builtins.c (get_object_alignment_2): Minor tweak.

* builtins.c (get_object_alignment_2): Minor tweak.
	* tree-ssa-loop-ivopts.c (may_be_unaligned_p): Rewrite.

From-SVN: r206576

gcc/ChangeLog

@@ -1,7 +1,12 @@
+2014-01-13  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* builtins.c (get_object_alignment_2): Minor tweak.
+	* tree-ssa-loop-ivopts.c (may_be_unaligned_p): Rewrite.
+
 2014-01-13  Christian Bruel  <christian.bruel@st.com>
 
 	* config/sh/sh-mem.cc (sh_expand_cmpnstr): Unroll small sizes and
-	  optimized non constant lengths.
+	optimized non constant lengths.
 
 2014-01-13  Jakub Jelinek  <jakub@redhat.com>
 

gcc/builtins.c

@@ -434,7 +434,7 @@ get_object_alignment_2 (tree exp, unsigned int *alignp,
      alignment that can prevail.  */
   if (offset)
     {
-      int trailing_zeros = tree_ctz (offset);
+      unsigned int trailing_zeros = tree_ctz (offset);
       if (trailing_zeros < HOST_BITS_PER_INT)
 	{
 	  unsigned int inner = (1U << trailing_zeros) * BITS_PER_UNIT;

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2014-01-13  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/loop_optimization17.adb: New test.
+	* gnat.dg/loop_optimization17_pkg.ad[sb]: New helper.
+
 2014-01-13  Christian Bruel  <christian.bruel@st.com>
 
 	* gcc.target/sh/cmpstrn.c: New case.

gcc/testsuite/gnat.dg/loop_optimization17.adb

@@ -0,0 +1,22 @@
+-- { dg-do run }
+-- { dg-options "-O" }
+
+with Loop_Optimization17_Pkg; use Loop_Optimization17_Pkg;
+
+procedure Loop_Optimization17 is
+
+  Data : Arr;
+
+begin
+
+  Data := (others => (I  => 0,
+                      V1 => (others => 0.0),
+                      V2 => (others => 0.0),
+                      S  => 0.0));
+
+  for I in Index_T'Range loop
+    Object (I).V1 := F (Data (I).V1);
+    Object (I).V2 := F (Data (I).V2);
+  end loop;
+
+end;

gcc/testsuite/gnat.dg/loop_optimization17_pkg.adb

@@ -0,0 +1,5 @@
+package body Loop_Optimization17_Pkg is
+
+  function F (V : Vector) return Vector is begin return V; end;
+
+end Loop_Optimization17_Pkg;

gcc/testsuite/gnat.dg/loop_optimization17_pkg.ads

@@ -0,0 +1,29 @@
+package Loop_Optimization17_Pkg is
+
+   type vector is array (1..3) of Long_Float;
+
+   type Rec is
+      record
+         I : Integer;
+         V1, V2 : Vector;
+         S : Long_Float;
+      end record;
+
+   for  Rec  use
+      record
+         I  at   0 range  0 .. 31;
+         V1 at   4 range  0 .. 191;
+         V2 at  28 range  0 .. 191;
+         S  at  52 range  0 .. 63;
+      end  record;
+   for Rec'Alignment use 4;
+   for Rec'Size use 480;
+
+   type Index_T is range 1 .. 5;
+   type Arr is array (Index_T) of Rec;
+
+   Object : Arr;
+
+   function F (V : Vector) return Vector;
+
+end Loop_Optimization17_Pkg;

gcc/tree-ssa-loop-ivopts.c

@@ -1668,50 +1668,30 @@ constant_multiple_of (tree top, tree bot, double_int *mul)
     }
 }
 
-/* Returns true if memory reference REF with step STEP may be unaligned.  */
+/* Return true if memory reference REF with step STEP may be unaligned.  */
 
 static bool
 may_be_unaligned_p (tree ref, tree step)
 {
-  tree base;
-  tree base_type;
-  HOST_WIDE_INT bitsize;
-  HOST_WIDE_INT bitpos;
-  tree toffset;
-  enum machine_mode mode;
-  int unsignedp, volatilep;
-  unsigned base_align;
-
   /* TARGET_MEM_REFs are translated directly to valid MEMs on the target,
      thus they are not misaligned.  */
   if (TREE_CODE (ref) == TARGET_MEM_REF)
     return false;
 
-  /* The test below is basically copy of what expr.c:normal_inner_ref
-     does to check whether the object must be loaded by parts when
-     STRICT_ALIGNMENT is true.  */
-  base = get_inner_reference (ref, &bitsize, &bitpos, &toffset, &mode,
-			      &unsignedp, &volatilep, true);
-  base_type = TREE_TYPE (base);
-  base_align = get_object_alignment (base);
-  base_align = MAX (base_align, TYPE_ALIGN (base_type));
+  unsigned int align = TYPE_ALIGN (TREE_TYPE (ref));
 
-  if (mode != BLKmode)
-    {
-      unsigned mode_align = GET_MODE_ALIGNMENT (mode);
+  unsigned HOST_WIDE_INT bitpos;
+  unsigned int ref_align;
+  get_object_alignment_1 (ref, &ref_align, &bitpos);
+  if (ref_align < align
+      || (bitpos % align) != 0
+      || (bitpos % BITS_PER_UNIT) != 0)
+    return true;
 
-      if (base_align < mode_align
-	  || (bitpos % mode_align) != 0
-	  || (bitpos % BITS_PER_UNIT) != 0)
-	return true;
-
-      if (toffset
-	  && (highest_pow2_factor (toffset) * BITS_PER_UNIT) < mode_align)
-	return true;
-
-      if ((highest_pow2_factor (step) * BITS_PER_UNIT) < mode_align)
-	return true;
-    }
+  unsigned int trailing_zeros = tree_ctz (step);
+  if (trailing_zeros < HOST_BITS_PER_INT
+      && (1U << trailing_zeros) * BITS_PER_UNIT < align)
+    return true;
 
   return false;
 }