This will allow us to control exactly what scratch register is
used for loading the constant.  Also, fix a theoretical problem
in recursing through tcg_out_movi, which may provide a different
value for in_prologue.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/sparc/tcg-target.c.inc | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/tcg/sparc/tcg-target.c.inc b/tcg/sparc/tcg-target.c.inc
index 0c062c60eb..7e3758b798 100644
--- a/tcg/sparc/tcg-target.c.inc
+++ b/tcg/sparc/tcg-target.c.inc
@@ -414,7 +414,8 @@ static void tcg_out_movi_imm13(TCGContext *s, TCGReg ret, int32_t arg)
 }
 
 static void tcg_out_movi_int(TCGContext *s, TCGType type, TCGReg ret,
-                             tcg_target_long arg, bool in_prologue)
+                             tcg_target_long arg, bool in_prologue,
+                             TCGReg scratch)
 {
     tcg_target_long hi, lo = (int32_t)arg;
     tcg_target_long test, lsb;
@@ -471,22 +472,24 @@ static void tcg_out_movi_int(TCGContext *s, TCGType type, TCGReg ret,
     /* A 64-bit constant decomposed into 2 32-bit pieces.  */
     if (check_fit_i32(lo, 13)) {
         hi = (arg - lo) >> 32;
-        tcg_out_movi(s, TCG_TYPE_I32, ret, hi);
+        tcg_out_movi_int(s, TCG_TYPE_I32, ret, hi, in_prologue, scratch);
         tcg_out_arithi(s, ret, ret, 32, SHIFT_SLLX);
         tcg_out_arithi(s, ret, ret, lo, ARITH_ADD);
     } else {
+        tcg_debug_assert(scratch != TCG_REG_G0);
         hi = arg >> 32;
-        tcg_out_movi(s, TCG_TYPE_I32, ret, hi);
-        tcg_out_movi(s, TCG_TYPE_I32, TCG_REG_T2, lo);
+        tcg_out_movi_int(s, TCG_TYPE_I32, ret, hi, in_prologue, scratch);
+        tcg_out_movi_int(s, TCG_TYPE_I32, scratch, lo, in_prologue, TCG_REG_G0);
         tcg_out_arithi(s, ret, ret, 32, SHIFT_SLLX);
-        tcg_out_arith(s, ret, ret, TCG_REG_T2, ARITH_OR);
+        tcg_out_arith(s, ret, ret, scratch, ARITH_OR);
     }
 }
 
 static void tcg_out_movi(TCGContext *s, TCGType type,
                          TCGReg ret, tcg_target_long arg)
 {
-    tcg_out_movi_int(s, type, ret, arg, false);
+    tcg_debug_assert(ret != TCG_REG_T2);
+    tcg_out_movi_int(s, type, ret, arg, false, TCG_REG_T2);
 }
 
 static void tcg_out_ldst_rr(TCGContext *s, TCGReg data, TCGReg a1,
@@ -837,7 +840,7 @@ static void tcg_out_call_nodelay(TCGContext *s, const tcg_insn_unit *dest,
     } else {
         uintptr_t desti = (uintptr_t)dest;
         tcg_out_movi_int(s, TCG_TYPE_PTR, TCG_REG_T1,
-                         desti & ~0xfff, in_prologue);
+                         desti & ~0xfff, in_prologue, TCG_REG_O7);
         tcg_out_arithi(s, TCG_REG_O7, TCG_REG_T1, desti & 0xfff, JMPL);
     }
 }
@@ -1013,7 +1016,8 @@ static void tcg_target_qemu_prologue(TCGContext *s)
 
 #ifndef CONFIG_SOFTMMU
     if (guest_base != 0) {
-        tcg_out_movi_int(s, TCG_TYPE_PTR, TCG_GUEST_BASE_REG, guest_base, true);
+        tcg_out_movi_int(s, TCG_TYPE_PTR, TCG_GUEST_BASE_REG, guest_base,
+                         true, TCG_REG_T1);
         tcg_regset_set_reg(s->reserved_regs, TCG_GUEST_BASE_REG);
     }
 #endif
-- 
2.25.1

On Fri, 4 Feb 2022 at 07:53, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> This will allow us to control exactly what scratch register is
> used for loading the constant.  Also, fix a theoretical problem
> in recursing through tcg_out_movi, which may provide a different
> value for in_prologue.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  tcg/sparc/tcg-target.c.inc | 20 ++++++++++++--------
>  1 file changed, 12 insertions(+), 8 deletions(-)

>  static void tcg_out_movi(TCGContext *s, TCGType type,
>                           TCGReg ret, tcg_target_long arg)
>  {
> -    tcg_out_movi_int(s, type, ret, arg, false);
> +    tcg_debug_assert(ret != TCG_REG_T2);
> +    tcg_out_movi_int(s, type, ret, arg, false, TCG_REG_T2);

Here we assert that 'ret' isn't TCG_REG_T2, but in
tcg_out_addsub2_i64() we do:

           tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_T2, bh);
and
           tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_T2, bh + (is_sub ? -1 : 1));

Otherwise looks OK.

thanks
-- PMM

On 2/5/22 04:35, Peter Maydell wrote:
> On Fri, 4 Feb 2022 at 07:53, Richard Henderson
> <richard.henderson@linaro.org> wrote:
>>
>> This will allow us to control exactly what scratch register is
>> used for loading the constant.  Also, fix a theoretical problem
>> in recursing through tcg_out_movi, which may provide a different
>> value for in_prologue.
>>
>> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>> ---
>>   tcg/sparc/tcg-target.c.inc | 20 ++++++++++++--------
>>   1 file changed, 12 insertions(+), 8 deletions(-)
> 
>>   static void tcg_out_movi(TCGContext *s, TCGType type,
>>                            TCGReg ret, tcg_target_long arg)
>>   {
>> -    tcg_out_movi_int(s, type, ret, arg, false);
>> +    tcg_debug_assert(ret != TCG_REG_T2);
>> +    tcg_out_movi_int(s, type, ret, arg, false, TCG_REG_T2);
> 
> Here we assert that 'ret' isn't TCG_REG_T2, but in
> tcg_out_addsub2_i64() we do:
> 
>             tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_T2, bh);
> and
>             tcg_out_movi(s, TCG_TYPE_I64, TCG_REG_T2, bh + (is_sub ? -1 : 1));
> 
> Otherwise looks OK.

Oops.  Good catch.  I shouldn't have moved the assert.


r~