[arm] Simplify run-time CPU selection.

src/base/build_config.h

 // Copyright 2014 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.
 
 #ifndef V8_BASE_BUILD_CONFIG_H_
 #define V8_BASE_BUILD_CONFIG_H_
 
 #include "include/v8config.h"
 
 // Processor architecture detection.  For more info on what's defined, see:
@@ skipping 37 matching lines @@
 #define V8_HOST_ARCH_32_BIT 1
 #endif
 #else
 #error "Host architecture was not detected as supported by v8"
 #endif
 
 #if defined(__ARM_ARCH_7A__) || \
     defined(__ARM_ARCH_7R__) || \
     defined(__ARM_ARCH_7__)
 # define CAN_USE_ARMV7_INSTRUCTIONS 1
+# ifdef __ARM_ARCH_EXT_IDIV__
+#  define CAN_USE_SUDIV 1
+# endif
 # ifndef CAN_USE_VFP3_INSTRUCTIONS
-#  define CAN_USE_VFP3_INSTRUCTIONS
+#  define CAN_USE_VFP3_INSTRUCTIONS 1
 # endif
 #endif
 
 #if defined(__ARM_ARCH_8A__)
+# define CAN_USE_ARMV7_INSTRUCTIONS 1
+# define CAN_USE_SUDIV 1
 # define CAN_USE_ARMV8_INSTRUCTIONS 1
+# ifndef CAN_USE_VFP3_INSTRUCTIONS
+#  define CAN_USE_VFP3_INSTRUCTIONS 1
+# endif
 #endif
 
 
 // Target architecture detection. This may be set externally. If not, detect
 // in the same way as the host architecture, that is, target the native
 // environment as presented by the compiler.
 #if !V8_TARGET_ARCH_X64 && !V8_TARGET_ARCH_IA32 && !V8_TARGET_ARCH_X87 &&   \
     !V8_TARGET_ARCH_ARM && !V8_TARGET_ARCH_ARM64 && !V8_TARGET_ARCH_MIPS && \
     !V8_TARGET_ARCH_MIPS64 && !V8_TARGET_ARCH_PPC && !V8_TARGET_ARCH_S390
 #if defined(_M_X64) || defined(__x86_64__)
@@ skipping 122 matching lines @@
 // Number of bits to represent the page size for paged spaces. The value of 20
 // gives 1Mb bytes per page.
 #if V8_HOST_ARCH_PPC && V8_TARGET_ARCH_PPC && V8_OS_LINUX
 // Bump up for Power Linux due to larger (64K) page size.
 const int kPageSizeBits = 22;
 #else
 const int kPageSizeBits = 20;
 #endif
 
 #endif  // V8_BASE_BUILD_CONFIG_H_