Extend is_cond_scalar_reduction to handle bit_and/bit_xor/bit_ior.

This will enable transformation like

-  # sum1_50 = PHI <prephitmp_64(13), 0(4)>
-  # sum2_52 = PHI <sum2_21(13), 0(4)>
+  # sum1_50 = PHI <_87(13), 0(4)>
+  # sum2_52 = PHI <_89(13), 0(4)>
   # ivtmp_62 = PHI <ivtmp_61(13), 64(4)>
   i.2_7 = (long unsigned int) i_49;
   _8 = i.2_7 * 8;
...
   vec1_i_38 = vec1_29 >> _10;
   vec2_i_39 = vec2_31 >> _10;
   _11 = vec1_i_38 & 1;
-  _63 = tmp_37 ^ sum1_50;
-  prephitmp_64 = _11 == 0 ? sum1_50 : _63;
+  _ifc__86 = _11 != 0 ? tmp_37 : 0;
+  _87 = sum1_50 ^ _ifc__86;
   _12 = vec2_i_39 & 1;
:

so that vectorizer won't failed due to

  /* If this isn't a nested cycle or if the nested cycle reduction value
     is used ouside of the inner loop we cannot handle uses of the reduction
     value.  */
  if (nlatch_def_loop_uses > 1 || nphi_def_loop_uses > 1)
    {
      if (dump_enabled_p ())
	dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
			 "reduction used in loop.\n");
      return NULL;
    }

gcc/ChangeLog:

	PR tree-optimization/103126
	* tree-vect-loop.c (neutral_op_for_reduction): Remove static.
	* tree-vectorizer.h (neutral_op_for_reduction): Declare.
	* tree-if-conv.c : Include tree-vectorizer.h.
	(is_cond_scalar_reduction): Handle
	BIT_XOR_EXPR/BIT_IOR_EXPR/BIT_AND_EXPR.
	(convert_scalar_cond_reduction): Ditto.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/ifcvt-reduction-logic-op.c: New test.

1 files changed, 13 insertions, 7 deletions

diff --git a/gcc/tree-if-conv.c b/gcc/tree-if-conv.c
index b165dc0..e88ddc9 100644
--- a/gcc/tree-if-conv.c
+++ b/gcc/tree-if-conv.c
@@ -120,6 +120,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa-sccvn.h"
 #include "tree-cfgcleanup.h"
 #include "tree-ssa-dse.h"
+#include "tree-vectorizer.h"
 
 /* Only handle PHIs with no more arguments unless we are asked to by
    simd pragma.  */
@@ -1732,7 +1733,11 @@ is_cond_scalar_reduction (gimple *phi, gimple **reduc, tree arg_0, tree arg_1,
       reduction_op = gimple_assign_rhs_code (stmt);
     }
 
-  if (reduction_op != PLUS_EXPR && reduction_op != MINUS_EXPR)
+  if (reduction_op != PLUS_EXPR
+      && reduction_op != MINUS_EXPR
+      && reduction_op != BIT_IOR_EXPR
+      && reduction_op != BIT_XOR_EXPR
+      && reduction_op != BIT_AND_EXPR)
     return false;
   r_op1 = gimple_assign_rhs1 (stmt);
   r_op2 = gimple_assign_rhs2 (stmt);
@@ -1742,7 +1747,7 @@ is_cond_scalar_reduction (gimple *phi, gimple **reduc, tree arg_0, tree arg_1,
 
   /* Make R_OP1 to hold reduction variable.  */
   if (r_nop2 == PHI_RESULT (header_phi)
-      && reduction_op == PLUS_EXPR)
+      && commutative_tree_code (reduction_op))
     {
       std::swap (r_op1, r_op2);
       std::swap (r_nop1, r_nop2);
@@ -1811,7 +1816,8 @@ convert_scalar_cond_reduction (gimple *reduc, gimple_stmt_iterator *gsi,
   tree rhs1 = gimple_assign_rhs1 (reduc);
   tree tmp = make_temp_ssa_name (TREE_TYPE (rhs1), NULL, "_ifc_");
   tree c;
-  tree zero = build_zero_cst (TREE_TYPE (rhs1));
+  enum tree_code reduction_op  = gimple_assign_rhs_code (reduc);
+  tree op_nochange = neutral_op_for_reduction (TREE_TYPE (rhs1), reduction_op, NULL);
   gimple_seq stmts = NULL;
 
   if (dump_file && (dump_flags & TDF_DETAILS))
@@ -1824,14 +1830,14 @@ convert_scalar_cond_reduction (gimple *reduc, gimple_stmt_iterator *gsi,
      of reduction rhs.  */
   c = fold_build_cond_expr (TREE_TYPE (rhs1),
 			    unshare_expr (cond),
-			    swap ? zero : op1,
-			    swap ? op1 : zero);
+			    swap ? op_nochange : op1,
+			    swap ? op1 : op_nochange);
 
   /* Create assignment stmt and insert it at GSI.  */
   new_assign = gimple_build_assign (tmp, c);
   gsi_insert_before (gsi, new_assign, GSI_SAME_STMT);
-  /* Build rhs for unconditional increment/decrement.  */
-  rhs = gimple_build (&stmts, gimple_assign_rhs_code (reduc),
+  /* Build rhs for unconditional increment/decrement/logic_operation.  */
+  rhs = gimple_build (&stmts, reduction_op,
 		      TREE_TYPE (rhs1), op0, tmp);
 
   if (has_nop)