Fix OMP SIMD clone mask register and query

The following removes the confusion around num_mask_args that was
added to properly "guess" the number of mask elements in a AVX512
mask that's just represented as int.  The actual mistake lies in
the mixup of 'ncopies' which is used to track the number of
OMP SIMD calls to be emitted rather than the number of input
vectors.  So this reverts the earlier r16-5374-g5c2fdfc24e343c,
uses the proper 'ncopies' for loop mask record/query and adjusts
the guessing of the SIMD arg mask elements.

	PR tree-optimization/122762
	PR tree-optimization/122736
	PR tree-optimization/122790
	* cgraph.h (cgraph_simd_clone_arg::linear_step): Document
	use for SIMD_CLONE_ARG_TYPE_MASK.
	* omp-simd-clone.cc (simd_clone_adjust_argument_types):
	Record the number of mask arguments in linear_step if
	mask_mode is not VOIDmode.
	* tree-vect-stmts.cc (vectorizable_simd_clone_call):
	Remove num_mask_args computation, use a proper ncopies
	to query/register loop masks, use linear_step for the
	number of mask arguments when determining the number of
	mask elements in a mask argument.

	* gcc.dg/vect/vect-simd-clone-23.c: New testcase.

gcc/cgraph.h

@@ -805,7 +805,9 @@ struct GTY(()) cgraph_simd_clone_arg {
   /* For arg_type SIMD_CLONE_ARG_TYPE_LINEAR_*CONSTANT_STEP this is
      the constant linear step, if arg_type is
      SIMD_CLONE_ARG_TYPE_LINEAR_*VARIABLE_STEP, this is index of
-     the uniform argument holding the step, otherwise 0.  */
+     the uniform argument holding the step, otherwise 0.
+     For arg_type SIMD_CLONE_ARG_TYPE_MASK and a mask_mode that is
+     not VOIDmode, this is the number of mask arguments.  */
   HOST_WIDE_INT linear_step;
 };
 

gcc/omp-simd-clone.cc

@@ -892,6 +892,10 @@ simd_clone_adjust_argument_types (struct cgraph_node *node)
       sc->args[i].orig_type = base_type;
       sc->args[i].arg_type = SIMD_CLONE_ARG_TYPE_MASK;
       sc->args[i].vector_type = mask_type;
+      /* Record the number of mask copies when that is difficult to
+	 compute.  */
+      if (sc->mask_mode != VOIDmode)
+	sc->args[i].linear_step = k;
     }
 
   if (!node->definition)

gcc/testsuite/gcc.dg/vect/vect-simd-clone-23.c

@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target vect_simd_clones } */
+/* { dg-additional-options "-fopenmp-simd" } */
+/* { dg-additional-options "-mavx512bw" { target avx512bw } } */
+
+#pragma omp declare simd simdlen(32) inbranch
+int __attribute__((const)) baz (int x);
+
+short a[1024];
+
+void __attribute__((noipa))
+foo (int n, int * __restrict b)
+{
+  for (int i = 0; i < n; ++i)
+    if (a[i])
+      b[i] = baz (b[i]);
+}

gcc/tree-vect-stmts.cc

@@ -4055,7 +4055,7 @@ vectorizable_simd_clone_call (vec_info *vinfo, stmt_vec_info stmt_info,
   bb_vec_info bb_vinfo = dyn_cast <bb_vec_info> (vinfo);
   class loop *loop = loop_vinfo ? LOOP_VINFO_LOOP (loop_vinfo) : NULL;
   tree fndecl, new_temp;
-  int ncopies, j;
+  int j;
   auto_vec<simd_call_arg_info> arginfo;
   vec<tree> vargs = vNULL;
   size_t i, nargs;
@@ -4211,6 +4211,8 @@ vectorizable_simd_clone_call (vec_info *vinfo, stmt_vec_info stmt_info,
 	  && TREE_CODE (op) == SSA_NAME)
 	vect_simd_lane_linear (op, loop, &thisarginfo);
 
+      if (!vectype)
+	vectype = thisarginfo.vectype;
       arginfo.quick_push (thisarginfo);
     }
 
@@ -4339,13 +4341,6 @@ vectorizable_simd_clone_call (vec_info *vinfo, stmt_vec_info stmt_info,
   if (bestn == NULL)
     return false;
 
