diff mbox

[2/2] SH epilogue unwind, backend parts

Message ID 4FB62907.9080006@codesourcery.com
State New
Headers show

Commit Message

Chung-Lin Tang May 18, 2012, 10:48 a.m. UTC 
And here are the backend parts for supporting epilogue unwind for SH,
ccing Kaz. Note that this needs the prior dwarf2 pass changes in too, or
else occasional ICEs ensue.

About the issue on unneeded post-return CFI, mentioned before on
libc-alpha, this patch currently does produce such directives. The
generated unwind info should still be correct, though will need other
changes to be optimal.

Thanks,
Chung-Lin

2012-05-18  Chung-Lin Tang  <cltang@codesourcery.com>

	* config/sh/sh.c (output_stack_adjust): Remove !epilogue_p
	condition for generating REG_FRAME_RELATED_EXPR note.
	(pop): Add code for generating REG_CFA_RESTORE,
	REG_CFA_ADJUST_CFA notes. Set RTX_FRAME_RELATED_P to 1.
	(sh_expand_epilogue): Use frame_insn() for FP to SP move.
	Set 'frame_p' of calls to output_stack_adjust() to 'true'.

Comments

Kaz Kojima May 18, 2012, 9:45 p.m. UTC | #1 
Chung-Lin Tang <cltang@codesourcery.com> wrote:
> And here are the backend parts for supporting epilogue unwind for SH,
> ccing Kaz. Note that this needs the prior dwarf2 pass changes in too, or
> else occasional ICEs ensue.
> 
> About the issue on unneeded post-return CFI, mentioned before on
> libc-alpha, this patch currently does produce such directives. The
> generated unwind info should still be correct, though will need other
> changes to be optimal.
> 
> Thanks,
> Chung-Lin
> 
> 2012-05-18  Chung-Lin Tang  <cltang@codesourcery.com>
> 
> 	* config/sh/sh.c (output_stack_adjust): Remove !epilogue_p
> 	condition for generating REG_FRAME_RELATED_EXPR note.
> 	(pop): Add code for generating REG_CFA_RESTORE,
> 	REG_CFA_ADJUST_CFA notes. Set RTX_FRAME_RELATED_P to 1.
> 	(sh_expand_epilogue): Use frame_insn() for FP to SP move.
> 	Set 'frame_p' of calls to output_stack_adjust() to 'true'.

The patch is OK.  Thanks for working on this!

Regards,
	kaz
diff mbox

Patch

Index: config/sh/sh.c
===================================================================
--- config/sh/sh.c	(revision 187548)
+++ config/sh/sh.c	(working copy)
@@ -6460,11 +6460,10 @@  output_stack_adjust (int size, rtx reg, int epilog
 	      emit_insn (GEN_MOV (const_reg, GEN_INT (size)));
 	      insn = emit_fn (GEN_ADD3 (reg, reg, const_reg));
 	    }
-	  if (! epilogue_p)
-	    add_reg_note (insn, REG_FRAME_RELATED_EXPR,
-			  gen_rtx_SET (VOIDmode, reg,
-				       gen_rtx_PLUS (SImode, reg,
-						     GEN_INT (size))));
+	  add_reg_note (insn, REG_FRAME_RELATED_EXPR,
+			gen_rtx_SET (VOIDmode, reg,
+				     gen_rtx_PLUS (SImode, reg,
+						   GEN_INT (size))));
 	}
     }
 }
@@ -6509,7 +6508,7 @@  push (int rn)
 static void
 pop (int rn)
 {
-  rtx x;
+  rtx x, sp_reg, reg;
   if (rn == FPUL_REG)
     x = gen_pop_fpul ();
   else if (rn == FPSCR_REG)
@@ -6527,7 +6526,18 @@  pop (int rn)
     x = gen_pop (gen_rtx_REG (SImode, rn));
 
   x = emit_insn (x);
+
+  sp_reg = gen_rtx_REG (SImode, STACK_POINTER_REGNUM);
+  reg = copy_rtx (GET_CODE (PATTERN (x)) == PARALLEL
+		  ? SET_DEST (XVECEXP (PATTERN (x), 0, 0))
+		  : SET_DEST (PATTERN (x)));
+  add_reg_note (x, REG_CFA_RESTORE, reg);
+  add_reg_note (x, REG_CFA_ADJUST_CFA,
+		gen_rtx_SET (SImode, sp_reg,
+			     plus_constant (SImode, sp_reg,
+					    GET_MODE_SIZE (GET_MODE (reg)))));
   add_reg_note (x, REG_INC, gen_rtx_REG (SImode, STACK_POINTER_REGNUM));
+  RTX_FRAME_RELATED_P (x) = 1;
 }
 
 /* Generate code to push the regs specified in the mask.  */
@@ -7410,14 +7420,14 @@  sh_expand_epilogue (bool sibcall_p)
 	 See PR/18032 and PR/40313.  */
       emit_insn (gen_blockage ());
       output_stack_adjust (frame_size, hard_frame_pointer_rtx, e,
-			   &live_regs_mask, false);
+			   &live_regs_mask, true);
 
       /* We must avoid moving the stack pointer adjustment past code
 	 which reads from the local frame, else an interrupt could
 	 occur after the SP adjustment and clobber data in the local
 	 frame.  */
       emit_insn (gen_blockage ());
-      emit_insn (GEN_MOV (stack_pointer_rtx, hard_frame_pointer_rtx));
+      frame_insn (GEN_MOV (stack_pointer_rtx, hard_frame_pointer_rtx));
     }
   else if (frame_size)
     {
@@ -7427,7 +7437,7 @@  sh_expand_epilogue (bool sibcall_p)
 	 frame.  */
       emit_insn (gen_blockage ());
       output_stack_adjust (frame_size, stack_pointer_rtx, e,
-			   &live_regs_mask, false);
+			   &live_regs_mask, true);
     }
 
   if (SHMEDIA_REGS_STACK_ADJUST ())
@@ -7644,7 +7654,7 @@  sh_expand_epilogue (bool sibcall_p)
   output_stack_adjust (crtl->args.pretend_args_size
 		       + save_size + d_rounding
 		       + crtl->args.info.stack_regs * 8,
-		       stack_pointer_rtx, e, NULL, false);
+		       stack_pointer_rtx, e, NULL, true);
 
   if (crtl->calls_eh_return)
     emit_insn (GEN_ADD3 (stack_pointer_rtx, stack_pointer_rtx,