backport: re PR target/61055 ([avr] wrong test instruction after increment with -O1)

gcc/
	Backport from 2014-05-09 trunk r210267
	PR target/61055
	* config/avr/avr.md (cc): Add new attribute set_vzn.
	(addqi3, negqi2) [cc]:
	Set cc insn attribute to set_vzn instead of set_zn for alternatives
	with INC, DEC or NEG.
	* config/avr/avr.c (avr_notice_update_cc): Handle SET_VZN.
	(avr_out_plus_1): ADIW sets cc0 to CC_SET_CZN.
	INC, DEC set cc0 to CC_CLOBBER.

gcc/testsuite/
	Backport from 2014-05-09 trunk r210267
	PR target/61055
	* gcc.target/avr/torture/pr61055.c: New test.

From-SVN: r210270

gcc/ChangeLog

@@ -1,3 +1,16 @@
+2014-05-09  Georg-Johann Lay  <avr@gjlay.de>
+
+	Backport from 2014-05-09 trunk r210267
+
+	PR target/61055
+	* config/avr/avr.md (cc): Add new attribute set_vzn.
+	(addqi3, negqi2) [cc]:
+	Set cc insn attribute to set_vzn instead of set_zn for alternatives
+	with INC, DEC or NEG.
+	* config/avr/avr.c (avr_notice_update_cc): Handle SET_VZN.
+	(avr_out_plus_1): ADIW sets cc0 to CC_SET_CZN.
+	INC, DEC set cc0 to CC_CLOBBER.
+
 2014-05-08  Charles Baylis  <charles.baylis@linaro.org>
 
 	Backport from mainline

gcc/config/avr/avr.c

@@ -2175,6 +2175,12 @@ notice_update_cc (rtx body ATTRIBUTE_UNUSED, rtx insn)
 	}
       break;
 
+    case CC_SET_VZN:
+      /* Insn like INC, DEC, NEG that set Z,N,V.  We currently don't make use
+         of this combination, cf. also PR61055.  */
+      CC_STATUS_INIT;
+      break;
+
     case CC_SET_CZN:
       /* Insn sets the Z,N,C flags of CC to recog_operand[0].
          The V flag may or may not be known but that's ok because
@@ -5949,7 +5955,7 @@ avr_out_plus_1 (rtx *xop, int *plen, enum rtx_code code, int *pcc)
                                op, plen, 1);
 
                   if (n_bytes == 2 && PLUS == code)
-                      *pcc = CC_SET_ZN;
+                      *pcc = CC_SET_CZN;
                 }
 
               i++;
@@ -5971,6 +5977,7 @@ avr_out_plus_1 (rtx *xop, int *plen, enum rtx_code code, int *pcc)
         {
           avr_asm_len ((code == PLUS) ^ (val8 == 1) ? "dec %0" : "inc %0",
                        op, plen, 1);
+          *pcc = CC_CLOBBER;
           break;
         }
 

gcc/config/avr/avr.md

@@ -90,7 +90,7 @@
 (include "constraints.md")
   
 ;; Condition code settings.
-(define_attr "cc" "none,set_czn,set_zn,set_n,compare,clobber,
+(define_attr "cc" "none,set_czn,set_vzn,set_zn,set_n,compare,clobber,
                    out_plus, out_plus_noclobber,ldi"
   (const_string "none"))
 
@@ -1056,7 +1056,7 @@
 	inc %0\;inc %0
 	dec %0\;dec %0"
   [(set_attr "length" "1,1,1,1,2,2")
-   (set_attr "cc" "set_czn,set_czn,set_zn,set_zn,set_zn,set_zn")])
+   (set_attr "cc" "set_czn,set_czn,set_vzn,set_vzn,set_vzn,set_vzn")])
 
 
 (define_expand "addhi3"
@@ -3876,7 +3876,7 @@
   ""
   "neg %0"
   [(set_attr "length" "1")
-   (set_attr "cc" "set_zn")])
+   (set_attr "cc" "set_vzn")])
 
 (define_insn "*negqihi2"
   [(set (match_operand:HI 0 "register_operand"                        "=r")

gcc/testsuite/ChangeLog

@@ -1,3 +1,10 @@
+2014-05-09  Georg-Johann Lay  <avr@gjlay.de>
+
+	Backport from 2014-05-09 trunk r210267
+
+	PR target/61055
+	* gcc.target/avr/torture/pr61055.c: New test.
+
 2014-05-07  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline

gcc/testsuite/gcc.target/avr/torture/pr61055.c

@@ -0,0 +1,88 @@
+/* { dg-do run } */
+/* { dg-options { -fno-peephole2 } } */
+
+#include <stdlib.h>
+
+typedef __UINT16_TYPE__ uint16_t;
+typedef __INT16_TYPE__  int16_t;
+typedef __UINT8_TYPE__  uint8_t;
+
+uint8_t __attribute__((noinline,noclone))
+fun_inc (uint8_t c0)
+{
+  register uint8_t c asm ("r15") = c0;
+
+  /* Force target value into R15 (lower register)  */
+  asm ("" : "+l" (c));
+
+  c++;
+  if (c >= 0x80)
+    c = 0;
+  
+  asm ("" : "+l" (c));
+
+  return c;
+}
+
+uint8_t __attribute__((noinline,noclone))
+fun_dec (uint8_t c0)
+{
+  register uint8_t c asm ("r15") = c0;
+
+  /* Force target value into R15 (lower register)  */
+  asm ("" : "+l" (c));
+
+  c--;
+  if (c < 0x80)
+    c = 0;
+  
+  asm ("" : "+l" (c));
+
+  return c;
+}
+
+
+uint8_t __attribute__((noinline,noclone))
+fun_neg (uint8_t c0)
+{
+  register uint8_t c asm ("r15") = c0;
+
+  c = -c;
+  if (c >= 0x80)
+    c = 0;
+
+  return c;
+}
+
+uint16_t __attribute__((noinline,noclone))
+fun_adiw (uint16_t c0)
+{
+  register uint16_t c asm ("r24") = c0;
+
+  /* Force target value into R24 (for ADIW) */
+  asm ("" : "+r" (c));
+
+  c += 2;
+  if (c >= 0x8000)
+    c = 0;
+
+  asm ("" : "+r" (c));
+  
+  return c;
+}
+
+
+int main()
+{
+  if (fun_inc (0x7f) != 0)
+    abort();
+  
+  if (fun_neg (0x80) != 0)
+    abort();
+  
+  if (fun_adiw (0x7ffe) != 0)
+    abort();
+
+  exit (0);
+  return 0;
+}