[gcc r12-7198] [gimplefe] Add vector_mask attribute to get access to vector bools

[Richard Biener <rguenth@gcc.gnu.org>]

https://gcc.gnu.org/g:ae117af43944101ca47b99b743c85a3c528b4b4f

commit r12-7198-gae117af43944101ca47b99b743c85a3c528b4b4f
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Feb 11 12:43:22 2022 +0100

    [gimplefe] Add vector_mask attribute to get access to vector bools
    
    The following adds __attribute__((vector_mask)) to get access to
    the corresponding mask type for a vector type.  The implementation
    simply uses truth_type_for so creating a mask type that's not
    what the target would choose as canonical, say a AVX2 style one
    when AVX512VL is enabled, is not possible.  It might be possible
    to provide access to that with an optional argument specifying
    the precision of the bool element.  The syntax is as simple as
    
    typedef vector_type mask_type __attribute__((vector_mask));
    
    In theory this allows to create unit testcases for vector
    lowering and ISEL.
    
    2022-02-11  Richard Biener  <rguenther@suse.de>
    
    gcc/c-family/
            * c-attribs.cc (c_common_attribute_table): Add entry for
            vector_mask.
            (handle_vector_mask_attribute): New.
    
    gcc/c/
            * gimple-parser.cc (c_parser_gimple_statement): Properly parse
            VEC_COND_EXPRs.
    
    gcc/testsuite/
            * gcc.dg/gimplefe-48.c: New testcase.

Diff:
---
 gcc/c-family/c-attribs.cc          | 36 ++++++++++++++++++++++++++++++++++++
 gcc/c/gimple-parser.cc             | 12 ++++++++----
 gcc/testsuite/gcc.dg/gimplefe-48.c | 20 ++++++++++++++++++++
 3 files changed, 64 insertions(+), 4 deletions(-)

diff --git a/gcc/c-family/c-attribs.cc b/gcc/c-family/c-attribs.cc
index 4fb5dbd1409..3849dba90b2 100644
--- a/gcc/c-family/c-attribs.cc
+++ b/gcc/c-family/c-attribs.cc
@@ -129,6 +129,8 @@ static tree handle_unavailable_attribute (tree *, tree, tree, int,
 					  bool *);
 static tree handle_vector_size_attribute (tree *, tree, tree, int,
 					  bool *) ATTRIBUTE_NONNULL(3);
+static tree handle_vector_mask_attribute (tree *, tree, tree, int,
+					  bool *) ATTRIBUTE_NONNULL(3);
 static tree handle_nonnull_attribute (tree *, tree, tree, int, bool *);
 static tree handle_nonstring_attribute (tree *, tree, tree, int, bool *);
 static tree handle_nothrow_attribute (tree *, tree, tree, int, bool *);
@@ -417,6 +419,8 @@ const struct attribute_spec c_common_attribute_table[] =
 			      handle_unavailable_attribute, NULL },
   { "vector_size",	      1, 1, false, true, false, true,
 			      handle_vector_size_attribute, NULL },
+  { "vector_mask",	      0, 0, false, true, false, true,
+			      handle_vector_mask_attribute, NULL },
   { "visibility",	      1, 1, false, false, false, false,
 			      handle_visibility_attribute, NULL },
   { "tls_model",	      1, 1, true,  false, false, false,
@@ -4419,6 +4423,38 @@ handle_vector_size_attribute (tree *node, tree name, tree args,
   return NULL_TREE;
 }
 
+/* Handle a "vector_mask" attribute; arguments as in
+   struct attribute_spec.handler.  */
+
+static tree
+handle_vector_mask_attribute (tree *node, tree name, tree,
+			      int ARG_UNUSED (flags),
+			      bool *no_add_attrs)
+{
+  *no_add_attrs = true;
+  if (!flag_gimple)
+    {
+      warning (OPT_Wattributes, "%qE attribute ignored", name);
+      return NULL_TREE;
+    }
+
+  /* Determine the "base" type to apply the attribute to.  */
+  tree type = type_for_vector_size (*node);
+  if (!VECTOR_TYPE_P (type) || VECTOR_BOOLEAN_TYPE_P (type))
+    {
+      warning (OPT_Wattributes, "%qE attribute only supported on "
+	       "non-mask vector types", name);
+      return NULL_TREE;
+    }
+
+  tree new_type = truth_type_for (type);
+
+  /* Build back pointers if needed.  */
+  *node = lang_hooks.types.reconstruct_complex_type (*node, new_type);
+
+  return NULL_TREE;
+}
+
 /* Handle the "nonnull" attribute.  */
 
 static tree
diff --git a/gcc/c/gimple-parser.cc b/gcc/c/gimple-parser.cc
index 51ddd86f23a..31075237c98 100644
--- a/gcc/c/gimple-parser.cc
+++ b/gcc/c/gimple-parser.cc
@@ -860,9 +860,10 @@ c_parser_gimple_statement (gimple_parser &parser, gimple_seq *seq)
   if (lhs.value != error_mark_node
       && rhs.value != error_mark_node)
     {
-      /* If we parsed a comparison and the next token is a '?' then
-         parse a conditional expression.  */
-      if (COMPARISON_CLASS_P (rhs.value)
+      /* If we parsed a comparison or an identifier and the next token
+	 is a '?' then parse a conditional expression.  */
+      if ((COMPARISON_CLASS_P (rhs.value)
+	   || SSA_VAR_P (rhs.value))
 	  && c_parser_next_token_is (parser, CPP_QUERY))
 	{
 	  struct c_expr trueval, falseval;
@@ -874,7 +875,10 @@ c_parser_gimple_statement (gimple_parser &parser, gimple_seq *seq)
 	  if (trueval.value == error_mark_node
 	      || falseval.value == error_mark_node)
 	    return;
-	  rhs.value = build3_loc (loc, COND_EXPR, TREE_TYPE (trueval.value),
+	  rhs.value = build3_loc (loc,
+				  VECTOR_TYPE_P (TREE_TYPE (rhs.value))
+				  ? VEC_COND_EXPR : COND_EXPR,
+				  TREE_TYPE (trueval.value),
 				  rhs.value, trueval.value, falseval.value);
 	}
       if (get_gimple_rhs_class (TREE_CODE (rhs.value)) == GIMPLE_INVALID_RHS)
diff --git a/gcc/testsuite/gcc.dg/gimplefe-48.c b/gcc/testsuite/gcc.dg/gimplefe-48.c
new file mode 100644
index 00000000000..1399cc9d79a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/gimplefe-48.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fgimple -Wno-psabi -w" } */
+/* { dg-additional-options "-mavx2" { target x86_64-*-* i?86-*-* } } */
+
+typedef int v8si __attribute__((vector_size(8*sizeof(int))));
+typedef v8si v8sib __attribute__((vector_mask));
+
+v8si res;
+
+void __GIMPLE (ssa) foo (v8si v1, v8si v2, v8si v3, v8si v4)
+{
+  v8sib tem;
+  v8si resr;
+
+__BB(2):
+  tem_3 = v1_1(D) <= v2_2(D);
+  resr_4 = tem_3 ? v3_5(D) : v4_6(D);
+  res = resr_4;
+  return;
+}