diff -Naur qemu-0.9.1/target-arm/cpu.h qemu-0.9.1.patched/target-arm/cpu.h
--- qemu-0.9.1/target-arm/cpu.h	2008-01-06 20:38:44.000000000 +0100
+++ qemu-0.9.1.patched/target-arm/cpu.h	2008-11-12 10:35:29.000000000 +0100
@@ -84,9 +84,17 @@
     uint32_t fiq_regs[5];
 
     /* cpsr flag cache for faster execution */
+    /* All the NZCV flags may be set independently (MSR cpsr_f, #0xe0000000 works) */
+    /* All the flags are zero or one; the flags are calculated less often than they are
+     * read, since ARM code only sets flags when it knows they will be read and often
+     * they are read more than once. */
+    /* I note an assumption that in boolean true is the value 1. i.e. (0 == 0) == 1. */
+    /* TODO: Establish whether storing the flags as 8 bit values is more efficient */
+    uint32_t NF; /* 0 or 1 */
+    uint32_t ZF; /* 0 or 1 */
     uint32_t CF; /* 0 or 1 */
-    uint32_t VF; /* V is the bit 31. All other bits are undefined */
-    uint32_t NZF; /* N is bit 31. Z is computed from NZF */
+    uint32_t VF; /* 0 or 1 */
+
     uint32_t QF; /* 0 or 1 */
     uint32_t GE; /* cpsr[19:16] */
     int thumb; /* cprs[5]. 0 = arm mode, 1 = thumb mode. */
@@ -255,10 +263,8 @@
 /* Return the current xPSR value.  */
 static inline uint32_t xpsr_read(CPUARMState *env)
 {
-    int ZF;
-    ZF = (env->NZF == 0);
-    return (env->NZF & 0x80000000) | (ZF << 30)
-        | (env->CF << 29) | ((env->VF & 0x80000000) >> 3) | (env->QF << 27)
+    return (env->NF << 31) | (env->ZF << 30)
+        | (env->CF << 29) | (env->VF << 28) | (env->QF << 27)
         | (env->thumb << 24) | ((env->condexec_bits & 3) << 25)
         | ((env->condexec_bits & 0xfc) << 8)
         | env->v7m.exception;
@@ -267,11 +273,11 @@
 /* Set the xPSR.  Note that some bits of mask must be all-set or all-clear.  */
 static inline void xpsr_write(CPUARMState *env, uint32_t val, uint32_t mask)
 {
-    /* NOTE: N = 1 and Z = 1 cannot be stored currently */
     if (mask & CPSR_NZCV) {
-        env->NZF = (val & 0xc0000000) ^ 0x40000000;
+        env->NF = (val >> 31);
+        env->ZF = (val >> 30) & 1;
         env->CF = (val >> 29) & 1;
-        env->VF = (val << 3) & 0x80000000;
+        env->VF = (val >> 28) & 1;
     }
     if (mask & CPSR_Q)
         env->QF = ((val & CPSR_Q) != 0);
diff -Naur qemu-0.9.1/target-arm/helper.c qemu-0.9.1.patched/target-arm/helper.c
--- qemu-0.9.1/target-arm/helper.c	2008-01-06 20:38:44.000000000 +0100
+++ qemu-0.9.1.patched/target-arm/helper.c	2008-11-12 10:37:26.000000000 +0100
@@ -275,10 +275,8 @@
 
 uint32_t cpsr_read(CPUARMState *env)
 {
-    int ZF;
-    ZF = (env->NZF == 0);
-    return env->uncached_cpsr | (env->NZF & 0x80000000) | (ZF << 30) |
-        (env->CF << 29) | ((env->VF & 0x80000000) >> 3) | (env->QF << 27)
+    return env->uncached_cpsr | (env->NF << 31) | (env->ZF << 30)
+        | (env->CF << 29) | (env->VF << 28) | (env->QF << 27)
         | (env->thumb << 5) | ((env->condexec_bits & 3) << 25)
         | ((env->condexec_bits & 0xfc) << 8)
         | (env->GE << 16);
@@ -286,11 +284,11 @@
 
 void cpsr_write(CPUARMState *env, uint32_t val, uint32_t mask)
 {
-    /* NOTE: N = 1 and Z = 1 cannot be stored currently */
     if (mask & CPSR_NZCV) {
-        env->NZF = (val & 0xc0000000) ^ 0x40000000;
+        env->NF = (val >> 31) & 1;
+        env->ZF = (val >> 30) & 1;
         env->CF = (val >> 29) & 1;
-        env->VF = (val << 3) & 0x80000000;
+        env->VF = (val >> 28) & 1;
     }
     if (mask & CPSR_Q)
         env->QF = ((val & CPSR_Q) != 0);
diff -Naur qemu-0.9.1/target-arm/op.c qemu-0.9.1.patched/target-arm/op.c
--- qemu-0.9.1/target-arm/op.c	2008-01-06 20:38:44.000000000 +0100
+++ qemu-0.9.1.patched/target-arm/op.c	2008-11-12 10:14:42.000000000 +0100
@@ -141,9 +141,10 @@
     unsigned int src1;
     src1 = T0;
     T0 += T1;
-    env->NZF = T0;
+    env->NF = (T0 >> 31) & 1;
+    env->ZF = T0 == 0;
     env->CF = T0 < src1;
-    env->VF = (src1 ^ T1 ^ -1) & (src1 ^ T0);
+    env->VF = (((src1 ^ T1 ^ -1) & (src1 ^ T0)) >> 31) & 1;
 }
 
 void OPPROTO op_adcl_T0_T1(void)
@@ -162,8 +163,9 @@
         T0 += T1 + 1;
         env->CF = T0 <= src1;
     }
-    env->VF = (src1 ^ T1 ^ -1) & (src1 ^ T0);
-    env->NZF = T0;
+    env->VF = (((src1 ^ T1 ^ -1) & (src1 ^ T0)) >> 31) & 1;
+    env->NF = (T0 >> 31) & 1;
+    env->ZF = T0 == 0;
     FORCE_RET();
 }
 
@@ -179,9 +181,10 @@
     unsigned int src1;                          \
     src1 = T0;                                  \
     T0 -= T1;                                   \
-    env->NZF = T0;                              \
+    env->NF = (T0 >> 31) & 1;                   \
+    env->ZF = T0 == 0;                          \
     env->CF = src1 >= T1;                       \
-    env->VF = (src1 ^ T1) & (src1 ^ T0);        \
+    env->VF = (((src1 ^ T1) & (src1 ^ T0)) >> 31) & 1;\
     res = T0;                                   \
 }                                               \
                                                 \
@@ -201,8 +204,9 @@
         T0 = T0 - T1;                           \
         env->CF = src1 >= T1;                   \
     }                                           \
-    env->VF = (src1 ^ T1) & (src1 ^ T0);        \
-    env->NZF = T0;                              \
+    env->VF = (((src1 ^ T1) & (src1 ^ T0)) >> 31) & 1;\
+    env->NF = (T0 >> 31) & 1;                   \
+    env->ZF = T0 == 0;                          \
     res = T0;                                   \
     FORCE_RET();                                \
 }
@@ -243,26 +247,28 @@
 
 void OPPROTO op_logic_T0_cc(void)
 {
-    env->NZF = T0;
+    env->NF = (T0 >> 31) & 1;
+    env->ZF = T0 == 0;
 }
 
 void OPPROTO op_logic_T1_cc(void)
 {
-    env->NZF = T1;
+    env->NF = (T1 >> 31) & 1;
+    env->ZF = T1 == 0;
 }
 
