target-arm: Don't leak TCG temp for UNDEFs in Neon load/store space

Move the allocation and freeing of the TCG temp used for the address for
Neon load/store instructions so that we don't allocate the temporary
until we've done enough decoding to know that the instruction is not
an UNDEF pattern; this avoids leaking the TCG temp in these cases.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

target-arm/translate.c

@@ -3810,7 +3810,6 @@ static int disas_neon_ls_insn(CPUState * env, DisasContext *s, uint32_t insn)
     rn = (insn >> 16) & 0xf;
     rm = insn & 0xf;
     load = (insn & (1 << 21)) != 0;
-    addr = tcg_temp_new_i32();
     if ((insn & (1 << 23)) == 0) {
         /* Load store all elements.  */
         op = (insn >> 8) & 0xf;
@@ -3822,6 +3821,7 @@ static int disas_neon_ls_insn(CPUState * env, DisasContext *s, uint32_t insn)
         spacing = neon_ls_element_type[op].spacing;
         if (size == 3 && (interleave | spacing) != 1)
             return 1;
+        addr = tcg_temp_new_i32();
         load_reg_var(s, addr, rn);
         stride = (1 << size) * interleave;
         for (reg = 0; reg < nregs; reg++) {
@@ -3907,6 +3907,7 @@ static int disas_neon_ls_insn(CPUState * env, DisasContext *s, uint32_t insn)
             }
             rd += spacing;
         }
+        tcg_temp_free_i32(addr);
         stride = nregs * 8;
     } else {
         size = (insn >> 10) & 3;
@@ -3932,6 +3933,7 @@ static int disas_neon_ls_insn(CPUState * env, DisasContext *s, uint32_t insn)
             if (nregs == 3 && a == 1) {
                 return 1;
             }
+            addr = tcg_temp_new_i32();
             load_reg_var(s, addr, rn);
             if (nregs == 1) {
                 /* VLD1 to all lanes: bit 5 indicates how many Dregs to write */
@@ -3955,6 +3957,7 @@ static int disas_neon_ls_insn(CPUState * env, DisasContext *s, uint32_t insn)
                     rd += stride;
                 }
             }
+            tcg_temp_free_i32(addr);
             stride = (1 << size) * nregs;
         } else {
             /* Single element.  */
@@ -3976,6 +3979,7 @@ static int disas_neon_ls_insn(CPUState * env, DisasContext *s, uint32_t insn)
                 abort();
             }
             nregs = ((insn >> 8) & 3) + 1;
+            addr = tcg_temp_new_i32();
             load_reg_var(s, addr, rn);
             for (reg = 0; reg < nregs; reg++) {
                 if (load) {
@@ -4017,10 +4021,10 @@ static int disas_neon_ls_insn(CPUState * env, DisasContext *s, uint32_t insn)
                 rd += stride;
                 tcg_gen_addi_i32(addr, addr, 1 << size);
             }
+            tcg_temp_free_i32(addr);
             stride = nregs * (1 << size);
         }
     }
-    tcg_temp_free_i32(addr);
     if (rm != 15) {
         TCGv base;