Patchwork [mem-ref2] Fix memmove folding

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Submitter Richard Guenther
Date June 10, 2010, 3:02 p.m.
Message ID <alpine.LNX.2.00.1006101701130.1429@zhemvz.fhfr.qr>
Download mbox | patch
Permalink /patch/55228/
State New
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Comments

Richard Guenther - June 10, 2010, 3:02 p.m.
to handle MEM_REF arguments.  As we fold during gimplification also
after gimplifying arguments we can drop the INDIRECT_REF path and
rely on gimplified arguments.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to the
branch.

Richard.

2010-06-10  Richard Guenther  <rguenther@suse.de>

	* builtins.c (fold_builtin_memory_op): Simplify and handle
	MEM_REFs in folding memmove to memcpy.

Patch

Index: builtins.c
===================================================================
--- builtins.c	(revision 160434)
+++ builtins.c	(working copy)
@@ -8370,37 +8376,26 @@  fold_builtin_memory_op (location_t loc,
 	    }
 
 	  /* If *src and *dest can't overlap, optimize into memcpy as well.  */
-	  srcvar = build_fold_indirect_ref_loc (loc, src);
-	  destvar = build_fold_indirect_ref_loc (loc, dest);
-	  if (srcvar
-	      && !TREE_THIS_VOLATILE (srcvar)
-	      && destvar
-	      && !TREE_THIS_VOLATILE (destvar))
+	  if (TREE_CODE (src) == ADDR_EXPR
+	      && TREE_CODE (dest) == ADDR_EXPR)
 	    {
 	      tree src_base, dest_base, fn;
 	      HOST_WIDE_INT src_offset = 0, dest_offset = 0;
 	      HOST_WIDE_INT size = -1;
 	      HOST_WIDE_INT maxsize = -1;
 
-	      src_base = srcvar;
-	      if (handled_component_p (src_base))
-		src_base = get_ref_base_and_extent (src_base, &src_offset,
-						    &size, &maxsize);
-	      dest_base = destvar;
-	      if (handled_component_p (dest_base))
-		dest_base = get_ref_base_and_extent (dest_base, &dest_offset,
-						     &size, &maxsize);
+	      srcvar = TREE_OPERAND (src, 0);
+	      src_base = get_ref_base_and_extent (srcvar, &src_offset,
+						  &size, &maxsize);
+	      destvar = TREE_OPERAND (dest, 0);
+	      dest_base = get_ref_base_and_extent (destvar, &dest_offset,
+						   &size, &maxsize);
 	      if (host_integerp (len, 1))
-		{
-		  maxsize = tree_low_cst (len, 1);
-		  if (maxsize
-		      > INTTYPE_MAXIMUM (HOST_WIDE_INT) / BITS_PER_UNIT)
-		    maxsize = -1;
-		  else
-		    maxsize *= BITS_PER_UNIT;
-		}
+		maxsize = tree_low_cst (len, 1);
 	      else
 		maxsize = -1;
+	      src_offset /= BITS_PER_UNIT;
+	      dest_offset /= BITS_PER_UNIT;
 	      if (SSA_VAR_P (src_base)
 		  && SSA_VAR_P (dest_base))
 		{
@@ -8409,13 +8404,25 @@  fold_builtin_memory_op (location_t loc,
 					   dest_offset, maxsize))
 		    return NULL_TREE;
 		}
-	      else if (TREE_CODE (src_base) == INDIRECT_REF
-		       && TREE_CODE (dest_base) == INDIRECT_REF)
+	      else if (TREE_CODE (src_base) == MEM_REF
+		       && TREE_CODE (dest_base) == MEM_REF)
 		{
+		  double_int off;
 		  if (! operand_equal_p (TREE_OPERAND (src_base, 0),
-					 TREE_OPERAND (dest_base, 0), 0)
-		      || ranges_overlap_p (src_offset, maxsize,
-					   dest_offset, maxsize))
+					 TREE_OPERAND (dest_base, 0), 0))
+		    return NULL_TREE;
+		  off = double_int_add (mem_ref_offset (src_base),
+					shwi_to_double_int (src_offset));
+		  if (!double_int_fits_in_shwi_p (off))
+		    return NULL_TREE;
+		  src_offset = off.low;
+		  off = double_int_add (mem_ref_offset (dest_base),
+					shwi_to_double_int (dest_offset));
+		  if (!double_int_fits_in_shwi_p (off))
+		    return NULL_TREE;
+		  dest_offset = off.low;
+		  if (ranges_overlap_p (src_offset, maxsize,
+					dest_offset, maxsize))
 		    return NULL_TREE;
 		}
 	      else