[Linux-ia64] Re: gas generates incorrect ia64 unwind rlen values

Keith Owens
2002-12-16T22:12:25Z

On 16 Dec 2002 16:25:15 -0500,
Jim Wilson <wilson@redhat.com> wrote:
>>RH 7.2-ia64, Dec 15 2001.
>
>The tools for this release were based on Summer 2000 FSF sources with patches.
>So they are about 2.5 years old now.

I know, but AFAICT it is the latest that is available on the RH site
for ia64. If there is a more recent binutils ia64.rpm, point me at it
and I will try it.

>Are you sure this is an assembler problem? If the compiler is emitting bad
>unwind directives, then it could be a compiler problem. You didn't mention
>anything about looking at assembly code.

See my follow up mail about memset.S, that is pure assembler. But just
to be sure, here is traps.c::ia64_fault assembler output. No spurious
unwind directives from gcc but unwind is still wrong.

.text
.align 16
.align 32
.global ia64_fault#
.proc ia64_fault#
ia64_fault:
.prologue 12, 37
.save ar.pfs, r38
alloc r38 = ar.pfs, 4, 3, 5, 0
.fframe 256
adds r12 = -256, r12
movl r14 = 34359738383
.save rp, r37
mov r37 = b0
;;
.body
and r14 = r14, r33
movl r15 = 34359738372
[454 lines omitted for brevity]
.L2933:
mov r39 = r36
mov r40 = r33
br.call.sptk.many b0 = ia32_intercept#
;;
cmp4.ne p6, p7 = 0, r8
(p7) br.cond.dpnt .L2880
addl r39 = @ltoff(.LC39), gp
;;
ld8 r39 = [r39]
br.call.sptk.many b0 = printk#
;;
adds r14 = 8, r36
addl r39 = @ltoff(.LC40), gp
mov r41 = r34
;;
ld8 r40 = [r14]
ld8 r39 = [r39]
mov r42 = r33
mov r43 = r35
br.call.sptk.many b0 = printk#
[unwind tables in the object say that the body ends here]
;;
addl r39 = 11, r0
mov r40 = r13
br.call.sptk.many b0 = force_sig#
;;
br .L2880
.L2935:
adds r34 = 144, r12
addl r40 = @ltoff(.LC41), gp
shr.u r41 = r33, 16
;;
mov r39 = r34
ld8 r40 = [r40]
br.call.sptk.many b0 = sprintf#
;;
br .L2882
.L2936:
adds r34 = 144, r12
addl r40 = @ltoff(.LC42), gp
mov r41 = r32
;;
mov r39 = r34
ld8 r40 = [r40]
br.call.sptk.many b0 = sprintf#
;;
.L2882:
mov r39 = r34
mov r40 = r36
mov r41 = r33
br.call.sptk.many b0 = die_if_kernel#
;;
addl r39 = 4, r0
mov r40 = r13
br.call.sptk.many b0 = force_sig#
;;
.L2880:
mov ar.pfs = r38
mov b0 = r37
.restore sp
adds r12 = 256, r12
br.ret.sptk.many b0
.endp ia64_fault#