system/cpu-timers: Introduce ICountMode enumerator

Rather than having to lookup for what the 0, 1, 2, ...
icount values are, use a enum definition.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20231208113529.74067-4-philmd@linaro.org>

accel/tcg/icount-common.c

@@ -49,21 +49,19 @@ static bool icount_sleep = true;
 /* Arbitrarily pick 1MIPS as the minimum allowable speed.  */
 #define MAX_ICOUNT_SHIFT 10
 
-/*
- * 0 = Do not count executed instructions.
- * 1 = Fixed conversion of insn to ns via "shift" option
- * 2 = Runtime adaptive algorithm to compute shift
- */
-int use_icount;
+/* Do not count executed instructions */
+ICountMode use_icount = ICOUNT_DISABLED;
 
 static void icount_enable_precise(void)
 {
-    use_icount = 1;
+    /* Fixed conversion of insn to ns via "shift" option */
+    use_icount = ICOUNT_PRECISE;
 }
 
 static void icount_enable_adaptive(void)
 {
-    use_icount = 2;
+    /* Runtime adaptive algorithm to compute shift */
+    use_icount = ICOUNT_ADAPTATIVE;
 }
 
 /*
@@ -256,7 +254,7 @@ static void icount_warp_rt(void)
         int64_t warp_delta;
 
         warp_delta = clock - timers_state.vm_clock_warp_start;
-        if (icount_enabled() == 2) {
+        if (icount_enabled() == ICOUNT_ADAPTATIVE) {
             /*
              * In adaptive mode, do not let QEMU_CLOCK_VIRTUAL run too far
              * ahead of real time (it might already be ahead so careful not

include/sysemu/cpu-timers.h

@@ -17,18 +17,24 @@ void cpu_timers_init(void);
 
 /* icount - Instruction Counter API */
 
-/*
- * icount enablement state:
+/**
+ * ICountMode: icount enablement state:
  *
- * 0 = Disabled - Do not count executed instructions.
- * 1 = Enabled - Fixed conversion of insn to ns via "shift" option
- * 2 = Enabled - Runtime adaptive algorithm to compute shift
+ * @ICOUNT_DISABLED: Disabled - Do not count executed instructions.
+ * @ICOUNT_PRECISE: Enabled - Fixed conversion of insn to ns via "shift" option
+ * @ICOUNT_ADAPTATIVE: Enabled - Runtime adaptive algorithm to compute shift
  */
+typedef enum {
+    ICOUNT_DISABLED = 0,
+    ICOUNT_PRECISE,
+    ICOUNT_ADAPTATIVE,
+} ICountMode;
+
 #ifdef CONFIG_TCG
-extern int use_icount;
+extern ICountMode use_icount;
 #define icount_enabled() (use_icount)
 #else
-#define icount_enabled() 0
+#define icount_enabled() ICOUNT_DISABLED
 #endif
 
 /*

stubs/icount.c

@@ -4,7 +4,7 @@
 
 /* icount - Instruction Counter API */
 
-int use_icount;
+ICountMode use_icount = ICOUNT_DISABLED;
 
 void icount_update(CPUState *cpu)
 {

system/cpu-timers.c

@@ -154,7 +154,7 @@ static bool adjust_timers_state_needed(void *opaque)
 
 static bool icount_shift_state_needed(void *opaque)
 {
-    return icount_enabled() == 2;
+    return icount_enabled() == ICOUNT_ADAPTATIVE;
 }
 
 /*

target/arm/helper.c

@@ -948,7 +948,8 @@ static int64_t cycles_ns_per(uint64_t cycles)
 
 static bool instructions_supported(CPUARMState *env)
 {
-    return icount_enabled() == 1; /* Precise instruction counting */
+    /* Precise instruction counting */
+    return icount_enabled() == ICOUNT_PRECISE;
 }
 
 static uint64_t instructions_get_count(CPUARMState *env)