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* [PATCH] PR target/66819: Allow indirect sibcall with register arguments
@ 2015-07-09 10:54 H.J. Lu
  2015-07-09 11:04 ` Uros Bizjak
  2015-07-10 16:30 ` Uros Bizjak
  0 siblings, 2 replies; 8+ messages in thread
From: H.J. Lu @ 2015-07-09 10:54 UTC (permalink / raw)
  To: gcc-patches; +Cc: Uros Bizjak

Indirect sibcall with register arguments is OK when there is register
available for argument passing.

OK for trunk if there is no regression?


H.J.
---
gcc/

	PR target/66819
	* config/i386/i386.c (ix86_function_ok_for_sibcall): Allow
	indirect sibcall with register arguments if register available
	for argument passing.
	(init_cumulative_args): Set cfun->machine->arg_reg_available_p
	to cum->nregs != 0.
	(function_arg_advance_32): Set cfun->machine->arg_reg_available_p
	to 0 when setting cum->nregs = 0.
	* config/i386/i386.h (machine_function): Add arg_reg_available_p.

gcc/testsuite/

	PR target/66819
	* gcc.target/i386/pr66819-1.c: New test.
	* gcc.target/i386/pr66819-2.c: Likewise.
	* gcc.target/i386/pr66819-3.c: Likewise.
	* gcc.target/i386/pr66819-4.c: Likewise.
	* gcc.target/i386/pr66819-5.c: Likewise.
---
 gcc/config/i386/i386.c                    | 15 +++++++++------
 gcc/config/i386/i386.h                    |  3 +++
 gcc/testsuite/gcc.target/i386/pr66819-1.c |  8 ++++++++
 gcc/testsuite/gcc.target/i386/pr66819-2.c |  8 ++++++++
 gcc/testsuite/gcc.target/i386/pr66819-3.c | 10 ++++++++++
 gcc/testsuite/gcc.target/i386/pr66819-4.c | 12 ++++++++++++
 gcc/testsuite/gcc.target/i386/pr66819-5.c | 10 ++++++++++
 7 files changed, 60 insertions(+), 6 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-1.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-2.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-3.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-4.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-5.c

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 54ee6f3..85e59a8 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -5628,12 +5628,12 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
       if (!decl
 	  || (TARGET_DLLIMPORT_DECL_ATTRIBUTES && DECL_DLLIMPORT_P (decl)))
 	{
-	  if (ix86_function_regparm (type, NULL) >= 3)
-	    {
-	      /* ??? Need to count the actual number of registers to be used,
-		 not the possible number of registers.  Fix later.  */
-	      return false;
-	    }
+	  /* FIXME: The symbol indirect call doesn't need a
+	     call-clobbered register.  But we don't know if
+	     this is a symbol indirect call or not  here.  */
+	  if (ix86_function_regparm (type, NULL) >= 3
+	      && !cfun->machine->arg_reg_available_p)
+	    return false;
 	}
     }
 
@@ -6567,6 +6567,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
                    ? X86_64_REGPARM_MAX
                    : X86_64_MS_REGPARM_MAX);
     }
+  cfun->machine->arg_reg_available_p = cum->nregs != 0;
   if (TARGET_SSE)
     {
       cum->sse_nregs = SSE_REGPARM_MAX;
@@ -6636,6 +6637,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
 	  else
 	    cum->nregs = ix86_function_regparm (fntype, fndecl);
 	}
+      cfun->machine->arg_reg_available_p = cum->nregs != 0;
 
       /* Set up the number of SSE registers used for passing SFmode
 	 and DFmode arguments.  Warn for mismatching ABI.  */
@@ -7584,6 +7586,7 @@ pass_in_reg:
 	{
 	  cum->nregs = 0;
 	  cum->regno = 0;
+	  cfun->machine->arg_reg_available_p = 0;
 	}
       break;
 
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 74334ff..0b6e304 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -2479,6 +2479,9 @@ struct GTY(()) machine_function {
   /* If true, it is safe to not save/restore DRAP register.  */
   BOOL_BITFIELD no_drap_save_restore : 1;
 
+  /* If true, there is register available for argument passing.  */
+  BOOL_BITFIELD arg_reg_available_p : 1;
+
   /* During prologue/epilogue generation, the current frame state.
      Otherwise, the frame state at the end of the prologue.  */
   struct machine_frame_state fs;
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-1.c b/gcc/testsuite/gcc.target/i386/pr66819-1.c
new file mode 100644
index 0000000..7c8a1ab
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-1.c
@@ -0,0 +1,8 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mregparm=3" } */
+/* { dg-final { scan-assembler-not "call" } } */
+
+void foo(void (*bar)(void))
+{
+  bar();
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-2.c b/gcc/testsuite/gcc.target/i386/pr66819-2.c
new file mode 100644
index 0000000..9de4f97
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-2.c
@@ -0,0 +1,8 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-fPIC -O2 -mregparm=3" } */
+/* { dg-final { scan-assembler-not "call" } } */
+
+void foo(void (*bar)(void))
+{
+  bar();
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-3.c b/gcc/testsuite/gcc.target/i386/pr66819-3.c
new file mode 100644
index 0000000..3bc5a34
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-3.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mregparm=3" } */
+/* { dg-final { scan-assembler-not "call" } } */
+
+void (*bar)(int, int);
+
+void foo(int i, int j)
+{
+  bar(i, j);
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-4.c b/gcc/testsuite/gcc.target/i386/pr66819-4.c
new file mode 100644
index 0000000..18b2ccf
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-4.c
@@ -0,0 +1,12 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mregparm=3" } */
+/* { dg-final { scan-assembler-not "call" } } */
+
+#include <stdarg.h>
+
+void (*bar)(int, va_list); 
+
+void foo(int i, va_list args)
+{
+  bar(i, args);
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-5.c b/gcc/testsuite/gcc.target/i386/pr66819-5.c
new file mode 100644
index 0000000..6b019d1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-5.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mregparm=3" } */
+/* { dg-final { scan-assembler "call" } } */
+
+void (*bar)(int, int, int);
+
+void foo(int i, int j, int k)
+{
+  bar(i, j, k);
+}
-- 
2.4.3

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] PR target/66819: Allow indirect sibcall with register arguments
  2015-07-09 10:54 [PATCH] PR target/66819: Allow indirect sibcall with register arguments H.J. Lu
@ 2015-07-09 11:04 ` Uros Bizjak
  2015-07-09 11:12   ` H.J. Lu
  2015-07-10 16:30 ` Uros Bizjak
  1 sibling, 1 reply; 8+ messages in thread
From: Uros Bizjak @ 2015-07-09 11:04 UTC (permalink / raw)
  To: H.J. Lu; +Cc: gcc-patches

On Thu, Jul 9, 2015 at 12:54 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> Indirect sibcall with register arguments is OK when there is register
> available for argument passing.
>
> OK for trunk if there is no regression?
>
>
> H.J.
> ---
> gcc/
>
>         PR target/66819
>         * config/i386/i386.c (ix86_function_ok_for_sibcall): Allow
>         indirect sibcall with register arguments if register available
>         for argument passing.
>         (init_cumulative_args): Set cfun->machine->arg_reg_available_p
>         to cum->nregs != 0.
>         (function_arg_advance_32): Set cfun->machine->arg_reg_available_p
>         to 0 when setting cum->nregs = 0.
>         * config/i386/i386.h (machine_function): Add arg_reg_available_p.
>
> gcc/testsuite/
>
>         PR target/66819
>         * gcc.target/i386/pr66819-1.c: New test.
>         * gcc.target/i386/pr66819-2.c: Likewise.
>         * gcc.target/i386/pr66819-3.c: Likewise.
>         * gcc.target/i386/pr66819-4.c: Likewise.
>         * gcc.target/i386/pr66819-5.c: Likewise.
> ---
>  gcc/config/i386/i386.c                    | 15 +++++++++------
>  gcc/config/i386/i386.h                    |  3 +++
>  gcc/testsuite/gcc.target/i386/pr66819-1.c |  8 ++++++++
>  gcc/testsuite/gcc.target/i386/pr66819-2.c |  8 ++++++++
>  gcc/testsuite/gcc.target/i386/pr66819-3.c | 10 ++++++++++
>  gcc/testsuite/gcc.target/i386/pr66819-4.c | 12 ++++++++++++
>  gcc/testsuite/gcc.target/i386/pr66819-5.c | 10 ++++++++++
>  7 files changed, 60 insertions(+), 6 deletions(-)
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-1.c
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-2.c
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-3.c
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-4.c
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-5.c
>
> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> index 54ee6f3..85e59a8 100644
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -5628,12 +5628,12 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
>        if (!decl
>           || (TARGET_DLLIMPORT_DECL_ATTRIBUTES && DECL_DLLIMPORT_P (decl)))
>         {
> -         if (ix86_function_regparm (type, NULL) >= 3)
> -           {
> -             /* ??? Need to count the actual number of registers to be used,
> -                not the possible number of registers.  Fix later.  */
> -             return false;
> -           }
> +         /* FIXME: The symbol indirect call doesn't need a
> +            call-clobbered register.  But we don't know if
> +            this is a symbol indirect call or not  here.  */
> +         if (ix86_function_regparm (type, NULL) >= 3
> +             && !cfun->machine->arg_reg_available_p)
> +           return false;
>         }
>      }

Why can't we directly look at nregs != 0 in the above code? AFAICS,
nregs accurately tracks number of available argument registers.

Uros.

> @@ -6567,6 +6567,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
>                     ? X86_64_REGPARM_MAX
>                     : X86_64_MS_REGPARM_MAX);
>      }
> +  cfun->machine->arg_reg_available_p = cum->nregs != 0;
>    if (TARGET_SSE)
>      {
>        cum->sse_nregs = SSE_REGPARM_MAX;
> @@ -6636,6 +6637,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
>           else
>             cum->nregs = ix86_function_regparm (fntype, fndecl);
>         }
> +      cfun->machine->arg_reg_available_p = cum->nregs != 0;
>
>        /* Set up the number of SSE registers used for passing SFmode
>          and DFmode arguments.  Warn for mismatching ABI.  */
> @@ -7584,6 +7586,7 @@ pass_in_reg:
>         {
>           cum->nregs = 0;
>           cum->regno = 0;
> +         cfun->machine->arg_reg_available_p = 0;
>         }
>        break;
>
> diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
> index 74334ff..0b6e304 100644
> --- a/gcc/config/i386/i386.h
> +++ b/gcc/config/i386/i386.h
> @@ -2479,6 +2479,9 @@ struct GTY(()) machine_function {
>    /* If true, it is safe to not save/restore DRAP register.  */
>    BOOL_BITFIELD no_drap_save_restore : 1;
>
> +  /* If true, there is register available for argument passing.  */
> +  BOOL_BITFIELD arg_reg_available_p : 1;
> +
>    /* During prologue/epilogue generation, the current frame state.
>       Otherwise, the frame state at the end of the prologue.  */
>    struct machine_frame_state fs;
> diff --git a/gcc/testsuite/gcc.target/i386/pr66819-1.c b/gcc/testsuite/gcc.target/i386/pr66819-1.c
> new file mode 100644
> index 0000000..7c8a1ab
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr66819-1.c
> @@ -0,0 +1,8 @@
> +/* { dg-do compile { target ia32 } } */
> +/* { dg-options "-O2 -mregparm=3" } */
> +/* { dg-final { scan-assembler-not "call" } } */
> +
> +void foo(void (*bar)(void))
> +{
> +  bar();
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr66819-2.c b/gcc/testsuite/gcc.target/i386/pr66819-2.c
> new file mode 100644
> index 0000000..9de4f97
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr66819-2.c
> @@ -0,0 +1,8 @@
> +/* { dg-do compile { target ia32 } } */
> +/* { dg-options "-fPIC -O2 -mregparm=3" } */
> +/* { dg-final { scan-assembler-not "call" } } */
> +
> +void foo(void (*bar)(void))
> +{
> +  bar();
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr66819-3.c b/gcc/testsuite/gcc.target/i386/pr66819-3.c
> new file mode 100644
> index 0000000..3bc5a34
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr66819-3.c
> @@ -0,0 +1,10 @@
> +/* { dg-do compile { target ia32 } } */
> +/* { dg-options "-O2 -mregparm=3" } */
> +/* { dg-final { scan-assembler-not "call" } } */
> +
> +void (*bar)(int, int);
> +
> +void foo(int i, int j)
> +{
> +  bar(i, j);
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr66819-4.c b/gcc/testsuite/gcc.target/i386/pr66819-4.c
> new file mode 100644
> index 0000000..18b2ccf
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr66819-4.c
> @@ -0,0 +1,12 @@
> +/* { dg-do compile { target ia32 } } */
> +/* { dg-options "-O2 -mregparm=3" } */
> +/* { dg-final { scan-assembler-not "call" } } */
> +
> +#include <stdarg.h>
> +
> +void (*bar)(int, va_list);
> +
> +void foo(int i, va_list args)
> +{
> +  bar(i, args);
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr66819-5.c b/gcc/testsuite/gcc.target/i386/pr66819-5.c
> new file mode 100644
> index 0000000..6b019d1
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr66819-5.c
> @@ -0,0 +1,10 @@
> +/* { dg-do compile { target ia32 } } */
> +/* { dg-options "-O2 -mregparm=3" } */
> +/* { dg-final { scan-assembler "call" } } */
> +
> +void (*bar)(int, int, int);
> +
> +void foo(int i, int j, int k)
> +{
> +  bar(i, j, k);
> +}
> --
> 2.4.3
>

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] PR target/66819: Allow indirect sibcall with register arguments
  2015-07-09 11:04 ` Uros Bizjak
@ 2015-07-09 11:12   ` H.J. Lu
  0 siblings, 0 replies; 8+ messages in thread
From: H.J. Lu @ 2015-07-09 11:12 UTC (permalink / raw)
  To: Uros Bizjak; +Cc: gcc-patches

On Thu, Jul 9, 2015 at 4:04 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
> On Thu, Jul 9, 2015 at 12:54 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> Indirect sibcall with register arguments is OK when there is register
>> available for argument passing.
>>
>> OK for trunk if there is no regression?
>>
>>
>> H.J.
>> ---
>> gcc/
>>
>>         PR target/66819
>>         * config/i386/i386.c (ix86_function_ok_for_sibcall): Allow
>>         indirect sibcall with register arguments if register available
>>         for argument passing.
>>         (init_cumulative_args): Set cfun->machine->arg_reg_available_p
>>         to cum->nregs != 0.
>>         (function_arg_advance_32): Set cfun->machine->arg_reg_available_p
>>         to 0 when setting cum->nregs = 0.
>>         * config/i386/i386.h (machine_function): Add arg_reg_available_p.
>>
>> gcc/testsuite/
>>
>>         PR target/66819
>>         * gcc.target/i386/pr66819-1.c: New test.
>>         * gcc.target/i386/pr66819-2.c: Likewise.
>>         * gcc.target/i386/pr66819-3.c: Likewise.
>>         * gcc.target/i386/pr66819-4.c: Likewise.
>>         * gcc.target/i386/pr66819-5.c: Likewise.
>> ---
>>  gcc/config/i386/i386.c                    | 15 +++++++++------
>>  gcc/config/i386/i386.h                    |  3 +++
>>  gcc/testsuite/gcc.target/i386/pr66819-1.c |  8 ++++++++
>>  gcc/testsuite/gcc.target/i386/pr66819-2.c |  8 ++++++++
>>  gcc/testsuite/gcc.target/i386/pr66819-3.c | 10 ++++++++++
>>  gcc/testsuite/gcc.target/i386/pr66819-4.c | 12 ++++++++++++
>>  gcc/testsuite/gcc.target/i386/pr66819-5.c | 10 ++++++++++
>>  7 files changed, 60 insertions(+), 6 deletions(-)
>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-1.c
>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-2.c
>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-3.c
>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-4.c
>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-5.c
>>
>> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
>> index 54ee6f3..85e59a8 100644
>> --- a/gcc/config/i386/i386.c
>> +++ b/gcc/config/i386/i386.c
>> @@ -5628,12 +5628,12 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
>>        if (!decl
>>           || (TARGET_DLLIMPORT_DECL_ATTRIBUTES && DECL_DLLIMPORT_P (decl)))
>>         {
>> -         if (ix86_function_regparm (type, NULL) >= 3)
>> -           {
>> -             /* ??? Need to count the actual number of registers to be used,
>> -                not the possible number of registers.  Fix later.  */
>> -             return false;
>> -           }
>> +         /* FIXME: The symbol indirect call doesn't need a
>> +            call-clobbered register.  But we don't know if
>> +            this is a symbol indirect call or not  here.  */
>> +         if (ix86_function_regparm (type, NULL) >= 3
>> +             && !cfun->machine->arg_reg_available_p)
>> +           return false;
>>         }
>>      }
>
> Why can't we directly look at nregs != 0 in the above code? AFAICS,
> nregs accurately tracks number of available argument registers.
>

I tried it first.  But nregs isn't accessible from ix86_function_ok_for_sibcall.

-- 
H.J.

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] PR target/66819: Allow indirect sibcall with register arguments
  2015-07-09 10:54 [PATCH] PR target/66819: Allow indirect sibcall with register arguments H.J. Lu
  2015-07-09 11:04 ` Uros Bizjak
@ 2015-07-10 16:30 ` Uros Bizjak
  2015-07-10 17:10   ` H.J. Lu
  1 sibling, 1 reply; 8+ messages in thread
From: Uros Bizjak @ 2015-07-10 16:30 UTC (permalink / raw)
  To: H.J. Lu; +Cc: gcc-patches

On Thu, Jul 9, 2015 at 12:54 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> Indirect sibcall with register arguments is OK when there is register
> available for argument passing.
>
> OK for trunk if there is no regression?
>
>
> H.J.
> ---
> gcc/
>
>         PR target/66819
>         * config/i386/i386.c (ix86_function_ok_for_sibcall): Allow
>         indirect sibcall with register arguments if register available
>         for argument passing.
>         (init_cumulative_args): Set cfun->machine->arg_reg_available_p
>         to cum->nregs != 0.
>         (function_arg_advance_32): Set cfun->machine->arg_reg_available_p
>         to 0 when setting cum->nregs = 0.

Do we also need similar functionality for 64bit ABIs? What happens if
we are out of argument regs there?

>         * config/i386/i386.h (machine_function): Add arg_reg_available_p.
>
> gcc/testsuite/
>
>         PR target/66819
>         * gcc.target/i386/pr66819-1.c: New test.
>         * gcc.target/i386/pr66819-2.c: Likewise.
>         * gcc.target/i386/pr66819-3.c: Likewise.
>         * gcc.target/i386/pr66819-4.c: Likewise.
>         * gcc.target/i386/pr66819-5.c: Likewise.
> ---
>  gcc/config/i386/i386.c                    | 15 +++++++++------
>  gcc/config/i386/i386.h                    |  3 +++
>  gcc/testsuite/gcc.target/i386/pr66819-1.c |  8 ++++++++
>  gcc/testsuite/gcc.target/i386/pr66819-2.c |  8 ++++++++
>  gcc/testsuite/gcc.target/i386/pr66819-3.c | 10 ++++++++++
>  gcc/testsuite/gcc.target/i386/pr66819-4.c | 12 ++++++++++++
>  gcc/testsuite/gcc.target/i386/pr66819-5.c | 10 ++++++++++
>  7 files changed, 60 insertions(+), 6 deletions(-)
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-1.c
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-2.c
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-3.c
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-4.c
>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-5.c
>
> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> index 54ee6f3..85e59a8 100644
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -5628,12 +5628,12 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
>        if (!decl
>           || (TARGET_DLLIMPORT_DECL_ATTRIBUTES && DECL_DLLIMPORT_P (decl)))
>         {
> -         if (ix86_function_regparm (type, NULL) >= 3)
> -           {
> -             /* ??? Need to count the actual number of registers to be used,
> -                not the possible number of registers.  Fix later.  */
> -             return false;
> -           }
> +         /* FIXME: The symbol indirect call doesn't need a
> +            call-clobbered register.  But we don't know if
> +            this is a symbol indirect call or not  here.  */
> +         if (ix86_function_regparm (type, NULL) >= 3
> +             && !cfun->machine->arg_reg_available_p)

Isn't enough to look at arg_reg_available here?

> +           return false;
>         }
>      }
>
> @@ -6567,6 +6567,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
>                     ? X86_64_REGPARM_MAX
>                     : X86_64_MS_REGPARM_MAX);
>      }
> +  cfun->machine->arg_reg_available_p = cum->nregs != 0;

false instead of 0. This is a boolean.

>    if (TARGET_SSE)
>      {
>        cum->sse_nregs = SSE_REGPARM_MAX;
> @@ -6636,6 +6637,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
>           else
>             cum->nregs = ix86_function_regparm (fntype, fndecl);
>         }
> +      cfun->machine->arg_reg_available_p = cum->nregs != 0;

IMO, cum->nregs > 0 would be more descriptive.

>        /* Set up the number of SSE registers used for passing SFmode
>          and DFmode arguments.  Warn for mismatching ABI.  */
> @@ -7584,6 +7586,7 @@ pass_in_reg:
>         {
>           cum->nregs = 0;
>           cum->regno = 0;
> +         cfun->machine->arg_reg_available_p = 0;
>         }
>        break;
>
> diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
> index 74334ff..0b6e304 100644
> --- a/gcc/config/i386/i386.h
> +++ b/gcc/config/i386/i386.h
> @@ -2479,6 +2479,9 @@ struct GTY(()) machine_function {
>    /* If true, it is safe to not save/restore DRAP register.  */
>    BOOL_BITFIELD no_drap_save_restore : 1;
>
> +  /* If true, there is register available for argument passing.  */
> +  BOOL_BITFIELD arg_reg_available_p : 1;

This is not a predicate, but a boolean flag. Please remove _p from the name.

> +
>    /* During prologue/epilogue generation, the current frame state.
>       Otherwise, the frame state at the end of the prologue.  */
>    struct machine_frame_state fs;
> diff --git a/gcc/testsuite/gcc.target/i386/pr66819-1.c b/gcc/testsuite/gcc.target/i386/pr66819-1.c
> new file mode 100644
> index 0000000..7c8a1ab
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr66819-1.c
> @@ -0,0 +1,8 @@
> +/* { dg-do compile { target ia32 } } */
> +/* { dg-options "-O2 -mregparm=3" } */
> +/* { dg-final { scan-assembler-not "call" } } */
> +
> +void foo(void (*bar)(void))
> +{
> +  bar();
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr66819-2.c b/gcc/testsuite/gcc.target/i386/pr66819-2.c
> new file mode 100644
> index 0000000..9de4f97
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr66819-2.c
> @@ -0,0 +1,8 @@
> +/* { dg-do compile { target ia32 } } */
> +/* { dg-options "-fPIC -O2 -mregparm=3" } */
> +/* { dg-final { scan-assembler-not "call" } } */
> +
> +void foo(void (*bar)(void))
> +{
> +  bar();
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr66819-3.c b/gcc/testsuite/gcc.target/i386/pr66819-3.c
> new file mode 100644
> index 0000000..3bc5a34
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr66819-3.c
> @@ -0,0 +1,10 @@
> +/* { dg-do compile { target ia32 } } */
> +/* { dg-options "-O2 -mregparm=3" } */
> +/* { dg-final { scan-assembler-not "call" } } */
> +
> +void (*bar)(int, int);
> +
> +void foo(int i, int j)
> +{
> +  bar(i, j);
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr66819-4.c b/gcc/testsuite/gcc.target/i386/pr66819-4.c
> new file mode 100644
> index 0000000..18b2ccf
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr66819-4.c
> @@ -0,0 +1,12 @@
> +/* { dg-do compile { target ia32 } } */
> +/* { dg-options "-O2 -mregparm=3" } */
> +/* { dg-final { scan-assembler-not "call" } } */
> +
> +#include <stdarg.h>
> +
> +void (*bar)(int, va_list);
> +
> +void foo(int i, va_list args)
> +{
> +  bar(i, args);
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/pr66819-5.c b/gcc/testsuite/gcc.target/i386/pr66819-5.c
> new file mode 100644
> index 0000000..6b019d1
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr66819-5.c
> @@ -0,0 +1,10 @@
> +/* { dg-do compile { target ia32 } } */
> +/* { dg-options "-O2 -mregparm=3" } */
> +/* { dg-final { scan-assembler "call" } } */
> +
> +void (*bar)(int, int, int);
> +
> +void foo(int i, int j, int k)
> +{
> +  bar(i, j, k);
> +}
> --
> 2.4.3
>

