more accuracy fixes

[picodrive.git] / cpu / Cyclone / OpLogic.cpp

diff --git a/cpu/Cyclone/OpLogic.cpp b/cpu/Cyclone/OpLogic.cpp
index 7623704..65d2293 100644 (file)
--- a/cpu/Cyclone/OpLogic.cpp
+++ b/cpu/Cyclone/OpLogic.cpp
@@ -403,7 +403,7 @@ static int EmitAsr(int op,int type,int dir,int count,int size,int usereg)
       ot("\n");\r
     }\r
 \r
-    if (type==0 && dir) ot("  mov r3,r0 ;@ save old value for V flag calculation\n");\r
+    if (type==0 && dir) ot("  adds r3,r0,#0 ;@ save old value for V flag calculation, also clear V\n");\r
 \r
     ot(";@ Shift register:\n");\r
     if (type==0) ot("  movs r0,r0,%s %s\n",dir?"asl":"asr",pct);\r
@@ -434,7 +434,8 @@ static int EmitAsr(int op,int type,int dir,int count,int size,int usereg)
       ot("  mov r1,#0x80000000\n");\r
       ot("  ands r3,r3,r1,asr %s\n", pct);\r
       ot("  cmpne r3,r1,asr %s\n", pct);\r
-      ot("  biceq r9,r9,#0x10000000\n");\r
+      ot("  eoreq r1,r0,r3\n"); // above check doesn't catch (-1)<<(32+), so we need this\r
+      ot("  tsteq r1,#0x80000000\n");\r
       ot("  orrne r9,r9,#0x10000000\n");\r
       ot("\n");\r
     }\r