microblaze: Compute masks for alignment checks at translation time.

Thanks to Blue Swirl for reporting.
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@gmail.com>

target-microblaze/op_helper.c

@@ -206,27 +206,18 @@ uint32_t helper_pcmpbf(uint32_t a, uint32_t b)
     return 0;
 }
 
-void helper_memalign(uint32_t addr, uint32_t dr, uint32_t wr, uint32_t size)
+void helper_memalign(uint32_t addr, uint32_t dr, uint32_t wr, uint32_t mask)
 {
-    uint32_t mask;
-
-    switch (size) {
-        case 4: mask = 3; break;
-        case 2: mask = 1; break;
-        default:
-        case 1: mask = 0; break;
-    }
-
     if (addr & mask) {
-            qemu_log("unaligned access addr=%x size=%d, wr=%d\n",
-                     addr, size, wr);
+            qemu_log("unaligned access addr=%x mask=%x, wr=%d\n",
+                     addr, mask, wr);
             if (!(env->sregs[SR_MSR] & MSR_EE)) {
                 return;
             }
 
             env->sregs[SR_ESR] = ESR_EC_UNALIGNED_DATA | (wr << 10) \
                                  | (dr & 31) << 5;
-            if (size == 4) {
+            if (mask == 3) {
                 env->sregs[SR_ESR] |= 1 << 11;
             }
             helper_raise_exception(EXCP_HW_EXCP);

target-microblaze/translate.c

@@ -814,7 +814,7 @@ static void dec_load(DisasContext *dc)
     /* Verify alignment if needed.  */
     if ((dc->env->pvr.regs[2] & PVR2_UNALIGNED_EXC_MASK) && size > 1) {
         gen_helper_memalign(*addr, tcg_const_tl(dc->rd),
-                            tcg_const_tl(0), tcg_const_tl(size));
+                            tcg_const_tl(0), tcg_const_tl(size - 1));
     }
 
     if (dc->rd) {
@@ -858,7 +858,7 @@ static void dec_store(DisasContext *dc)
     /* Verify alignment if needed.  */
     if ((dc->env->pvr.regs[2] & PVR2_UNALIGNED_EXC_MASK) && size > 1) {
         gen_helper_memalign(*addr, tcg_const_tl(dc->rd),
-                            tcg_const_tl(1), tcg_const_tl(size));
+                            tcg_const_tl(1), tcg_const_tl(size - 1));
     }
 
     gen_store(dc, *addr, cpu_R[dc->rd], size);