From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jason Merrill <jason@cygnus.com>
To: tot@trema.com (Teemu Torma), egcs@cygnus.com
Subject: Re: Flow analysis confused by exception handling
Date: Tue, 02 Dec 1997 02:25:00 -0000
Message-id: <u967p8caa5.fsf@yorick.cygnus.com>
References: <199712020947.KAA05490.cygnus.egcs@lev.labs.trema.com>
X-SW-Source: 1997-12/msg00078.html

>>>>> Teemu Torma <tot@trema.com> writes:

> The problem I sent few days ago about register being clobbered
> in sparc while throwing seems to be actually flow analysis problem.
> In the following code, the initial assignment to `i' gets deleted
> because the next instruction also assigns it.

Does this fix the problem?

Tue Dec  2 01:42:33 1997  Jason Merrill  <jason@yorick.cygnus.com>

	* flow.c (find_basic_blocks): A CALL_INSN that can throw starts
	a new basic block.
	(find_basic_blocks_1): Likewise.

Index: flow.c
===================================================================
RCS file: /cvs/cvsfiles/devo/gcc/flow.c,v
retrieving revision 1.100
diff -c -r1.100 flow.c
*** flow.c	1997/11/28 04:44:47	1.100
--- flow.c	1997/12/02 09:25:06
***************
*** 304,309 ****
--- 304,310 ----
    {
      register RTX_CODE prev_code = JUMP_INSN;
      register RTX_CODE code;
+     int eh_region = 0;
  
      max_uid_for_flow = 0;
  
***************
*** 316,322 ****
  	    || (GET_RTX_CLASS (code) == 'i'
  		&& (prev_code == JUMP_INSN
  		    || (prev_code == CALL_INSN
! 			&& nonlocal_label_list != 0)
  		    || prev_code == BARRIER)))
  	  i++;
  
--- 317,323 ----
  	    || (GET_RTX_CLASS (code) == 'i'
  		&& (prev_code == JUMP_INSN
  		    || (prev_code == CALL_INSN
! 			&& (nonlocal_label_list != 0 || eh_region))
  		    || prev_code == BARRIER)))
  	  i++;
  
***************
*** 325,330 ****
--- 326,335 ----
  
  	if (code != NOTE)
  	  prev_code = code;
+ 	else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_BEG)
+ 	  ++eh_region;
+ 	else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_EH_REGION_END)
+ 	  --eh_region;
        }
    }
  
***************
*** 420,426 ****
  	       || (GET_RTX_CLASS (code) == 'i'
  		   && (prev_code == JUMP_INSN
  		       || (prev_code == CALL_INSN
! 			   && nonlocal_label_list != 0
  			   && ! find_reg_note (insn, REG_RETVAL, NULL_RTX))
  		       || prev_code == BARRIER)))
  	{
--- 425,431 ----
  	       || (GET_RTX_CLASS (code) == 'i'
  		   && (prev_code == JUMP_INSN
  		       || (prev_code == CALL_INSN
! 			   && (nonlocal_label_list != 0 || eh_note)
  			   && ! find_reg_note (insn, REG_RETVAL, NULL_RTX))
  		       || prev_code == BARRIER)))
  	{