Re: [PATCH v4 4/4] ree: Improve ree pass for rs6000 target using defined ABI interfaces.

2023-05-19 Thread Jeff Law via Gcc-patches




On 5/16/23 06:35, Ajit Agarwal wrote:



On 29/04/23 5:03 am, Jeff Law wrote:



On 4/28/23 16:42, Hans-Peter Nilsson wrote:

On Sat, 22 Apr 2023, Ajit Agarwal via Gcc-patches wrote:


Hello All:

This new version of patch 4 use improve ree pass for rs6000 target using 
defined ABI interfaces.
Bootstrapped and regtested on power64-linux-gnu.

Thanks & Regards
Ajit


 ree: Improve ree pass for rs6000 target using defined abi interfaces

  For rs6000 target we see redundant zero and sign
  extension and done to improve ree pass to eliminate
  such redundant zero and sign extension using defines
  ABI interfaces.

  2023-04-22  Ajit Kumar Agarwal  

gcc/ChangeLog:

  * ree.cc (combline_reaching_defs): Add zero_extend
  using defined abi interfaces.
  (add_removable_extension): use of defined abi interfaces
  for no reaching defs.
  (abi_extension_candidate_return_reg_p): New defined ABI function.
  (abi_extension_candidate_p): New defined ABI function.
  (abi_extension_candidate_argno_p): New defined ABI function.
  (abi_handle_regs_without_defs_p): New defined ABI function.

gcc/testsuite/ChangeLog:

  * g++.target/powerpc/zext-elim-3.C
---
   gcc/ree.cc    | 176 +++---
   .../g++.target/powerpc/zext-elim-3.C  |  16 ++
   2 files changed, 162 insertions(+), 30 deletions(-)
   create mode 100644 gcc/testsuite/g++.target/powerpc/zext-elim-3.C

diff --git a/gcc/ree.cc b/gcc/ree.cc
index 413aec7c8eb..0de96b1ece1 100644
--- a/gcc/ree.cc
+++ b/gcc/ree.cc
@@ -473,7 +473,8 @@ get_defs (rtx_insn *insn, rtx reg, vec *dest)
   break;
   }
   -  gcc_assert (use != NULL);
+  if (use == NULL)
+    return NULL;
       ref_chain = DF_REF_CHAIN (use);
   @@ -514,7 +515,8 @@ get_uses (rtx_insn *insn, rtx reg)
   if (REGNO (DF_REF_REG (def)) == REGNO (reg))
     break;
   -  gcc_assert (def != NULL);
+  if (def == NULL)
+    return NULL;
       ref_chain = DF_REF_CHAIN (def);
   @@ -750,6 +752,103 @@ get_extended_src_reg (rtx src)
     return src;
   }
   +/* Return TRUE if the candidate insn is zero extend and regno is
+   an return  registers.  */
+
+static bool
+abi_extension_candidate_return_reg_p (rtx_insn *insn, int regno)
+{
+  rtx set = single_set (insn);
+
+  if (GET_CODE (SET_SRC (set)) !=  ZERO_EXTEND)
+    return false;
+
+  if (FUNCTION_VALUE_REGNO_P (regno))
+    return true;
+
+  return false;
+}
+
+/* Return TRUE if reg source operand of zero_extend is argument registers
+   and not return registers and source and destination operand are same
+   and mode of source and destination operand are not same.  */
+
+static bool
+abi_extension_candidate_p (rtx_insn *insn)
+{
+  rtx set = single_set (insn);
+
+  if (GET_CODE (SET_SRC (set)) !=  ZERO_EXTEND)
+    return false;
+
+  machine_mode ext_dst_mode = GET_MODE (SET_DEST (set));
+  rtx orig_src = XEXP (SET_SRC (set),0);
+
+  bool copy_needed
+    = (REGNO (SET_DEST (set)) != REGNO (XEXP (SET_SRC (set), 0)));
+
+  if (!copy_needed && ext_dst_mode != GET_MODE (orig_src)
+  && FUNCTION_ARG_REGNO_P (REGNO (orig_src))
+  && !abi_extension_candidate_return_reg_p (insn, REGNO (orig_src)))
+    return true;
+
+  return false;
+}
+
+/* Return TRUE if the candidate insn is zero extend and regno is
+   an argument registers.  */
+
+static bool
+abi_extension_candidate_argno_p (rtx_code code, int regno)
+{
+  if (code !=  ZERO_EXTEND)
+    return false;
+
+  if (FUNCTION_ARG_REGNO_P (regno))
+    return true;
+
+  return false;
+}


