sched-deps: respect deps->readonly in macro-fusion (PR 84566)

	PR rtl-optimization/84566
	* sched-deps.c (sched_analyze_insn): Check deps->readonly when invoking
	sched_macro_fuse_insns.

From-SVN: r259322

gcc/ChangeLog

 2018-04-11  Alexander Monakov  <amonakov@ispras.ru>
 
+	PR rtl-optimization/84566
+	* sched-deps.c (sched_analyze_insn): Check deps->readonly when invoking
+	sched_macro_fuse_insns.
+
+2018-04-11  Alexander Monakov  <amonakov@ispras.ru>
+
 	PR target/84301
 	* sched-rgn.c (add_branch_dependences): Move sel_sched_p check here...
 	(compute_block_dependences): ... from here.

gcc/sched-deps.c

@@ -2897,7 +2897,8 @@ sched_analyze_insn (struct deps_desc *deps, rtx x, rtx_insn *insn)
 			 && code == SET);
 
   /* Group compare and branch insns for macro-fusion.  */
-  if (targetm.sched.macro_fusion_p
+  if (!deps->readonly
+      && targetm.sched.macro_fusion_p
       && targetm.sched.macro_fusion_p ())
     sched_macro_fuse_insns (insn);