path: root/meta/recipes-devtools/gcc/gcc-4.6.0/gcc-4_6-branch-backports/0392-2011-06-06-Richard-Guenther-rguenther-suse.de.patch

From 701245b3347bb4ac5433de15e4c69924c2d1a7e8 Mon Sep 17 00:00:00 2001
From: rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Mon, 6 Jun 2011 10:13:23 +0000
Subject: [PATCH] 2011-06-06  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/48702
	* tree-ssa-address.c (create_mem_ref_raw): Create MEM_REFs
	only when we know the base address is within bounds.
	* tree-ssa-alias.c (indirect_ref_may_alias_decl_p): Do not
	assume the base address of TARGET_MEM_REFs is in bounds.
	(indirect_refs_may_alias_p): Fix TARGET_MEM_REF without index tests.

	* gcc.dg/torture/pr48702.c: New testcase.

	Backport from mainline
	2011-05-31  Jakub Jelinek  <jakub@redhat.com>

	PR rtl-optimization/49235
	* tree-ssa-address.c (gen_addr_rtx): Ignore base if it is const0_rtx.
	(create_mem_ref_raw): Create MEM_REF even if base is INTEGER_CST.

	* gcc.dg/pr49235.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_6-branch@174688 138bc75d-0d04-0410-961f-82ee72b054a4

index 1a7b287..b3199f9 100644
new file mode 100644
index 0000000..f1e589f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr49235.c
@@ -0,0 +1,25 @@
+/* PR rtl-optimization/49235 */
+/* { dg-do compile { target { int32plus } } } */
+/* { dg-options "-O -fno-delete-null-pointer-checks -fno-tree-scev-cprop -ftree-vectorize -fno-vect-cost-model -w" } */
+
+void
+foo (void)
+{
+  unsigned i;
+  unsigned *p = 0;
+  for (i = 0; i < 4; ++i)
+    *p++ = 0;
+  for (i = 0; i < 4; ++i)
+    *p++ = 0;
+}
+
+void
+bar (void)
+{
+  unsigned i;
+  unsigned *p = (unsigned *) (__UINTPTR_TYPE__) 0x12340000;
+  for (i = 0; i < 4; ++i)
+    *p++ = 0;
+  for (i = 0; i < 4; ++i)
+    *p++ = 0;
+}
diff --git a/gcc/testsuite/gcc.dg/torture/pr48702.c b/gcc/testsuite/gcc.dg/torture/pr48702.c
new file mode 100644
index 0000000..1ec371d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr48702.c
@@ -0,0 +1,47 @@
+/* { dg-do run } */
+
+extern void abort (void);
+
+#define LEN 4
+
+static inline void unpack(int  array[LEN])
+{
+  int ii, val;
+  val = 1;
+  for (ii = 0; ii < LEN; ii++) {
+      array[ii] = val % 2;
+      val = val / 2;
+  }
+}
+
+static inline int  pack(int  array[LEN])
+{
+  int ans, ii;
+  ans = 0;
+  for (ii = LEN-1; ii >= 0; ii--) {
+      ans = 2 * ans + array[ii];
+  }
+  return ans;
+}
+
+int __attribute__((noinline))
+foo()
+{
+  int temp, ans;
+  int array[LEN];
+  unpack(array);
+  temp = array[0];
+  array[0] = array[2];
+  array[2] = temp;
+  ans = pack(array);
+  return ans;
+}
+
+int main(void)
+{
+  int val;
+  val = foo();
+  if (val != 4)
+    abort ();
+  return 0;
+}
diff --git a/gcc/tree-ssa-address.c b/gcc/tree-ssa-address.c
index a9ca835..437460d 100644
--- a/gcc/tree-ssa-address.c
+++ b/gcc/tree-ssa-address.c
@@ -1,5 +1,5 @@
 /* Memory address lowering and addressing mode selection.
-   Copyright (C) 2004, 2006, 2007, 2008, 2009, 2010
+   Copyright (C) 2004, 2006, 2007, 2008, 2009, 2010, 2011
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -129,7 +129,7 @@ gen_addr_rtx (enum machine_mode address_mode,
       *addr = act_elem;
     }
 
-  if (base)
+  if (base && base != const0_rtx)
     {
       if (*addr)
 	*addr = simplify_gen_binary (PLUS, address_mode, base, *addr);
@@ -361,8 +361,11 @@ create_mem_ref_raw (tree type, tree alias_ptr_type, struct mem_address *addr,
       index2 = addr->base;
     }
 
-  /* If possible use a plain MEM_REF instead of a TARGET_MEM_REF.  */
-  if (alias_ptr_type
+  /* If possible use a plain MEM_REF instead of a TARGET_MEM_REF.
+     ???  As IVOPTs does not follow restrictions to where the base
+     pointer may point to create a MEM_REF only if we know that
+     base is valid.  */
+  if ((TREE_CODE (base) == ADDR_EXPR || TREE_CODE (base) == INTEGER_CST)
       && (!index2 || integer_zerop (index2))
       && (!addr->index || integer_zerop (addr->index)))
     return fold_build2 (MEM_REF, type, base, addr->offset);
diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
index 8434179..1d213df 100644
--- a/gcc/tree-ssa-alias.c
+++ b/gcc/tree-ssa-alias.c
@@ -719,8 +719,9 @@ indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED, tree base1,
 			       alias_set_type base2_alias_set, bool tbaa_p)
 {
   tree ptr1;
-  tree ptrtype1;
+  tree ptrtype1, dbase2;
   HOST_WIDE_INT offset1p = offset1, offset2p = offset2;
+  HOST_WIDE_INT doffset1, doffset2;
 
   ptr1 = TREE_OPERAND (base1, 0);
 
