fix MIPS bignum config and implementation

--- includes a fix for gmp with long long configuration,
 but that's now disabled for MIPS to keep things
 simpler

src/racket/sconfig.h

@@ -388,10 +388,6 @@
 
 # define USE_TIMEZONE_AND_ALTZONE_VAR
 
-# ifdef _ABIN32
-#  define USE_LONG_LONG_FOR_BIGDIG
-# endif
-
 # define FLAGS_ALREADY_SET
 
 #endif

src/racket/src/bignum.c

@@ -81,20 +81,23 @@ void scheme_bignum_use_fuel(long n);
 #endif
 
 #if defined(USE_LONG_LONG_FOR_BIGDIG)
-# define TOP_BITS_MASK 0xFFFFFFFF00000000
+# define TOP_BITS_MASK ((bigdig)0xFFFFFFFF << 32)
 # define BOTTOM_BITS_MASK 0x00000000FFFFFFFF
+# define FIRST_BIT_MASK_LL ((bigdig)FIRST_BIT_MASK << 32)
+#else
+# define FIRST_BIT_MASK_LL FIRST_BIT_MASK
 #endif
 
 #if defined(SIXTY_FOUR_BIT_INTEGERS) || defined(USE_LONG_LONG_FOR_BIGDIG)
 # define BIG_RADIX 18446744073709551616.0 /* = 0x10000000000000000 */
-# define ALL_ONES 0xFFFFFFFFFFFFFFFF
 # define WORD_SIZE 64
 #else
 # define BIG_RADIX 4294967296.0 /* = 0x100000000 */
-# define ALL_ONES 0xFFFFFFFF
 # define WORD_SIZE 32
 #endif
 
+# define ALL_ONES (~(bigdig)0)
+
 READ_ONLY static Scheme_Object *bignum_one;
 
 void scheme_init_bignum() {
@@ -402,7 +405,7 @@ int scheme_bignum_get_long_long_val(const Scheme_Object *o, mzlonglong *v)
   } else if (SCHEME_BIGLEN(o) == 0) {
     *v = 0;
     return 1;
-  } else if (SCHEME_BIGDIG(o)[MAX_BN_SIZE_FOR_LL - 1] == FIRST_BIT_MASK 
+  } else if (SCHEME_BIGDIG(o)[MAX_BN_SIZE_FOR_LL - 1] == FIRST_BIT_MASK_LL 
 # ifndef USE_LONG_LONG_FOR_BIGDIG
 	     && !SCHEME_BIGDIG(o)[0]
 # endif
@@ -413,7 +416,7 @@ int scheme_bignum_get_long_long_val(const Scheme_Object *o, mzlonglong *v)
     v2 = (v2 << 63);
     *v = v2;
     return 1;
-  } else if ((SCHEME_BIGDIG(o)[MAX_BN_SIZE_FOR_LL - 1] & FIRST_BIT_MASK) != 0) { /* Won't fit into a signed long long */
+  } else if ((SCHEME_BIGDIG(o)[MAX_BN_SIZE_FOR_LL - 1] & FIRST_BIT_MASK_LL) != 0) { /* Won't fit into a signed long long */
     return 0;
   } else {
     mzlonglong v2;
@@ -444,7 +447,7 @@ int scheme_bignum_get_unsigned_long_long_val(const Scheme_Object *o, umzlonglong
   } else {
     umzlonglong v2;
     v2 = SCHEME_BIGDIG(o)[0];
-    if (SCHEME_BIGLEN(o)) {
+    if (SCHEME_BIGLEN(o) > 1) {
       v2 |= ((umzlonglong)SCHEME_BIGDIG(o)[1]) << 32;
     }
     *v = v2;

src/racket/src/gmp/gmp.c

@@ -52,7 +52,7 @@ THREAD_LOCAL_DECL(static void *gmp_mem_pool);
 # define MP_BASES_BIG_BASE_10            CNST_LIMB(0x8ac7230489e80000)
 # define MP_BASES_BIG_BASE_INVERTED_10   CNST_LIMB(0xd83c94fb6d2ac34a)
 # define MP_BASES_NORMALIZATION_STEPS_10 0
-# define GMP_NUMB_MASK 0xFFFFFFFFFFFFFFFF
+# define GMP_NUMB_MASK (~(mp_limb_t)0)
 #endif
 
