[Qemu-devel] [4900] ARMv6: fix SIMD add/sub carry flags (Vincent Palatin).

[Andrzej Zaborowski]

Revision: 4900
          http://svn.sv.gnu.org/viewvc/?view=rev&root=qemu&revision=4900
Author:   balrog
Date:     2008-07-19 10:46:13 +0000 (Sat, 19 Jul 2008)

Log Message:
-----------
ARMv6: fix SIMD add/sub carry flags (Vincent Palatin).

After a quick code review, it seems to be a bad cut-n-paste between
16-bit and 8-bit UADD/USUB, indeed UADD8/USUB8 tries to set GE bits by
pair instead of one at a time.
Besides, the addition operations (UADD8/UADD16) set GE bits to "NOT
carry" instead of "carry" (probably once again due to a copy of the
substraction code which sets flags to "NOT borrow")

Modified Paths:
--------------
    trunk/target-arm/helper.c

Modified: trunk/target-arm/helper.c
===================================================================
--- trunk/target-arm/helper.c   2008-07-19 10:34:35 UTC (rev 4899)
+++ trunk/target-arm/helper.c   2008-07-19 10:46:13 UTC (rev 4900)
@@ -2059,7 +2059,7 @@
     uint32_t sum; \
     sum = (uint32_t)(uint16_t)(a) + (uint32_t)(uint16_t)(b); \
     RESULT(sum, n, 16); \
-    if ((sum >> 16) == 0) \
+    if ((sum >> 16) == 1) \
         ge |= 3 << (n * 2); \
     } while(0)
 
@@ -2067,8 +2067,8 @@
     uint32_t sum; \
     sum = (uint32_t)(uint8_t)(a) + (uint32_t)(uint8_t)(b); \
     RESULT(sum, n, 8); \
-    if ((sum >> 8) == 0) \
-        ge |= 3 << (n * 2); \
+    if ((sum >> 8) == 1) \
+        ge |= 1 << n; \
     } while(0)
 
 #define SUB16(a, b, n) do { \
@@ -2084,7 +2084,7 @@
     sum = (uint32_t)(uint8_t)(a) - (uint32_t)(uint8_t)(b); \
     RESULT(sum, n, 8); \
     if ((sum >> 8) == 0) \
-        ge |= 3 << (n * 2); \
+        ge |= 1 << n; \
     } while(0)
 
 #define PFX u