re PR target/57516 ([avr] Incorrect fixed-point rounding result in the overflow case)

gcc/
	PR target/57516
	* config/avr/avr-fixed.md (round<mode>3_const): Turn expander to insn.
	* config/avr/avr.md (adjust_len): Add `round'.
	* config/avr/avr-protos.h (avr_out_round): New prototype.
	(avr_out_plus): Add `out_label' argument.
	* config/avr/avr.c (avr_out_plus_1): Add `out_label' argument.
	(avr_out_plus): Pass down `out_label' to avr_out_plus_1.
	Handle the case where `insn' is just a pattern.
	(avr_out_bitop): Handle the case where `insn' is just a pattern.
	(avr_out_round): New function.
	(avr_adjust_insn_length): Handle ADJUST_LEN_ROUND.

libgcc/
	PR target/57516
	* config/avr/lib1funcs-fixed.S (__roundqq3, __rounduqq3)
	(__round_s2_const, __round_u2_const)
	(__round_s4_const, __round_u4_const, __round_x8):
	Saturate result if addition result cannot be represented.

gcc/testsuite/
	PR target/57516
	* gcc.target/avr/torture/builtins-4-roundfx.c (test2hr, test2k):
	Adjust to corrected rounding.

From-SVN: r201051

2 files changed, 34 insertions, 21 deletions

diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog
index 506fa43bdc0..9020a643946 100644
--- a/libgcc/ChangeLog
+++ b/libgcc/ChangeLog
@@ -1,3 +1,11 @@
+2013-07-19  Georg-Johann Lay  <avr@gjlay.de>
+
+	PR target/57516
+	* config/avr/lib1funcs-fixed.S (__roundqq3, __rounduqq3)
+	(__round_s2_const, __round_u2_const)
+	(__round_s4_const, __round_u4_const, __round_x8):
+	Saturate result if addition result cannot be represented.
+
 2013-07-15  Matthias Klose  <doko@ubuntu.com>
 
 	* libgcc2.c: Don't include <limits.h>.
diff --git a/libgcc/config/avr/lib1funcs-fixed.S b/libgcc/config/avr/lib1funcs-fixed.S
index d80389ce2ee..f920891e19e 100644
--- a/libgcc/config/avr/lib1funcs-fixed.S
+++ b/libgcc/config/avr/lib1funcs-fixed.S
@@ -1464,12 +1464,13 @@ DEFUN  __roundqq3
     ;; Add-Saturate 2^{-RP-1}
     add     A0, C0
     brvc 0f
-    ldi     A0, 0x7f
+    ldi     C0, 0x7f
+    rjmp 9f
 0:  ;; Mask out bits beyond RP
     lsl     C0
     neg     C0
     and     C0, A0
-    mov     C1, __tmp_reg__
+9:  mov     C1, __tmp_reg__
     ret
 ENDF  __roundqq3
 #endif /* L_roundqq3 */
@@ -1488,12 +1489,13 @@ DEFUN  __rounduqq3
     ;; Add-Saturate 2^{-RP-1}
     add     A0, C0
     brcc 0f
-    ldi     A0, 0xff
+    ldi     C0, 0xff
+    rjmp 9f
 0:  ;; Mask out bits beyond RP
     lsl     C0
     neg     C0
     and     C0, A0
-    mov     C1, __tmp_reg__
+9:  mov     C1, __tmp_reg__
     ret
 ENDF  __rounduqq3
 #endif /* L_rounduqq3 */
@@ -1565,16 +1567,17 @@ ENDF  __rounduha3
 
 DEFUN  __round_s2_const
     brvc 2f
-    ldi     A1, 0x7f
+    ldi     C1, 0x7f
     rjmp 1f
     ;; FALLTHRU (Barrier)
 ENDF  __round_s2_const
 
 DEFUN __round_u2_const
     brcc 2f
-    ldi     A1, 0xff
+    ldi     C1, 0xff
 1:
-    ldi     A0, 0xff
+    ldi     C0, 0xff
+    rjmp 9f
 2:
     ;; Saturation is performed now.
     ;; Currently, we have C[] = 2^{-RP-1}
@@ -1586,7 +1589,7 @@ DEFUN __round_u2_const
     ;; Clear the bits beyond the rounding point.
     and     C0, A0
     and     C1, A1
-    ret
+9:  ret
 ENDF  __round_u2_const
 
 #endif /* L_round_2_const */
@@ -1681,18 +1684,19 @@ ENDF  __roundusa3
 
 DEFUN  __round_s4_const
     brvc 2f
-    ldi     A3, 0x7f
+    ldi     C3, 0x7f
     rjmp 1f
     ;; FALLTHRU (Barrier)
 ENDF  __round_s4_const
 
 DEFUN __round_u4_const
     brcc 2f
-    ldi     A3, 0xff
+    ldi     C3, 0xff
 1:
-    ldi     A2, 0xff
-    ldi     A1, 0xff
-    ldi     A0, 0xff
+    ldi     C2, 0xff
+    ldi     C1, 0xff
+    ldi     C0, 0xff
+    rjmp 9f
 2:
     ;; Saturation is performed now.
     ;; Currently, we have C[] = 2^{-RP-1}
@@ -1707,7 +1711,7 @@ DEFUN __round_u4_const
     and     C1, A1
     and     C2, A2
     and     C3, A3
-    ret
+9:  ret
 ENDF  __round_u4_const
 
 #endif /* L_round_4_const */
@@ -1847,12 +1851,13 @@ DEFUN __round_x8
 1:  ;; Unsigned
     brcc    3f
     ;; Unsigned overflow: A[] = 0xff...
-2:  ldi     A7, 0xff
-    ldi     A6, 0xff
-    wmov    A0, A6
-    wmov    A2, A6
-    wmov    A4, A6
-    bld     A7, 7
+2:  ldi     C7, 0xff
+    ldi     C6, 0xff
+    wmov    C0, C6
+    wmov    C2, C6
+    wmov    C4, C6
+    bld     C7, 7
+    rjmp 9f
 3:
     ;;  C[] = -C[] - C[]
     push    A0
@@ -1869,7 +1874,7 @@ DEFUN __round_x8
     and     C5, A5
     and     C6, A6
     and     C7, A7
-    ;; Epilogue
+9:  ;; Epilogue
     pop r29
     pop r28
     pop r17