* config/arm/arm.c (arm_expand_prologue): Do tell the dwarf2 backend

        about the SP adjustment for saving the static chain pointer.
        * dwarf2out.c (dwarf2out_frame_debug_expr): Use the specified
        offset when setting a temporary CFA register.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@39554 138bc75d-0d04-0410-961f-82ee72b054a4

3 files changed, 30 insertions, 16 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 34d126daac6..d2562aa40bc 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2001-02-08  Jason Merrill  <jason@redhat.com>
+
+	* config/arm/arm.c (arm_expand_prologue): Do tell the dwarf2 backend
+	about the SP adjustment for saving the static chain pointer.
+	* dwarf2out.c (dwarf2out_frame_debug_expr): Use the specified
+	offset when setting a temporary CFA register.
+
 2001-02-08  Chandrakala Chavva  <cchavva@redhat.com>
 
 	* config.gcc : New targets, i386-*-chorusos*, sparc-*-chorusos*,
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index 53dd0dd0f09..d906b14c514 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -7804,27 +7804,34 @@ arm_expand_prologue ()
 		  
 	     If neither of these places is available, we abort (for now).
 
-	     Note - setting RTX_FRAME_RELATED_P on these insns breaks
-	     the dwarf2 parsing code in various bits of gcc.  This ought
-	     to be fixed sometime, but until then the flag is suppressed.
-	     [Use gcc/testsuite/gcc.c-torture/execute/921215-1.c with
-	     "-O3 -g" to test this].  */
+	     Note - we only need to tell the dwarf2 backend about the SP
+	     adjustment in the second variant; the static chain register
+	     doesn't need to be unwound, as it doesn't contain a value
+	     inherited from the caller.  */
 
 	  if (regs_ever_live[3] == 0)
 	    {
 	      insn = gen_rtx_REG (SImode, 3);
 	      insn = gen_rtx_SET (SImode, insn, ip_rtx);
 	      insn = emit_insn (insn);
-	      /* RTX_FRAME_RELATED_P (insn) = 1; */
 	    }
 	  else if (current_function_pretend_args_size == 0)
 	    {
+	      rtx dwarf;
 	      insn = gen_rtx_PRE_DEC (SImode, stack_pointer_rtx);
 	      insn = gen_rtx_MEM (SImode, insn);
 	      insn = gen_rtx_SET (VOIDmode, insn, ip_rtx);
 	      insn = emit_insn (insn);
-	      /* RTX_FRAME_RELATED_P (insn) = 1; */
+
 	      fp_offset = 4;
+
+	      /* Just tell the dwarf backend that we adjusted SP.  */
+	      dwarf = gen_rtx_SET (VOIDmode, stack_pointer_rtx,
+				   gen_rtx_PLUS (SImode, stack_pointer_rtx,
+						 GEN_INT (-fp_offset)));
+	      RTX_FRAME_RELATED_P (insn) = 1;
+	      REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_FRAME_RELATED_EXPR,
+						    dwarf, REG_NOTES (insn));
 	    }
 	  else
 	    /* FIXME - the way to handle this situation is to allow
@@ -7931,7 +7938,6 @@ arm_expand_prologue ()
 	      insn = gen_rtx_REG (SImode, 3);
 	      insn = gen_rtx_SET (SImode, ip_rtx, insn);
 	      insn = emit_insn (insn);
-	      /* RTX_FRAME_RELATED_P (insn) = 1; */
 	    }
 	  else /* if (current_function_pretend_args_size == 0) */
 	    {
@@ -7939,7 +7945,6 @@ arm_expand_prologue ()
 	      insn = gen_rtx_MEM (SImode, insn);
 	      insn = gen_rtx_SET (SImode, ip_rtx, insn);
 	      insn = emit_insn (insn);
-	      /* RTX_FRAME_RELATED_P (insn) = 1; */
 	    }
 	}
     }
diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index d8b33703b26..fa62101ef6f 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -1321,8 +1321,6 @@ dw_cfa_location cfa_temp;
   Rules  1- 4: Setting a register's value to cfa.reg or an expression
   	       with cfa.reg as the first operand changes the cfa.reg and its
 	       cfa.offset.
-	       (For an unknown reason, Rule 4 does not fully obey the
-	       invariant.)
 
   Rules  6- 9: Set a non-cfa.reg register value to a constant or an
 	       expression yielding a constant.  This sets cfa_temp.reg
@@ -1362,8 +1360,6 @@ dw_cfa_location cfa_temp;
   constraints: <reg1> != fp
   	       <reg1> != sp
   effects: cfa.reg = <reg1>
-  questions: Where is <const_int> used?
-	     Should cfa.offset be changed?
 
   Rule 5:
   (set <reg1> (plus <reg2>:cfa_temp.reg sp:cfa.reg))
@@ -1547,9 +1543,15 @@ dwarf2out_frame_debug_expr (expr, label)
 	      if (GET_CODE (XEXP (src, 0)) == REG
 		  && REGNO (XEXP (src, 0)) == cfa.reg
 		  && GET_CODE (XEXP (src, 1)) == CONST_INT)
-		/* Setting a temporary CFA register that will be copied
-		   into the FP later on.  */
-		cfa.reg = REGNO (dest);
+		{
+		  /* Setting a temporary CFA register that will be copied
+		     into the FP later on.  */
+		  offset = INTVAL (XEXP (src, 1));
+		  if (GET_CODE (src) == PLUS)
+		    offset = -offset;
+		  cfa.offset += offset;
+		  cfa.reg = REGNO (dest);
+		}
 	      /* Rule 5 */
 	      else
 		{