aarch64.c (aarch64_expand_prologue): For the load-pair with writeback instruction...

gcc/ChangeLog

2012-11-07  Yufeng Zhang  <yufeng.zhang@arm.com>

	* config/aarch64/aarch64.c (aarch64_expand_prologue): For the
	load-pair with writeback instruction, replace
	aarch64_set_frame_expr with add_reg_note (REG_CFA_ADJUST_CFA);
	add new local variable 'cfa_reg' and use it.

gcc/testsuite/ChangeLog

2012-11-07  Yufeng Zhang  <yufeng.zhang@arm.com>

	* gcc.target/aarch64/dwarf-cfa-reg.c: New test.

From-SVN: r193291

gcc/ChangeLog

+2012-11-07  Yufeng Zhang  <yufeng.zhang@arm.com>
+
+	* config/aarch64/aarch64.c (aarch64_expand_prologue): For the
+	load-pair with writeback instruction, replace
+	aarch64_set_frame_expr with add_reg_note (REG_CFA_ADJUST_CFA);
+	add new local variable 'cfa_reg' and use it.
+
 2012-11-07  Kaz Kojima  <kkojima@gcc.gnu.org>
 
 	PR middle-end/49220

gcc/config/aarch64/aarch64.c

@@ -1840,7 +1840,7 @@ aarch64_expand_prologue (void)
 	       - original_frame_size
 	       - cfun->machine->frame.saved_regs_size);
 
-  /* Store pairs and load pairs have a range only of +/- 512.  */
+  /* Store pairs and load pairs have a range only -512 to 504.  */
   if (offset >= 512)
     {
       /* When the frame has a large size, an initial decrease is done on
@@ -1988,6 +1988,7 @@ aarch64_expand_epilogue (bool for_sibcall)
   HOST_WIDE_INT original_frame_size, frame_size, offset;
   HOST_WIDE_INT fp_offset;
   rtx insn;
+  rtx cfa_reg;
 
   aarch64_layout_frame ();
   original_frame_size = get_frame_size () + cfun->machine->saved_varargs_size;
@@ -2000,7 +2001,9 @@ aarch64_expand_epilogue (bool for_sibcall)
 	       - original_frame_size
 	       - cfun->machine->frame.saved_regs_size);
 
-  /* Store pairs and load pairs have a range only of +/- 512.  */
+  cfa_reg = frame_pointer_needed ? hard_frame_pointer_rtx : stack_pointer_rtx;
+
+  /* Store pairs and load pairs have a range only -512 to 504.  */
   if (offset >= 512)
     {
       offset = original_frame_size + cfun->machine->frame.saved_regs_size;
@@ -2031,6 +2034,10 @@ aarch64_expand_epilogue (bool for_sibcall)
 				       hard_frame_pointer_rtx,
 				       GEN_INT (- fp_offset)));
       RTX_FRAME_RELATED_P (insn) = 1;
+      /* As SP is set to (FP - fp_offset), according to the rules in
+	 dwarf2cfi.c:dwarf2out_frame_debug_expr, CFA should be calculated
+	 from the value of SP from now on.  */
+      cfa_reg = stack_pointer_rtx;
     }
 
   aarch64_save_or_restore_callee_save_registers
@@ -2070,11 +2077,9 @@ aarch64_expand_epilogue (bool for_sibcall)
 				 GEN_INT (offset),
 				 GEN_INT (GET_MODE_SIZE (DImode) + offset)));
 	      RTX_FRAME_RELATED_P (XVECEXP (PATTERN (insn), 0, 2)) = 1;
-	      aarch64_set_frame_expr (gen_rtx_SET
-				      (Pmode,
-				       stack_pointer_rtx,
-				       gen_rtx_PLUS (Pmode, stack_pointer_rtx,
-						     GEN_INT (offset))));
+	      add_reg_note (insn, REG_CFA_ADJUST_CFA,
+			    (gen_rtx_SET (Pmode, stack_pointer_rtx,
+					  plus_constant (cfa_reg, offset))));
 	    }
 
 	  /* The first part of a frame-related parallel insn
@@ -2094,7 +2099,6 @@ aarch64_expand_epilogue (bool for_sibcall)
 	      RTX_FRAME_RELATED_P (insn) = 1;
 	    }
 	}
-
       else
 	{
 	  insn = emit_insn (gen_add2_insn (stack_pointer_rtx,

gcc/testsuite/ChangeLog

+2012-11-07  Yufeng Zhang  <yufeng.zhang@arm.com>
+
+	* gcc.target/aarch64/dwarf-cfa-reg.c: New test.
+
 2012-11-07  Kaz Kojima  <kkojima@gcc.gnu.org>
 
 	* gcc.c-torture/compile/pr49220.c: New test.

gcc/testsuite/gcc.target/aarch64/dwarf-cfa-reg.c

+/* Verify that CFA register is restored to SP after FP is restored.  */
+/* { dg-do compile } */
+/* { dg-options "-O0 -gdwarf-2" } */
+/* { dg-final { scan-assembler ".cfi_restore 30" } } */
+/* { dg-final { scan-assembler ".cfi_restore 29" } } */
+/* { dg-final { scan-assembler ".cfi_def_cfa 31, 0" } } */
+/* { dg-final { scan-assembler "ret" } } */
+
+int bar (unsigned int);
+
+int foo (void)
+{
+  return bar (0xcafe);
+}