@@ -744,11 +745,12 @@ indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED, tree base1,
      the pointer access is beyond the extent of the variable access.
      (the pointer base cannot validly point to an offset less than zero
      of the variable).
-     They also cannot alias if the pointer may not point to the decl.  */
-  if ((TREE_CODE (base1) != TARGET_MEM_REF
-       || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1)))
+     ???  IVOPTs creates bases that do not honor this restriction,
+     so do not apply this optimization for TARGET_MEM_REFs.  */
+  if (TREE_CODE (base1) != TARGET_MEM_REF
       && !ranges_overlap_p (MAX (0, offset1p), -1, offset2p, max_size2))
     return false;
+  /* They also cannot alias if the pointer may not point to the decl.  */
   if (!ptr_deref_may_alias_decl_p (ptr1, base2))
     return false;
 
@@ -771,20 +773,6 @@ indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED, tree base1,
   if (base2_alias_set == -1)
     base2_alias_set = get_alias_set (base2);
 
-  /* If both references are through the same type, they do not alias
-     if the accesses do not overlap.  This does extra disambiguation
-     for mixed/pointer accesses but requires strict aliasing.
-     For MEM_REFs we require that the component-ref offset we computed
-     is relative to the start of the type which we ensure by
-     comparing rvalue and access type and disregarding the constant
-     pointer offset.  */
-  if ((TREE_CODE (base1) != TARGET_MEM_REF
-       || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1)))
-      && (TREE_CODE (base1) != MEM_REF
-	  || same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) == 1)
-      && same_type_for_tbaa (TREE_TYPE (ptrtype1), TREE_TYPE (base2)) == 1)
-    return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
-
   /* When we are trying to disambiguate an access with a pointer dereference
      as base versus one with a decl as base we can use both the size
      of the decl and its dynamic type for extra disambiguation.
@@ -814,6 +802,48 @@ indirect_ref_may_alias_decl_p (tree ref1 ATTRIBUTE_UNUSED, tree base1,
       && tree_int_cst_lt (DECL_SIZE (base2), TYPE_SIZE (TREE_TYPE (ptrtype1))))
     return false;
 
+  if (!ref2)
+    return true;
+
+  /* If the decl is accressed via a MEM_REF, reconstruct the base
+     we can use for TBAA and an appropriately adjusted offset.  */
+  dbase2 = ref2;
+  while (handled_component_p (dbase2))
+    dbase2 = TREE_OPERAND (dbase2, 0);
+  doffset1 = offset1;
+  doffset2 = offset2;
+  if (TREE_CODE (dbase2) == MEM_REF
+      || TREE_CODE (dbase2) == TARGET_MEM_REF)
+    {
+      double_int moff = mem_ref_offset (dbase2);
+      moff = double_int_lshift (moff,
+				BITS_PER_UNIT == 8
+				? 3 : exact_log2 (BITS_PER_UNIT),
+				HOST_BITS_PER_DOUBLE_INT, true);
+      if (double_int_negative_p (moff))
+	doffset1 -= double_int_neg (moff).low;
+      else
+	doffset2 -= moff.low;
+    }
+
+  /* If either reference is view-converted, give up now.  */
+  if (same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) != 1
+      || same_type_for_tbaa (TREE_TYPE (dbase2),
+			     TREE_TYPE (reference_alias_ptr_type (dbase2))) != 1)
+    return true;
+
+  /* If both references are through the same type, they do not alias
+     if the accesses do not overlap.  This does extra disambiguation
+     for mixed/pointer accesses but requires strict aliasing.
+     For MEM_REFs we require that the component-ref offset we computed
+     is relative to the start of the type which we ensure by
+     comparing rvalue and access type and disregarding the constant
+     pointer offset.  */
+  if ((TREE_CODE (base1) != TARGET_MEM_REF
+       || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1)))
+      && same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (dbase2)) == 1)
+    return ranges_overlap_p (doffset1, max_size1, doffset2, max_size2);
+
   /* Do access-path based disambiguation.  */
   if (ref1 && ref2
       && handled_component_p (ref1)
@@ -942,12 +972,12 @@ indirect_refs_may_alias_p (tree ref1 ATTRIBUTE_UNUSED, tree base1,
   /* If both references are through the same type, they do not alias
      if the accesses do not overlap.  This does extra disambiguation
      for mixed/pointer accesses but requires strict aliasing.  */
-  if ((TREE_CODE (base1) != TARGET_MEM_REF || !TMR_INDEX (base1))
-      && (TREE_CODE (base2) != TARGET_MEM_REF || !TMR_INDEX (base2))
-      && (TREE_CODE (base1) != MEM_REF
-	  || same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) == 1)
-      && (TREE_CODE (base2) != MEM_REF
-	  || same_type_for_tbaa (TREE_TYPE (base2), TREE_TYPE (ptrtype2)) == 1)
+  if ((TREE_CODE (base1) != TARGET_MEM_REF
+       || (!TMR_INDEX (base1) && !TMR_INDEX2 (base1)))
+      && (TREE_CODE (base2) != TARGET_MEM_REF
+	  || (!TMR_INDEX (base2) && !TMR_INDEX2 (base2)))
+      && same_type_for_tbaa (TREE_TYPE (base1), TREE_TYPE (ptrtype1)) == 1
+      && same_type_for_tbaa (TREE_TYPE (base2), TREE_TYPE (ptrtype2)) == 1
       && same_type_for_tbaa (TREE_TYPE (ptrtype1),
 			     TREE_TYPE (ptrtype2)) == 1)
     return ranges_overlap_p (offset1, max_size1, offset2, max_size2);
-- 
1.7.0.4