I don't see anything in those functions that checks if
ZERO_EXTEND is actually a feature of the ABI, e.g. as opposed to
no extension or SIGN_EXTEND.  Do I miss something?

I don't think you missed anything.  That was one of the points I was making 
last week.  Somewhere, somehow we need to describe what the ABI mandates and 
guarantees.

So while what Ajit has done is a step forward, at some point the actual details 
of the ABI need to be described in a way that can be checked and consumed by 
REE.



The ABI we need for ree pass are the argument registers and return registers. 
Based on that I have described interfaces that we need. Other than that we dont 
any other ABI hooks. I have used FUNCTION_VALUE_REGNO_P and 
FuNCTION_ARG_REGNO_P abi hooks.
You're working with one of many ABIs, some of which have useful 
properties, some of which do not.


Simply testing FUNCTION_VALUE_REGNO_P/FUNCTION_ARG_REGNO_P is not 
sufficient.  You need to be able to query the ABI properties.


jeff


Re: [PATCH v4 4/4] ree: Improve ree pass for rs6000 target using defined ABI interfaces.

2023-05-16 Thread Ajit Agarwal via Gcc-patches



On 29/04/23 5:03 am, Jeff Law wrote:
> 
> 
> On 4/28/23 16:42, Hans-Peter Nilsson wrote:
>> On Sat, 22 Apr 2023, Ajit Agarwal via Gcc-patches wrote:
>>
>>> Hello All:
>>>
>>> This new version of patch 4 use improve ree pass for rs6000 target using 
>>> defined ABI interfaces.
>>> Bootstrapped and regtested on power64-linux-gnu.
>>>
>>> Thanks & Regards
>>> Ajit
>>>
>>>
>>> ree: Improve ree pass for rs6000 target using defined abi interfaces
>>>
>>>  For rs6000 target we see redundant zero and sign
>>>  extension and done to improve ree pass to eliminate
>>>  such redundant zero and sign extension using defines
>>>  ABI interfaces.
>>>
>>>  2023-04-22  Ajit Kumar Agarwal  
>>>
>>> gcc/ChangeLog:
>>>
>>>  * ree.cc (combline_reaching_defs): Add zero_extend
>>>  using defined abi interfaces.
>>>  (add_removable_extension): use of defined abi interfaces
>>>  for no reaching defs.
>>>  (abi_extension_candidate_return_reg_p): New defined ABI function.
>>>  (abi_extension_candidate_p): New defined ABI function.
>>>  (abi_extension_candidate_argno_p): New defined ABI function.
>>>  (abi_handle_regs_without_defs_p): New defined ABI function.
>>>
>>> gcc/testsuite/ChangeLog:
>>>
>>>  * g++.target/powerpc/zext-elim-3.C
>>> ---
>>>   gcc/ree.cc    | 176 +++---
>>>   .../g++.target/powerpc/zext-elim-3.C  |  16 ++
>>>   2 files changed, 162 insertions(+), 30 deletions(-)
>>>   create mode 100644 gcc/testsuite/g++.target/powerpc/zext-elim-3.C
>>>
>>> diff --git a/gcc/ree.cc b/gcc/ree.cc
>>> index 413aec7c8eb..0de96b1ece1 100644
>>> --- a/gcc/ree.cc
>>> +++ b/gcc/ree.cc
>>> @@ -473,7 +473,8 @@ get_defs (rtx_insn *insn, rtx reg, vec 
>>> *dest)
>>>   break;
>>>   }
>>>   -  gcc_assert (use != NULL);
>>> +  if (use == NULL)
>>> +    return NULL;
>>>       ref_chain = DF_REF_CHAIN (use);
