diff --git a/src/Makefile b/src/Makefile
index a96c1997..667fff56 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -212,7 +212,7 @@ TARGET_CC= $(STATIC_CC)
 TARGET_STCC= $(STATIC_CC)
 TARGET_DYNCC= $(DYNAMIC_CC)
 TARGET_LD= $(CROSS)$(CC)
-TARGET_AR= $(CROSS)ar rcus
+TARGET_AR= $(CROSS)ar rcus 2>/dev/null
 TARGET_STRIP= $(CROSS)strip
 
 TARGET_LIBPATH= $(or $(PREFIX),/usr/local)/$(or $(MULTILIB),lib)
@@ -312,7 +312,6 @@ ifeq (Windows,$(TARGET_SYS))
   TARGET_XSHLDFLAGS= -shared -Wl,--out-implib,$(TARGET_DLLDOTANAME)
   TARGET_DYNXLDOPTS=
 else
-  TARGET_AR+= 2>/dev/null
 ifeq (,$(shell $(TARGET_CC) -o /dev/null -c -x c /dev/null -fno-stack-protector 2>/dev/null || echo 1))
   TARGET_XCFLAGS+= -fno-stack-protector
 endif
diff --git a/src/lj_alloc.c b/src/lj_alloc.c
index a12ec8b4..70ca1e3b 100644
--- a/src/lj_alloc.c
+++ b/src/lj_alloc.c
@@ -302,7 +302,7 @@ static void *mmap_probe(size_t size)
 
 #if LJ_ALLOC_MMAP32
 
-#if defined(__sun__)
+#if LJ_TARGET_SOLARIS
 #define LJ_ALLOC_MMAP32_START	((uintptr_t)0x1000)
 #else
 #define LJ_ALLOC_MMAP32_START	((uintptr_t)0)
diff --git a/src/lj_arch.h b/src/lj_arch.h
index d65bc551..3e3581c2 100644
--- a/src/lj_arch.h
+++ b/src/lj_arch.h
@@ -8,6 +8,8 @@
 
 #include "lua.h"
 
+/* -- Target definitions -------------------------------------------------- */
+
 /* Target endianess. */
 #define LUAJIT_LE	0
 #define LUAJIT_BE	1
@@ -38,6 +40,14 @@
 #define LUAJIT_OS_BSD		4
 #define LUAJIT_OS_POSIX		5
 
+/* Number mode. */
+#define LJ_NUMMODE_SINGLE	0	/* Single-number mode only. */
+#define LJ_NUMMODE_SINGLE_DUAL	1	/* Default to single-number mode. */
+#define LJ_NUMMODE_DUAL		2	/* Dual-number mode only. */
+#define LJ_NUMMODE_DUAL_SINGLE	3	/* Default to dual-number mode. */
+
+/* -- Target detection ---------------------------------------------------- */
+
 /* Select native target if no target defined. */
 #ifndef LUAJIT_TARGET
 
@@ -74,7 +84,10 @@
        defined(__NetBSD__) || defined(__OpenBSD__) || \
        defined(__DragonFly__)) && !defined(__ORBIS__)
 #define LUAJIT_OS	LUAJIT_OS_BSD
-#elif (defined(__sun__) && defined(__svr4__)) || defined(__HAIKU__)
+#elif (defined(__sun__) && defined(__svr4__))
+#define LJ_TARGET_SOLARIS	1
+#define LUAJIT_OS	LUAJIT_OS_POSIX
+#elif defined(__HAIKU__)
 #define LUAJIT_OS	LUAJIT_OS_POSIX
 #elif defined(__CYGWIN__)
 #define LJ_TARGET_CYGWIN	1
@@ -103,6 +116,7 @@
 #define LJ_TARGET_WINDOWS	(LUAJIT_OS == LUAJIT_OS_WINDOWS)
 #define LJ_TARGET_LINUX		(LUAJIT_OS == LUAJIT_OS_LINUX)
 #define LJ_TARGET_OSX		(LUAJIT_OS == LUAJIT_OS_OSX)
+#define LJ_TARGET_BSD		(LUAJIT_OS == LUAJIT_OS_BSD)
 #define LJ_TARGET_IOS		(LJ_TARGET_OSX && (LUAJIT_TARGET == LUAJIT_ARCH_ARM || LUAJIT_TARGET == LUAJIT_ARCH_ARM64))
 #define LJ_TARGET_POSIX		(LUAJIT_OS > LUAJIT_OS_WINDOWS)
 #define LJ_TARGET_DLOPEN	LJ_TARGET_POSIX
@@ -142,10 +156,7 @@
 #endif
 #endif
 
-#define LJ_NUMMODE_SINGLE	0	/* Single-number mode only. */
-#define LJ_NUMMODE_SINGLE_DUAL	1	/* Default to single-number mode. */
-#define LJ_NUMMODE_DUAL		2	/* Dual-number mode only. */
-#define LJ_NUMMODE_DUAL_SINGLE	3	/* Default to dual-number mode. */
+/* -- Arch-specific settings ---------------------------------------------- */
 
