Patchwork Problem with ARM longcalls

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Submitter Bernd Schmidt
Date May 3, 2011, 1:10 p.m.
Message ID <4DBFFEA9.5030507@codesourcery.com>
Download mbox | patch
Permalink /patch/93785/
State New
Headers show

Comments

Bernd Schmidt - May 3, 2011, 1:10 p.m.
On 04/14/2011 03:00 PM, Richard Guenther wrote:
> On Thu, Apr 14, 2011 at 2:40 PM, Bernd Schmidt <bernds@codesourcery.com> wrote:
>> Ping.  Contains only changes outside config/arm.
>>
>> http://gcc.gnu.org/m/gcc-patches/2011-03/msg01509.html
> 
> Ok.

Committed this version on trunk (which has different code to initialize
first_function_block_is_cold). Tested again, with a profiledbootstrap
(which I hope exercised this code). I'll wait a few days and then put
the originally posted version on the branches.


Bernd

Patch

Index: ChangeLog
===================================================================
--- ChangeLog	(revision 173301)
+++ ChangeLog	(working copy)
@@ -1,3 +1,12 @@ 
+2011-05-03  Bernd Schmidt  <bernds@codesourcery.com>
+
+	* function.c (init_function_start): Call decide_function_section.
+	* varasm.c (decide_function_section): New function.
+	(assemble_start_function): When not using
+	flag_reorder_blocks_and_partition, don't compute in_cold_section_p
+	or first_function_block_is_cold.
+	* rtl.h (decide_function_section): Declare.
+
 2011-05-03  Uros Bizjak  <ubizjak@gmail.com>
 	    Jakub Jelinek  <jakub@redhat.com>
 
Index: testsuite/gcc.target/arm/cold-lc.c
===================================================================
--- testsuite/gcc.target/arm/cold-lc.c	(revision 0)
+++ testsuite/gcc.target/arm/cold-lc.c	(revision 0)
@@ -0,0 +1,22 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -mlong-calls" } */
+/* { dg-final { scan-assembler-not "bl\[^\n\]*dump_stack" } } */
+
+extern void dump_stack (void) __attribute__ ((__cold__)) __attribute__ ((noinline));
+struct thread_info {
+    struct task_struct *task;
+};
+extern struct thread_info *current_thread_info (void);
+
+void dump_stack (void)
+{
+    unsigned long stack;
+    show_stack ((current_thread_info ()->task), &stack);
+}
+
+void die (char *str, void *fp, int nr)
+{
+    dump_stack ();
+    while (1);
+}
+
Index: testsuite/ChangeLog
===================================================================
--- testsuite/ChangeLog	(revision 173301)
+++ testsuite/ChangeLog	(working copy)
@@ -1,3 +1,7 @@ 
+2011-05-03  Bernd Schmidt  <bernds@codesourcery.com>
+
+	* gcc.target/arm/cold-lc.c: New test.
+
 2011-05-03  Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/48774
Index: function.c
===================================================================
--- function.c	(revision 173297)
+++ function.c	(working copy)
@@ -4515,6 +4515,7 @@  init_function_start (tree subr)
   else
     allocate_struct_function (subr, false);
   prepare_function_start ();
+  decide_function_section (subr);
 
   /* Warn if this value is an aggregate type,
      regardless of which calling convention we are using for it.  */
Index: varasm.c
===================================================================
--- varasm.c	(revision 173297)
+++ varasm.c	(working copy)
@@ -1512,6 +1512,33 @@  notice_global_symbol (tree decl)
     }
 }
 
+/* If not using flag_reorder_blocks_and_partition, decide early whether the
+   current function goes into the cold section, so that targets can use
+   current_function_section during RTL expansion.  DECL describes the
+   function.  */
+
+void
+decide_function_section (tree decl)
+{
+  first_function_block_is_cold = false;
+
+  if (flag_reorder_blocks_and_partition)
+    /* We will decide in assemble_start_function.  */
+    return;
+
+ if (DECL_SECTION_NAME (decl))
+    {
+      struct cgraph_node *node = cgraph_get_node (current_function_decl);
+      /* Calls to function_section rely on first_function_block_is_cold
+	 being accurate.  */
+      first_function_block_is_cold = (node
+				      && node->frequency
+				      == NODE_FREQUENCY_UNLIKELY_EXECUTED);
+    }
+
+  in_cold_section_p = first_function_block_is_cold;
+}
+
 /* Output assembler code for the constant pool of a function and associated
    with defining the name of the function.  DECL describes the function.
    NAME is the function's name.  For the constant pool, we use the current
@@ -1524,7 +1551,6 @@  assemble_start_function (tree decl, cons
   char tmp_label[100];
   bool hot_label_written = false;
 
-  first_function_block_is_cold = false;
   if (flag_reorder_blocks_and_partition)
     {
       ASM_GENERATE_INTERNAL_LABEL (tmp_label, "LHOTB", const_labelno);
@@ -1559,6 +1585,8 @@  assemble_start_function (tree decl, cons
 
   if (flag_reorder_blocks_and_partition)
     {
+      first_function_block_is_cold = false;
+
       switch_to_section (unlikely_text_section ());
       assemble_align (DECL_ALIGN (decl));
       ASM_OUTPUT_LABEL (asm_out_file, crtl->subsections.cold_section_label);
@@ -1575,18 +1603,9 @@  assemble_start_function (tree decl, cons
 	  hot_label_written = true;
 	  first_function_block_is_cold = true;
 	}
-    }
-  else if (DECL_SECTION_NAME (decl))
-    {
-      struct cgraph_node *node = cgraph_get_node (current_function_decl);
-      /* Calls to function_section rely on first_function_block_is_cold
-	 being accurate.  */
-      first_function_block_is_cold = (node
-				      && node->frequency
-				      == NODE_FREQUENCY_UNLIKELY_EXECUTED);
+      in_cold_section_p = first_function_block_is_cold;
     }
 
-  in_cold_section_p = first_function_block_is_cold;
 
   /* Switch to the correct text section for the start of the function.  */
 
Index: rtl.h
===================================================================
--- rtl.h	(revision 173300)
+++ rtl.h	(working copy)
@@ -1668,6 +1668,7 @@  extern rtx get_pool_constant (rtx);
 extern rtx get_pool_constant_mark (rtx, bool *);
 extern enum machine_mode get_pool_mode (const_rtx);
 extern rtx simplify_subtraction (rtx);
+extern void decide_function_section (tree);
 
 /* In function.c  */
 extern rtx assign_stack_local (enum machine_mode, HOST_WIDE_INT, int);