @@ if env['standalone']:
     if not 'windows' in env['os']:
         env.Append(CXXFLAGS = ['-fPIC'])
         env.Append(LINKFLAGS = ['-static-libgcc','-static-libstdc++'])
-       
+
 if env['Werror']:
     env.Append(CXXFLAGS = ['-Werror'])
 
@@ -597,7 +601,7 @@ if env['debug']:
     else:
         env.Append(CXXFLAGS = ['-Z7','-MTd','-fms-compatibility','-fdelayed-template-parsing'])
         env.Append(LINKFLAGS = ['-DEBUG'])
- 
+
     env.Append(CPPDEFINES = ['ARM_COMPUTE_DEBUG_ENABLED'])
 else:
     if not 'windows' in env['os']: