ARM: simplify CPSR handling

Stash a pointer to the CPSR in the "struct arm", to help get rid
of the (common) references to its index in the register cache.

This removes almost all references to CPSR offsets outside of the
toplevel ARM code ... except a pair related to the current ARM11
"simulator" logic (which should be removable soonish).

This is a net minor code shrink of a few hundred bytes of object
code, and also makes the code more readable.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

src/target/armv4_5.h

@@ -62,17 +62,8 @@ extern const int armv4_5_core_reg_map[8][17];
 #define ARMV4_5_CORE_REG_MODE(cache, mode, num) \
 		cache->reg_list[armv4_5_core_reg_map[armv4_5_mode_to_number(mode)][num]]
 
-/* offsets into armv4_5 core register cache */
-enum
-{
-	ARMV4_5_CPSR = 31,
-	ARMV4_5_SPSR_FIQ = 32,
-	ARMV4_5_SPSR_IRQ = 33,
-	ARMV4_5_SPSR_SVC = 34,
-	ARMV4_5_SPSR_ABT = 35,
-	ARMV4_5_SPSR_UND = 36,
-	ARM_SPSR_MON = 39,
-};
+/* offset into armv4_5 core register cache -- OBSOLETE, DO NOT USE! */
+enum { ARMV4_5_CPSR = 31, };
 
 #define ARMV4_5_COMMON_MAGIC 0x0A450A45
 
@@ -91,6 +82,9 @@ struct arm
 	int common_magic;
 	struct reg_cache *core_cache;
 
+	/** Handle to the CPSR; valid in all core modes. */
+	struct reg *cpsr;
+
 	/**
 	 * Indicates what registers are in the ARM state core register set.
 	 * ARMV4_5_MODE_ANY indicates the standard set of 37 registers,