 #define MPN_DIVREM_OR_PREINV_DIVREM_1(qp,xsize,ap,size,d,dinv,shift)    \

src/racket/src/gmp/gmp.h

@@ -40,9 +40,15 @@ MA 02111-1307, USA. */
 # endif
 #endif
 
-#if (defined (__mips) || defined(mips)) && defined (_ABIN32)
+#if 0
+# if (defined (__mips) || defined(mips)) && defined (_ABIN32)
 /* Force the use of 64-bit limbs for all 64-bit MIPS CPUs if ABI permits.  */
-#define _LONG_LONG_LIMB
+# define _LONG_LONG_LIMB
+# endif
+#endif
+
+#ifdef USE_LONG_LONG_FOR_BIGDIG
+# define _LONG_LONG_LIMB
 #endif
 
 #if (__STDC__-0) || defined (__cplusplus)
@@ -607,5 +613,13 @@ enum
 #define gmp_version __gmp_version
 extern __gmp_const char *gmp_version;
 
+/* Test for gcc >= maj.min, as per __GNUC_PREREQ in glibc */
+#if defined (__GNUC__) && defined (__GNUC_MINOR__)
+#define __GMP_GNUC_PREREQ(maj, min) \
+  ((__GNUC__ << 16) + __GNUC_MINOR__ >= ((maj) << 16) + (min))
+#else
+#define __GMP_GNUC_PREREQ(maj, min)  0
+#endif
+
 #define __GMP_H__
 #endif /* __GMP_H__ */

src/racket/src/gmp/gmplonglong.h

@@ -618,26 +618,45 @@ extern USItype __MPN(udiv_qrnnd) _PROTO ((USItype *, USItype, USItype, USItype))
 #endif /* __m88000__ */
 
 #if defined (__mips) && W_TYPE_SIZE == 32
-#if __GNUC__ > 2 || __GNUC_MINOR__ >= 7
+#if __GMP_GNUC_PREREQ (4,4)
+#define umul_ppmm(w1, w0, u, v) \
+  do {                                                                  \
+    UDItype __ll = (UDItype)(u) * (v);                                  \
+    w1 = __ll >> 32;                                                    \
+    w0 = __ll;                                                          \
+  } while (0)
+#endif
+#if !defined (umul_ppmm) && __GMP_GNUC_PREREQ (2,7)
 #define umul_ppmm(w1, w0, u, v) \
   __asm__ ("multu %2,%3" : "=l" (w0), "=h" (w1) : "d" (u), "d" (v))
-#else
+#endif
+#if !defined (umul_ppmm)
 #define umul_ppmm(w1, w0, u, v) \
-  __asm__ ("multu %2,%3\n\tmflo %0\n\tmfhi %1"				\
+  __asm__ ("multu %2,%3\n\tmflo %0\n\tmfhi %1"                          \
-	   : "=d" (w0), "=d" (w1) : "d" (u), "d" (v))
+           : "=d" (w0), "=d" (w1) : "d" (u), "d" (v))
 #endif
 #define UMUL_TIME 10
 #define UDIV_TIME 100
 #endif /* __mips */
 
 #if (defined (__mips) && __mips >= 3) && W_TYPE_SIZE == 64
-#if __GNUC__ > 2 || __GNUC_MINOR__ >= 7
+#if __GMP_GNUC_PREREQ (4,4)
+#define umul_ppmm(w1, w0, u, v) \
+  do {                                                                  \
+    typedef unsigned int __ll_UTItype __attribute__((mode(TI)));        \
+    __ll_UTItype __ll = (__ll_UTItype)(u) * (v);                        \
+    w1 = __ll >> 64;                                                    \
+    w0 = __ll;                                                          \
+  } while (0)
+#endif
+#if !defined (umul_ppmm) && __GMP_GNUC_PREREQ (2,7)
 #define umul_ppmm(w1, w0, u, v) \
   __asm__ ("dmultu %2,%3" : "=l" (w0), "=h" (w1) : "d" (u), "d" (v))
-#else
+#endif
+#if !defined (umul_ppmm)
 #define umul_ppmm(w1, w0, u, v) \
-  __asm__ ("dmultu %2,%3\n\tmflo %0\n\tmfhi %1"				\
+  __asm__ ("dmultu %2,%3\n\tmflo %0\n\tmfhi %1"                         \
-	   : "=d" (w0), "=d" (w1) : "d" (u), "d" (v))
+           : "=d" (w0), "=d" (w1) : "d" (u), "d" (v))
 #endif
 #define UMUL_TIME 20
 #define UDIV_TIME 140