[ARC] Save/restore blink when in ISR.

gcc/
2017-03-27  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.c (arc_epilogue_uses): BLINK should be also
	restored when in interrupt.
	* config/arc/arc.md (simple_return): ARCv2 rtie instruction
	doesn't have delay slot.

2017-03-27  Claudiu Zissulescu  <claziss@synopsys.com>

	* testsuite/gcc.target/arc/interrupt-4.c: New file.

From-SVN: r246495

gcc/ChangeLog

+2017-03-27  Claudiu Zissulescu  <claziss@synopsys.com>
+
+	* config/arc/arc.c (arc_epilogue_uses): BLINK should be also
+	restored when in interrupt.
+	* config/arc/arc.md (simple_return): ARCv2 rtie instruction
+	doesn't have delay slot.
+
 2017-03-27  Richard Biener  <rguenther@suse.de>
 
 	PR ipa/79776

gcc/config/arc/arc.c

@@ -9381,9 +9381,10 @@ arc_can_follow_jump (const rtx_insn *follower, const rtx_insn *followee)
    Return true if REGNO should be added to the deemed uses of the epilogue.
 
    We use the return address
-   arc_return_address_regs[arc_compute_function_type (cfun)] .
-   But also, we have to make sure all the register restore instructions
-   are known to be live in interrupt functions.  */
+   arc_return_address_regs[arc_compute_function_type (cfun)].  But
+   also, we have to make sure all the register restore instructions
+   are known to be live in interrupt functions, plus the blink
+   register if it is clobbered by the isr.  */
 
 bool
 arc_epilogue_uses (int regno)
@@ -9396,7 +9397,8 @@ arc_epilogue_uses (int regno)
 	{
 	  if (!fixed_regs[regno])
 	    return true;
-	  return regno == arc_return_address_regs[cfun->machine->fn_type];
+	  return ((regno == arc_return_address_regs[cfun->machine->fn_type])
+		  || (regno == RETURN_ADDR_REGNUM));
 	}
       else
 	return regno == RETURN_ADDR_REGNUM;

gcc/config/arc/arc.md

@@ -4748,7 +4748,12 @@
   output_asm_insn (\"j%!%* [%0]%&\", &reg);
   return \"\";
 }
-  [(set_attr "type" "return")
+  [(set (attr "type")
+	(cond [(and (eq (symbol_ref "arc_compute_function_type (cfun)")
+			(symbol_ref "ARC_FUNCTION_ILINK1"))
+		    (match_test "TARGET_V2"))
+	       (const_string "brcc_no_delay_slot")]
+	      (const_string "return")))
    ; predicable won't help here since the canonical rtl looks different
    ; for branches.
    (set (attr "cond")

gcc/testsuite/ChangeLog

+2017-03-27  Claudiu Zissulescu  <claziss@synopsys.com>
+
+	* testsuite/gcc.target/arc/interrupt-4.c: New file.
+
 2017-03-27  Richard Biener  <rguenther@suse.de>
 
 	PR ipa/79776

gcc/testsuite/gcc.target/arc/interrupt-4.c

+#if defined (__ARCHS__) || defined (__ARCEM__)
+#define RILINK "ilink"
+#else
+#define RILINK "ilink1"
+#endif
+
+extern int gpio_int;
+extern int read_reg (int);
+
+void __attribute__ ((interrupt(RILINK)))
+isr_handler (void)
+{
+  gpio_int = read_reg (1);
+}
+/* { dg-final { scan-assembler-times "blink" 2 } } */