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* [Bug target/18032] New: [4.0.0] SH: wrong code for EH
@ 2004-10-16  8:22 kkojima at gcc dot gnu dot org
  2004-10-16  8:26 ` [Bug target/18032] " kkojima at gcc dot gnu dot org
                   ` (5 more replies)
  0 siblings, 6 replies; 7+ messages in thread
From: kkojima at gcc dot gnu dot org @ 2004-10-16  8:22 UTC (permalink / raw)
  To: gcc-bugs

The program below doesn't exit with 0 as expected when it's compiled
with -O2.  It works fine with -O1 or -O2 -fno-delayed-branch.

--
int *dummy;

void
bar (int *p)
{
  dummy = p;
}

void
foo (int x)
{
  int var;

  bar (&var);
  if (x)
    throw 1;
}

int
main ()
{ 
  try {
    foo (1);
  } catch (...) {
    return 0;
  }
  return 1;
}
--

With -O2, the function foo looks like:

_Z3fooi:
.LFB3:
	mov.l	r8,@-r15
.LCFI3:
	mov	r4,r8
	mov.l	r14,@-r15
.LCFI4:
	sts.l	pr,@-r15
.LCFI5:
	mov.l	.L11,r1
	add	#-4,r15
.LCFI6:
	mov	r15,r14
.LCFI7:
	jsr	@r1
	mov	r14,r4
	tst	r8,r8
	bf/s	.L10
	add	#4,r14
	mov	r14,r15
	lds.l	@r15+,pr
	mov.l	@r15+,r14
	rts	
	mov.l	@r15+,r8
	.align 5
.L10:
	mov.l	.L12,r0
	jsr	@r0
	mov	#4,r4
	mov	#1,r1
	mov.l	r1,@r0
	mov.l	.L13,r1
	mov	r0,r4
	mov.l	.L14,r5
	jsr	@r1
	mov	#0,r6
	...

Thus the throw part starting with .L10 is called after the excution of
"add #4,r14" in the delayed slot.  It seems that this doesn't match
the frame info of foo:

$ readelf -a ./a.out | grep foo
    99: 00400760   100 FUNC    GLOBAL DEFAULT   11 _Z3fooi

$ readelf --debug-dump=frames ./a.out
The section .eh_frame contains:
...
0000001c 00000028 00000020 FDE cie=00000000 pc=00400760..004007c4
  Augmentation data:     00 00 00 00

  DW_CFA_advance_loc: 2 to 00400762
  DW_CFA_def_cfa_offset: 4
  DW_CFA_offset: r8 at cfa-4
  DW_CFA_advance_loc: 4 to 00400766
  DW_CFA_def_cfa_offset: 8
  DW_CFA_advance_loc: 2 to 00400768
  DW_CFA_def_cfa_offset: 12
  DW_CFA_advance_loc: 4 to 0040076c
  DW_CFA_def_cfa_offset: 16
  DW_CFA_offset: r17 at cfa-12
  DW_CFA_offset: r14 at cfa-8
  DW_CFA_advance_loc: 2 to 0040076e
  DW_CFA_def_cfa_reg: r14
  DW_CFA_nop
  DW_CFA_nop

which assumes that r14 points the bottom of the frame when the throw
part is called.

-- 
           Summary: [4.0.0] SH: wrong code for EH
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: target
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: kkojima at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: sh4-unknown-linux-gnu
  GCC host triplet: sh4-unknown-linux-gnu
GCC target triplet: sh4-unknown-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18032


^ permalink raw reply	[flat|nested] 7+ messages in thread
end of thread, other threads:[~2004-10-20 17:39 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2004-10-16  8:22 [Bug target/18032] New: [4.0.0] SH: wrong code for EH kkojima at gcc dot gnu dot org
2004-10-16  8:26 ` [Bug target/18032] " kkojima at gcc dot gnu dot org
2004-10-16 13:58 ` pinskia at gcc dot gnu dot org
2004-10-18 15:49 ` amylaar at gcc dot gnu dot org
2004-10-18 22:43 ` kkojima at gcc dot gnu dot org
2004-10-20 13:57 ` cvs-commit at gcc dot gnu dot org
2004-10-20 17:39 ` pinskia at gcc dot gnu dot org

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