-  unsigned int num_mask_args = 0;
-  for (i = 0; i < bestn->simdclone->nargs; i++)
-    if (bestn->simdclone->args[i].arg_type == SIMD_CLONE_ARG_TYPE_MASK)
-      num_mask_args++;
-  if (!SCALAR_INT_MODE_P (bestn->simdclone->mask_mode))
-    gcc_assert (num_mask_args <= 1);
-
   for (i = 0; i < nargs; i++)
     {
       if ((arginfo[i].dt == vect_constant_def
@@ -4403,7 +4398,7 @@ vectorizable_simd_clone_call (vec_info *vinfo, stmt_vec_info stmt_info,
 	    {
 	      if (!SCALAR_INT_MODE_P (TYPE_MODE (arginfo[i].vectype))
 		  || maybe_ne (exact_div (bestn->simdclone->simdlen,
-					  num_mask_args),
+					  bestn->simdclone->args[i].linear_step),
 			       TYPE_VECTOR_SUBPARTS (arginfo[i].vectype)))
 		{
 		  /* FORNOW we only have partial support for integer-type masks
@@ -4431,7 +4426,7 @@ vectorizable_simd_clone_call (vec_info *vinfo, stmt_vec_info stmt_info,
 
   fndecl = bestn->decl;
   nunits = bestn->simdclone->simdlen;
-  ncopies = vector_unroll_factor (vf * group_size, nunits);
+  int ncopies = vector_unroll_factor (vf * group_size, nunits);
 
   /* If the function isn't const, only allow it in simd loops where user
      has asserted that at least nunits consecutive iterations can be
@@ -4440,6 +4435,11 @@ vectorizable_simd_clone_call (vec_info *vinfo, stmt_vec_info stmt_info,
       && gimple_vuse (stmt))
     return false;
 
+  /* ncopies is the number of SIMD clone calls we create, since simdlen
+     is not necessarily matching nunits of the vector types used, track
+     that in ncopies_in.  */
+  int ncopies_in = vect_get_num_vectors (vf * group_size, vectype);
+
   /* Sanity check: make sure that at least one copy of the vectorized stmt
      needs to be generated.  */
   gcc_assert (ncopies >= 1);
@@ -4491,20 +4491,9 @@ vectorizable_simd_clone_call (vec_info *vinfo, stmt_vec_info stmt_info,
 	    case SIMD_CLONE_ARG_TYPE_MASK:
 	      if (loop_vinfo
 		  && LOOP_VINFO_CAN_USE_PARTIAL_VECTORS_P (loop_vinfo))
-		{
-		  tree arg_vectype;
-		  if (SCALAR_INT_MODE_P
-			(TYPE_MODE (bestn->simdclone->args[i].vector_type)))
-		    arg_vectype = build_truth_vector_type_for_mode
-			(exact_div (bestn->simdclone->simdlen, num_mask_args),
-			 TYPE_MODE (bestn->simdclone->args[i].vector_type));
-		  else
-		    arg_vectype = bestn->simdclone->args[i].vector_type;
-		  vect_record_loop_mask (loop_vinfo,
-					 &LOOP_VINFO_MASKS (loop_vinfo),
-					 ncopies * num_mask_args, arg_vectype,
-					 op);
-		}
+		vect_record_loop_mask (loop_vinfo,
+				       &LOOP_VINFO_MASKS (loop_vinfo),
+				       ncopies_in, vectype, op);
 	      break;
 	    }
 	}
@@ -4694,7 +4683,7 @@ vectorizable_simd_clone_call (vec_info *vinfo, stmt_vec_info stmt_info,
 				= &LOOP_VINFO_MASKS (loop_vinfo);
 			      tree loop_mask
 				= vect_get_loop_mask (loop_vinfo, gsi,
-						      loop_masks, ncopies,
+						      loop_masks, ncopies_in,
 						      vectype, j);
 			      vec_oprnd0
 				= prepare_vec_mask (loop_vinfo,
@@ -4728,11 +4717,10 @@ vectorizable_simd_clone_call (vec_info *vinfo, stmt_vec_info stmt_info,
 	      else if (SCALAR_INT_MODE_P (bestn->simdclone->mask_mode))
 		{
 		  atype = bestn->simdclone->args[i].vector_type;
-		  /* Guess the number of lanes represented by atype.  */
 		  poly_uint64 atype_subparts
 		    = exact_div (bestn->simdclone->simdlen,
-				 num_mask_args);
-		  o = vector_unroll_factor (nunits, atype_subparts);
+				 bestn->simdclone->args[i].linear_step);
+		  o = bestn->simdclone->args[i].linear_step;
 		  for (m = j * o; m < (j + 1) * o; m++)
 		    {
 		      if (m == 0)
@@ -4756,7 +4744,7 @@ vectorizable_simd_clone_call (vec_info *vinfo, stmt_vec_info stmt_info,
 				= &LOOP_VINFO_MASKS (loop_vinfo);
 			      tree loop_mask
 				= vect_get_loop_mask (loop_vinfo, gsi,
-						      loop_masks, ncopies,
+						      loop_masks, ncopies_in,
 						      vectype, j);
 			      vec_oprnd0
 				= prepare_vec_mask (loop_vinfo,