Share some ARM target dependent code from GDB with GDBServer

This patch is in preparation for software single stepping support on ARM
it shares some functions and definitions that will be needed.

No regressions, tested on ubuntu 14.04 ARMv7 and x86.
With gdbserver-{native,extended} / { -marm -mthumb }

Not tested: wince/bsd build.

gdb/ChangeLog:

	* arch/arm.c (bitcount): Move from arm-tdep.c.
	(condition_true): Likewise.
	* arch/arm.h (Instruction Definitions): Move form arm-tdep.h.
	(condition_true): Move defenition from arm-tdep.h.
	(bitcount): Likewise.
	* arm-tdep.c (condition_true): Move to arch/arm.c.
	(bitcount): Likewise.
	* arm-tdep.h (Instruction Definitions): Move to arch/arm.h.
	* arm-wince-tdep.c: Include arch/arm.h.
	* armnbsd-tdep.c: Likewise.

2 files changed, 94 insertions, 2 deletions

diff --git a/gdb/arch/arm.c b/gdb/arch/arm.c
index b11c684..426377f 100644
--- a/gdb/arch/arm.c
+++ b/gdb/arch/arm.c
@@ -20,8 +20,7 @@
 #include "common-defs.h"
 #include "arm.h"
 
-/* Return the size in bytes of the complete Thumb instruction whose
-   first halfword is INST1.  */
+/* See arm.h.  */
 
 int
 thumb_insn_size (unsigned short inst1)
@@ -31,3 +30,60 @@ thumb_insn_size (unsigned short inst1)
   else
     return 2;
 }
+
+/* See arm.h.  */
+
+int
+bitcount (unsigned long val)
+{
+  int nbits;
+  for (nbits = 0; val != 0; nbits++)
+    val &= val - 1;		/* Delete rightmost 1-bit in val.  */
+  return nbits;
+}
+
+/* See arm.h.  */
+
+int
+condition_true (unsigned long cond, unsigned long status_reg)
+{
+  if (cond == INST_AL || cond == INST_NV)
+    return 1;
+
+  switch (cond)
+    {
+    case INST_EQ:
+      return ((status_reg & FLAG_Z) != 0);
+    case INST_NE:
+      return ((status_reg & FLAG_Z) == 0);
+    case INST_CS:
+      return ((status_reg & FLAG_C) != 0);
+    case INST_CC:
+      return ((status_reg & FLAG_C) == 0);
+    case INST_MI:
+      return ((status_reg & FLAG_N) != 0);
+    case INST_PL:
+      return ((status_reg & FLAG_N) == 0);
+    case INST_VS:
+      return ((status_reg & FLAG_V) != 0);
+    case INST_VC:
+      return ((status_reg & FLAG_V) == 0);
+    case INST_HI:
+      return ((status_reg & (FLAG_C | FLAG_Z)) == FLAG_C);
+    case INST_LS:
+      return ((status_reg & (FLAG_C | FLAG_Z)) != FLAG_C);
+    case INST_GE:
+      return (((status_reg & FLAG_N) == 0) == ((status_reg & FLAG_V) == 0));
+    case INST_LT:
+      return (((status_reg & FLAG_N) == 0) != ((status_reg & FLAG_V) == 0));
+    case INST_GT:
+      return (((status_reg & FLAG_Z) == 0)
+	      && (((status_reg & FLAG_N) == 0)
+		  == ((status_reg & FLAG_V) == 0)));
+    case INST_LE:
+      return (((status_reg & FLAG_Z) != 0)
+	      || (((status_reg & FLAG_N) == 0)
+		  != ((status_reg & FLAG_V) == 0)));
+    }
+  return 1;
+}
diff --git a/gdb/arch/arm.h b/gdb/arch/arm.h
index a054776..1a877bc 100644
--- a/gdb/arch/arm.h
+++ b/gdb/arch/arm.h
@@ -58,6 +58,36 @@ enum gdb_regnum {
   ARM_LAST_FP_ARG_REGNUM = ARM_F3_REGNUM
 };
 
+/* Instruction condition field values.  */
+#define INST_EQ		0x0
+#define INST_NE		0x1
+#define INST_CS		0x2
+#define INST_CC		0x3
+#define INST_MI		0x4
+#define INST_PL		0x5
+#define INST_VS		0x6
+#define INST_VC		0x7
+#define INST_HI		0x8
+#define INST_LS		0x9
+#define INST_GE		0xa
+#define INST_LT		0xb
+#define INST_GT		0xc
+#define INST_LE		0xd
+#define INST_AL		0xe
+#define INST_NV		0xf
+
+#define FLAG_N		0x80000000
+#define FLAG_Z		0x40000000
+#define FLAG_C		0x20000000
+#define FLAG_V		0x10000000
+
+#define CPSR_T		0x20
+
+#define XPSR_T		0x01000000
+
+/* Size of integer registers.  */
+#define INT_REGISTER_SIZE		4
+
 /* Addresses for calling Thumb functions have the bit 0 set.
    Here are some macros to test, set, or clear bit 0 of addresses.  */
 #define IS_THUMB_ADDR(addr)    ((addr) & 1)
@@ -68,4 +98,10 @@ enum gdb_regnum {
    first halfword is INST1.  */
 int thumb_insn_size (unsigned short inst1);
 
+/* Returns true if the condition evaluates to true.  */
+int condition_true (unsigned long cond, unsigned long status_reg);
+
+/* Return number of 1-bits in VAL.  */
+int bitcount (unsigned long val);
+
 #endif