target-arm: Rename ARM_FEATURE_DIV to _THUMB_DIV

Rename the ARM_FEATURE_DIV feature bit to _THUMB_DIV, to
make room for a new feature switch enabling DIV in the ARM
encoding. (Cores may implement either (a) no divide insns
(b) divide insns in Thumb encodings only (c) divide insns
in both ARM and Thumb encodings.)
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

target-arm/cpu.h

@@ -366,7 +366,7 @@ enum arm_features {
     ARM_FEATURE_VFP3,
     ARM_FEATURE_VFP_FP16,
     ARM_FEATURE_NEON,
-    ARM_FEATURE_DIV,
+    ARM_FEATURE_THUMB_DIV, /* divide supported in Thumb encoding */
     ARM_FEATURE_M, /* Microcontroller profile.  */
     ARM_FEATURE_OMAPCP, /* OMAP specific CP15 ops handling.  */
     ARM_FEATURE_THUMB2EE,

target-arm/helper.c

@@ -193,7 +193,7 @@ static void cpu_reset_model_id(CPUARMState *env, uint32_t id)
         set_feature(env, ARM_FEATURE_THUMB2);
         set_feature(env, ARM_FEATURE_V7);
         set_feature(env, ARM_FEATURE_M);
-        set_feature(env, ARM_FEATURE_DIV);
+        set_feature(env, ARM_FEATURE_THUMB_DIV);
         break;
     case ARM_CPUID_ANY: /* For userspace emulation.  */
         set_feature(env, ARM_FEATURE_V4T);
@@ -207,7 +207,7 @@ static void cpu_reset_model_id(CPUARMState *env, uint32_t id)
         set_feature(env, ARM_FEATURE_VFP_FP16);
         set_feature(env, ARM_FEATURE_NEON);
         set_feature(env, ARM_FEATURE_THUMB2EE);
-        set_feature(env, ARM_FEATURE_DIV);
+        set_feature(env, ARM_FEATURE_THUMB_DIV);
         set_feature(env, ARM_FEATURE_V7MP);
         break;
     case ARM_CPUID_TI915T:

target-arm/translate.c

@@ -8513,8 +8513,9 @@ static int disas_thumb2_insn(CPUState *env, DisasContext *s, uint16_t insn_hw1)
             tmp2 = load_reg(s, rm);
             if ((op & 0x50) == 0x10) {
                 /* sdiv, udiv */
-                if (!arm_feature(env, ARM_FEATURE_DIV))
+                if (!arm_feature(env, ARM_FEATURE_THUMB_DIV)) {
                     goto illegal_op;
+                }
                 if (op & 0x20)
                     gen_helper_udiv(tmp, tmp, tmp2);
                 else