commit 906434011f09a5afe60fbb644db6995a5ca21f0d
parent c07cebbbf622a949747349a219b2ba5973c4359c
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 28 Jun 2000 14:03:10 -0300
better (?) treatment for 16-bit machines
Diffstat:
| M | llimits.h | | | 62 | +++++++++++++++++++++++++++++++++++++++++++------------------- |
1 file changed, 43 insertions(+), 19 deletions(-)
diff --git a/llimits.h b/llimits.h
@@ -1,5 +1,5 @@
/*
-** $Id: llimits.h,v 1.9 2000/06/06 16:27:11 roberto Exp roberto $
+** $Id: llimits.h,v 1.10 2000/06/16 17:16:34 roberto Exp roberto $
** Limits, basic types, and some other "instalation-dependent" definitions
** See Copyright Notice in lua.h
*/
@@ -12,6 +12,25 @@
#include <stddef.h>
+
+/*
+** try to find number of bits in an integer
+*/
+#ifndef BITS_INT
+/* avoid overflows in comparison */
+#if INT_MAX-20 < 32760
+#define BITS_INT 16
+#else
+#if INT_MAX > 2147483640L
+/* machine has at least 32 bits */
+#define BITS_INT 32
+#else
+#error "you must define BITS_INT with number of bits in an integer"
+#endif
+#endif
+#endif
+
+
/*
** Define the type `number' of Lua
** GREP LUA_NUMBER to change that
@@ -66,51 +85,56 @@ typedef unsigned long Instruction;
/*
-** limits for opcode arguments.
+** size and position of opcode arguments.
** For an instruction with 2 bytes, size is 16, and size_b can be 5
+** (accordingly, size_u will be 10, and size_a will be 5)
*/
#define SIZE_INSTRUCTION 32
-#define SIZE_OP 6
#define SIZE_B 9
+#define SIZE_OP 6
#define SIZE_U (SIZE_INSTRUCTION-SIZE_OP)
#define POS_U SIZE_OP
#define POS_B SIZE_OP
#define SIZE_A (SIZE_INSTRUCTION-(SIZE_OP+SIZE_B))
#define POS_A (SIZE_OP+SIZE_B)
-#define MAXARG_U ((1<<SIZE_U)-1)
-#define MAXARG_S (MAXARG_U>>1) /* `S' is signed */
-#define MAXARG_A ((1<<SIZE_A)-1)
-#define MAXARG_B ((1<<SIZE_B)-1)
-
/*
-** we use int to manipulate most arguments, so they must fit
+** limits for opcode arguments.
+** we use (signed) int to manipulate most arguments,
+** so they must fit in BITS_INT-1 bits (-1 for signal)
*/
-#if MAXARG_U > MAX_INT
-#undef MAXARG_U
+#if SIZE_U < BITS_INT-1
+#define MAXARG_U ((1<<SIZE_U)-1)
+#define MAXARG_S (MAXARG_U>>1) /* `S' is signed */
+#else
#define MAXARG_U MAX_INT
-#endif
-
-#if MAXARG_S > MAX_INT
-#undef MAXARG_S
#define MAXARG_S MAX_INT
#endif
-#if MAXARG_A > MAX_INT
-#undef MAXARG_A
+#if SIZE_A < BITS_INT-1
+#define MAXARG_A ((1<<SIZE_A)-1)
+#else
#define MAXARG_A MAX_INT
#endif
-#if MAXARG_B > MAX_INT
-#undef MAXARG_B
+#if SIZE_B < BITS_INT-1
+#define MAXARG_B ((1<<SIZE_B)-1)
+#else
#define MAXARG_B MAX_INT
#endif
/* maximum stack size in a function */
+#ifndef MAXSTACK
+#define MAXSTACK 250
+#endif
+
+#if MAXSTACK > MAXARG_B
+#undef MAXSTACK
#define MAXSTACK MAXARG_B
+#endif
/* maximum number of local variables */
