[Squeak-Commits] squeak/platforms/Cross/vm sq.h,1.9,1.10

[Ned K. <ne...@us...>]

Update of /cvsroot/squeak/squeak/platforms/Cross/vm
In directory sc8-pr-cvs1:/tmp/cvs-serv846/platforms/Cross/vm

Modified Files:
	sq.h 
Log Message:
Fix for GCC 3.* float optimization bug on little-endian machines.
Committed to trunk at recommendation of Andreas Raab.


Index: sq.h
===================================================================
RCS file: /cvsroot/squeak/squeak/platforms/Cross/vm/sq.h,v
retrieving revision 1.9
retrieving revision 1.10
diff -C2 -d -r1.9 -r1.10
*** sq.h	20 May 2003 18:57:27 -0000	1.9
--- sq.h	12 Nov 2003 23:10:31 -0000	1.10
***************
*** 58,77 ****
  */
  #if defined(DOUBLE_WORD_ALIGNMENT) || defined(DOUBLE_WORD_ORDER)
  # ifdef DOUBLE_WORD_ORDER
  /* word-based copy with swapping for non-PowerPC order */
! #   define storeFloatAtfrom(i, floatVarName) \
! 	*((int *) (i) + 0) = *((int *) &(floatVarName) + 1); \
! 	*((int *) (i) + 1) = *((int *) &(floatVarName) + 0);
! #   define fetchFloatAtinto(i, floatVarName) \
! 	*((int *) &(floatVarName) + 0) = *((int *) (i) + 1); \
! 	*((int *) &(floatVarName) + 1) = *((int *) (i) + 0);
  # else /*!DOUBLE_WORD_ORDER*/
  /* word-based copy for machines with alignment restrictions */
! #   define storeFloatAtfrom(i, floatVarName) \
! 	*((int *) (i) + 0) = *((int *) &(floatVarName) + 0); \
! 	*((int *) (i) + 1) = *((int *) &(floatVarName) + 1);
! #   define fetchFloatAtinto(i, floatVarName) \
! 	*((int *) &(floatVarName) + 0) = *((int *) (i) + 0); \
! 	*((int *) &(floatVarName) + 1) = *((int *) (i) + 1);
  # endif /*!DOUBLE_WORD_ORDER*/
  #else /*!(DOUBLE_WORD_ORDER||DOUBLE_WORD_ALIGNMENT)*/
--- 58,79 ----
  */
  #if defined(DOUBLE_WORD_ALIGNMENT) || defined(DOUBLE_WORD_ORDER)
+ /* this is to allow strict aliasing assumption in the optimizer */
+ typedef union { double d; int i[sizeof(double) / sizeof(int)]; } _swapper;
  # ifdef DOUBLE_WORD_ORDER
  /* word-based copy with swapping for non-PowerPC order */
! #   define storeFloatAtfrom(intPointerToFloat, floatVarName) \
! 	*((int *)(intPointerToFloat) + 0) = ((_swapper *)(&floatVarName))->i[1]; \
! 	*((int *)(intPointerToFloat) + 1) = ((_swapper *)(&floatVarName))->i[0];
! #   define fetchFloatAtinto(intPointerToFloat, floatVarName) \
! 	((_swapper *)(&floatVarName))->i[1] = *((int *)(intPointerToFloat) + 0); \
! 	((_swapper *)(&floatVarName))->i[0] = *((int *)(intPointerToFloat) + 1);
  # else /*!DOUBLE_WORD_ORDER*/
  /* word-based copy for machines with alignment restrictions */
! #   define storeFloatAtfrom(intPointerToFloat, floatVarName) \
! 	*((int *)(intPointerToFloat) + 0) = ((_swapper *)(&floatVarName))->i[0]; \
! 	*((int *)(intPointerToFloat) + 1) = ((_swapper *)(&floatVarName))->i[1];
! #   define fetchFloatAtinto(intPointerToFloat, floatVarName) \
! 	((_swapper *)(&floatVarName))->i[0] = *((int *)(intPointerToFloat) + 0); \
! 	((_swapper *)(&floatVarName))->i[1] = *((int *)(intPointerToFloat) + 1);
  # endif /*!DOUBLE_WORD_ORDER*/
  #else /*!(DOUBLE_WORD_ORDER||DOUBLE_WORD_ALIGNMENT)*/