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] PR target/66819: Allow indirect sibcall with register arguments
  2015-07-10 16:30 ` Uros Bizjak
@ 2015-07-10 17:10   ` H.J. Lu
  2015-07-10 17:21     ` Uros Bizjak
  0 siblings, 1 reply; 8+ messages in thread
From: H.J. Lu @ 2015-07-10 17:10 UTC (permalink / raw)
  To: Uros Bizjak; +Cc: gcc-patches

[-- Attachment #1: Type: text/plain, Size: 4998 bytes --]

On Fri, Jul 10, 2015 at 9:30 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
> On Thu, Jul 9, 2015 at 12:54 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> Indirect sibcall with register arguments is OK when there is register
>> available for argument passing.
>>
>> OK for trunk if there is no regression?
>>
>>
>> H.J.
>> ---
>> gcc/
>>
>>         PR target/66819
>>         * config/i386/i386.c (ix86_function_ok_for_sibcall): Allow
>>         indirect sibcall with register arguments if register available
>>         for argument passing.
>>         (init_cumulative_args): Set cfun->machine->arg_reg_available_p
>>         to cum->nregs != 0.
>>         (function_arg_advance_32): Set cfun->machine->arg_reg_available_p
>>         to 0 when setting cum->nregs = 0.
>
> Do we also need similar functionality for 64bit ABIs? What happens if
> we are out of argument regs there?

64-bit is OK since we have rax, r10 and r11 as scratch registers which
aren't used to pass arguments.

>>         * config/i386/i386.h (machine_function): Add arg_reg_available_p.
>>
>> gcc/testsuite/
>>
>>         PR target/66819
>>         * gcc.target/i386/pr66819-1.c: New test.
>>         * gcc.target/i386/pr66819-2.c: Likewise.
>>         * gcc.target/i386/pr66819-3.c: Likewise.
>>         * gcc.target/i386/pr66819-4.c: Likewise.
>>         * gcc.target/i386/pr66819-5.c: Likewise.
>> ---
>>  gcc/config/i386/i386.c                    | 15 +++++++++------
>>  gcc/config/i386/i386.h                    |  3 +++
>>  gcc/testsuite/gcc.target/i386/pr66819-1.c |  8 ++++++++
>>  gcc/testsuite/gcc.target/i386/pr66819-2.c |  8 ++++++++
>>  gcc/testsuite/gcc.target/i386/pr66819-3.c | 10 ++++++++++
>>  gcc/testsuite/gcc.target/i386/pr66819-4.c | 12 ++++++++++++
>>  gcc/testsuite/gcc.target/i386/pr66819-5.c | 10 ++++++++++
>>  7 files changed, 60 insertions(+), 6 deletions(-)
>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-1.c
>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-2.c
>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-3.c
>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-4.c
>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-5.c
>>
>> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
>> index 54ee6f3..85e59a8 100644
>> --- a/gcc/config/i386/i386.c
>> +++ b/gcc/config/i386/i386.c
>> @@ -5628,12 +5628,12 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
>>        if (!decl
>>           || (TARGET_DLLIMPORT_DECL_ATTRIBUTES && DECL_DLLIMPORT_P (decl)))
>>         {
>> -         if (ix86_function_regparm (type, NULL) >= 3)
>> -           {
>> -             /* ??? Need to count the actual number of registers to be used,
>> -                not the possible number of registers.  Fix later.  */
>> -             return false;
>> -           }
>> +         /* FIXME: The symbol indirect call doesn't need a
>> +            call-clobbered register.  But we don't know if
>> +            this is a symbol indirect call or not  here.  */
>> +         if (ix86_function_regparm (type, NULL) >= 3
>> +             && !cfun->machine->arg_reg_available_p)
>
> Isn't enough to look at arg_reg_available here?

We need to check ix86_function_regparm since nregs is 0 if
-mregparm=N isn't used and pr65753.c will fail.

>> +           return false;
>>         }
>>      }
>>
>> @@ -6567,6 +6567,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
>>                     ? X86_64_REGPARM_MAX
>>                     : X86_64_MS_REGPARM_MAX);
>>      }
>> +  cfun->machine->arg_reg_available_p = cum->nregs != 0;
>
> false instead of 0. This is a boolean.

Updated.

>>    if (TARGET_SSE)
>>      {
>>        cum->sse_nregs = SSE_REGPARM_MAX;
>> @@ -6636,6 +6637,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
>>           else
>>             cum->nregs = ix86_function_regparm (fntype, fndecl);
>>         }
>> +      cfun->machine->arg_reg_available_p = cum->nregs != 0;
>
> IMO, cum->nregs > 0 would be more descriptive.

Updated.

>>        /* Set up the number of SSE registers used for passing SFmode
>>          and DFmode arguments.  Warn for mismatching ABI.  */
>> @@ -7584,6 +7586,7 @@ pass_in_reg:
>>         {
>>           cum->nregs = 0;
>>           cum->regno = 0;
>> +         cfun->machine->arg_reg_available_p = 0;
>>         }
>>        break;
>>
>> diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
>> index 74334ff..0b6e304 100644
>> --- a/gcc/config/i386/i386.h
>> +++ b/gcc/config/i386/i386.h
>> @@ -2479,6 +2479,9 @@ struct GTY(()) machine_function {
>>    /* If true, it is safe to not save/restore DRAP register.  */
>>    BOOL_BITFIELD no_drap_save_restore : 1;
>>
>> +  /* If true, there is register available for argument passing.  */
>> +  BOOL_BITFIELD arg_reg_available_p : 1;
>
> This is not a predicate, but a boolean flag. Please remove _p from the name.

Updated.

Here is the updated patch.  OK for trunk?

Thanks.

-- 
H.J.

[-- Attachment #2: 0001-Allow-indirect-sibcall-with-register-arguments.patch --]
[-- Type: text/x-patch, Size: 6137 bytes --]

From 3bcd6c122684d896840b2feb756e9b9ab8723ecc Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Wed, 8 Jul 2015 21:10:25 -0700
Subject: [PATCH] Allow indirect sibcall with register arguments

Indirect sibcall with register arguments is OK when there is register
available for argument passing.

gcc/

	PR target/66819
	* config/i386/i386.c (ix86_function_ok_for_sibcall): Allow
	indirect sibcall with register arguments if register available
	for argument passing.
	(init_cumulative_args): Set cfun->machine->arg_reg_available
	to cum->nregs != 0.
	(function_arg_advance_32): Set cfun->machine->arg_reg_available
	to 0 when setting cum->nregs = 0.
	* config/i386/i386.h (machine_function): Add arg_reg_available.

gcc/testsuite/

	PR target/66819
	* gcc.target/i386/pr66819-1.c: New test.
	* gcc.target/i386/pr66819-2.c: Likewise.
	* gcc.target/i386/pr66819-3.c: Likewise.
	* gcc.target/i386/pr66819-4.c: Likewise.
	* gcc.target/i386/pr66819-5.c: Likewise.
---
 gcc/config/i386/i386.c                    | 16 ++++++++++------
 gcc/config/i386/i386.h                    |  3 +++
 gcc/testsuite/gcc.target/i386/pr66819-1.c |  8 ++++++++
 gcc/testsuite/gcc.target/i386/pr66819-2.c |  8 ++++++++
 gcc/testsuite/gcc.target/i386/pr66819-3.c | 10 ++++++++++
 gcc/testsuite/gcc.target/i386/pr66819-4.c | 12 ++++++++++++
 gcc/testsuite/gcc.target/i386/pr66819-5.c | 10 ++++++++++
 7 files changed, 61 insertions(+), 6 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-1.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-2.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-3.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-4.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-5.c

