rs6000: Fix branch_comparison_operator

	* config/rs6000/predicates.md (branch_comparison_operator): Allow only
	the comparison codes that make sense for the mode used, and only the
	codes that can be done with a single branch instruction.

From-SVN: r277976

gcc/ChangeLog

+2019-11-08  Segher Boessenkool  <segher@kernel.crashing.org>
+
+	* config/rs6000/predicates.md (branch_comparison_operator): Allow only
+	the comparison codes that make sense for the mode used, and only the
+	codes that can be done with a single branch instruction.
+
 2019-11-08  Andre Vieira  <andre.simoesdiasvieira@arm.com>
 
 	PR tree-optimization/92351

gcc/config/rs6000/predicates.md

@@ -1134,10 +1134,14 @@
 ;; validate_condition_mode is an assertion.
 (define_predicate "branch_comparison_operator"
    (and (match_operand 0 "comparison_operator")
-	(and (match_test "GET_MODE_CLASS (GET_MODE (XEXP (op, 0))) == MODE_CC")
-	     (match_test "validate_condition_mode (GET_CODE (op),
-						   GET_MODE (XEXP (op, 0))),
-			  1"))))
+	(match_test "GET_MODE_CLASS (GET_MODE (XEXP (op, 0))) == MODE_CC")
+	(if_then_else (match_test "GET_MODE (XEXP (op, 0)) == CCFPmode
+				   && !flag_finite_math_only")
+		      (match_code "lt,gt,eq,unordered,unge,unle,ne,ordered")
+		      (match_code "lt,ltu,le,leu,gt,gtu,ge,geu,eq,ne"))
+	(match_test "validate_condition_mode (GET_CODE (op),
+					      GET_MODE (XEXP (op, 0))),
+		     1")))
 
 ;; Return 1 if OP is an unsigned comparison operator.
 (define_predicate "unsigned_comparison_operator"