>>>   @@ -514,7 +515,8 @@ get_uses (rtx_insn *insn, rtx reg)
>>>   if (REGNO (DF_REF_REG (def)) == REGNO (reg))
>>>     break;
>>>   -  gcc_assert (def != NULL);
>>> +  if (def == NULL)
>>> +    return NULL;
>>>       ref_chain = DF_REF_CHAIN (def);
>>>   @@ -750,6 +752,103 @@ get_extended_src_reg (rtx src)
>>>     return src;
>>>   }
>>>   +/* Return TRUE if the candidate insn is zero extend and regno is
>>> +   an return  registers.  */
>>> +
>>> +static bool
>>> +abi_extension_candidate_return_reg_p (rtx_insn *insn, int regno)
>>> +{
>>> +  rtx set = single_set (insn);
>>> +
>>> +  if (GET_CODE (SET_SRC (set)) !=  ZERO_EXTEND)
>>> +    return false;
>>> +
>>> +  if (FUNCTION_VALUE_REGNO_P (regno))
>>> +    return true;
>>> +
>>> +  return false;
>>> +}
>>> +
>>> +/* Return TRUE if reg source operand of zero_extend is argument registers
>>> +   and not return registers and source and destination operand are same
>>> +   and mode of source and destination operand are not same.  */
>>> +
>>> +static bool
>>> +abi_extension_candidate_p (rtx_insn *insn)
>>> +{
>>> +  rtx set = single_set (insn);
>>> +
>>> +  if (GET_CODE (SET_SRC (set)) !=  ZERO_EXTEND)
>>> +    return false;
>>> +
>>> +  machine_mode ext_dst_mode = GET_MODE (SET_DEST (set));
>>> +  rtx orig_src = XEXP (SET_SRC (set),0);
>>> +
>>> +  bool copy_needed
>>> +    = (REGNO (SET_DEST (set)) != REGNO (XEXP (SET_SRC (set), 0)));
>>> +
>>> +  if (!copy_needed && ext_dst_mode != GET_MODE (orig_src)
>>> +  && FUNCTION_ARG_REGNO_P (REGNO (orig_src))
>>> +  && !abi_extension_candidate_return_reg_p (insn, REGNO (orig_src)))
>>> +    return true;
>>> +
>>> +  return false;
>>> +}
>>> +
>>> +/* Return TRUE if the candidate insn is zero extend and regno is
>>> +   an argument registers.  */
>>> +
>>> +static bool
>>> +abi_extension_candidate_argno_p (rtx_code code, int regno)
>>> +{
>>> +  if (code !=  ZERO_EXTEND)
>>> +    return false;
>>> +
>>> +  if (FUNCTION_ARG_REGNO_P (regno))
>>> +    return true;
>>> +
>>> +  return false;
>>> +}
>>
>> I don't see anything in those functions that checks if
>> ZERO_EXTEND is actually a feature of the ABI, e.g. as opposed to
>> no extension or SIGN_EXTEND.  Do I miss something?
> I don't think you missed anything.  That was one of the points I was making 
> last week.  Somewhere, somehow we need to describe what the ABI mandates and 
> guarantees.
> 
> So while what Ajit has done is a step forward, at some point the actual 
> details of the ABI need to be described in a way that can be checked and 
> consumed by REE.


The ABI we need for ree pass are the argument registers and return registers. 
Based on that I have described interfaces that we need. Other than that we dont 
any other ABI hooks. I have used FUNCTION_VALUE_REGNO_P and 
FuNCTION_ARG_REGNO_P abi hooks.

Thanks & Regards
Ajit
> 
> Jeff


Re: [PATCH v4 4/4] ree: Improve ree pass for rs6000 target using defined ABI interfaces.

