[gcc r13-6296] tree-optimization/108888 - call if-conversion

[gcc r13-6296] tree-optimization/108888 - call if-conversion

[Richard Biener]

https://gcc.gnu.org/g:31cc5821223a096ef61743bff520f4a0dbba5872

commit r13-6296-g31cc5821223a096ef61743bff520f4a0dbba5872
Author: Richard Biener <rguenther@suse.de>
Date:   Thu Feb 23 11:03:03 2023 +0100

    tree-optimization/108888 - call if-conversion
    
    The following makes sure to only predicate calls necessary.
    
            PR tree-optimization/108888
            * tree-if-conv.cc (if_convertible_stmt_p): Set PLF_2 on
            calls to predicate.
            (predicate_statements): Only predicate calls with PLF_2.
    
            * g++.dg/torture/pr108888.C: New testcase.

Diff:
---
 gcc/testsuite/g++.dg/torture/pr108888.C | 18 ++++++++++++++++++
 gcc/tree-if-conv.cc                     | 17 ++++++++++-------
 2 files changed, 28 insertions(+), 7 deletions(-)

diff --git a/gcc/testsuite/g++.dg/torture/pr108888.C b/gcc/testsuite/g++.dg/torture/pr108888.C
new file mode 100644
index 00000000000..29a22e21102
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr108888.C
@@ -0,0 +1,18 @@
+// { dg-do compile }
+
+int scaleValueSaturate_scalefactor, scaleValueSaturate___trans_tmp_2,
+    scaleValuesSaturate_i;
+int scaleValueSaturate(int value) {
+  int result = __builtin_clz(value);
+  if (value)
+    if (-result <= scaleValueSaturate_scalefactor)
+      return 0;
+  return scaleValueSaturate___trans_tmp_2;
+}
+short scaleValuesSaturate_dst;
+short *scaleValuesSaturate_src;
+void scaleValuesSaturate() {
+  for (; scaleValuesSaturate_i; scaleValuesSaturate_i++)
+    scaleValuesSaturate_dst =
+        scaleValueSaturate(scaleValuesSaturate_src[scaleValuesSaturate_i]);
+}
diff --git a/gcc/tree-if-conv.cc b/gcc/tree-if-conv.cc
index a7a8406374d..0e384e36394 100644
--- a/gcc/tree-if-conv.cc
+++ b/gcc/tree-if-conv.cc
@@ -1099,6 +1099,7 @@ if_convertible_stmt_p (gimple *stmt, vec<data_reference_p> refs)
 		   n = n->simdclone->next_clone)
 		if (n->simdclone->inbranch)
 		  {
+		    gimple_set_plf (stmt, GF_PLF_2, true);
 		    need_to_predicate = true;
 		    return true;
 		  }
@@ -2541,7 +2542,8 @@ predicate_statements (loop_p loop)
 	      release_defs (stmt);
 	      continue;
 	    }
-	  else if (gimple_plf (stmt, GF_PLF_2))
+	  else if (gimple_plf (stmt, GF_PLF_2)
+		   && is_gimple_assign (stmt))
 	    {
 	      tree lhs = gimple_assign_lhs (stmt);
 	      tree mask;
@@ -2625,13 +2627,14 @@ predicate_statements (loop_p loop)
 	      gimple_assign_set_rhs1 (stmt, ifc_temp_var (type, rhs, &gsi));
 	      update_stmt (stmt);
 	    }
-
-	  /* Convert functions that have a SIMD clone to IFN_MASK_CALL.  This
-	     will cause the vectorizer to match the "in branch" clone variants,
-	     and serves to build the mask vector in a natural way.  */
-	  gcall *call = dyn_cast <gcall *> (gsi_stmt (gsi));
-	  if (call && !gimple_call_internal_p (call))
+	  else if (gimple_plf (stmt, GF_PLF_2)
+		   && is_gimple_call (stmt))
 	    {
+	      /* Convert functions that have a SIMD clone to IFN_MASK_CALL.
+		 This will cause the vectorizer to match the "in branch"
+		 clone variants, and serves to build the mask vector
+		 in a natural way.  */
+	      gcall *call = dyn_cast <gcall *> (gsi_stmt (gsi));
 	      tree orig_fn = gimple_call_fn (call);
 	      int orig_nargs = gimple_call_num_args (call);
 	      auto_vec<tree> args;