Add ARMv8 detection in CpuFeatures.

src/flag-definitions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file defines all of the flags.  It is separated into different section,
 // for Debug, Release, Logging and Profiling, etc.  To add a new flag, find the
 // correct section, and use one of the DEFINE_ macros, without a trailing ';'.
 //
 // This include does not have a guard, because it is a template-style include,
 // which can be included multiple times in different modes.  It expects to have
@@ skipping 96 matching lines @@
 #if (defined CAN_USE_VFP3_INSTRUCTIONS) || !(defined ARM_TEST_NO_FEATURE_PROBE)
 #define ENABLE_VFP3_DEFAULT true
 #else
 #define ENABLE_VFP3_DEFAULT false
 #endif
 #if (defined CAN_USE_ARMV7_INSTRUCTIONS) || !(defined ARM_TEST_NO_FEATURE_PROBE)
 #define ENABLE_ARMV7_DEFAULT true
 #else
 #define ENABLE_ARMV7_DEFAULT false
 #endif
+#if (defined CAN_USE_ARMV8_INSTRUCTIONS) || !(defined ARM_TEST_NO_FEATURE_PROBE)
+#define ENABLE_ARMV8_DEFAULT true
+#else
+#define ENABLE_ARMV8_DEFAULT false
+#endif
 #if (defined CAN_USE_VFP32DREGS) || !(defined ARM_TEST_NO_FEATURE_PROBE)
 #define ENABLE_32DREGS_DEFAULT true
 #else
 #define ENABLE_32DREGS_DEFAULT false
 #endif
 #if (defined CAN_USE_NEON) || !(defined ARM_TEST_NO_FEATURE_PROBE)
 # define ENABLE_NEON_DEFAULT true
 #else
 # define ENABLE_NEON_DEFAULT false
 #endif
@@ skipping 267 matching lines @@
 DEFINE_BOOL(code_comments, false, "emit comments in code disassembly")
 DEFINE_BOOL(enable_sse3, true, "enable use of SSE3 instructions if available")
 DEFINE_BOOL(enable_sse4_1, true,
             "enable use of SSE4.1 instructions if available")
 DEFINE_BOOL(enable_sahf, true,
             "enable use of SAHF instruction if available (X64 only)")
 DEFINE_BOOL(enable_vfp3, ENABLE_VFP3_DEFAULT,
             "enable use of VFP3 instructions if available")
 DEFINE_BOOL(enable_armv7, ENABLE_ARMV7_DEFAULT,
             "enable use of ARMv7 instructions if available (ARM only)")
+DEFINE_BOOL(enable_armv8, ENABLE_ARMV8_DEFAULT,
+            "enable use of ARMv8 instructions if available (ARM 32-bit only)")
 DEFINE_BOOL(enable_neon, ENABLE_NEON_DEFAULT,
             "enable use of NEON instructions if available (ARM only)")
 DEFINE_BOOL(enable_sudiv, true,
             "enable use of SDIV and UDIV instructions if available (ARM only)")
 DEFINE_BOOL(enable_mls, true,
             "enable use of MLS instructions if available (ARM only)")
 DEFINE_BOOL(enable_movw_movt, false,
             "enable loading 32-bit constant by means of movw/movt "
             "instruction pairs (ARM only)")
 DEFINE_BOOL(enable_unaligned_accesses, true,
@@ skipping 537 matching lines @@
 #undef DEFINE_ALIAS_FLOAT
 #undef DEFINE_ALIAS_ARGS
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META
 #undef FLAG_MODE_DEFINE_IMPLICATIONS
 
 #undef COMMA