2023-05-02 Thread Peter Bergner via Gcc-patches
On 4/28/23 6:49 PM, Hans-Peter Nilsson wrote:
> On Fri, 28 Apr 2023, Jeff Law wrote:
>> So while what Ajit has done is a step forward, at some point the actual
>> details of the ABI need to be described in a way that can be checked and
>> consumed by REE.
> 
> IIRC I also commented and suggested a few target macros that 
> *should* have helped to that effect.  Ajit, I suggest you see my 
> previous reply in this or a related conversation.

To be specific, Hans Peter said earlier:


On 3/30/23 7:01 PM, Hans-Peter Nilsson wrote:
> Pardon the arm-chair development mode but it sounds like 
> re-inventing the TARGET_PROMOTE_* hooks...
> 
> Maybe just hook up TARGET_PROMOTE_FUNCTION_MODE to ree.c (as 
> "you" already already define it for "rs6000")?


Peter




Re: [PATCH v4 4/4] ree: Improve ree pass for rs6000 target using defined ABI interfaces.

2023-05-01 Thread Segher Boessenkool
Hi!

On Sat, Apr 22, 2023 at 02:36:20PM +0530, Ajit Agarwal wrote:
> * ree.cc (combline_reaching_defs): Add zero_extend
> using defined abi interfaces.

Typo.  Also, please don't wrap lines early.  Also, you are missing some
changes in this file in the changelog.

> (add_removable_extension): use of defined abi interfaces
> for no reaching defs.

Capital U.

> (abi_extension_candidate_return_reg_p): New defined ABI function.

What does that even mean?  An "ABI function"?

> --- a/gcc/ree.cc
> +++ b/gcc/ree.cc
> @@ -473,7 +473,8 @@ get_defs (rtx_insn *insn, rtx reg, vec *dest)
>   break;
>  }
>  
> -  gcc_assert (use != NULL);
> +  if (use == NULL)
> +return NULL;

If it is suddenly allowed to have nil here, some comment somewhere needs
to change as well.

> new file mode 100644
> index 000..1d443af066a
> --- /dev/null
> +++ b/gcc/testsuite/g++.target/powerpc/zext-elim-3.C
> @@ -0,0 +1,16 @@
> +/* { dg-do compile { target { powerpc*-*-* } } } */

This is required of all file in g++.target/powerpc/ already:
# Exit immediately if this isn't a PowerPC target.
if {![istarget powerpc*-*-*] } then {
  return
}

so please don't repeat that here.

> +/* { dg-require-effective-target lp64 } */

Is that required?!

> +/* { dg-require-effective-target powerpc_p9vector_ok } */
> +/* { dg-options "-mcpu=power9 -O2 -free" } */

Why does this need p9?  We should test this on older systems as well, it
is a problem as old as the world!

> +void *memset(void *b, int c, unsigned long len)
> +{
> +  unsigned long i;
> +
> +  for (i = 0; i < len; i++)
> +((unsigned char *)b)[i] = c;
> +
> +   return b;
> +}
> +
> +/* { dg-final { scan-assembler-not "rlwinm" } } */

Please at least use {\mrlwinm\M}.  There are many other insns that can
be used for this same purpose as well.  We should at least test rldicl
here as well.


Segher


Re: [PATCH v4 4/4] ree: Improve ree pass for rs6000 target using defined ABI interfaces.

2023-04-28 Thread Hans-Peter Nilsson
On Fri, 28 Apr 2023, Jeff Law wrote:
> On 4/28/23 16:42, Hans-Peter Nilsson wrote:
> > On Sat, 22 Apr 2023, Ajit Agarwal via Gcc-patches wrote:
> > I don't see anything in those functions that checks if
> > ZERO_EXTEND is actually a feature of the ABI, e.g. as opposed to
> > no extension or SIGN_EXTEND.  Do I miss something?
> I don't think you missed anything.  That was one of the points I was making
> last week.  Somewhere, somehow we need to describe what the ABI mandates and
> guarantees.

Right, I thought this was the new version.

> So while what Ajit has done is a step forward, at some point the actual
> details of the ABI need to be described in a way that can be checked and
> consumed by REE.

