New function for checking misalignment

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/ibm/gcc-4_3-branch@151786 138bc75d-0d04-0410-961f-82ee72b054a4

8 files changed, 107 insertions, 3 deletions

diff --git a/gcc/ChangeLog.power7 b/gcc/ChangeLog.power7
index 93b05db2eb7..25da653394d 100644
--- a/gcc/ChangeLog.power7
+++ b/gcc/ChangeLog.power7
@@ -1,3 +1,20 @@
+2009-09-17  Revital Eres  <eres@il.ibm.com>
+
+	* doc/tm.texi (TARGET_SUPPORT_VECTOR_MISALIGNMENT): Document.
+	* targhooks.c (default_builtin_support_vector_misalignment):
+	New builtin function.
+	* targhooks.h (default_builtin_support_vector_misalignment):
+	Declare.
+	* target.h (builtin_support_vector_misalignment):
+	New field in struct gcc_target.
+	* tree-vectorizer.c (vect_supportable_dr_alignment): Call
+	new builtin function.
+	* target-def.h (TARGET_SUPPORT_VECTOR_MISALIGNMENT):
+	Define.
+	* config/rs6000/rs6000.c
+	(rs6000_builtin_support_vector_misalignment): New function.
+	(TARGET_SUPPORT_VECTOR_MISALIGNMENT): Define.
+
 2009-07-28  Michael Meissner  <meissner@linux.vnet.ibm.com>
 
 	* config/rs6000/vector.md (vector_copysign<mode>3): Use
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 84735d82c12..0c9d96fc2df 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -924,6 +924,10 @@ static tree rs6000_builtin_mask_for_load (void);
 static tree rs6000_builtin_mul_widen_even (tree);
 static tree rs6000_builtin_mul_widen_odd (tree);
 static tree rs6000_builtin_conversion (enum tree_code, tree);
+static bool rs6000_builtin_support_vector_misalignment (enum
+                                                        machine_mode,
+                                                        const_tree,
+                                                        int, bool);
 
 static void def_builtin (int, const char *, tree, int);
 static bool rs6000_vector_alignment_reachable (const_tree, bool);
@@ -1279,6 +1283,10 @@ static const char alt_reg_names[][8] =
 #undef TARGET_VECTOR_ALIGNMENT_REACHABLE
 #define TARGET_VECTOR_ALIGNMENT_REACHABLE rs6000_vector_alignment_reachable
 
+#undef TARGET_SUPPORT_VECTOR_MISALIGNMENT
+#define TARGET_SUPPORT_VECTOR_MISALIGNMENT            \
+   rs6000_builtin_support_vector_misalignment
+
 #undef TARGET_INIT_BUILTINS
 #define TARGET_INIT_BUILTINS rs6000_init_builtins
 
@@ -2863,6 +2871,37 @@ rs6000_vector_alignment_reachable (const_tree type ATTRIBUTE_UNUSED, bool is_pac
     }
 }
 
+/* Return true if the vector misalignment factor is supported by the
+   target.  */
+bool
+rs6000_builtin_support_vector_misalignment (enum machine_mode mode,
+                                            const_tree type,
+                                            int misalignment,
+                                            bool is_packed)
+{
+  if (TARGET_VSX)
+    {
+      /* Return if movmisalign pattern is not supported for this mode.  */
+      if (optab_handler (movmisalign_optab, mode)->insn_code ==
+          CODE_FOR_nothing)
+        return false;
+
+      if (misalignment == -1)
+      {
+        /* misalignment factor is unknown at compile time but we know
+           it's word aligned.  */
+        if (rs6000_vector_alignment_reachable (type, is_packed))
+          return true;
+        return false;
+      }
+      /* VSX supports word-aligned vector.  */
+      if (misalignment % 4 == 0)
+      return true;
+    }
+  return false;
+}
+
+
 /* Handle generic options of the form -mfoo=yes/no.
    NAME is the option name.
    VALUE is the option value.
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 5e37f27b48a..580aa86586a 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -5541,6 +5541,14 @@ the vectorized function shall be of vector type @var{vec_type_out} and the
 argument types should be @var{vec_type_in}.
 @end deftypefn
 
+@deftypefn {Target Hook} bool TARGET_SUPPORT_VECTOR_MISALIGNMENT (enum machine_mode @var{mode}, tree @var{type}, int @var{misalignment}, bool @var{is_packed})
+This hook should return true if the target supports misaligned vector
+store/load of a specific factor denoted in the @var{misalignment}
+parameter.  The vector store/load should be of machine mode @var{mode} and
+the elements in the vectors should be of type @var{type}.  @var{is_packed}
+parameter is true if the memory access is defined in a packed struct.
+@end deftypefn
+
 @node Anchored Addresses
 @section Anchored Addresses
 @cindex anchored addresses
diff --git a/gcc/target-def.h b/gcc/target-def.h
index 9d9c5d94554..8f1d2e8db79 100644
--- a/gcc/target-def.h
+++ b/gcc/target-def.h
@@ -364,6 +364,8 @@
 #define TARGET_VECTORIZE_BUILTIN_VECTORIZATION_COST 0
 #define TARGET_VECTOR_ALIGNMENT_REACHABLE \
   default_builtin_vector_alignment_reachable
+#define TARGET_SUPPORT_VECTOR_MISALIGNMENT \
+  default_builtin_support_vector_misalignment
 
