re PR fortran/17675 ([Regression w.r.t. g77] Alignment constraints not honored in EQUIVALENCE)

2004-01-16  Paul Brook  <paul@codesourcery.com>

	PR fortran/17675
	* trans-common.c (translate_common): Remove duplicate function call.
	(finish_equivalences): Preserve alignment when biasing offsets.
testsuite/
	* gfortran.dg/common_4.f90: New test.

From-SVN: r93724

gcc/fortran/ChangeLog

+2004-01-16  Paul Brook  <paul@codesourcery.com>
+
+	PR fortran/17675
+	* trans-common.c (translate_common): Remove duplicate function call.
+	(finish_equivalences): Preserve alignment when biasing offsets.
+
 2005-01-15  Tobias Schl"uter  <tobias.schlueter@physik.uni-muenchen.de
 
 	* primary.c (check_digit): Call 'ISXDIGIT' instead of assuming

gcc/fortran/trans-common.c

@@ -803,7 +803,6 @@ translate_common (gfc_common_head *common, gfc_symbol *var_list)
 		       common->name, &common->where);
 
 	  offset = align_segment (&align);
-	  apply_segment_offset (current_segment, offset);
 
 	  if (offset & (max_align - 1))
 	    {
@@ -851,7 +850,8 @@ finish_equivalences (gfc_namespace *ns)
 {
   gfc_equiv *z, *y;
   gfc_symbol *sym;
-  HOST_WIDE_INT min_offset;
+  HOST_WIDE_INT offset;
+  unsigned HOST_WIDE_INT align;
 
   for (z = ns->equiv; z; z = z->next)
     for (y = z->eq; y; y = y->eq)
@@ -864,13 +864,13 @@ finish_equivalences (gfc_namespace *ns)
         /* All objects directly or indirectly equivalenced with this symbol.  */
         add_equivalences ();
 
-        /* Bias the offsets to to start at zero.  */
-        min_offset = -current_segment->offset;
+	/* Align the block.  */
+	offset = align_segment (&align);
 
-	/* Ensure the block is properly aligned.  */
-	min_offset += align_segment (NULL);
+	/* Ensure all offsets are positive.  */
+	offset -= current_segment->offset & ~(align - 1);
 
-	apply_segment_offset (current_segment, min_offset);
+	apply_segment_offset (current_segment, offset);
 
 	/* Create the decl.  */
         create_common (NULL, current_segment);

gcc/testsuite/ChangeLog

+2004-01-16  Paul Brook  <paul@codesourcery.com>
+
+	* gfortran.dg/common_4.f90: New test.
+
 2005-01-15  Hans-Peter Nilsson  <hp@axis.com>
 
 	PR rtl-optimization/19462

gcc/testsuite/gfortran.dg/common_4.f90

+! { dg-do run }
+! Suppress warnings about misaligned common blocks.
+! { dg-options "-w" }
+! Check misaligned common blocks.
+program prog
+  common /block/ a, b, c
+  integer*1 a
+  integer*4 b, c
+  a = 1
+  b = HUGE(b)
+  c = 2
+  call foo
+end program
+subroutine foo
+  common /block/ a, b, c
+  integer*1 a
+  integer*4 b, c
+  if (a .ne. 1 .or. b .ne. HUGE(b) .or. c .ne. 2) call abort
+end subroutine