IIRC I also commented and suggested a few target macros that 
*should* have helped to that effect.  Ajit, I suggest you see my 
previous reply in this or a related conversation.

brgds, H-P


Re: [PATCH v4 4/4] ree: Improve ree pass for rs6000 target using defined ABI interfaces.

2023-04-28 Thread Jeff Law via Gcc-patches




On 4/28/23 16:42, Hans-Peter Nilsson wrote:

On Sat, 22 Apr 2023, Ajit Agarwal via Gcc-patches wrote:


Hello All:

This new version of patch 4 use improve ree pass for rs6000 target using 
defined ABI interfaces.
Bootstrapped and regtested on power64-linux-gnu.

Thanks & Regards
Ajit


ree: Improve ree pass for rs6000 target using defined abi interfaces

 For rs6000 target we see redundant zero and sign
 extension and done to improve ree pass to eliminate
 such redundant zero and sign extension using defines
 ABI interfaces.

 2023-04-22  Ajit Kumar Agarwal  

gcc/ChangeLog:

 * ree.cc (combline_reaching_defs): Add zero_extend
 using defined abi interfaces.
 (add_removable_extension): use of defined abi interfaces
 for no reaching defs.
 (abi_extension_candidate_return_reg_p): New defined ABI function.
 (abi_extension_candidate_p): New defined ABI function.
 (abi_extension_candidate_argno_p): New defined ABI function.
 (abi_handle_regs_without_defs_p): New defined ABI function.

gcc/testsuite/ChangeLog:

 * g++.target/powerpc/zext-elim-3.C
---
  gcc/ree.cc| 176 +++---
  .../g++.target/powerpc/zext-elim-3.C  |  16 ++
  2 files changed, 162 insertions(+), 30 deletions(-)
  create mode 100644 gcc/testsuite/g++.target/powerpc/zext-elim-3.C

diff --git a/gcc/ree.cc b/gcc/ree.cc
index 413aec7c8eb..0de96b1ece1 100644
--- a/gcc/ree.cc
+++ b/gcc/ree.cc
@@ -473,7 +473,8 @@ get_defs (rtx_insn *insn, rtx reg, vec *dest)
break;
  }
  
-  gcc_assert (use != NULL);

+  if (use == NULL)
+return NULL;
  
ref_chain = DF_REF_CHAIN (use);
  
@@ -514,7 +515,8 @@ get_uses (rtx_insn *insn, rtx reg)

  if (REGNO (DF_REF_REG (def)) == REGNO (reg))
break;
  
-  gcc_assert (def != NULL);

+  if (def == NULL)
+return NULL;
  
ref_chain = DF_REF_CHAIN (def);
  
@@ -750,6 +752,103 @@ get_extended_src_reg (rtx src)

return src;
  }
  
+/* Return TRUE if the candidate insn is zero extend and regno is

+   an return  registers.  */
+
+static bool
+abi_extension_candidate_return_reg_p (rtx_insn *insn, int regno)
+{
+  rtx set = single_set (insn);
+
+  if (GET_CODE (SET_SRC (set)) !=  ZERO_EXTEND)
+return false;
+
+  if (FUNCTION_VALUE_REGNO_P (regno))
+return true;
+
+  return false;
+}
+
+/* Return TRUE if reg source operand of zero_extend is argument registers
+   and not return registers and source and destination operand are same
+   and mode of source and destination operand are not same.  */
+
+static bool
+abi_extension_candidate_p (rtx_insn *insn)
+{
+  rtx set = single_set (insn);
+
+  if (GET_CODE (SET_SRC (set)) !=  ZERO_EXTEND)
+return false;
+
+  machine_mode ext_dst_mode = GET_MODE (SET_DEST (set));
+  rtx orig_src = XEXP (SET_SRC (set),0);
+
+  bool copy_needed
+= (REGNO (SET_DEST (set)) != REGNO (XEXP (SET_SRC (set), 0)));
+
+  if (!copy_needed && ext_dst_mode != GET_MODE (orig_src)
+  && FUNCTION_ARG_REGNO_P (REGNO (orig_src))
+  && !abi_extension_candidate_return_reg_p (insn, REGNO (orig_src)))
+return true;
+
+  return false;
+}
+
+/* Return TRUE if the candidate insn is zero extend and regno is
+   an argument registers.  */
+
+static bool
+abi_extension_candidate_argno_p (rtx_code code, int regno)
+{
+  if (code !=  ZERO_EXTEND)
+return false;
+
+  if (FUNCTION_ARG_REGNO_P (regno))
+return true;
+
+  return false;
+}


