diff --git a/tcg/hppa/tcg-target.c b/tcg/hppa/tcg-target.c
index 68f77ba..e5aed91 100644
--- a/tcg/hppa/tcg-target.c
+++ b/tcg/hppa/tcg-target.c
@@ -22,6 +22,10 @@
  * THE SOFTWARE.
  */
 
+#if TCG_TARGET_REG_BITS != 32
+#error unsupported
+#endif
+
 #ifndef NDEBUG
 static const char * const tcg_target_reg_names[TCG_TARGET_NB_REGS] = {
     "%r0", "%r1", "%rp", "%r3", "%r4", "%r5", "%r6", "%r7",
diff --git a/tcg/hppa/tcg-target.h b/tcg/hppa/tcg-target.h
index be5895f..122edce 100644
--- a/tcg/hppa/tcg-target.h
+++ b/tcg/hppa/tcg-target.h
@@ -25,10 +25,6 @@
 #ifndef TCG_TARGET_HPPA
 #define TCG_TARGET_HPPA 1
 
-#if TCG_TARGET_REG_BITS != 32
-#error unsupported
-#endif
-
 #define TCG_TARGET_WORDS_BIGENDIAN
 
 #define TCG_TARGET_NB_REGS 32
diff --git a/tcg/i386/tcg-target.h b/tcg/i386/tcg-target.h
index 1f6c7eb..d32d7ef 100644
--- a/tcg/i386/tcg-target.h
+++ b/tcg/i386/tcg-target.h
@@ -24,12 +24,14 @@
 #ifndef TCG_TARGET_I386 
 #define TCG_TARGET_I386 1
 
-//#define TCG_TARGET_WORDS_BIGENDIAN
+#undef TCG_TARGET_WORDS_BIGENDIAN
 
-#if TCG_TARGET_REG_BITS == 64
-# define TCG_TARGET_NB_REGS 16
+#ifdef __x86_64__
+# define TCG_TARGET_REG_BITS  64
+# define TCG_TARGET_NB_REGS   16
 #else
-# define TCG_TARGET_NB_REGS 8
+# define TCG_TARGET_REG_BITS  32
+# define TCG_TARGET_NB_REGS    8
 #endif
 
 typedef enum {
diff --git a/tcg/sparc/tcg-target.h b/tcg/sparc/tcg-target.h
index c0d3abc..2edf858 100644
--- a/tcg/sparc/tcg-target.h
+++ b/tcg/sparc/tcg-target.h
@@ -24,6 +24,14 @@
 #ifndef TCG_TARGET_SPARC 
 #define TCG_TARGET_SPARC 1
 
+#if UINTPTR_MAX == UINT32_MAX
+# define TCG_TARGET_REG_BITS 32
+#elif UINTPTR_MAX == UINT64_MAX
+# define TCG_TARGET_REG_BITS 64
+#else
+# error Unknown pointer size for tcg target
+#endif
+
 #define TCG_TARGET_WORDS_BIGENDIAN
 
 #define TCG_TARGET_NB_REGS 32
diff --git a/tcg/tcg.h b/tcg/tcg.h
index 2fce485..8a5e55b 100644
--- a/tcg/tcg.h
+++ b/tcg/tcg.h
@@ -23,13 +23,17 @@
  */
 #include "qemu-common.h"
 
-/* Target word size (must be identical to pointer size). */
-#if UINTPTR_MAX == UINT32_MAX
-# define TCG_TARGET_REG_BITS 32
-#elif UINTPTR_MAX == UINT64_MAX
-# define TCG_TARGET_REG_BITS 64
-#else
-# error Unknown pointer size for tcg target
+#include "tcg-target.h"
+
+/* Default target word size to pointer size.  */
+#ifndef TCG_TARGET_REG_BITS
+# if UINTPTR_MAX == UINT32_MAX
+#  define TCG_TARGET_REG_BITS 32
+# elif UINTPTR_MAX == UINT64_MAX
+#  define TCG_TARGET_REG_BITS 64
+# else
+#  error Unknown pointer size for tcg target
+# endif
 #endif
 
 #if TCG_TARGET_REG_BITS == 32
@@ -46,7 +50,6 @@
 #error unsupported
 #endif
 
-#include "tcg-target.h"
 #include "tcg-runtime.h"
 
 #if TCG_TARGET_NB_REGS <= 32
diff --git a/tcg/tci/tcg-target.h b/tcg/tci/tcg-target.h
index 02e0da1..c2ecfbe 100644
--- a/tcg/tci/tcg-target.h
+++ b/tcg/tci/tcg-target.h
@@ -44,6 +44,14 @@
 
 #define TCG_TARGET_INTERPRETER 1
 
+#if UINTPTR_MAX == UINT32_MAX
+# define TCG_TARGET_REG_BITS 32
+#elif UINTPTR_MAX == UINT64_MAX
+# define TCG_TARGET_REG_BITS 64
+#else
+# error Unknown pointer size for tci target
+#endif
+
 #ifdef CONFIG_DEBUG_TCG
 /* Enable debug output. */
 #define CONFIG_DEBUG_TCG_INTERPRETER