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 57b8acc..c0a1993 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -5629,12 +5629,12 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
       if (!decl
 	  || (TARGET_DLLIMPORT_DECL_ATTRIBUTES && DECL_DLLIMPORT_P (decl)))
 	{
-	  if (ix86_function_regparm (type, NULL) >= 3)
-	    {
-	      /* ??? Need to count the actual number of registers to be used,
-		 not the possible number of registers.  Fix later.  */
-	      return false;
-	    }
+	  /* ??? The symbol indirect call doesn't need a
+	     call-clobbered register.  But we don't know if
+	     this is a symbol indirect call or not here.  */
+	  if (ix86_function_regparm (type, NULL) >= 3
+	      && !cfun->machine->arg_reg_available)
+	    return false;
 	}
     }
 
@@ -6610,6 +6610,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
       if (stdarg_p (fntype))
 	{
 	  cum->nregs = 0;
+	  cfun->machine->arg_reg_available = false;
 	  cum->sse_nregs = 0;
 	  cum->mmx_nregs = 0;
 	  cum->warn_avx512f = false;
@@ -6642,6 +6643,8 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
 	 and DFmode arguments.  Warn for mismatching ABI.  */
       cum->float_in_sse = ix86_function_sseregparm (fntype, fndecl, true);
     }
+
+  cfun->machine->arg_reg_available = (cum->nregs > 0);
 }
 
 /* Return the "natural" mode for TYPE.  In most cases, this is just TYPE_MODE.
@@ -7584,6 +7587,7 @@ pass_in_reg:
       if (cum->nregs <= 0)
 	{
 	  cum->nregs = 0;
+	  cfun->machine->arg_reg_available = false;
 	  cum->regno = 0;
 	}
       break;
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 74334ff..14006c8 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -2479,6 +2479,9 @@ struct GTY(()) machine_function {
   /* If true, it is safe to not save/restore DRAP register.  */
   BOOL_BITFIELD no_drap_save_restore : 1;
 
+  /* If true, there is register available for argument passing.  */
+  BOOL_BITFIELD arg_reg_available : 1;
+
   /* During prologue/epilogue generation, the current frame state.
      Otherwise, the frame state at the end of the prologue.  */
   struct machine_frame_state fs;
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-1.c b/gcc/testsuite/gcc.target/i386/pr66819-1.c
new file mode 100644
index 0000000..7c8a1ab
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-1.c
@@ -0,0 +1,8 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mregparm=3" } */
+/* { dg-final { scan-assembler-not "call" } } */
+
+void foo(void (*bar)(void))
+{
+  bar();
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-2.c b/gcc/testsuite/gcc.target/i386/pr66819-2.c
new file mode 100644
index 0000000..9de4f97
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-2.c
@@ -0,0 +1,8 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-fPIC -O2 -mregparm=3" } */
+/* { dg-final { scan-assembler-not "call" } } */
+
+void foo(void (*bar)(void))
+{
+  bar();
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-3.c b/gcc/testsuite/gcc.target/i386/pr66819-3.c
new file mode 100644
index 0000000..3bc5a34
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-3.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mregparm=3" } */
+/* { dg-final { scan-assembler-not "call" } } */
+
+void (*bar)(int, int);
+
+void foo(int i, int j)
+{
+  bar(i, j);
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-4.c b/gcc/testsuite/gcc.target/i386/pr66819-4.c
new file mode 100644
index 0000000..18b2ccf
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-4.c
@@ -0,0 +1,12 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mregparm=3" } */
+/* { dg-final { scan-assembler-not "call" } } */
+
+#include <stdarg.h>
+
+void (*bar)(int, va_list); 
+
+void foo(int i, va_list args)
+{
+  bar(i, args);
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-5.c b/gcc/testsuite/gcc.target/i386/pr66819-5.c
new file mode 100644
index 0000000..6b019d1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-5.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mregparm=3" } */
+/* { dg-final { scan-assembler "call" } } */
+
+void (*bar)(int, int, int);
+
+void foo(int i, int j, int k)
+{
+  bar(i, j, k);
+}
-- 
2.4.3


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] PR target/66819: Allow indirect sibcall with register arguments
  2015-07-10 17:10   ` H.J. Lu
@ 2015-07-10 17:21     ` Uros Bizjak
  2015-07-10 17:58       ` H.J. Lu
  0 siblings, 1 reply; 8+ messages in thread
From: Uros Bizjak @ 2015-07-10 17:21 UTC (permalink / raw)
  To: H.J. Lu; +Cc: gcc-patches

On Fri, Jul 10, 2015 at 7:10 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Fri, Jul 10, 2015 at 9:30 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
>> On Thu, Jul 9, 2015 at 12:54 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>> Indirect sibcall with register arguments is OK when there is register
>>> available for argument passing.
>>>
>>> OK for trunk if there is no regression?
>>>
>>>
>>> H.J.
>>> ---
>>> gcc/
>>>
>>>         PR target/66819
>>>         * config/i386/i386.c (ix86_function_ok_for_sibcall): Allow
>>>         indirect sibcall with register arguments if register available
>>>         for argument passing.
>>>         (init_cumulative_args): Set cfun->machine->arg_reg_available_p
>>>         to cum->nregs != 0.

Please update the above entry for nregs > 0.

>>>         (function_arg_advance_32): Set cfun->machine->arg_reg_available_p
>>>         to 0 when setting cum->nregs = 0.
>>
>> Do we also need similar functionality for 64bit ABIs? What happens if
>> we are out of argument regs there?
>
> 64-bit is OK since we have rax, r10 and r11 as scratch registers which
> aren't used to pass arguments.

Maybe this fact should be added as a comment in some appropriate place.

>>>         * config/i386/i386.h (machine_function): Add arg_reg_available_p.
>>>
>>> gcc/testsuite/
>>>
>>>         PR target/66819
>>>         * gcc.target/i386/pr66819-1.c: New test.
>>>         * gcc.target/i386/pr66819-2.c: Likewise.
>>>         * gcc.target/i386/pr66819-3.c: Likewise.
>>>         * gcc.target/i386/pr66819-4.c: Likewise.
>>>         * gcc.target/i386/pr66819-5.c: Likewise.
>>> ---
>>>  gcc/config/i386/i386.c                    | 15 +++++++++------
>>>  gcc/config/i386/i386.h                    |  3 +++
>>>  gcc/testsuite/gcc.target/i386/pr66819-1.c |  8 ++++++++
>>>  gcc/testsuite/gcc.target/i386/pr66819-2.c |  8 ++++++++
>>>  gcc/testsuite/gcc.target/i386/pr66819-3.c | 10 ++++++++++
>>>  gcc/testsuite/gcc.target/i386/pr66819-4.c | 12 ++++++++++++
>>>  gcc/testsuite/gcc.target/i386/pr66819-5.c | 10 ++++++++++
>>>  7 files changed, 60 insertions(+), 6 deletions(-)
>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-1.c
>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-2.c
>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-3.c
>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-4.c
>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-5.c
>>>
>>> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
>>> index 54ee6f3..85e59a8 100644
>>> --- a/gcc/config/i386/i386.c
>>> +++ b/gcc/config/i386/i386.c
>>> @@ -5628,12 +5628,12 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
>>>        if (!decl
>>>           || (TARGET_DLLIMPORT_DECL_ATTRIBUTES && DECL_DLLIMPORT_P (decl)))
>>>         {
>>> -         if (ix86_function_regparm (type, NULL) >= 3)
>>> -           {
>>> -             /* ??? Need to count the actual number of registers to be used,
>>> -                not the possible number of registers.  Fix later.  */
>>> -             return false;
>>> -           }
>>> +         /* FIXME: The symbol indirect call doesn't need a
>>> +            call-clobbered register.  But we don't know if
>>> +            this is a symbol indirect call or not  here.  */
>>> +         if (ix86_function_regparm (type, NULL) >= 3
>>> +             && !cfun->machine->arg_reg_available_p)
>>
>> Isn't enough to look at arg_reg_available here?
>
> We need to check ix86_function_regparm since nregs is 0 if
> -mregparm=N isn't used and pr65753.c will fail.