I don't see anything in those functions that checks if
ZERO_EXTEND is actually a feature of the ABI, e.g. as opposed to
no extension or SIGN_EXTEND.  Do I miss something?
I don't think you missed anything.  That was one of the points I was 
making last week.  Somewhere, somehow we need to describe what the ABI 
mandates and guarantees.


So while what Ajit has done is a step forward, at some point the actual 
details of the ABI need to be described in a way that can be checked and 
consumed by REE.


Jeff


Re: [PATCH v4 4/4] ree: Improve ree pass for rs6000 target using defined ABI interfaces.

2023-04-28 Thread Hans-Peter Nilsson
On Sat, 22 Apr 2023, Ajit Agarwal via Gcc-patches wrote:

> Hello All:
> 
> This new version of patch 4 use improve ree pass for rs6000 target using 
> defined ABI interfaces.
> Bootstrapped and regtested on power64-linux-gnu.
> 
> Thanks & Regards
> Ajit
> 
> 
>   ree: Improve ree pass for rs6000 target using defined abi interfaces
> 
> For rs6000 target we see redundant zero and sign
> extension and done to improve ree pass to eliminate
> such redundant zero and sign extension using defines
> ABI interfaces.
> 
> 2023-04-22  Ajit Kumar Agarwal  
> 
> gcc/ChangeLog:
> 
> * ree.cc (combline_reaching_defs): Add zero_extend
> using defined abi interfaces.
> (add_removable_extension): use of defined abi interfaces
> for no reaching defs.
> (abi_extension_candidate_return_reg_p): New defined ABI function.
> (abi_extension_candidate_p): New defined ABI function.
> (abi_extension_candidate_argno_p): New defined ABI function.
> (abi_handle_regs_without_defs_p): New defined ABI function.
> 
> gcc/testsuite/ChangeLog:
> 
> * g++.target/powerpc/zext-elim-3.C
> ---
>  gcc/ree.cc| 176 +++---
>  .../g++.target/powerpc/zext-elim-3.C  |  16 ++
>  2 files changed, 162 insertions(+), 30 deletions(-)
>  create mode 100644 gcc/testsuite/g++.target/powerpc/zext-elim-3.C
> 
> diff --git a/gcc/ree.cc b/gcc/ree.cc
> index 413aec7c8eb..0de96b1ece1 100644
> --- a/gcc/ree.cc
> +++ b/gcc/ree.cc
> @@ -473,7 +473,8 @@ get_defs (rtx_insn *insn, rtx reg, vec *dest)
>   break;
>  }
>  
> -  gcc_assert (use != NULL);
> +  if (use == NULL)
> +return NULL;
>  
>ref_chain = DF_REF_CHAIN (use);
>  
> @@ -514,7 +515,8 @@ get_uses (rtx_insn *insn, rtx reg)
>  if (REGNO (DF_REF_REG (def)) == REGNO (reg))
>break;
>  
> -  gcc_assert (def != NULL);
> +  if (def == NULL)
> +return NULL;
>  
>ref_chain = DF_REF_CHAIN (def);
>  
> @@ -750,6 +752,103 @@ get_extended_src_reg (rtx src)
>return src;
>  }
>  
> +/* Return TRUE if the candidate insn is zero extend and regno is
> +   an return  registers.  */
> +
> +static bool
> +abi_extension_candidate_return_reg_p (rtx_insn *insn, int regno)
> +{
> +  rtx set = single_set (insn);
> +
> +  if (GET_CODE (SET_SRC (set)) !=  ZERO_EXTEND)
> +return false;
> +
> +  if (FUNCTION_VALUE_REGNO_P (regno))
> +return true;
> +
> +  return false;
> +}
> +
> +/* Return TRUE if reg source operand of zero_extend is argument registers
> +   and not return registers and source and destination operand are same
> +   and mode of source and destination operand are not same.  */
> +
> +static bool
> +abi_extension_candidate_p (rtx_insn *insn)
> +{
> +  rtx set = single_set (insn);
> +
> +  if (GET_CODE (SET_SRC (set)) !=  ZERO_EXTEND)
> +return false;
> +
> +  machine_mode ext_dst_mode = GET_MODE (SET_DEST (set));
> +  rtx orig_src = XEXP (SET_SRC (set),0);
> +
> +  bool copy_needed
> += (REGNO (SET_DEST (set)) != REGNO (XEXP (SET_SRC (set), 0)));
> +
> +  if (!copy_needed && ext_dst_mode != GET_MODE (orig_src)
> +  && FUNCTION_ARG_REGNO_P (REGNO (orig_src))
> +  && !abi_extension_candidate_return_reg_p (insn, REGNO (orig_src)))
> +return true;
> +
> +  return false;
> +}
> +
> +/* Return TRUE if the candidate insn is zero extend and regno is
> +   an argument registers.  */
> +
> +static bool
> +abi_extension_candidate_argno_p (rtx_code code, int regno)
> +{
> +  if (code !=  ZERO_EXTEND)
> +return false;
> +
> +  if (FUNCTION_ARG_REGNO_P (regno))
> +return true;
> +
> +  return false;
> +}