 #define TARGET_VECTORIZE                                                \
   {									\
@@ -373,7 +375,8 @@
     TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_EVEN,                            \
     TARGET_VECTORIZE_BUILTIN_MUL_WIDEN_ODD,				\
     TARGET_VECTORIZE_BUILTIN_VECTORIZATION_COST,			\
-    TARGET_VECTOR_ALIGNMENT_REACHABLE					\
+    TARGET_VECTOR_ALIGNMENT_REACHABLE,					\
+    TARGET_SUPPORT_VECTOR_MISALIGNMENT					\		
   }
 
 #define TARGET_DEFAULT_TARGET_FLAGS 0
diff --git a/gcc/target.h b/gcc/target.h
index eb391c5e9c3..b1b900e1dca 100644
--- a/gcc/target.h
+++ b/gcc/target.h
@@ -438,6 +438,11 @@ struct gcc_target
     /* Return true if vector alignment is reachable (by peeling N
        iterations) for the given type.  */
     bool (* vector_alignment_reachable) (const_tree, bool);
+    /* Return true if the target supports misaligned store/load of a
+       specific factor denoted in the third parameter.  The last parameter
+       is true if the access is defined in a packed struct.  */
+    bool (* builtin_support_vector_misalignment) (enum machine_mode,
+                                                  const_tree, int, bool);
   } vectorize;
 
   /* The initial value of target_flags.  */
diff --git a/gcc/targhooks.c b/gcc/targhooks.c
index e995ec9d69a..274ac684cc5 100644
--- a/gcc/targhooks.c
+++ b/gcc/targhooks.c
@@ -691,6 +691,23 @@ tree default_mangle_decl_assembler_name (tree decl ATTRIBUTE_UNUSED,
    return id;
 }
 
+/* By default, assume that a target supports any factor of misalignment
+   memory access if it supports movmisalign patten. 
+   is_packed is true if the memory access is defined in a packed struct.  */
+bool
+default_builtin_support_vector_misalignment (enum machine_mode mode,
+					     const_tree type
+					     ATTRIBUTE_UNUSED,
+					     int misalignment
+					     ATTRIBUTE_UNUSED,
+					     bool is_packed
+					     ATTRIBUTE_UNUSED)
+{
+  if (optab_handler (movmisalign_optab, mode)->insn_code != CODE_FOR_nothing)
+    return true;
+  return false;
+}
+
 bool
 default_builtin_vector_alignment_reachable (const_tree type, bool is_packed)
 {
diff --git a/gcc/targhooks.h b/gcc/targhooks.h
index 1018eb5f653..45f41b1108a 100644
--- a/gcc/targhooks.h
+++ b/gcc/targhooks.h
@@ -70,6 +70,10 @@ extern tree default_builtin_vectorized_conversion (enum tree_code, tree);
 extern tree default_builtin_reciprocal (enum built_in_function, bool, bool);
 
 extern bool default_builtin_vector_alignment_reachable (const_tree, bool);
+extern bool
+default_builtin_support_vector_misalignment (enum machine_mode mode,
+					     const_tree,
+					     int, bool); 
 
 /* These are here, and not in hooks.[ch], because not all users of
    hooks.h include tm.h, and thus we don't have CUMULATIVE_ARGS.  */
diff --git a/gcc/tree-vectorizer.c b/gcc/tree-vectorizer.c
index 6e2cccaec2d..7d595f469a6 100644
--- a/gcc/tree-vectorizer.c
+++ b/gcc/tree-vectorizer.c
@@ -1938,6 +1938,9 @@ vect_supportable_dr_alignment (struct data_reference *dr)
 
   if (DR_IS_READ (dr))
     {
+      bool is_packed = false;
+      tree type = (TREE_TYPE (DR_REF (dr)));
+
       if (optab_handler (vec_realign_load_optab, mode)->insn_code != 
 						   	     CODE_FOR_nothing
 	  && (!targetm.vectorize.builtin_mask_for_load
@@ -1949,9 +1952,17 @@ vect_supportable_dr_alignment (struct data_reference *dr)
 	    else
 	      return dr_explicit_realign_optimized;
 	}
+      if (!known_alignment_for_access_p (dr))
+        {
+          tree ba = DR_BASE_OBJECT (dr);
+
+          if (ba)
+            is_packed = contains_packed_reference (ba);
+        }
 
-      if (optab_handler (movmisalign_optab, mode)->insn_code != 
-							     CODE_FOR_nothing)
+      if (targetm.vectorize.
+          builtin_support_vector_misalignment (mode, type,
+                                               DR_MISALIGNMENT (dr), is_packed))
 	/* Can't software pipeline the loads, but can at least do them.  */
 	return dr_unaligned_supported;
     }