Re: [patch 2/5] add hook to track when splitting is complete

[Richard Biener]

On Sat, Oct 21, 2017 at 11:17 PM, Sandra Loosemore
 wrote:
> On 10/20/2017 02:24 AM, Richard Biener wrote:
>>
>> On Fri, Oct 20, 2017 at 4:09 AM, Sandra Loosemore
>>  wrote:
>>>
>>> This patch adds a function to indicate whether the split1 pass has run
>>> yet.  This is used in part 3 of the patch set to decide whether 32-bit
>>> symbolic constant expressions are permitted, e.g. in
>>> TARGET_LEGITIMATE_ADDRESS_P and the movsi expander.
>>>
>>> Since there's currently no usable hook for querying the pass manager
>>> where it is relative to another pass, I implemented this using a
>>> target-specific pass that runs directly after split1 and does nothing
>>> but set a flag.
>>
>>
>> "Nice" hack ;)  The only currently existing way would be to add a property
>> to the IL state like
>>
>> const pass_data pass_data_split_all_insns =
>> {
>>RTL_PASS, /* type */
>>"split1", /* name */
>>OPTGROUP_NONE, /* optinfo_flags */
>>TV_NONE, /* tv_id */
>>0, /* properties_required */
>>PROP_rtl_split_insns, /* properties_provided */
>>0, /* properties_destroyed */
>>
>> and test that via cfun->curr_properties & PROP_rtl_split_insns
>>
>> Having run split might be a important enough change to warrant this.
>> Likewise reload_completed and reload_in_progress could be transitioned
>> to IL properties.
>>
>> Richard.
>
>
> Well, here's a new version of this patch that implements what you suggested
> above.  It's certainly simpler than the original version, or the WIP patch I
> posted before to add a general hook based on enumerating the passes.  Is
> this OK?

+#define PROP_rtl_split_insns   (1 << 17)   /* split1 completed.  */

/* RTL has insns split.  */

that is, do not mention 'split1' specifically.

Ok with that change.

Thanks,
Richard.

> -Sandra
>

Re: [patch 2/5] add hook to track when splitting is complete

[Sandra Loosemore]

On 10/20/2017 02:24 AM, Richard Biener wrote:

On Fri, Oct 20, 2017 at 4:09 AM, Sandra Loosemore
 wrote:

This patch adds a function to indicate whether the split1 pass has run
yet.  This is used in part 3 of the patch set to decide whether 32-bit
symbolic constant expressions are permitted, e.g. in
TARGET_LEGITIMATE_ADDRESS_P and the movsi expander.

Since there's currently no usable hook for querying the pass manager
where it is relative to another pass, I implemented this using a
target-specific pass that runs directly after split1 and does nothing
but set a flag.


"Nice" hack ;)  The only currently existing way would be to add a property
to the IL state like

const pass_data pass_data_split_all_insns =
{
   RTL_PASS, /* type */
   "split1", /* name */
   OPTGROUP_NONE, /* optinfo_flags */
   TV_NONE, /* tv_id */
   0, /* properties_required */
   PROP_rtl_split_insns, /* properties_provided */
   0, /* properties_destroyed */

and test that via cfun->curr_properties & PROP_rtl_split_insns

Having run split might be a important enough change to warrant this.
Likewise reload_completed and reload_in_progress could be transitioned
to IL properties.

Richard.


Well, here's a new version of this patch that implements what you 
suggested above.  It's certainly simpler than the original version, or 
the WIP patch I posted before to add a general hook based on enumerating 
the passes.  Is this OK?


-Sandra

2017-10-21  Sandra Loosemore  

	gcc/
	* tree-hass.h (PROP_rtl_split_insns): Define.
	* recog.c (pass_data_split_all_insns): Provide PROP_rtl_split_insns.
	* config/nios2/nios2.c: Adjust includes.
	(nios2_symbolic_constant_allowed): New.
diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
index 9f76d82..21bde1c 100644
--- a/gcc/tree-pass.h
+++ b/gcc/tree-pass.h
@@ -223,6 +223,7 @@ protected:
 		   current choices have
 		   been optimized.  */
 #define PROP_gimple_lomp_dev	(1 << 16)	/* done omp_device_lower */
+#define PROP_rtl_split_insns	(1 << 17)	/* split1 completed.  */
 
