Remove explicit padding from struct definitions

Modern compilers align structs appropriately according to the alignment
requirements of the member types. Removing the padding reduces the size
of many of the structs, and the alignment remains the same.

Author: jodavies

sources/extcmd.c

@@ -280,7 +280,6 @@ typedef struct ExternalChannel {
 	int fsend;       /*stdin of the external process*/
 	int killSignal; /*signal to kill*/
 	int daemonize;/*0 --neither setsid nor daemonize, !=0 -- full daemonization*/
-	PADPOINTER(0,3,0,0);
 } EXTHANDLE;
 
 

sources/form3.h

@@ -235,7 +235,7 @@ typedef ULONG RLONG;  /* Used in reken.c. */
 typedef int64_t MLONG;  /* See commentary in minos.h. */
 /*
  * NOTE: we don't use the standard _Bool (or C++ bool) because its size is
- * implementation-dependent and messes up the traditional PADXXX macros.
+ * implementation-dependent.
  */
 typedef char BOOL;
                                                        /* E.g. in 32-bits */
@@ -279,79 +279,6 @@ template<typename T> struct calc {
 #endif
 #endif
 
-/*
- * Macros to be inserted at the end of a structure to align the whole structure.
- *
- * In the currently available systems,
- *   sizeof(POSITION) >= sizeof(pointers) == sizeof(LONG) >= sizeof(int)
- *                    >= sizeof(WORD) >= sizeof(UBYTE) = 1.
- * (POSITION is defined in struct.h and contains only an off_t variable.)
- * Thus, if we put members of a structure in this order and use those macros,
- * then we can align the data without relying on extra paddings added by
- * the compiler. For example,
- *   typedef struct {
- *     int *a;
- *     LONG b;
- *     WORD c[2];
- *     UBYTE d;
- *     PADPOINTER(1,0,2,1);
- *   } A;
- *   typedef struct {
- *     POSITION p;
- *     A a;  // aligned same as pointers
- *     int *b;
- *     LONG c;
- *     UBYTE d;
- *     PADPOSITION(1,1,0,0,1+sizeof(A));
- *   } B;
- * The cost for the use of those PADXXX macros is a padding (>= 1 byte) will
- * be always inserted even in the case that no padding is actually needed.
- *
- * Numbers for the arguments have to be calculated manually and so very
- * error-prone. Be careful!
- *
- * Note that there is a 32-bit system in which off_t is aligned on 8-byte
- * boundary, (e.g., Cygwin with large file support), but still the above
- * inequalities are satisfied.
- *
- * The legendary story of these macros--they fixed some problems in ancient
- * times when compilers were unreliable and didn't know how to correctly compute
- * structure paddings--has been handed down, though nowadays there are only
- * disadvantages for them in practice (ancient compilers most likely can't
- * compile C99 and C++98+TR1 sources anyway).
- */
-#define PADDUMMY(type, size) \
-	UBYTE d_u_m_m_y[form_alignof(type) - ((size) & (form_alignof(type) - 1))]
-#define PADPOSITION(ptr_,long_,int_,word_,byte_) \
-	PADDUMMY(off_t, \
-		+ sizeof(int *) * (ptr_) \
-		+ sizeof(LONG)  * (long_) \
-		+ sizeof(int)   * (int_) \
-		+ sizeof(WORD)  * (word_) \
-		+ sizeof(UBYTE) * (byte_) \
-	)
-#define PADPOINTER(long_,int_,word_,byte_) \
-	PADDUMMY(int *, \
-		+ sizeof(LONG)  * (long_) \
-		+ sizeof(int)   * (int_) \
-		+ sizeof(WORD)  * (word_) \
-		+ sizeof(UBYTE) * (byte_) \
-	)
-#define PADLONG(int_,word_,byte_) \
-	PADDUMMY(LONG, \
-		+ sizeof(int)   * (int_) \
-		+ sizeof(WORD)  * (word_) \
-		+ sizeof(UBYTE) * (byte_) \
-	)
-#define PADINT(word_,byte_) \
-	PADDUMMY(int, \
-		+ sizeof(WORD)  * (word_) \
-		+ sizeof(UBYTE) * (byte_) \
-	)
-#define PADWORD(byte_) \
-	PADDUMMY(WORD, \
-		+ sizeof(UBYTE) * (byte_) \
-	)
 
 /*
 #define WITHPCOUNTER

sources/optimize.cc

@@ -129,7 +129,6 @@ class tree_node {
 	int num_visits;
 	WORD var;
 	bool finished;
-	PADPOINTER(1,1,1,1);
 
 	tree_node (int _var=0):
 		sum_results(0), num_visits(0), var(_var), finished(false) {}

sources/parallel.c

@@ -2480,7 +2480,6 @@ typedef struct {
 	VectorStruct(WORD) buf;
 	LONG size;
 	WORD type;
-	PADPOINTER(1,0,1,0);
 } dollar_buf;
 
 /* Buffers used to store data for each variable from each slave. */

sources/parallel.h

@@ -158,7 +158,6 @@ typedef struct {
 	int *from;
 	int numbufs;          /* number of cyclic buffers */
 	int active;           /* flag telling which buffer is active */
-	PADPOINTER(0,2,0,0);
 } PF_BUFFER;
 
 /*
@@ -182,7 +181,6 @@ typedef struct ParallelVars {
 	int         log;            /* flag for logging mode */
 	WORD        numsbufs;       /* number of cyclic send buffers (PF.sbuf->numbufs) */
 	WORD        numrbufs;       /* number of cyclic receive buffers (PF.rbufs[i]->numbufs, i=1,...numtasks-1) */
-	PADPOSITION(2,0,8,2,0);
 } PARALLELVARS;
 
 extern PARALLELVARS PF;

sources/poly.h

@@ -171,8 +171,6 @@ class poly {
 
 	static void push_heap (PHEAD WORD **, int);
 	static void pop_heap (PHEAD WORD **, int);
-
-	PADPOINTER(1,0,2,0);
 };
 
 // comparison class for monomials (for std::sort)