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[PATCH v1 2/4] target/microblaze: div: Rename and reorder function args

Edgar E. Iglesias posted 4 patches 2 months, 3 weeks ago
Maintainers: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
There is a newer version of this series
[PATCH v1 2/4] target/microblaze: div: Rename and reorder function args
Posted by Edgar E. Iglesias 2 months, 3 weeks ago 
From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>

Rename and reorder function args to better match with spec
and pseudo code.

No functional change.

Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
---
 target/microblaze/op_helper.c | 18 +++++++++---------
 target/microblaze/translate.c | 12 ++----------
 2 files changed, 11 insertions(+), 19 deletions(-)

diff --git a/target/microblaze/op_helper.c b/target/microblaze/op_helper.c
index 470526ee92..092977b3e1 100644
--- a/target/microblaze/op_helper.c
+++ b/target/microblaze/op_helper.c
@@ -69,9 +69,9 @@ void helper_raise_exception(CPUMBState *env, uint32_t index)
     cpu_loop_exit(cs);
 }
 
-static bool check_divz(CPUMBState *env, uint32_t b, uintptr_t ra)
+static bool check_divz(CPUMBState *env, uint32_t divisor, uintptr_t pc)
 {
-    if (unlikely(b == 0)) {
+    if (unlikely(divisor == 0)) {
         env->msr |= MSR_DZ;
 
         if ((env->msr & MSR_EE) &&
@@ -80,27 +80,27 @@ static bool check_divz(CPUMBState *env, uint32_t b, uintptr_t ra)
 
             env->esr = ESR_EC_DIVZERO;
             cs->exception_index = EXCP_HW_EXCP;
-            cpu_loop_exit_restore(cs, ra);
+            cpu_loop_exit_restore(cs, pc);
         }
         return false;
     }
     return true;
 }
 
-uint32_t helper_divs(CPUMBState *env, uint32_t a, uint32_t b)
+uint32_t helper_divs(CPUMBState *env, uint32_t ra, uint32_t rb)
 {
-    if (!check_divz(env, b, GETPC())) {
+    if (!check_divz(env, ra, GETPC())) {
         return 0;
     }
-    return (int32_t)a / (int32_t)b;
+    return (int32_t)rb / (int32_t)ra;
 }
 
-uint32_t helper_divu(CPUMBState *env, uint32_t a, uint32_t b)
+uint32_t helper_divu(CPUMBState *env, uint32_t ra, uint32_t rb)
 {
-    if (!check_divz(env, b, GETPC())) {
+    if (!check_divz(env, ra, GETPC())) {
         return 0;
     }
-    return a / b;
+    return rb / ra;
 }
 
 /* raise FPU exception.  */
diff --git a/target/microblaze/translate.c b/target/microblaze/translate.c
index 5098a1db4d..2f5fd5c271 100644
--- a/target/microblaze/translate.c
+++ b/target/microblaze/translate.c
@@ -450,16 +450,8 @@ DO_TYPEA0_CFG(flt, use_fpu >= 2, true, gen_flt)
 DO_TYPEA0_CFG(fint, use_fpu >= 2, true, gen_fint)
 DO_TYPEA0_CFG(fsqrt, use_fpu >= 2, true, gen_fsqrt)
 
-/* Does not use ENV_WRAPPER3, because arguments are swapped as well. */
-static void gen_idiv(TCGv_i32 out, TCGv_i32 ina, TCGv_i32 inb)
-{
-    gen_helper_divs(out, tcg_env, inb, ina);
-}
-
-static void gen_idivu(TCGv_i32 out, TCGv_i32 ina, TCGv_i32 inb)
-{
-    gen_helper_divu(out, tcg_env, inb, ina);
-}
+ENV_WRAPPER3(gen_idiv, gen_helper_divs)
+ENV_WRAPPER3(gen_idivu, gen_helper_divu)
 
 DO_TYPEA_CFG(idiv, use_div, true, gen_idiv)
 DO_TYPEA_CFG(idivu, use_div, true, gen_idivu)
-- 
2.43.0
Re: [PATCH v1 2/4] target/microblaze: div: Rename and reorder function args
Posted by Richard Henderson 2 months, 3 weeks ago 
On 8/25/25 08:27, Edgar E. Iglesias wrote:
> From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>
> 
> Rename and reorder function args to better match with spec
> and pseudo code.
> 
> No functional change.
> 
> Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
> ---
>   target/microblaze/op_helper.c | 18 +++++++++---------
>   target/microblaze/translate.c | 12 ++----------
>   2 files changed, 11 insertions(+), 19 deletions(-)
> 
> diff --git a/target/microblaze/op_helper.c b/target/microblaze/op_helper.c
> index 470526ee92..092977b3e1 100644
> --- a/target/microblaze/op_helper.c
> +++ b/target/microblaze/op_helper.c
> @@ -69,9 +69,9 @@ void helper_raise_exception(CPUMBState *env, uint32_t index)
>       cpu_loop_exit(cs);
>   }
>   
> -static bool check_divz(CPUMBState *env, uint32_t b, uintptr_t ra)
> +static bool check_divz(CPUMBState *env, uint32_t divisor, uintptr_t pc)

The name GETPC notwithstanding, I don't think ra -> pc is a good rename.