 #define PROP_trees \
   (PROP_gimple_any | PROP_gimple_lcf | PROP_gimple_leh | PROP_gimple_lomp)
diff --git a/gcc/recog.c b/gcc/recog.c
index b8e9b1b..6bf8164 100644
--- a/gcc/recog.c
+++ b/gcc/recog.c
@@ -3862,7 +3862,7 @@ const pass_data pass_data_split_all_insns =
   OPTGROUP_NONE, /* optinfo_flags */
   TV_NONE, /* tv_id */
   0, /* properties_required */
-  0, /* properties_provided */
+  PROP_rtl_split_insns, /* properties_provided */
   0, /* properties_destroyed */
   0, /* todo_flags_start */
   0, /* todo_flags_finish */
diff --git a/gcc/config/nios2/nios2.c b/gcc/config/nios2/nios2.c
index 3e55673..f5963d4 100644
--- a/gcc/config/nios2/nios2.c
+++ b/gcc/config/nios2/nios2.c
@@ -48,6 +48,7 @@
 #include "langhooks.h"
 #include "stor-layout.h"
 #include "builtins.h"
+#include "tree-pass.h"
 
 /* This file should be included last.  */
 #include "target-def.h"
@@ -1976,6 +1977,19 @@ nios2_validate_compare (machine_mode mode, rtx *cmp, rtx *op1, rtx *op2)
 
 /* Addressing modes and constants.  */
 
+/* Symbolic constants are split into high/lo_sum pairs during the 
+   split1 pass.  After that, they are not considered legitimate addresses.
+   This function returns true if in a pre-split context where these
+   constants are allowed.  */
+static bool
+nios2_symbolic_constant_allowed (void)
+{
+  /* The reload_completed check is for the benefit of
+ nios2_asm_output_mi_thunk and perhaps other places that try to
+ emulate a post-reload pass.  */
+  return !(cfun->curr_properties & PROP_rtl_split_insns) && !reload_completed;
+}
+
 /* Return true if X is constant expression with a reference to an
"ordinary" symbol; not GOT-relative, not GP-relative, not TLS.  */
 static bool

Re: [patch 2/5] add hook to track when splitting is complete

[Richard Biener]

On Fri, Oct 20, 2017 at 4:09 AM, Sandra Loosemore
 wrote:
> This patch adds a function to indicate whether the split1 pass has run
> yet.  This is used in part 3 of the patch set to decide whether 32-bit
> symbolic constant expressions are permitted, e.g. in
> TARGET_LEGITIMATE_ADDRESS_P and the movsi expander.
>
> Since there's currently no usable hook for querying the pass manager
> where it is relative to another pass, I implemented this using a
> target-specific pass that runs directly after split1 and does nothing
> but set a flag.

"Nice" hack ;)  The only currently existing way would be to add a property
to the IL state like

const pass_data pass_data_split_all_insns =
{
  RTL_PASS, /* type */
  "split1", /* name */
  OPTGROUP_NONE, /* optinfo_flags */
  TV_NONE, /* tv_id */
  0, /* properties_required */
  PROP_rtl_split_insns, /* properties_provided */
  0, /* properties_destroyed */

and test that via cfun->curr_properties & PROP_rtl_split_insns

Having run split might be a important enough change to warrant this.
Likewise reload_completed and reload_in_progress could be transitioned
to IL properties.

Richard.

> -Sandra
>

[patch 2/5] add hook to track when splitting is complete

[Sandra Loosemore]

This patch adds a function to indicate whether the split1 pass has run
yet.  This is used in part 3 of the patch set to decide whether 32-bit
symbolic constant expressions are permitted, e.g. in
TARGET_LEGITIMATE_ADDRESS_P and the movsi expander.

Since there's currently no usable hook for querying the pass manager
where it is relative to another pass, I implemented this using a
target-specific pass that runs directly after split1 and does nothing
but set a flag.

