Re: [Linux-ia64] epilogue count exceeds number of nested prologues

From: David Mosberger <davidm_at_napali.hpl.hp.com>
Date: 2002-04-09 14:46:39
Hi Randolph,

>>>>> On Sun, 7 Apr 2002 17:17:14 -0700, Randolph Chung <randolph@tausq.org> said:

  Randolph> Hi all,
  Randolph> While trying to compile mozilla with libffi, the configure phase
  Randolph> dies with a message:

  Randolph> Error: Epilogue count of 4294967296 exceeds number of nested prologues
  Randolph> (0)

  Randolph> I see that this message comes from a patch submitted by David in
  Randolph> February. Is libffi broken? What is needed to fix it?


  Randolph> The offending assembly code is attached. it's the ".restore sp"
  Randolph> near the end that is triggering the error.

I'm unable to reproduce this.  If I'm understanding you right, the
problem occurred during the configure phase of mozilla (not libffi).
I just rebuilt Mozilla from the current CVS tree with gcc3.1
pre-release and the current CVS binutils.  It built just fine and the
resulting binary seems to work flawlessly.

>From the assembly code you provided, it looks as if conftest.c tried
to call FFI_STATIC_CLOSURE() from within a function, which can't
possibly work.

Can you provide a more precise pointer where this conftest.c is being
generated?

Thanks,

	--david

  Randolph> .file	"conftest.i"
  Randolph> .pred.safe_across_calls p1-p5,p16-p63
  Randolph> .text
  Randolph> .align 16
  Randolph> .global main#
  Randolph> .proc main#
  Randolph> main:
  Randolph> .prologue 2, 2
  Randolph> .vframe r2
  Randolph> mov r2 = r12
  Randolph> .body
  Randolph> ;;
  Randolph> #APP
  Randolph> .data
  Randolph> .align 8
  Randolph> 1:   data8 @fptr(ffi_closure_UNIX)
  Randolph> data8 1b
  Randolph> data8 0
  Randolph> data8 bar
  Randolph> data8 @fptr(baz)
  Randolph> data8 quux
  Randolph> .text
  Randolph> .global foo
  Randolph> .proc foo
  Randolph> foo:
  Randolph> addl r16 = @ltoff(1b), gp;;
  Randolph> ld8  gp = [r16];;
  Randolph> ld8  r17 = [gp];;
  Randolph> ld8  r19 = [r17],8;
  Randolph> adds r18 = 16,gp;;
  Randolph> ld8  r20 = [r17];;
  Randolph> st8  [r18]=r20;
  Randolph> mov b6 = r19
  Randolph> br.cond.sptk.many b6
  Randolph> .endp

  Randolph> #NO_APP
  Randolph> ;;
  Randolph> mov r8 = r0
  Randolph> .restore sp
  Randolph> mov r12 = r2
  Randolph> br.ret.sptk.many b0
  Randolph> .endp main#
  Randolph> .ident	"GCC: (GNU) 3.0.4"


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  Randolph> http://lists.linuxia64.org/lists/listinfo/linux-ia64
Received on Mon Apr 08 21:48:16 2002

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