[postgis-tickets] r17582 - Strip out getMachineEndian() in favour of configure-time check

[Paul Ramsey]

Author: pramsey
Date: 2019-07-02 12:47:06 -0700 (Tue, 02 Jul 2019)
New Revision: 17582

Modified:
   trunk/liblwgeom/liblwgeom_internal.h
   trunk/liblwgeom/lookup3.c
   trunk/liblwgeom/lwin_wkb.c
   trunk/liblwgeom/lwout_wkb.c
   trunk/liblwgeom/lwutil.c
Log:
Strip out getMachineEndian() in favour of configure-time check


Modified: trunk/liblwgeom/liblwgeom_internal.h
===================================================================
--- trunk/liblwgeom/liblwgeom_internal.h	2019-07-02 09:48:14 UTC (rev 17581)
+++ trunk/liblwgeom/liblwgeom_internal.h	2019-07-02 19:47:06 UTC (rev 17582)
@@ -123,9 +123,11 @@
 #ifdef WORDS_BIGENDIAN
 #define SIZE_GET(varsize) ((varsize) & 0x3FFFFFFF)
 #define SIZE_SET(varsize, len) ((varsize) = ((len) & 0x3FFFFFFF))
+#define IS_BIG_ENDIAN 1
 #else
 #define SIZE_GET(varsize) (((varsize) >> 2) & 0x3FFFFFFF)
 #define SIZE_SET(varsize, len) ((varsize) = (((uint32_t)(len)) << 2))
+#define IS_BIG_ENDIAN 0
 #endif
 
 /**
@@ -165,7 +167,6 @@
 /* Machine endianness */
 #define XDR 0 /* big endian */
 #define NDR 1 /* little endian */
-extern char getMachineEndian(void);
 uint64_t uint32_interleave_2(uint32_t u1, uint32_t u2);
 
 

Modified: trunk/liblwgeom/lookup3.c
===================================================================
--- trunk/liblwgeom/lookup3.c	2019-07-02 09:48:14 UTC (rev 17581)
+++ trunk/liblwgeom/lookup3.c	2019-07-02 19:47:06 UTC (rev 17582)
@@ -47,7 +47,10 @@
  * My best guess at if you are big-endian or little-endian.  This may
  * need adjustment.
  */
-#if (defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && \
+#if (defined(WORDS_BIGENDIAN))
+# define HASH_LITTLE_ENDIAN 0
+# define HASH_BIG_ENDIAN 1
+#elif (defined(__BYTE_ORDER) && defined(__LITTLE_ENDIAN) && \
      __BYTE_ORDER == __LITTLE_ENDIAN) || \
     (defined(i386) || defined(__i386__) || defined(__i486__) || \
      defined(__i586__) || defined(__i686__) || defined(vax) || defined(MIPSEL))
@@ -67,7 +70,6 @@
 #define hashmask(n) (hashsize(n)-1)
 #define rot(x,k) (((x)<<(k)) | ((x)>>(32-(k))))
 
-
 #if 0
 static uint32_t hashword(const uint32_t *k, size_t length, uint32_t initval);
 static void hashword2 (const uint32_t *k, size_t length, uint32_t *pc, uint32_t *pb);

Modified: trunk/liblwgeom/lwin_wkb.c
===================================================================
--- trunk/liblwgeom/lwin_wkb.c	2019-07-02 09:48:14 UTC (rev 17581)
+++ trunk/liblwgeom/lwin_wkb.c	2019-07-02 19:47:06 UTC (rev 17582)
@@ -689,17 +689,14 @@
 
 	/* Check the endianness of our input  */
 	s->swap_bytes = LW_FALSE;
-	if( getMachineEndian() == NDR ) /* Machine arch is little */
-	{
-		if ( ! wkb_little_endian )    /* Data is big! */
-			s->swap_bytes = LW_TRUE;
-	}
-	else                              /* Machine arch is big */
-	{
-		if ( wkb_little_endian )      /* Data is little! */
-			s->swap_bytes = LW_TRUE;
-	}
 
+	/* Machine arch is big endian, request is for little */
+	if (IS_BIG_ENDIAN && wkb_little_endian)
+		s->swap_bytes = LW_TRUE;
+	/* Machine arch is little endian, request is for big */
+	else if ((!IS_BIG_ENDIAN) && (!wkb_little_endian))
+		s->swap_bytes = LW_TRUE;
+
 	/* Read the type number */
 	wkb_type = integer_from_wkb_state(s);
 	LWDEBUGF(4,"Got WKB type number: 0x%X", wkb_type);

Modified: trunk/liblwgeom/lwout_wkb.c
===================================================================
--- trunk/liblwgeom/lwout_wkb.c	2019-07-02 09:48:14 UTC (rev 17581)
+++ trunk/liblwgeom/lwout_wkb.c	2019-07-02 19:47:06 UTC (rev 17582)
@@ -182,8 +182,8 @@
 static inline int wkb_swap_bytes(uint8_t variant)
 {
 	/* If requested variant matches machine arch, we don't have to swap! */
-	if ( ((variant & WKB_NDR) && (getMachineEndian() == NDR)) ||
-	     ((! (variant & WKB_NDR)) && (getMachineEndian() == XDR)) )
+	if (((variant & WKB_NDR) && !IS_BIG_ENDIAN) ||
+	    ((!(variant & WKB_NDR)) && IS_BIG_ENDIAN))
 	{
 		return LW_FALSE;
 	}
@@ -826,10 +826,10 @@
 	if ( ! (variant & WKB_NDR || variant & WKB_XDR) ||
 	       (variant & WKB_NDR && variant & WKB_XDR) )
 	{
-		if ( getMachineEndian() == NDR )
+		if (IS_BIG_ENDIAN)
+			variant = variant | WKB_XDR;
+		else
 			variant = variant | WKB_NDR;
-		else
-			variant = variant | WKB_XDR;
 	}
 
 	/* Allocate the buffer */

Modified: trunk/liblwgeom/lwutil.c
===================================================================
--- trunk/liblwgeom/lwutil.c	2019-07-02 09:48:14 UTC (rev 17581)
+++ trunk/liblwgeom/lwutil.c	2019-07-02 19:47:06 UTC (rev 17582)
@@ -330,16 +330,6 @@
 }
 
 
-char
-getMachineEndian(void)
-{
-	static int endian_check_int = 1; /* don't modify this!!! */
-
-	return *((char *) &endian_check_int); /* 0 = big endian | xdr,
-	                                       * 1 = little endian | ndr
-	                                       */
-}
-
 void
 error_if_srid_mismatch(int32_t srid1, int32_t srid2)
 {