RISC-V: Fix interrupt support for -g.

	gcc/
	* config/riscv/riscv.c (riscv_expand_epilogue): Use emit_jump_insn
	instead of emit_insn for interrupt returns.
	* config/riscv/riscv.md (riscv_met): Add (return) to rtl.
	(riscv_sret, riscv_uret): Likewise.

	gcc/testsuite/
	* gcc.target/riscv/interrupt-debug.c: New.

From-SVN: r262327

gcc/ChangeLog

+2018-07-02  Jim Wilson  <jimw@sifive.com>
+
+	* config/riscv/riscv.c (riscv_expand_epilogue): Use emit_jump_insn
+	instead of emit_insn for interrupt returns.
+	* config/riscv/riscv.md (riscv_met): Add (return) to rtl.
+	(riscv_sret, riscv_uret): Likewise.
+
 2018-07-02  David Malcolm  <dmalcolm@redhat.com>
 
 	* pretty-print.c (selftest::test_pp_format): Move save and restore

gcc/config/riscv/riscv.c

@@ -3985,11 +3985,11 @@ riscv_expand_epilogue (int style)
       enum riscv_privilege_levels mode = cfun->machine->interrupt_mode;
 
       if (mode == MACHINE_MODE)
-	emit_insn (gen_riscv_mret ());
+	emit_jump_insn (gen_riscv_mret ());
       else if (mode == SUPERVISOR_MODE)
-	emit_insn (gen_riscv_sret ());
+	emit_jump_insn (gen_riscv_sret ());
       else
-	emit_insn (gen_riscv_uret ());
+	emit_jump_insn (gen_riscv_uret ());
     }
   else if (style != SIBCALL_RETURN)
     emit_jump_insn (gen_simple_return_internal (ra));

gcc/config/riscv/riscv.md

@@ -2328,17 +2328,20 @@
   "fsflags\t%0")
 
 (define_insn "riscv_mret"
-  [(unspec_volatile [(const_int 0)] UNSPECV_MRET)]
+  [(return)
+   (unspec_volatile [(const_int 0)] UNSPECV_MRET)]
   ""
   "mret")
 
 (define_insn "riscv_sret"
-  [(unspec_volatile [(const_int 0)] UNSPECV_SRET)]
+  [(return)
+   (unspec_volatile [(const_int 0)] UNSPECV_SRET)]
   ""
   "sret")
 
 (define_insn "riscv_uret"
-  [(unspec_volatile [(const_int 0)] UNSPECV_URET)]
+  [(return)
+   (unspec_volatile [(const_int 0)] UNSPECV_URET)]
   ""
   "uret")
 

gcc/testsuite/ChangeLog

+2018-07-02  Jim Wilson  <jimw@sifive.com>
+
+	* gcc.target/riscv/interrupt-debug.c: New.
+
 2018-07-02  Paolo Carlini  <paolo.carlini@oracle.com>
 
 	* g++.dg/diagnostic/thread-thread_local.C: New.

gcc/testsuite/gcc.target/riscv/interrupt-debug.c

+/* Verify that we can compile with debug info.  */
+/* { dg-do compile } */
+/* { dg-options "-Og -g" } */
+extern int var1;
+extern int var2;
+extern void sub2 (void);
+
+void __attribute__ ((interrupt))
+sub (void)
+{
+  if (var1)
+    var2 = 0;
+  else
+    sub2 ();
+}