 /* Set target architecture properties. */
 #if LUAJIT_TARGET == LUAJIT_ARCH_X86
@@ -407,9 +418,7 @@
 #error "No target architecture defined"
 #endif
 
-#ifndef LJ_PAGESIZE
-#define LJ_PAGESIZE		4096
-#endif
+/* -- Checks for requirements --------------------------------------------- */
 
 /* Check for minimum required compiler versions. */
 #if defined(__GNUC__)
@@ -485,6 +494,8 @@
 #endif
 #endif
 
+/* -- Derived defines ----------------------------------------------------- */
+
 /* Enable or disable the dual-number mode for the VM. */
 #if (LJ_ARCH_NUMMODE == LJ_NUMMODE_SINGLE && LUAJIT_NUMMODE == 2) || \
     (LJ_ARCH_NUMMODE == LJ_NUMMODE_DUAL && LUAJIT_NUMMODE == 1)
@@ -582,6 +593,10 @@
 #define LJ_TARGET_UNALIGNED	0
 #endif
 
+#ifndef LJ_PAGESIZE
+#define LJ_PAGESIZE		4096
+#endif
+
 /* Various workarounds for embedded operating systems or weak C runtimes. */
 #if defined(__ANDROID__) || defined(__symbian__) || LJ_TARGET_XBOX360 || LJ_TARGET_WINDOWS
 #define LUAJIT_NO_LOG2
diff --git a/src/lj_gdbjit.c b/src/lj_gdbjit.c
index 69585e51..5b9fe0ad 100644
--- a/src/lj_gdbjit.c
+++ b/src/lj_gdbjit.c
@@ -363,7 +363,7 @@ static const ELFheader elfhdr_template = {
   .eosabi = 12,
 #elif defined(__DragonFly__)
   .eosabi = 0,
-#elif (defined(__sun__) && defined(__svr4__))
+#elif LJ_TARGET_SOLARIS
   .eosabi = 6,
 #else
   .eosabi = 0,
diff --git a/src/ps4build.bat b/src/ps4build.bat
index e4a7defe..e83c674a 100644
--- a/src/ps4build.bat
+++ b/src/ps4build.bat
@@ -27,12 +27,12 @@
 @set DASMDIR=..\dynasm
 @set DASM=%DASMDIR%\dynasm.lua
 @set ALL_LIB=lib_base.c lib_math.c lib_bit.c lib_string.c lib_table.c lib_io.c lib_os.c lib_package.c lib_debug.c lib_jit.c lib_ffi.c
-@set GC64=-DLUAJIT_ENABLE_GC64
+@set GC64=
 @set DASC=vm_x64.dasc
 
 @if "%1" neq "gc32" goto :NOGC32
 @shift
-@set GC64=
+@set GC64=-DLUAJIT_DISABLE_GC64
 @set DASC=vm_x86.dasc
 :NOGC32
 
diff --git a/src/vm_x64.dasc b/src/vm_x64.dasc
index c714f4c7..77a579d5 100644
--- a/src/vm_x64.dasc
+++ b/src/vm_x64.dasc
@@ -4734,7 +4734,7 @@ static void emit_asm_debug(BuildCtx *ctx)
 	".LEFDE1:\n\n", (int)ctx->codesz - fcofs);
 #endif
 #if !LJ_NO_UNWIND
-#if (defined(__sun__) && defined(__svr4__))
+#if LJ_TARGET_SOLARIS
     fprintf(ctx->fp, "\t.section .eh_frame,\"a\",@unwind\n");
 #else
     fprintf(ctx->fp, "\t.section .eh_frame,\"a\",@progbits\n");
diff --git a/src/vm_x86.dasc b/src/vm_x86.dasc
index c3999e7c..57c8e4fc 100644
--- a/src/vm_x86.dasc
+++ b/src/vm_x86.dasc
@@ -5548,7 +5548,7 @@ static void emit_asm_debug(BuildCtx *ctx)
 	".LEFDE1:\n\n", (int)ctx->codesz - fcofs);
 #endif
 #if !LJ_NO_UNWIND
-#if (defined(__sun__) && defined(__svr4__))
+#if LJ_TARGET_SOLARIS
 #if LJ_64
     fprintf(ctx->fp, "\t.section .eh_frame,\"a\",@unwind\n");
 #else
diff --git a/src/xb1build.bat b/src/xb1build.bat
index 847e84a5..12c73dd6 100644
--- a/src/xb1build.bat
+++ b/src/xb1build.bat
@@ -9,7 +9,7 @@
 
 @setlocal
 @echo ---- Host compiler ----
-@set LJCOMPILE=cl /nologo /c /MD /O2 /W3 /D_CRT_SECURE_NO_DEPRECATE /DLUAJIT_ENABLE_GC64
+@set LJCOMPILE=cl /nologo /c /MD /O2 /W3 /D_CRT_SECURE_NO_DEPRECATE
 @set LJLINK=link /nologo
 @set LJMT=mt /nologo
 @set DASMDIR=..\dynasm