OK. Please add this comment, is not that obvious.

>
>>> +           return false;
>>>         }
>>>      }
>>>
>>> @@ -6567,6 +6567,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
>>>                     ? X86_64_REGPARM_MAX
>>>                     : X86_64_MS_REGPARM_MAX);
>>>      }
>>> +  cfun->machine->arg_reg_available_p = cum->nregs != 0;
>>
>> false instead of 0. This is a boolean.
>
> Updated.
>
>>>    if (TARGET_SSE)
>>>      {
>>>        cum->sse_nregs = SSE_REGPARM_MAX;
>>> @@ -6636,6 +6637,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
>>>           else
>>>             cum->nregs = ix86_function_regparm (fntype, fndecl);
>>>         }
>>> +      cfun->machine->arg_reg_available_p = cum->nregs != 0;
>>
>> IMO, cum->nregs > 0 would be more descriptive.
>
> Updated.
>
>>>        /* Set up the number of SSE registers used for passing SFmode
>>>          and DFmode arguments.  Warn for mismatching ABI.  */
>>> @@ -7584,6 +7586,7 @@ pass_in_reg:
>>>         {
>>>           cum->nregs = 0;
>>>           cum->regno = 0;
>>> +         cfun->machine->arg_reg_available_p = 0;
>>>         }
>>>        break;
>>>
>>> diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
>>> index 74334ff..0b6e304 100644
>>> --- a/gcc/config/i386/i386.h
>>> +++ b/gcc/config/i386/i386.h
>>> @@ -2479,6 +2479,9 @@ struct GTY(()) machine_function {
>>>    /* If true, it is safe to not save/restore DRAP register.  */
>>>    BOOL_BITFIELD no_drap_save_restore : 1;
>>>
>>> +  /* If true, there is register available for argument passing.  */
>>> +  BOOL_BITFIELD arg_reg_available_p : 1;
>>
>> This is not a predicate, but a boolean flag. Please remove _p from the name.
>
> Updated.
>
> Here is the updated patch.  OK for trunk?

OK with a small comment additions.

+  /* If true, there is register available for argument passing.  */
+  BOOL_BITFIELD arg_reg_available : 1;
+

Please mention here that this is for 32bit targets only.

Thanks,
Uros.

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] PR target/66819: Allow indirect sibcall with register arguments
  2015-07-10 17:21     ` Uros Bizjak
@ 2015-07-10 17:58       ` H.J. Lu
  2015-07-10 19:54         ` Uros Bizjak
  0 siblings, 1 reply; 8+ messages in thread
From: H.J. Lu @ 2015-07-10 17:58 UTC (permalink / raw)
  To: Uros Bizjak; +Cc: gcc-patches

[-- Attachment #1: Type: text/plain, Size: 5842 bytes --]

On Fri, Jul 10, 2015 at 10:21 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
> On Fri, Jul 10, 2015 at 7:10 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> On Fri, Jul 10, 2015 at 9:30 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
>>> On Thu, Jul 9, 2015 at 12:54 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>>> Indirect sibcall with register arguments is OK when there is register
>>>> available for argument passing.
>>>>
>>>> OK for trunk if there is no regression?
>>>>
>>>>
>>>> H.J.
>>>> ---
>>>> gcc/
>>>>
>>>>         PR target/66819
>>>>         * config/i386/i386.c (ix86_function_ok_for_sibcall): Allow
>>>>         indirect sibcall with register arguments if register available
>>>>         for argument passing.
>>>>         (init_cumulative_args): Set cfun->machine->arg_reg_available_p
>>>>         to cum->nregs != 0.
>
> Please update the above entry for nregs > 0.
>
>>>>         (function_arg_advance_32): Set cfun->machine->arg_reg_available_p
>>>>         to 0 when setting cum->nregs = 0.
>>>
>>> Do we also need similar functionality for 64bit ABIs? What happens if
>>> we are out of argument regs there?
>>
>> 64-bit is OK since we have rax, r10 and r11 as scratch registers which
>> aren't used to pass arguments.
>
> Maybe this fact should be added as a comment in some appropriate place.
>
>>>>         * config/i386/i386.h (machine_function): Add arg_reg_available_p.
>>>>
>>>> gcc/testsuite/
>>>>
>>>>         PR target/66819
>>>>         * gcc.target/i386/pr66819-1.c: New test.
>>>>         * gcc.target/i386/pr66819-2.c: Likewise.
>>>>         * gcc.target/i386/pr66819-3.c: Likewise.
>>>>         * gcc.target/i386/pr66819-4.c: Likewise.
>>>>         * gcc.target/i386/pr66819-5.c: Likewise.
>>>> ---
>>>>  gcc/config/i386/i386.c                    | 15 +++++++++------
>>>>  gcc/config/i386/i386.h                    |  3 +++
>>>>  gcc/testsuite/gcc.target/i386/pr66819-1.c |  8 ++++++++
>>>>  gcc/testsuite/gcc.target/i386/pr66819-2.c |  8 ++++++++
>>>>  gcc/testsuite/gcc.target/i386/pr66819-3.c | 10 ++++++++++
>>>>  gcc/testsuite/gcc.target/i386/pr66819-4.c | 12 ++++++++++++
>>>>  gcc/testsuite/gcc.target/i386/pr66819-5.c | 10 ++++++++++
>>>>  7 files changed, 60 insertions(+), 6 deletions(-)
>>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-1.c
>>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-2.c
>>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-3.c
>>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-4.c
>>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-5.c
>>>>
>>>> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
>>>> index 54ee6f3..85e59a8 100644
>>>> --- a/gcc/config/i386/i386.c
>>>> +++ b/gcc/config/i386/i386.c
>>>> @@ -5628,12 +5628,12 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
>>>>        if (!decl
>>>>           || (TARGET_DLLIMPORT_DECL_ATTRIBUTES && DECL_DLLIMPORT_P (decl)))
>>>>         {
>>>> -         if (ix86_function_regparm (type, NULL) >= 3)
>>>> -           {
>>>> -             /* ??? Need to count the actual number of registers to be used,
>>>> -                not the possible number of registers.  Fix later.  */
>>>> -             return false;
>>>> -           }
>>>> +         /* FIXME: The symbol indirect call doesn't need a
>>>> +            call-clobbered register.  But we don't know if
>>>> +            this is a symbol indirect call or not  here.  */
>>>> +         if (ix86_function_regparm (type, NULL) >= 3
>>>> +             && !cfun->machine->arg_reg_available_p)
>>>
>>> Isn't enough to look at arg_reg_available here?
>>
>> We need to check ix86_function_regparm since nregs is 0 if
>> -mregparm=N isn't used and pr65753.c will fail.
>
> OK. Please add this comment, is not that obvious.
>
>>
>>>> +           return false;
>>>>         }
>>>>      }
>>>>
>>>> @@ -6567,6 +6567,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
>>>>                     ? X86_64_REGPARM_MAX
>>>>                     : X86_64_MS_REGPARM_MAX);
>>>>      }
>>>> +  cfun->machine->arg_reg_available_p = cum->nregs != 0;
>>>
>>> false instead of 0. This is a boolean.
>>
>> Updated.
>>
>>>>    if (TARGET_SSE)
>>>>      {
>>>>        cum->sse_nregs = SSE_REGPARM_MAX;
>>>> @@ -6636,6 +6637,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
>>>>           else
>>>>             cum->nregs = ix86_function_regparm (fntype, fndecl);
>>>>         }
>>>> +      cfun->machine->arg_reg_available_p = cum->nregs != 0;
>>>
>>> IMO, cum->nregs > 0 would be more descriptive.
>>
>> Updated.
>>
>>>>        /* Set up the number of SSE registers used for passing SFmode
>>>>          and DFmode arguments.  Warn for mismatching ABI.  */
>>>> @@ -7584,6 +7586,7 @@ pass_in_reg:
>>>>         {
>>>>           cum->nregs = 0;
>>>>           cum->regno = 0;
>>>> +         cfun->machine->arg_reg_available_p = 0;
>>>>         }
>>>>        break;
>>>>
>>>> diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
>>>> index 74334ff..0b6e304 100644
>>>> --- a/gcc/config/i386/i386.h
>>>> +++ b/gcc/config/i386/i386.h
>>>> @@ -2479,6 +2479,9 @@ struct GTY(()) machine_function {
>>>>    /* If true, it is safe to not save/restore DRAP register.  */
>>>>    BOOL_BITFIELD no_drap_save_restore : 1;
>>>>
>>>> +  /* If true, there is register available for argument passing.  */
>>>> +  BOOL_BITFIELD arg_reg_available_p : 1;
>>>
>>> This is not a predicate, but a boolean flag. Please remove _p from the name.
>>
>> Updated.
>>
>> Here is the updated patch.  OK for trunk?
>
> OK with a small comment additions.
>
> +  /* If true, there is register available for argument passing.  */
> +  BOOL_BITFIELD arg_reg_available : 1;
> +
>
> Please mention here that this is for 32bit targets only.
>

Updated. Is this one OK?

