From 2ee67fbb886cbfab54a1e5a80e6a807e38a564ce Mon Sep 17 00:00:00 2001
From: Julian Brown <julian@codesourcery.com>
Date: Fri, 20 Nov 2009 16:48:28 +0000
Subject: [PATCH] arm.h (ASM_OUTPUT_REG_PUSH): Handle STATIC_CHAIN_REGNUM
 specially for Thumb-1.

	gcc/
	* config/arm/arm.h (ASM_OUTPUT_REG_PUSH): Handle STATIC_CHAIN_REGNUM
	specially for Thumb-1.
	(ASM_OUTPUT_REG_POP): Likewise.

From-SVN: r154372
---
 gcc/ChangeLog        |  6 ++++++
 gcc/config/arm/arm.h | 22 +++++++++++++++++++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b6cf53af8f8..4a7f32e4708 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2009-11-20  Julian Brown  <julian@codesourcery.com>
+
+	* config/arm/arm.h (ASM_OUTPUT_REG_PUSH): Handle STATIC_CHAIN_REGNUM
+	specially for Thumb-1.
+	(ASM_OUTPUT_REG_POP): Likewise.
+
 2009-11-19  Jason Merrill  <jason@redhat.com>
 
 	* dwarf2out.c (get_context_die): Take TYPE_MAIN_VARIANT.
diff --git a/gcc/config/arm/arm.h b/gcc/config/arm/arm.h
index 663f07edb3f..98abdb1ff0b 100644
--- a/gcc/config/arm/arm.h
+++ b/gcc/config/arm/arm.h
@@ -2274,24 +2274,44 @@ extern int making_const_table;
 #define ASM_APP_OFF (TARGET_THUMB1 ? "\t.code\t16\n" : \
 		     TARGET_THUMB2 ? "\t.thumb\n" : "")
 
-/* Output a push or a pop instruction (only used when profiling).  */
+/* Output a push or a pop instruction (only used when profiling).
+   We can't push STATIC_CHAIN_REGNUM (r12) directly with Thumb-1.  We know
+   that ASM_OUTPUT_REG_PUSH will be matched with ASM_OUTPUT_REG_POP, and
+   that r7 isn't used by the function profiler, so we can use it as a
+   scratch reg.  WARNING: This isn't safe in the general case!  It may be
+   sensitive to future changes in final.c:profile_function.  */
 #define ASM_OUTPUT_REG_PUSH(STREAM, REGNO)		\
   do							\
     {							\
       if (TARGET_ARM)					\
 	asm_fprintf (STREAM,"\tstmfd\t%r!,{%r}\n",	\
 		     STACK_POINTER_REGNUM, REGNO);	\
+      else if (TARGET_THUMB1				\
+	       && (REGNO) == STATIC_CHAIN_REGNUM)	\
+	{						\
+	  asm_fprintf (STREAM, "\tpush\t{r7}\n");	\
+	  asm_fprintf (STREAM, "\tmov\tr7, %r\n", REGNO);\
+	  asm_fprintf (STREAM, "\tpush\t{r7}\n");	\
+	}						\
       else						\
 	asm_fprintf (STREAM, "\tpush {%r}\n", REGNO);	\
     } while (0)
 
 
+/* See comment for ASM_OUTPUT_REG_PUSH concerning Thumb-1 issue.  */
 #define ASM_OUTPUT_REG_POP(STREAM, REGNO)		\
   do							\
     {							\
       if (TARGET_ARM)					\
 	asm_fprintf (STREAM, "\tldmfd\t%r!,{%r}\n",	\
 		     STACK_POINTER_REGNUM, REGNO);	\
+      else if (TARGET_THUMB1				\
+	       && (REGNO) == STATIC_CHAIN_REGNUM)	\
+	{						\
+	  asm_fprintf (STREAM, "\tpop\t{r7}\n");	\
+	  asm_fprintf (STREAM, "\tmov\t%r, r7\n", REGNO);\
+	  asm_fprintf (STREAM, "\tpop\t{r7}\n");	\
+	}						\
       else						\
 	asm_fprintf (STREAM, "\tpop {%r}\n", REGNO);	\
     } while (0)