[4.3 PATCH] Fix vector x = y = (vectortype) { ... } (PR tree-optimization/36991)

[Jakub Jelinek]

Hi!

On the 4.3 branch when gimplify_init_constructor is called with MODIFY_EXPR
and want_value is true (e.g. when the result of assignment is assigned to
another var), gimplify_init_constructor appends the MODIFY_EXPR to pre_p,
which means it is never converted to GIMPLE_MODIFY_STMT.
On the trunk this problem obviously doesn't exist after tuples merge ;)

Will commit after bootstrap/regtesting it (+ testcase to the trunk too).

2008-08-01  Jakub Jelinek  <jakub@redhat.com>

	PR tree-optimization/36991
	* gimplify.c (gimplify_init_constructor): Call tree_to_gimple_tuple
	on expr_p before appending it to pre_p.

	* gcc.dg/pr36991.c: New test.

--- gcc/gimplify.c.jj	2008-06-06 21:26:14.000000000 +0200
+++ gcc/gimplify.c	2008-08-01 15:51:55.000000000 +0200
@@ -3044,6 +3044,8 @@ zero_sized_type (const_tree type)
   return false;
 }
 
+static void tree_to_gimple_tuple (tree *);
+
 /* A subroutine of gimplify_init_constructor.  Generate individual
    MODIFY_EXPRs for a CONSTRUCTOR.  OBJECT is the LHS against which the
    assignments should happen.  ELTS is the CONSTRUCTOR_ELTS of the
@@ -3452,6 +3454,8 @@ gimplify_init_constructor (tree *expr_p,
     return GS_ERROR;
   else if (want_value)
     {
+      tree_to_gimple_tuple (expr_p);
+
       append_to_statement_list (*expr_p, pre_p);
       *expr_p = object;
       return GS_OK;
--- gcc/testsuite/gcc.dg/pr36991.c.jj	2008-08-01 16:02:55.000000000 +0200
+++ gcc/testsuite/gcc.dg/pr36991.c	2008-08-01 16:02:35.000000000 +0200
@@ -0,0 +1,12 @@
+/* PR tree-optimization/36991 */
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+typedef float V __attribute__ ((vector_size (16)));
+typedef union { V v[4][4]; } U;
+
+void
+foo (float x, float y, U *z)
+{
+  z->v[1][0] = z->v[0][1] = (V) { x, y, 0, 0 };
+}

	Jakub