 #define EIP (env->regs[15])
 
 void OPPROTO op_test_eq(void)
 {
-    if (env->NZF == 0)
+    if (env->ZF)
         GOTO_LABEL_PARAM(1);;
     FORCE_RET();
 }
 
 void OPPROTO op_test_ne(void)
 {
-    if (env->NZF != 0)
+    if (!env->ZF)
         GOTO_LABEL_PARAM(1);;
     FORCE_RET();
 }
@@ -283,70 +289,70 @@
 
 void OPPROTO op_test_mi(void)
 {
-    if ((env->NZF & 0x80000000) != 0)
+    if (env->NF)
         GOTO_LABEL_PARAM(1);
     FORCE_RET();
 }
 
 void OPPROTO op_test_pl(void)
 {
-    if ((env->NZF & 0x80000000) == 0)
+    if (!env->NF)
         GOTO_LABEL_PARAM(1);
     FORCE_RET();
 }
 
 void OPPROTO op_test_vs(void)
 {
-    if ((env->VF & 0x80000000) != 0)
+    if (env->VF)
         GOTO_LABEL_PARAM(1);
     FORCE_RET();
 }
 
 void OPPROTO op_test_vc(void)
 {
-    if ((env->VF & 0x80000000) == 0)
+    if (!env->VF)
         GOTO_LABEL_PARAM(1);
     FORCE_RET();
 }
 
 void OPPROTO op_test_hi(void)
 {
-    if (env->CF != 0 && env->NZF != 0)
+    if (env->CF && !env->ZF)
         GOTO_LABEL_PARAM(1);
     FORCE_RET();
 }
 
 void OPPROTO op_test_ls(void)
 {
-    if (env->CF == 0 || env->NZF == 0)
+    if (!env->CF || env->ZF)
         GOTO_LABEL_PARAM(1);
     FORCE_RET();
 }
 
 void OPPROTO op_test_ge(void)
 {
-    if (((env->VF ^ env->NZF) & 0x80000000) == 0)
+    if (env->VF == env->NF)
         GOTO_LABEL_PARAM(1);
     FORCE_RET();
 }
 
 void OPPROTO op_test_lt(void)
 {
-    if (((env->VF ^ env->NZF) & 0x80000000) != 0)
+    if (env->VF != env->NF)
         GOTO_LABEL_PARAM(1);
     FORCE_RET();
 }
 
 void OPPROTO op_test_gt(void)
 {
-    if (env->NZF != 0 && ((env->VF ^ env->NZF) & 0x80000000) == 0)
+    if (!env->ZF && (env->NF == env->VF))
         GOTO_LABEL_PARAM(1);
     FORCE_RET();
 }
 
 void OPPROTO op_test_le(void)
 {
-    if (env->NZF == 0 || ((env->VF ^ env->NZF) & 0x80000000) != 0)
+    if (env->ZF || (env->NF != env->VF))
         GOTO_LABEL_PARAM(1);
     FORCE_RET();
 }
@@ -476,7 +482,8 @@
 
 void OPPROTO op_logicq_cc(void)
 {
-    env->NZF = (T1 & 0x80000000) | ((T0 | T1) != 0);
+    env->ZF = ((T0 | T1) != 0);
+    env->NF = (T1 >> 31);
 }
 
 /* memory access */
@@ -902,7 +909,8 @@
 	env->CF = (T0 >> (32 - shift)) & 1;
 	T0 = T0 << shift;
     }
-    env->NZF = T0;
+    env->NF = (T0 >> 31) & 1;
+    env->ZF = T0 == 0;
     FORCE_RET();
 }
 
@@ -924,7 +932,8 @@
 	env->CF = (T0 >> (shift - 1)) & 1;
 	T0 = T0 >> shift;
     }
-    env->NZF = T0;
+    env->NF = (T0 >> 31) & 1;
+    env->ZF = T0 == 0;
     FORCE_RET();
 }
 
@@ -953,7 +962,8 @@
 	env->CF = (T0 >> (shift - 1)) & 1;
 	T0 = ((int32_t)T0) >> shift;
     }
-    env->NZF = T0;
+    env->NF = (T0 >> 31) & 1;
+    env->ZF = T0 == 0;
     FORCE_RET();
 }