Thanks.


-- 
H.J.

[-- Attachment #2: 0001-Allow-indirect-sibcall-with-register-arguments.patch --]
[-- Type: text/x-patch, Size: 6807 bytes --]

From 528ddcbfa2d66c6b34dea88d9ad64593be89159e Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Wed, 8 Jul 2015 21:10:25 -0700
Subject: [PATCH] Allow indirect sibcall with register arguments

Indirect sibcall with register arguments is OK when there is register
available for argument passing.

gcc/

	PR target/66819
	* config/i386/i386.c (ix86_function_ok_for_sibcall): Allow
	indirect sibcall with register arguments if register available
	for argument passing.
	(init_cumulative_args): Set cfun->machine->arg_reg_available
	to (cum->nregs > 0) or to true if function has a variable
	argument list.
	(function_arg_advance_32): Set cfun->machine->arg_reg_available
	to false if cum->nregs <= 0.
	* config/i386/i386.h (machine_function): Add arg_reg_available.

gcc/testsuite/

	PR target/66819
	* gcc.target/i386/pr66819-1.c: New test.
	* gcc.target/i386/pr66819-2.c: Likewise.
	* gcc.target/i386/pr66819-3.c: Likewise.
	* gcc.target/i386/pr66819-4.c: Likewise.
	* gcc.target/i386/pr66819-5.c: Likewise.
---
 gcc/config/i386/i386.c                    | 23 +++++++++++++++++------
 gcc/config/i386/i386.h                    |  7 +++++++
 gcc/testsuite/gcc.target/i386/pr66819-1.c |  8 ++++++++
 gcc/testsuite/gcc.target/i386/pr66819-2.c |  8 ++++++++
 gcc/testsuite/gcc.target/i386/pr66819-3.c | 10 ++++++++++
 gcc/testsuite/gcc.target/i386/pr66819-4.c | 12 ++++++++++++
 gcc/testsuite/gcc.target/i386/pr66819-5.c | 10 ++++++++++
 7 files changed, 72 insertions(+), 6 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-1.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-2.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-3.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-4.c
 create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-5.c

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 6929caf..0f96452 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -5629,12 +5629,16 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
       if (!decl
 	  || (TARGET_DLLIMPORT_DECL_ATTRIBUTES && DECL_DLLIMPORT_P (decl)))
 	{
-	  if (ix86_function_regparm (type, NULL) >= 3)
-	    {
-	      /* ??? Need to count the actual number of registers to be used,
-		 not the possible number of registers.  Fix later.  */
-	      return false;
-	    }
+	  /* Check if regparm >= 3 since arg_reg_available is set to
+	     false if regparm == 0.  If regparm is 1 or 2, there is
+	     always a call-clobbered register available.
+
+	     ??? The symbol indirect call doesn't need a call-clobbered
+	     register.  But we don't know if this is a symbol indirect
+	     call or not here.  */
+	  if (ix86_function_regparm (type, NULL) >= 3
+	      && !cfun->machine->arg_reg_available)
+	    return false;
 	}
     }
 
@@ -6610,6 +6614,10 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
       if (stdarg_p (fntype))
 	{
 	  cum->nregs = 0;
+	  /* Since in 32-bit, variable arguments are always passed on
+	     stack, there is scratch register available for indirect
+	     sibcall.  */
+	  cfun->machine->arg_reg_available = true;
 	  cum->sse_nregs = 0;
 	  cum->mmx_nregs = 0;
 	  cum->warn_avx512f = false;
@@ -6642,6 +6650,8 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
 	 and DFmode arguments.  Warn for mismatching ABI.  */
       cum->float_in_sse = ix86_function_sseregparm (fntype, fndecl, true);
     }
+
+  cfun->machine->arg_reg_available = (cum->nregs > 0);
 }
 
 /* Return the "natural" mode for TYPE.  In most cases, this is just TYPE_MODE.
@@ -7584,6 +7594,7 @@ pass_in_reg:
       if (cum->nregs <= 0)
 	{
 	  cum->nregs = 0;
+	  cfun->machine->arg_reg_available = false;
 	  cum->regno = 0;
 	}
       break;
diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
index 74334ff..0fcf391 100644
--- a/gcc/config/i386/i386.h
+++ b/gcc/config/i386/i386.h
@@ -2479,6 +2479,13 @@ struct GTY(()) machine_function {
   /* If true, it is safe to not save/restore DRAP register.  */
   BOOL_BITFIELD no_drap_save_restore : 1;
 
+  /* If true, there is register available for argument passing.  This
+     is used only in ix86_function_ok_for_sibcall by 32-bit to determine
+     if there is scratch register available for indirect sibcall.  In
+     64-bit, rax, r10 and r11 are scratch registers which aren't used to
+     pass arguments and can be used for indirect sibcall.  */
+  BOOL_BITFIELD arg_reg_available : 1;
+
   /* During prologue/epilogue generation, the current frame state.
      Otherwise, the frame state at the end of the prologue.  */
   struct machine_frame_state fs;
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-1.c b/gcc/testsuite/gcc.target/i386/pr66819-1.c
new file mode 100644
index 0000000..7c8a1ab
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-1.c
@@ -0,0 +1,8 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mregparm=3" } */
+/* { dg-final { scan-assembler-not "call" } } */
+
+void foo(void (*bar)(void))
+{
+  bar();
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-2.c b/gcc/testsuite/gcc.target/i386/pr66819-2.c
new file mode 100644
index 0000000..9de4f97
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-2.c
@@ -0,0 +1,8 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-fPIC -O2 -mregparm=3" } */
+/* { dg-final { scan-assembler-not "call" } } */
+
+void foo(void (*bar)(void))
+{
+  bar();
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-3.c b/gcc/testsuite/gcc.target/i386/pr66819-3.c
new file mode 100644
index 0000000..3bc5a34
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-3.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mregparm=3" } */
+/* { dg-final { scan-assembler-not "call" } } */
+
+void (*bar)(int, int);
+
+void foo(int i, int j)
+{
+  bar(i, j);
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-4.c b/gcc/testsuite/gcc.target/i386/pr66819-4.c
new file mode 100644
index 0000000..18b2ccf
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-4.c
@@ -0,0 +1,12 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mregparm=3" } */
+/* { dg-final { scan-assembler-not "call" } } */
+
+#include <stdarg.h>
+
+void (*bar)(int, va_list); 
+
+void foo(int i, va_list args)
+{
+  bar(i, args);
+}
diff --git a/gcc/testsuite/gcc.target/i386/pr66819-5.c b/gcc/testsuite/gcc.target/i386/pr66819-5.c
new file mode 100644
index 0000000..6b019d1
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66819-5.c
@@ -0,0 +1,10 @@
+/* { dg-do compile { target ia32 } } */
+/* { dg-options "-O2 -mregparm=3" } */
+/* { dg-final { scan-assembler "call" } } */
+
+void (*bar)(int, int, int);
+
+void foo(int i, int j, int k)
+{
+  bar(i, j, k);
+}
-- 
2.4.3