I don't see anything in those functions that checks if 
ZERO_EXTEND is actually a feature of the ABI, e.g. as opposed to 
no extension or SIGN_EXTEND.  Do I miss something?

Also, "!=  ZERO_EXTEND" has too many spaces, copy-pasted in 
several (all?) places.

Also, s/an return  registers/a return register/ (three errors).

brgds, H-P


[PATCH v4 4/4] ree: Improve ree pass for rs6000 target using defined ABI interfaces.

2023-04-22 Thread Ajit Agarwal via Gcc-patches
Hello All:

This new version of patch 4 use improve ree pass for rs6000 target using 
defined ABI interfaces.
Bootstrapped and regtested on power64-linux-gnu.

Thanks & Regards
Ajit


ree: Improve ree pass for rs6000 target using defined abi interfaces

For rs6000 target we see redundant zero and sign
extension and done to improve ree pass to eliminate
such redundant zero and sign extension using defines
ABI interfaces.

2023-04-22  Ajit Kumar Agarwal  

gcc/ChangeLog:

* ree.cc (combline_reaching_defs): Add zero_extend
using defined abi interfaces.
(add_removable_extension): use of defined abi interfaces
for no reaching defs.
(abi_extension_candidate_return_reg_p): New defined ABI function.
(abi_extension_candidate_p): New defined ABI function.
(abi_extension_candidate_argno_p): New defined ABI function.
(abi_handle_regs_without_defs_p): New defined ABI function.

gcc/testsuite/ChangeLog:

* g++.target/powerpc/zext-elim-3.C
---
 gcc/ree.cc| 176 +++---
 .../g++.target/powerpc/zext-elim-3.C  |  16 ++
 2 files changed, 162 insertions(+), 30 deletions(-)
 create mode 100644 gcc/testsuite/g++.target/powerpc/zext-elim-3.C

diff --git a/gcc/ree.cc b/gcc/ree.cc
index 413aec7c8eb..0de96b1ece1 100644
--- a/gcc/ree.cc
+++ b/gcc/ree.cc
@@ -473,7 +473,8 @@ get_defs (rtx_insn *insn, rtx reg, vec *dest)
break;
 }
 
-  gcc_assert (use != NULL);
+  if (use == NULL)
+return NULL;
 
   ref_chain = DF_REF_CHAIN (use);
 
@@ -514,7 +515,8 @@ get_uses (rtx_insn *insn, rtx reg)
 if (REGNO (DF_REF_REG (def)) == REGNO (reg))
   break;
 