-Sandra

2017-10-19  Sandra Loosemore  

	gcc/
	* config/nios2/nios2_protos.h (nios2_init_expanders): Declare.
	* config/nios2/nios2.c: Adjust includes.
	(split_completed): New.
	(nios2_symbolic_constant_allowed): New.
	(nios2_init_expanders): New.
	(nios2_postsplit_pass_data): New.
	(class pass_nios2_postsplit): New.
	(make_nios2_postsplit): New.
	(nios2_option_override): Register postsplit pass.
	* config/nios2/nios2.h (INIT_EXPANDERS): Define.
diff --git a/gcc/config/nios2/nios2-protos.h b/gcc/config/nios2/nios2-protos.h
index 4478334..925d46a 100644
--- a/gcc/config/nios2/nios2-protos.h
+++ b/gcc/config/nios2/nios2-protos.h
@@ -28,6 +28,7 @@ extern void nios2_expand_prologue (void);
 extern void nios2_expand_epilogue (bool);
 extern bool nios2_expand_return (void);
 extern void nios2_function_profiler (FILE *, int);
+extern void nios2_init_expanders (void);
 
 #ifdef RTX_CODE
 extern bool nios2_emit_move_sequence (rtx *, machine_mode);
diff --git a/gcc/config/nios2/nios2.c b/gcc/config/nios2/nios2.c
index 659250a..120adb5 100644
--- a/gcc/config/nios2/nios2.c
+++ b/gcc/config/nios2/nios2.c
@@ -47,6 +47,8 @@
 #include "toplev.h"
 #include "langhooks.h"
 #include "stor-layout.h"
+#include "tree-pass.h"
+#include "context.h"
 #include "builtins.h"
 
 /* This file should be included last.  */
@@ -101,6 +103,71 @@ static int custom_code_index[256];
 static bool custom_code_conflict = false;
 
 
+/* Support for target-specific postsplit pass.  */
+
+/* Symbolic constants are split into high/lo_sum pairs during the 
+   split1 pass.  After that, they are not considered legitimate addresses.
+   In order to keep track of whether or not we can generate or recognize
+   symbolic constants, we use a target-specific pass that runs 
+   immediately after split1 and does nothing but set a flag we can check.  */
+
+static bool split_completed = false;
+
+static bool
+nios2_symbolic_constant_allowed (void)
+{
+  /* The reload_completed check is for the benefit of
+ nios2_asm_output_mi_thunk and perhaps other places that try to
+ emulate a post-reload pass.  */
+  return !split_completed && !reload_completed;
+}
+
+/* Use INIT_EXPANDERS to ensure that split_completed is reset before
+   compiling every function.  */
+void
+nios2_init_expanders (void)
+{
+  split_completed = false;
+}
+
+namespace {
+
+static const pass_data nios2_postsplit_pass_data =
+{
+  RTL_PASS,  	// type
+  "nios2_postsplit",	// name
+  OPTGROUP_NONE, 	// optinfo_flags
+  TV_REST_OF_COMPILATION,// tv_id
+  0, 	// properties_required
+  0, 	// properties_provided
+  0, 	// properties_destroyed
+  0, 	// todo_flags_start
+  0		 	// todo_flags_finish
+};
+
+class pass_nios2_postsplit : public rtl_opt_pass
+{
+ public:
+  pass_nios2_postsplit (gcc::context *ctxt)
+: rtl_opt_pass (nios2_postsplit_pass_data, ctxt)
+  {}
+
+  virtual unsigned int execute (function *)
+{
+  split_completed = true;
+  return 0;
+}
+};
+
+} /* Anonymous namespace */
+
+rtl_opt_pass *
+make_nios2_postsplit (gcc::context *ctxt)
+{
+  return new pass_nios2_postsplit (ctxt);
+}
+
+
 /* Definition of builtin function types for nios2.  */
 
 #define N2_FTYPES\
@@ -1407,6 +1474,12 @@ nios2_option_override (void)
 
   nios2_custom_check_insns ();
 
+  /* Register target-specific passes.  */
+  opt_pass *postsplit = make_nios2_postsplit (g);
+  struct register_pass_info finish_split_info
+= { postsplit, "split1", 1, PASS_POS_INSERT_AFTER };
+  register_pass (_split_info);
+
   /* Save the initial options in case the user does function specific
  options.  */
   target_option_default_node = target_option_current_node
diff --git a/gcc/config/nios2/nios2.h b/gcc/config/nios2/nios2.h
index 10bebfb..d077dc5 100644
--- a/gcc/config/nios2/nios2.h
+++ b/gcc/config/nios2/nios2.h
@@ -503,6 +503,9 @@ do {\
 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL)		\
   (flag_pic ? DW_EH_PE_aligned : DW_EH_PE_sdata4)
 
+/* Target-specific initialization.  */
+#define INIT_EXPANDERS nios2_init_expanders ()
+
 /* Misc. parameters.  */
 
 #define STORE_FLAG_VALUE 1