Remove ARM support for soft float (pre-VFP2)

src/flag-definitions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 291 matching lines @@
             "enable use of SSE3 instructions if available")
 DEFINE_bool(enable_sse4_1, true,
             "enable use of SSE4.1 instructions if available")
 DEFINE_bool(enable_cmov, true,
             "enable use of CMOV instruction if available")
 DEFINE_bool(enable_rdtsc, true,
             "enable use of RDTSC instruction if available")
 DEFINE_bool(enable_sahf, true,
             "enable use of SAHF instruction if available (X64 only)")
 DEFINE_bool(enable_vfp3, true,
-            "enable use of VFP3 instructions if available - this implies "
-            "enabling ARMv7 and VFP2 instructions (ARM only)")
+            "enable use of VFP3 instructions if available")
 DEFINE_bool(enable_vfp2, true,
-            "enable use of VFP2 instructions if available")
+            "this flag is no longer supported, VFP2 support is a basic "
+            "requirement for V8 on ARM")

[Yang, 2013/04/05 10:07:01]

Not sure why we don't just remove this flag. Specifying an non-existing flag
doesn't break anything, so it would stay backward-compatible.

If you want to make it a warning for embedders or something, you could put an
ASSERT(FLAG_enable_vfp2) somewhere.

[danno, 2013/04/08 19:45:33]

Done.

 DEFINE_bool(enable_armv7, true,
             "enable use of ARMv7 instructions if available (ARM only)")
 DEFINE_bool(enable_sudiv, true,
             "enable use of SDIV and UDIV 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,
             "enable unaligned accesses for ARMv7 (ARM only)")
 DEFINE_bool(enable_32dregs, true,
@@ skipping 431 matching lines @@
 #undef DEFINE_bool
 #undef DEFINE_int
 #undef DEFINE_string
 #undef DEFINE_implication
 
 #undef FLAG_MODE_DECLARE
 #undef FLAG_MODE_DEFINE
 #undef FLAG_MODE_DEFINE_DEFAULTS
 #undef FLAG_MODE_META
 #undef FLAG_MODE_DEFINE_IMPLICATIONS