Add LTGT operator support for amdgcn

Fixes ICE in testcase gcc.dg/pr81228.c

2020-01-30  Andrew Stubbs  <ams@codesourcery.com>

	gcc/
	* config/gcn/gcn.c (print_operand): Handle LTGT.
	* config/gcn/predicates.md (gcn_fp_compare_operator): Allow ltgt.

gcc/ChangeLog

+2020-01-30  Andrew Stubbs  <ams@codesourcery.com>
+
+	* config/gcn/gcn.c (print_operand): Handle LTGT.
+	* config/gcn/predicates.md (gcn_fp_compare_operator): Allow ltgt.
+
 2020-01-30  Richard Biener  <rguenther@suse.de>
 
 	* tree-pretty-print.c (dump_generic_node): Wrap VECTOR_CST

gcc/config/gcn/gcn.c

@@ -5929,6 +5929,9 @@ print_operand (FILE *file, rtx x, int code)
 	  case UNORDERED:
 	    s = "_u_";
 	    break;
+	  case LTGT:
+	    s = "_lg_";
+	    break;
 	  default:
 	    output_operand_lossage ("invalid %%xn code");
 	    return;

gcc/config/gcn/predicates.md

@@ -165,7 +165,7 @@
   (match_code "eq,ne,gt,ge,lt,le,gtu,geu,ltu,leu"))
 
 (define_predicate "gcn_fp_compare_operator"
-  (match_code "eq,ne,gt,ge,lt,le,gtu,geu,ltu,leu,ordered,unordered"))
+  (match_code "eq,ne,gt,ge,lt,le,gtu,geu,ltu,leu,ordered,unordered,ltgt"))
 
 (define_predicate "unary_operator"
   (match_code "not,popcount"))