re PR middle-end/60092 (posix_memalign not recognized to derive alias and alignment info)

2014-02-07  Richard Biener  <rguenther@suse.de>

	PR middle-end/60092
	* gimple-low.c (lower_builtin_posix_memalign): New function.
	(lower_stmt): Call it to lower posix_memalign in a way
	to make alignment info accessible.

	* gcc.dg/vect/pr60092-2.c: New testcase.

From-SVN: r207598

4 files changed, 93 insertions, 5 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 38a5f43..df9bc3e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2014-02-07  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/60092
+	* gimple-low.c (lower_builtin_posix_memalign): New function.
+	(lower_stmt): Call it to lower posix_memalign in a way
+	to make alignment info accessible.
+
 2014-02-07  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/60082
diff --git a/gcc/gimple-low.c b/gcc/gimple-low.c
index 5fbcf3f3..01e9e9c 100644
--- a/gcc/gimple-low.c
+++ b/gcc/gimple-low.c
@@ -83,6 +83,7 @@ static void lower_gimple_bind (gimple_stmt_iterator *, struct lower_data *);
 static void lower_try_catch (gimple_stmt_iterator *, struct lower_data *);
 static void lower_gimple_return (gimple_stmt_iterator *, struct lower_data *);
 static void lower_builtin_setjmp (gimple_stmt_iterator *);
+static void lower_builtin_posix_memalign (gimple_stmt_iterator *);
 
 
 /* Lower the body of current_function_decl from High GIMPLE into Low
@@ -327,12 +328,19 @@ lower_stmt (gimple_stmt_iterator *gsi, struct lower_data *data)
 	  }
 
 	if (decl
-	    && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL
-	    && DECL_FUNCTION_CODE (decl) == BUILT_IN_SETJMP)
+	    && DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL)
 	  {
-	    lower_builtin_setjmp (gsi);
-	    data->cannot_fallthru = false;
-	    return;
+	    if (DECL_FUNCTION_CODE (decl) == BUILT_IN_SETJMP)
+	      {
+		lower_builtin_setjmp (gsi);
+		data->cannot_fallthru = false;
+		return;
+	      }
+	    else if (DECL_FUNCTION_CODE (decl) == BUILT_IN_POSIX_MEMALIGN)
+	      {
+		lower_builtin_posix_memalign (gsi);
+		return;
+	      }
 	  }
 
 	if (decl && (flags_from_decl_or_type (decl) & ECF_NORETURN))
@@ -771,6 +779,49 @@ lower_builtin_setjmp (gimple_stmt_iterator *gsi)
   /* Remove the call to __builtin_setjmp.  */
   gsi_remove (gsi, false);
 }
+
+/* Lower calls to posix_memalign to
+     posix_memalign (ptr, align, size);
+     tem = *ptr;
+     tem = __builtin_assume_aligned (tem, align);
+     *ptr = tem;
+   or to
+     void *tem;
+     posix_memalign (&tem, align, size);
+     ttem = tem;
+     ttem = __builtin_assume_aligned (ttem, align);
+     ptr = tem;
+   in case the first argument was &ptr.  That way we can get at the
+   alignment of the heap pointer in CCP.  */
+
+static void
+lower_builtin_posix_memalign (gimple_stmt_iterator *gsi)
+{
+  gimple stmt = gsi_stmt (*gsi);
+  tree pptr = gimple_call_arg (stmt, 0);
+  tree align = gimple_call_arg (stmt, 1);
+  tree ptr = create_tmp_reg (ptr_type_node, NULL);
+  if (TREE_CODE (pptr) == ADDR_EXPR)
+    {
+      tree tem = create_tmp_var (ptr_type_node, NULL);
+      TREE_ADDRESSABLE (tem) = 1;
+      gimple_call_set_arg (stmt, 0, build_fold_addr_expr (tem));
+      stmt = gimple_build_assign (ptr, tem);
+    }
+  else
+    stmt = gimple_build_assign (ptr,
+				fold_build2 (MEM_REF, ptr_type_node, pptr,
+					     build_int_cst (ptr_type_node, 0)));
+  gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
+  stmt = gimple_build_call (builtin_decl_implicit (BUILT_IN_ASSUME_ALIGNED),
+			    2, ptr, align);
+  gimple_call_set_lhs (stmt, ptr);
+  gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
+  stmt = gimple_build_assign (fold_build2 (MEM_REF, ptr_type_node, pptr,
+					   build_int_cst (ptr_type_node, 0)),
+			      ptr);
+  gsi_insert_after (gsi, stmt, GSI_NEW_STMT);
+}
 
 
 /* Record the variables in VARS into function FN.  */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 32b6177..2e12145 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2014-02-07  Richard Biener  <rguenther@suse.de>
+
+	PR middle-end/60092
+	* gcc.dg/vect/pr60092-2.c: New testcase.
+
 2014-02-07  Jakub Jelinek  <jakub@redhat.com>
 
 	PR c++/60082
diff --git a/gcc/testsuite/gcc.dg/vect/pr60092-2.c b/gcc/testsuite/gcc.dg/vect/pr60092-2.c
new file mode 100644
index 0000000..7d2eb6e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr60092-2.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target vect_int } */
+
+int *foo (int n)
+{
+  int *p;
+  int *q;
+  void *tem;
+  if (posix_memalign (&tem, 256, n * sizeof (int)) != 0)
+    return (void *)0;
+  p = (int *)tem;
+  if (posix_memalign (&tem, 256, n * sizeof (int)) != 0)
+    return (void *)0;
+  q = (int *)tem;
+  bar (q);
+  int i;
+  for (i = 0; i < n; ++i)
+    p[i] = q[i] + q[i];
+  return p;
+}
+
+/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
+/* { dg-final { scan-tree-dump-not "Peeling for alignment will be applied" "vect" } } */
+/* { dg-final { scan-tree-dump-not "Vectorizing an unaligned access" "vect" } } */
+/* { dg-final { cleanup-tree-dump "vect" } } */