[PATCH RFC] gimplefe: expose MULT_HIGHPART_EXPR

[Alexander Monakov]

For testing generic expansion of MULT_HIGHPART_EXPR I chose to expose it
via the GIMPLE FE with the following patch.

"h*" is how tree-pretty-print dumps MULT_HIGHPART_EXPR.

This patch accepts "h<whitespace>*" which ideally shouldn't happen, but
I don't see a simple way to fix that.

Is this desirable for trunk?

Is there general policy for how fancy tree codes should be exposed in
the GIMPLE FE?

        * c/gimple-parser.c (c_parser_gimple_statement): Add "h*" for
        MULT_HIGHPART_EXPR.

diff --git a/gcc/c/gimple-parser.c b/gcc/c/gimple-parser.c
index 1be5d14dc2d..cf05c936166 100644
--- a/gcc/c/gimple-parser.c
+++ b/gcc/c/gimple-parser.c
@@ -450,6 +450,7 @@ c_parser_gimple_statement (c_parser *parser, gimple_seq 
*seq)
 
    gimple-binary-expression:
      gimple-unary-expression * gimple-unary-expression
+     gimple-unary-expression h* gimple-unary-expression
      gimple-unary-expression / gimple-unary-expression
      gimple-unary-expression % gimple-unary-expression
      gimple-unary-expression + gimple-unary-expression
@@ -544,6 +545,18 @@ c_parser_gimple_binary_expression (c_parser *parser)
     case CPP_OR_OR:
       c_parser_error (parser, "%<||%> not valid in GIMPLE");
       return ret;
+    case CPP_NAME:
+       {
+         tree id = c_parser_peek_token (parser)->value;
+         if (strcmp (IDENTIFIER_POINTER (id), "h") == 0
+             && c_parser_peek_2nd_token (parser)->type == CPP_MULT)
+           {
+             c_parser_consume_token (parser);
+             code = MULT_HIGHPART_EXPR;
+             break;
+           }
+       }
+      /* Fallthru.  */
     default:
       /* Not a binary expression.  */
       return lhs;