Re: [PATCH, PR tree-optimization/68327] Compute vectype for live phi nodes when copmputing VF

[Ilya Enkovich <enkovich dot gnu at gmail dot com>]

On 20 Nov 14:31, Ilya Enkovich wrote:
> 2015-11-20 14:28 GMT+03:00 Richard Biener <richard.guenther@gmail.com>:
> > On Wed, Nov 18, 2015 at 2:53 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
> >> 2015-11-18 16:44 GMT+03:00 Richard Biener <richard.guenther@gmail.com>:
> >>> On Wed, Nov 18, 2015 at 12:34 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
> >>>> Hi,
> >>>>
> >>>> When we compute vectypes we skip non-relevant phi nodes.  But we process non-relevant alive statements and thus may need vectype of non-relevant live phi node to compute mask vectype.  This patch enables vectype computation for live phi nodes.  Botostrapped and regtested on x86_64-unknown-linux-gnu.  OK for trunk?
> >>>
> >>> Hmm.  What breaks if you instead skip all !relevant stmts and not
> >>> compute vectype for life but not relevant ones?  We won't ever
> >>> "vectorize" !relevant ones, that is, we don't need their vector type.
> >>
> >> I tried it and got regression in SLP.  It expected non-null vectype
> >> for non-releveant but live statement. Regression was in
> >> gcc/gcc/testsuite/gfortran.fortran-torture/execute/pr43390.f90
> >
> > Because somebody put a vector type check before
> >
> >   if (!STMT_VINFO_RELEVANT_P (stmt_info) && !bb_vinfo)
> >     return false;
> >
> > @@ -7590,6 +7651,9 @@ vectorizable_comparison (gimple *stmt, g
> >    tree mask_type;
> >    tree mask;
> >
> > +  if (!STMT_VINFO_RELEVANT_P (stmt_info) && !bb_vinfo)
> > +    return false;
> > +
> >    if (!VECTOR_BOOLEAN_TYPE_P (vectype))
> >      return false;
> >
> > @@ -7602,8 +7666,6 @@ vectorizable_comparison (gimple *stmt, g
> >      ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
> >
> >    gcc_assert (ncopies >= 1);
> > -  if (!STMT_VINFO_RELEVANT_P (stmt_info) && !bb_vinfo)
> > -    return false;
> >
> >    if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def
> >        && !(STMT_VINFO_DEF_TYPE (stmt_info) == vect_nested_cycle
> >
> > fixes this particular fallout for me.
> 
> I'll try it.

With this fix it works fine, thanks!  Bootstrapped and regtested on x86_64-unknown-linux-gnu.  OK for trunk?

Ilya
--
gcc/

2015-11-20  Ilya Enkovich  <enkovich.gnu@gmail.com>
	    Richard Biener  <rguenther@suse.de>

	* tree-vect-loop.c (vect_determine_vectorization_factor): Don't
	compute vectype for non-relevant mask producers.
	* gcc/tree-vect-stmts.c (vectorizable_comparison): Check stmt
	relevance earlier.

gcc/testsuite/

2015-11-20  Ilya Enkovich  <enkovich.gnu@gmail.com>

	* gcc.dg/pr68327.c: New test.


diff --git a/gcc/testsuite/gcc.dg/pr68327.c b/gcc/testsuite/gcc.dg/pr68327.c
new file mode 100644
index 0000000..c3e6a94
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr68327.c
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O3" } */
+
+int a, d;
+char b, c;
+
+void
+fn1 ()
+{
+  int i = 0;
+  for (; i < 1; i++)
+    d = 1;
+  for (; b; b++)
+    a = 1 && (d & b);
+}
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index 80937ec..592372d 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -439,7 +439,8 @@ vect_determine_vectorization_factor (loop_vec_info loop_vinfo)
 		 compute a factor.  */
 	      if (TREE_CODE (scalar_type) == BOOLEAN_TYPE)
 		{
-		  mask_producers.safe_push (stmt_info);
+		  if (STMT_VINFO_RELEVANT_P (stmt_info))
+		    mask_producers.safe_push (stmt_info);
 		  bool_result = true;
 
 		  if (gimple_code (stmt) == GIMPLE_ASSIGN
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 0f64aaf..3723b26 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -7546,6 +7546,9 @@ vectorizable_comparison (gimple *stmt, gimple_stmt_iterator *gsi,
   tree mask_type;
   tree mask;
 
+  if (!STMT_VINFO_RELEVANT_P (stmt_info) && !bb_vinfo)
+    return false;
+
   if (!VECTOR_BOOLEAN_TYPE_P (vectype))
     return false;
 
@@ -7558,9 +7561,6 @@ vectorizable_comparison (gimple *stmt, gimple_stmt_iterator *gsi,
     ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
 
   gcc_assert (ncopies >= 1);
-  if (!STMT_VINFO_RELEVANT_P (stmt_info) && !bb_vinfo)
-    return false;
-
   if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def
       && !(STMT_VINFO_DEF_TYPE (stmt_info) == vect_nested_cycle
 	   && reduc_def))