-  gcc_assert (def != NULL);
+  if (def == NULL)
+return NULL;
 
   ref_chain = DF_REF_CHAIN (def);
 
@@ -750,6 +752,103 @@ get_extended_src_reg (rtx src)
   return src;
 }
 
+/* Return TRUE if the candidate insn is zero extend and regno is
+   an return  registers.  */
+
+static bool
+abi_extension_candidate_return_reg_p (rtx_insn *insn, int regno)
+{
+  rtx set = single_set (insn);
+
+  if (GET_CODE (SET_SRC (set)) !=  ZERO_EXTEND)
+return false;
+
+  if (FUNCTION_VALUE_REGNO_P (regno))
+return true;
+
+  return false;
+}
+
+/* Return TRUE if reg source operand of zero_extend is argument registers
+   and not return registers and source and destination operand are same
+   and mode of source and destination operand are not same.  */
+
+static bool
+abi_extension_candidate_p (rtx_insn *insn)
+{
+  rtx set = single_set (insn);
+
+  if (GET_CODE (SET_SRC (set)) !=  ZERO_EXTEND)
+return false;
+
+  machine_mode ext_dst_mode = GET_MODE (SET_DEST (set));
+  rtx orig_src = XEXP (SET_SRC (set),0);
+
+  bool copy_needed
+= (REGNO (SET_DEST (set)) != REGNO (XEXP (SET_SRC (set), 0)));
+
+  if (!copy_needed && ext_dst_mode != GET_MODE (orig_src)
+  && FUNCTION_ARG_REGNO_P (REGNO (orig_src))
+  && !abi_extension_candidate_return_reg_p (insn, REGNO (orig_src)))
+return true;
+
+  return false;
+}
+
+/* Return TRUE if the candidate insn is zero extend and regno is
+   an argument registers.  */
+
+static bool
+abi_extension_candidate_argno_p (rtx_code code, int regno)
+{
+  if (code !=  ZERO_EXTEND)
+return false;
+
+  if (FUNCTION_ARG_REGNO_P (regno))
+return true;
+
+  return false;
+}
+
+/* Return TRUE if the candidate insn doesn't have defs and have
+ * uses without RTX_BIN_ARITH/RTX_COMM_ARITH/RTX_UNARY rtx class.  */
+
+static bool
+abi_handle_regs_without_defs_p (rtx_insn *insn)
+{
+  if (side_effects_p (PATTERN (insn)))
+return false;
+
+  struct df_link *uses
+= get_uses (insn, SET_DEST (PATTERN (insn)));
+
+  if (!uses)
+return false;
+
+  for (df_link *use = uses; use; use = use->next)
+{
+  if (!use->ref)
+   return false;
+
+  if (BLOCK_FOR_INSN (insn)
+ != BLOCK_FOR_INSN (DF_REF_INSN (use->ref)))
+   return false;
+
+  rtx_insn *use_insn = DF_REF_INSN (use->ref);
+
+  if (GET_CODE (PATTERN (use_insn)) == SET)
+   {
+ rtx_code code = GET_CODE (SET_SRC (PATTERN (use_insn)));
+
+ if (GET_RTX_CLASS (code) == RTX_BIN_ARITH
+ || GET_RTX_CLASS (code) == RTX_COMM_ARITH
+ || GET_RTX_CLASS (code) == RTX_UNARY)
+   return false;
+   }
+ }
+  return true;
+}
+
 /* This function goes through all reaching defs of the source
of the candidate for elimination (CAND) and tries to combine
the extension with the definition instruction.  The changes
@@ -770,6 +869,11 @@ combine_reaching_defs (ext_cand *cand, const_rtx set_pat, 
ext_state *state)
 
   state->defs_list.truncate (0);
   state->copies_list.truncate (0);
+  rtx orig_src = XEXP (SET_SRC (cand->expr),0);
+
+  if (abi_extension_candidate_p (cand->insn)
+  && (!get_defs (cand->insn, orig_src, NULL)))
+return abi_handle_regs_without_defs_p (cand->insn);
 
   outcome = make_defs_and_copies_lists