PC often gets confused about whether that's a host or guest value.
RA (return address) is less so; it gets used often in core tcg.

If you really don't like RA, then perhaps "retaddr" (also with quite a bit of usage) or 
"unwind_pc" (no existing usage, but very descriptive).


r~
Re: [PATCH v1 2/4] target/microblaze: div: Rename and reorder function args
Posted by Philippe Mathieu-Daudé 2 months, 3 weeks ago 
On 25/8/25 01:32, Richard Henderson wrote:
> On 8/25/25 08:27, Edgar E. Iglesias wrote:
>> From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>
>>
>> Rename and reorder function args to better match with spec
>> and pseudo code.
>>
>> No functional change.
>>
>> Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
>> ---
>>   target/microblaze/op_helper.c | 18 +++++++++---------
>>   target/microblaze/translate.c | 12 ++----------
>>   2 files changed, 11 insertions(+), 19 deletions(-)
>>
>> diff --git a/target/microblaze/op_helper.c b/target/microblaze/ 
>> op_helper.c
>> index 470526ee92..092977b3e1 100644
>> --- a/target/microblaze/op_helper.c
>> +++ b/target/microblaze/op_helper.c
>> @@ -69,9 +69,9 @@ void helper_raise_exception(CPUMBState *env, 
>> uint32_t index)
>>       cpu_loop_exit(cs);
>>   }
>> -static bool check_divz(CPUMBState *env, uint32_t b, uintptr_t ra)
>> +static bool check_divz(CPUMBState *env, uint32_t divisor, uintptr_t pc)
> 
> The name GETPC notwithstanding, I don't think ra -> pc is a good rename.
> 
> PC often gets confused about whether that's a host or guest value.
> RA (return address) is less so; it gets used often in core tcg.
> 
> If you really don't like RA, then perhaps "retaddr" (also with quite a 
> bit of usage) or "unwind_pc" (no existing usage, but very descriptive).

+1 for 'unwind_pc'.

While thinking more about it, I noticed we don't document the
prototypes in "exec/cpu-common.h". Doing so we could rename
s/pc/unwind_pc/ and document @unwind_pc. Also these helpers
would be better declared in a TCG specific header. Anyway,
note for Richard, orthogonal to this patch ;)
Re: [PATCH v1 2/4] target/microblaze: div: Rename and reorder function args
Posted by Edgar E. Iglesias 2 months, 3 weeks ago 
On Mon, Aug 25, 2025 at 12:11:25PM +0200, Philippe Mathieu-Daudé wrote:
> On 25/8/25 01:32, Richard Henderson wrote:
> > On 8/25/25 08:27, Edgar E. Iglesias wrote:
> > > From: "Edgar E. Iglesias" <edgar.iglesias@amd.com>
> > > 
> > > Rename and reorder function args to better match with spec
> > > and pseudo code.
> > > 
> > > No functional change.
> > > 
> > > Signed-off-by: Edgar E. Iglesias <edgar.iglesias@amd.com>
> > > ---
> > >   target/microblaze/op_helper.c | 18 +++++++++---------
> > >   target/microblaze/translate.c | 12 ++----------
> > >   2 files changed, 11 insertions(+), 19 deletions(-)
> > > 
> > > diff --git a/target/microblaze/op_helper.c b/target/microblaze/
> > > op_helper.c
> > > index 470526ee92..092977b3e1 100644
> > > --- a/target/microblaze/op_helper.c
> > > +++ b/target/microblaze/op_helper.c
> > > @@ -69,9 +69,9 @@ void helper_raise_exception(CPUMBState *env,
> > > uint32_t index)
> > >       cpu_loop_exit(cs);
> > >   }
> > > -static bool check_divz(CPUMBState *env, uint32_t b, uintptr_t ra)
> > > +static bool check_divz(CPUMBState *env, uint32_t divisor, uintptr_t pc)
> > 
> > The name GETPC notwithstanding, I don't think ra -> pc is a good rename.
> > 
> > PC often gets confused about whether that's a host or guest value.
> > RA (return address) is less so; it gets used often in core tcg.
> > 
> > If you really don't like RA, then perhaps "retaddr" (also with quite a
> > bit of usage) or "unwind_pc" (no existing usage, but very descriptive).
> 
> +1 for 'unwind_pc'.


Sounds good!

Thanks,
Edgar

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