For building v8 using gn on aix_ppc64, linux_s390x and linux_ppc64.

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 17 matching lines @@
 #define V8_HOST_ARCH_ARM 1
 #define V8_HOST_ARCH_32_BIT 1
 #elif defined(__mips64)
 #define V8_HOST_ARCH_MIPS64 1
 #define V8_HOST_ARCH_64_BIT 1
 #elif defined(__MIPSEB__) || defined(__MIPSEL__)
 #define V8_HOST_ARCH_MIPS 1
 #define V8_HOST_ARCH_32_BIT 1
 #elif defined(__PPC__) || defined(_ARCH_PPC)
 #define V8_HOST_ARCH_PPC 1
-#if defined(__PPC64__) || defined(_ARCH_PPC64)
+#if defined(__PPC64__) || defined(_ARCH_PPC64) || defined(_ARCH_PPCGR)
 #define V8_HOST_ARCH_64_BIT 1
 #else
 #define V8_HOST_ARCH_32_BIT 1
 #endif
 #elif defined(__s390__) || defined(__s390x__)
 #define V8_HOST_ARCH_S390 1
 #if defined(__s390x__)
 #define V8_HOST_ARCH_64_BIT 1
 #else
 #define V8_HOST_ARCH_32_BIT 1
@@ skipping 35 matching lines @@
 #elif defined(_M_IX86) || defined(__i386__)
 #define V8_TARGET_ARCH_IA32 1
 #elif defined(__AARCH64EL__)
 #define V8_TARGET_ARCH_ARM64 1
 #elif defined(__ARMEL__)
 #define V8_TARGET_ARCH_ARM 1
 #elif defined(__mips64)
 #define V8_TARGET_ARCH_MIPS64 1
 #elif defined(__MIPSEB__) || defined(__MIPSEL__)
 #define V8_TARGET_ARCH_MIPS 1
+#elif defined(_ARCH_PPC)
+#define V8_TARGET_ARCH_PPC 1
 #else
 #error Target architecture was not detected as supported by v8
 #endif
 #endif
 
 // Determine architecture pointer size.
 #if V8_TARGET_ARCH_IA32
 #define V8_TARGET_ARCH_32_BIT 1
 #elif V8_TARGET_ARCH_X64
 #if !V8_TARGET_ARCH_32_BIT && !V8_TARGET_ARCH_64_BIT
@@ skipping 70 matching lines @@
 #define V8_TARGET_LITTLE_ENDIAN 1
 #endif
 #elif V8_TARGET_ARCH_MIPS64
 #if defined(__MIPSEB__) || defined(V8_TARGET_ARCH_MIPS64_BE)
 #define V8_TARGET_BIG_ENDIAN 1
 #else
 #define V8_TARGET_LITTLE_ENDIAN 1
 #endif
 #elif V8_TARGET_ARCH_X87
 #define V8_TARGET_LITTLE_ENDIAN 1
+#elif __BIG_ENDIAN__  // FOR PPCGR on AIX
+#define V8_TARGET_BIG_ENDIAN 1
 #elif V8_TARGET_ARCH_PPC_LE
 #define V8_TARGET_LITTLE_ENDIAN 1
 #elif V8_TARGET_ARCH_PPC_BE
 #define V8_TARGET_BIG_ENDIAN 1
 #elif V8_TARGET_ARCH_S390
 #if V8_TARGET_ARCH_S390_LE_SIM
 #define V8_TARGET_LITTLE_ENDIAN 1
 #else
 #define V8_TARGET_BIG_ENDIAN 1
 #endif
 #else
 #error Unknown target architecture endianness
 #endif
 
 #if defined(V8_TARGET_ARCH_IA32) || defined(V8_TARGET_ARCH_X64) || \
     defined(V8_TARGET_ARCH_X87)
 #define V8_TARGET_ARCH_STORES_RETURN_ADDRESS_ON_STACK 1
 #else
 #define V8_TARGET_ARCH_STORES_RETURN_ADDRESS_ON_STACK 0
 #endif
 
 // Number of bits to represent the page size for paged spaces. The value of 20
 // gives 1Mb bytes per page.
 const int kPageSizeBits = 19;
 
 #endif  // V8_BASE_BUILD_CONFIG_H_