target-mips: Fix some helper functions (VR54xx multiplication)

Commits b5dc7732 and
be24bb4f optimized the code
and removed the correct setting of t0. Fix this.

gcc-4.7 detected this bug because parameter arg1 was unused
but set in set_HIT0_LO and set_HI_LOT0.

Cc: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>
(cherry picked from commit 6fc97faf)
Signed-off-by: NMichael Roth <mdroth@linux.vnet.ibm.com>

target-mips/op_helper.c

@@ -192,115 +192,98 @@ static inline uint64_t get_HILO (void)
     return ((uint64_t)(env->active_tc.HI[0]) << 32) | (uint32_t)env->active_tc.LO[0];
 }
 
-static inline void set_HIT0_LO (target_ulong arg1, uint64_t HILO)
+static inline target_ulong set_HIT0_LO(uint64_t HILO)
 {
+    target_ulong tmp;
     env->active_tc.LO[0] = (int32_t)(HILO & 0xFFFFFFFF);
-    arg1 = env->active_tc.HI[0] = (int32_t)(HILO >> 32);
+    tmp = env->active_tc.HI[0] = (int32_t)(HILO >> 32);
+    return tmp;
 }
 
-static inline void set_HI_LOT0 (target_ulong arg1, uint64_t HILO)
+static inline target_ulong set_HI_LOT0(uint64_t HILO)
 {
-    arg1 = env->active_tc.LO[0] = (int32_t)(HILO & 0xFFFFFFFF);
+    target_ulong tmp = env->active_tc.LO[0] = (int32_t)(HILO & 0xFFFFFFFF);
     env->active_tc.HI[0] = (int32_t)(HILO >> 32);
+    return tmp;
 }
 
 /* Multiplication variants of the vr54xx. */
 target_ulong helper_muls (target_ulong arg1, target_ulong arg2)
 {
-    set_HI_LOT0(arg1, 0 - ((int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2));
-
-    return arg1;
+    return set_HI_LOT0(0 - ((int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2));
 }
 
 target_ulong helper_mulsu (target_ulong arg1, target_ulong arg2)
 {
-    set_HI_LOT0(arg1, 0 - ((uint64_t)(uint32_t)arg1 * (uint64_t)(uint32_t)arg2));
-
-    return arg1;
+    return set_HI_LOT0(0 - (uint64_t)(uint32_t)arg1 * (uint64_t)(uint32_t)arg2);
 }
 
 target_ulong helper_macc (target_ulong arg1, target_ulong arg2)
 {
-    set_HI_LOT0(arg1, ((int64_t)get_HILO()) + ((int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2));
-
-    return arg1;
+    return set_HI_LOT0((int64_t)get_HILO() + (int64_t)(int32_t)arg1 *
+                                             (int64_t)(int32_t)arg2);
 }
 
 target_ulong helper_macchi (target_ulong arg1, target_ulong arg2)
 {
-    set_HIT0_LO(arg1, ((int64_t)get_HILO()) + ((int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2));
-
-    return arg1;
+    return set_HIT0_LO((int64_t)get_HILO() + (int64_t)(int32_t)arg1 *
+                                             (int64_t)(int32_t)arg2);
 }
 
 target_ulong helper_maccu (target_ulong arg1, target_ulong arg2)
 {
-    set_HI_LOT0(arg1, ((uint64_t)get_HILO()) + ((uint64_t)(uint32_t)arg1 * (uint64_t)(uint32_t)arg2));
-
-    return arg1;
+    return set_HI_LOT0((uint64_t)get_HILO() + (uint64_t)(uint32_t)arg1 *
+                                              (uint64_t)(uint32_t)arg2);
 }
 
 target_ulong helper_macchiu (target_ulong arg1, target_ulong arg2)
 {
-    set_HIT0_LO(arg1, ((uint64_t)get_HILO()) + ((uint64_t)(uint32_t)arg1 * (uint64_t)(uint32_t)arg2));
-
-    return arg1;
+    return set_HIT0_LO((uint64_t)get_HILO() + (uint64_t)(uint32_t)arg1 *
+                                              (uint64_t)(uint32_t)arg2);
 }
 
 target_ulong helper_msac (target_ulong arg1, target_ulong arg2)
 {
-    set_HI_LOT0(arg1, ((int64_t)get_HILO()) - ((int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2));
-
-    return arg1;
+    return set_HI_LOT0((int64_t)get_HILO() - (int64_t)(int32_t)arg1 *
+                                             (int64_t)(int32_t)arg2);
 }
 
 target_ulong helper_msachi (target_ulong arg1, target_ulong arg2)
 {
-    set_HIT0_LO(arg1, ((int64_t)get_HILO()) - ((int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2));
-
-    return arg1;
+    return set_HIT0_LO((int64_t)get_HILO() - (int64_t)(int32_t)arg1 *
+                                             (int64_t)(int32_t)arg2);
 }
 
 target_ulong helper_msacu (target_ulong arg1, target_ulong arg2)
 {
-    set_HI_LOT0(arg1, ((uint64_t)get_HILO()) - ((uint64_t)(uint32_t)arg1 * (uint64_t)(uint32_t)arg2));
-
-    return arg1;
+    return set_HI_LOT0((uint64_t)get_HILO() - (uint64_t)(uint32_t)arg1 *
+                                              (uint64_t)(uint32_t)arg2);
 }
 
 target_ulong helper_msachiu (target_ulong arg1, target_ulong arg2)
 {
-    set_HIT0_LO(arg1, ((uint64_t)get_HILO()) - ((uint64_t)(uint32_t)arg1 * (uint64_t)(uint32_t)arg2));
-
-    return arg1;
+    return set_HIT0_LO((uint64_t)get_HILO() - (uint64_t)(uint32_t)arg1 *
+                                              (uint64_t)(uint32_t)arg2);
 }
 
 target_ulong helper_mulhi (target_ulong arg1, target_ulong arg2)
 {
-    set_HIT0_LO(arg1, (int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2);
-
-    return arg1;
+    return set_HIT0_LO((int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2);
 }
 
 target_ulong helper_mulhiu (target_ulong arg1, target_ulong arg2)
 {
-    set_HIT0_LO(arg1, (uint64_t)(uint32_t)arg1 * (uint64_t)(uint32_t)arg2);
-
-    return arg1;
+    return set_HIT0_LO((uint64_t)(uint32_t)arg1 * (uint64_t)(uint32_t)arg2);
 }
 
 target_ulong helper_mulshi (target_ulong arg1, target_ulong arg2)
 {
-    set_HIT0_LO(arg1, 0 - ((int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2));
-
-    return arg1;
+    return set_HIT0_LO(0 - (int64_t)(int32_t)arg1 * (int64_t)(int32_t)arg2);
 }
 
 target_ulong helper_mulshiu (target_ulong arg1, target_ulong arg2)
 {
-    set_HIT0_LO(arg1, 0 - ((uint64_t)(uint32_t)arg1 * (uint64_t)(uint32_t)arg2));
-
-    return arg1;
+    return set_HIT0_LO(0 - (uint64_t)(uint32_t)arg1 * (uint64_t)(uint32_t)arg2);
 }
 
 #ifdef TARGET_MIPS64