[PATCH] Fix PR66280

[Richard Biener]

In addition to the required backport of PR66251 (testing right now)
we need to fix hybrid stmt detection for trunk and for a related
testcase also on the branch.

Bootstrap and regtest running on x86_64-unknown-linux-gnu.

Richard.

2015-05-29  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/66280
        * tree-vect-slp.c (vect_detect_hybrid_slp_stmts): Fix pattern
        def-use walking.

        * g++.dg/torture/pr66280.C: New testcase.
        * g++.dg/torture/pr66280-2.C: Likewise.

Index: gcc/tree-vect-slp.c
===================================================================
*** gcc/tree-vect-slp.c (revision 223860)
--- gcc/tree-vect-slp.c (working copy)
*************** vect_detect_hybrid_slp_stmts (slp_tree n
*** 2031,2036 ****
--- 2031,2041 ----
      {
        /* Check if a pure SLP stmt has uses in non-SLP stmts.  */
        gcc_checking_assert (PURE_SLP_STMT (stmt_vinfo));
+       /* We always get the pattern stmt here, but for immediate
+        uses we have to use the LHS of the original stmt.  */
+       gcc_checking_assert (!STMT_VINFO_IN_PATTERN_P (stmt_vinfo));
+       if (STMT_VINFO_RELATED_STMT (stmt_vinfo))
+       stmt = STMT_VINFO_RELATED_STMT (stmt_vinfo);
        if (TREE_CODE (gimple_op (stmt, 0)) == SSA_NAME)
        FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, gimple_op (stmt, 0))
          if (gimple_bb (use_stmt)
Index: gcc/testsuite/g++.dg/torture/pr66280.C
===================================================================
*** gcc/testsuite/g++.dg/torture/pr66280.C      (revision 0)
--- gcc/testsuite/g++.dg/torture/pr66280.C      (working copy)
***************
*** 0 ****
--- 1,25 ----
+ // { dg-do compile }
+ 
+ typedef struct
+ {
+   short re;
+   short im;
+ } cint16_T;
+ typedef struct
+ {
+   int re;
+   int im;
+ } cint32_T;
+ int a;
+ short b;
+ cint16_T *c;
+ cint32_T *d, *e;
+ void
+ fn1 ()
+ {
+   for (; a; a++)
+     {
+       d[a].re = d[a].im = e[a].re = c[a].re * b;
+       e[a].im = c[a].im * b;
+     }
+ }
Index: gcc/testsuite/g++.dg/torture/pr66280-2.C
===================================================================
*** gcc/testsuite/g++.dg/torture/pr66280-2.C    (revision 0)
--- gcc/testsuite/g++.dg/torture/pr66280-2.C    (working copy)
***************
*** 0 ****
--- 1,25 ----
+ // { dg-do compile }
+ 
+ typedef struct
+ {
+   short re;
+   short im;
+ } cint16_T;
+ typedef struct
+ {
+   int re;
+   int im;
+ } cint32_T;
+ int a;
+ short b;
+ cint16_T *c;
+ cint32_T *d, *e;
+ void
+ fn1 ()
+ {
+   for (; a; a++)
+     {
+       d[a].re = d[a].im = e[a].im = c[a].im * b;
+       e[a].re = c[a].re * b;
+     }
+ }