^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH] PR target/66819: Allow indirect sibcall with register arguments
  2015-07-10 17:58       ` H.J. Lu
@ 2015-07-10 19:54         ` Uros Bizjak
  0 siblings, 0 replies; 8+ messages in thread
From: Uros Bizjak @ 2015-07-10 19:54 UTC (permalink / raw)
  To: H.J. Lu; +Cc: gcc-patches

On Fri, Jul 10, 2015 at 7:58 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Fri, Jul 10, 2015 at 10:21 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
>> On Fri, Jul 10, 2015 at 7:10 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>> On Fri, Jul 10, 2015 at 9:30 AM, Uros Bizjak <ubizjak@gmail.com> wrote:
>>>> On Thu, Jul 9, 2015 at 12:54 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>>>> Indirect sibcall with register arguments is OK when there is register
>>>>> available for argument passing.
>>>>>
>>>>> OK for trunk if there is no regression?
>>>>>
>>>>>
>>>>> H.J.
>>>>> ---
>>>>> gcc/
>>>>>
>>>>>         PR target/66819
>>>>>         * config/i386/i386.c (ix86_function_ok_for_sibcall): Allow
>>>>>         indirect sibcall with register arguments if register available
>>>>>         for argument passing.
>>>>>         (init_cumulative_args): Set cfun->machine->arg_reg_available_p
>>>>>         to cum->nregs != 0.
>>
>> Please update the above entry for nregs > 0.
>>
>>>>>         (function_arg_advance_32): Set cfun->machine->arg_reg_available_p
>>>>>         to 0 when setting cum->nregs = 0.
>>>>
>>>> Do we also need similar functionality for 64bit ABIs? What happens if
>>>> we are out of argument regs there?
>>>
>>> 64-bit is OK since we have rax, r10 and r11 as scratch registers which
>>> aren't used to pass arguments.
>>
>> Maybe this fact should be added as a comment in some appropriate place.
>>
>>>>>         * config/i386/i386.h (machine_function): Add arg_reg_available_p.
>>>>>
>>>>> gcc/testsuite/
>>>>>
>>>>>         PR target/66819
>>>>>         * gcc.target/i386/pr66819-1.c: New test.
>>>>>         * gcc.target/i386/pr66819-2.c: Likewise.
>>>>>         * gcc.target/i386/pr66819-3.c: Likewise.
>>>>>         * gcc.target/i386/pr66819-4.c: Likewise.
>>>>>         * gcc.target/i386/pr66819-5.c: Likewise.
>>>>> ---
>>>>>  gcc/config/i386/i386.c                    | 15 +++++++++------
>>>>>  gcc/config/i386/i386.h                    |  3 +++
>>>>>  gcc/testsuite/gcc.target/i386/pr66819-1.c |  8 ++++++++
>>>>>  gcc/testsuite/gcc.target/i386/pr66819-2.c |  8 ++++++++
>>>>>  gcc/testsuite/gcc.target/i386/pr66819-3.c | 10 ++++++++++
>>>>>  gcc/testsuite/gcc.target/i386/pr66819-4.c | 12 ++++++++++++
>>>>>  gcc/testsuite/gcc.target/i386/pr66819-5.c | 10 ++++++++++
>>>>>  7 files changed, 60 insertions(+), 6 deletions(-)
>>>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-1.c
>>>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-2.c
>>>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-3.c
>>>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-4.c
>>>>>  create mode 100644 gcc/testsuite/gcc.target/i386/pr66819-5.c
>>>>>
>>>>> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
>>>>> index 54ee6f3..85e59a8 100644
>>>>> --- a/gcc/config/i386/i386.c
>>>>> +++ b/gcc/config/i386/i386.c
>>>>> @@ -5628,12 +5628,12 @@ ix86_function_ok_for_sibcall (tree decl, tree exp)
>>>>>        if (!decl
>>>>>           || (TARGET_DLLIMPORT_DECL_ATTRIBUTES && DECL_DLLIMPORT_P (decl)))
>>>>>         {
>>>>> -         if (ix86_function_regparm (type, NULL) >= 3)
>>>>> -           {
>>>>> -             /* ??? Need to count the actual number of registers to be used,
>>>>> -                not the possible number of registers.  Fix later.  */
>>>>> -             return false;
>>>>> -           }
>>>>> +         /* FIXME: The symbol indirect call doesn't need a
>>>>> +            call-clobbered register.  But we don't know if
>>>>> +            this is a symbol indirect call or not  here.  */
>>>>> +         if (ix86_function_regparm (type, NULL) >= 3
>>>>> +             && !cfun->machine->arg_reg_available_p)
>>>>
>>>> Isn't enough to look at arg_reg_available here?
>>>
>>> We need to check ix86_function_regparm since nregs is 0 if
>>> -mregparm=N isn't used and pr65753.c will fail.
>>
>> OK. Please add this comment, is not that obvious.
>>
>>>
>>>>> +           return false;
>>>>>         }
>>>>>      }
>>>>>
>>>>> @@ -6567,6 +6567,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
>>>>>                     ? X86_64_REGPARM_MAX
>>>>>                     : X86_64_MS_REGPARM_MAX);
>>>>>      }
>>>>> +  cfun->machine->arg_reg_available_p = cum->nregs != 0;
>>>>
>>>> false instead of 0. This is a boolean.
>>>
>>> Updated.
>>>
>>>>>    if (TARGET_SSE)
>>>>>      {
>>>>>        cum->sse_nregs = SSE_REGPARM_MAX;
>>>>> @@ -6636,6 +6637,7 @@ init_cumulative_args (CUMULATIVE_ARGS *cum,  /* Argument info to initialize */
>>>>>           else
>>>>>             cum->nregs = ix86_function_regparm (fntype, fndecl);
>>>>>         }
>>>>> +      cfun->machine->arg_reg_available_p = cum->nregs != 0;
>>>>
>>>> IMO, cum->nregs > 0 would be more descriptive.
>>>
>>> Updated.
>>>
>>>>>        /* Set up the number of SSE registers used for passing SFmode
>>>>>          and DFmode arguments.  Warn for mismatching ABI.  */
>>>>> @@ -7584,6 +7586,7 @@ pass_in_reg:
>>>>>         {
>>>>>           cum->nregs = 0;
>>>>>           cum->regno = 0;
>>>>> +         cfun->machine->arg_reg_available_p = 0;
>>>>>         }
>>>>>        break;
>>>>>
>>>>> diff --git a/gcc/config/i386/i386.h b/gcc/config/i386/i386.h
>>>>> index 74334ff..0b6e304 100644
>>>>> --- a/gcc/config/i386/i386.h
>>>>> +++ b/gcc/config/i386/i386.h
>>>>> @@ -2479,6 +2479,9 @@ struct GTY(()) machine_function {
>>>>>    /* If true, it is safe to not save/restore DRAP register.  */
>>>>>    BOOL_BITFIELD no_drap_save_restore : 1;
>>>>>
>>>>> +  /* If true, there is register available for argument passing.  */
>>>>> +  BOOL_BITFIELD arg_reg_available_p : 1;
>>>>
>>>> This is not a predicate, but a boolean flag. Please remove _p from the name.
>>>
>>> Updated.
>>>
>>> Here is the updated patch.  OK for trunk?
>>
>> OK with a small comment additions.
>>
>> +  /* If true, there is register available for argument passing.  */
>> +  BOOL_BITFIELD arg_reg_available : 1;
>> +
>>
>> Please mention here that this is for 32bit targets only.
>>
>
> Updated. Is this one OK?

LGTM.

OK for mainline.

Thanks,
Uros.

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2015-07-10 19:54 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2015-07-09 10:54 [PATCH] PR target/66819: Allow indirect sibcall with register arguments H.J. Lu
2015-07-09 11:04 ` Uros Bizjak
2015-07-09 11:12   ` H.J. Lu
2015-07-10 16:30 ` Uros Bizjak
2015-07-10 17:10   ` H.J. Lu
2015-07-10 17:21     ` Uros Bizjak
2015-07-10 17:58       ` H.J. Lu
2015-07-10 19:54         ` Uros Bizjak

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