On Fri, Dec 6, 2019 at 6:27 PM Kwok Cheung Yeung <k...@codesourcery.com> wrote:
>
> Hello
>
> A number of the libgomp tests running with AMD GCN offloading fail with
> the following internal compiler error:
>
> during RTL pass: final
> /scratch/ci-cs/amdtest/upstream-offload/src/gcc-mainline/libgomp/testsuite/libgomp.fortran/examples-4/async_target-1.f90:
> In function 'pipedf_._omp_fn.2':
> /scratch/ci-cs/amdtest/upstream-offload/src/gcc-mainline/libgomp/testsuite/libgomp.fortran/examples-4/async_target-1.f90:49:
> internal compiler error: in dwarf2out_inline_entry, at dwarf2out.c:27682
> 0x626210 dwarf2out_inline_entry
>
> /scratch/ci-cs/amdtest/upstream-offload/src/gcc-mainline/gcc/dwarf2out.c:27682
> 0x9692c4 final_scan_insn_1
>
> /scratch/ci-cs/amdtest/upstream-offload/src/gcc-mainline/gcc/final.c:2435
> 0x969f4b final_scan_insn(rtx_insn*, _IO_FILE*, int, int, int*)
>
> /scratch/ci-cs/amdtest/upstream-offload/src/gcc-mainline/gcc/final.c:3152
> 0x96a214 final_1
>
> /scratch/ci-cs/amdtest/upstream-offload/src/gcc-mainline/gcc/final.c:2020
> 0x96ac7f rest_of_handle_final
>
> /scratch/ci-cs/amdtest/upstream-offload/src/gcc-mainline/gcc/final.c:4658
> 0x96ac7f execute
>
> /scratch/ci-cs/amdtest/upstream-offload/src/gcc-mainline/gcc/final.c:4736
>
> The ICE is due to an assert for debug_inline_points firing. The test
> case does not explicitly set this (using -ginline-points), so it is
> auto-detected.
>
> The problem arises because the host compiler enables it by default, but
> the offload compiler disables it. The host compiler generates the Gimple
> debug statements for inlined functions, then streams them out using the
> LTO mechanism. The accelerator compiler streams them in, encounters the
> unexpected debug statements and ICEs due to a failed assertion.
>
> It is possible to make GCN enable support inline-points by default, but
> I think it would be better to fix it for the general case where there is
> a disagreement between host and accelerator? This patch makes
> dwarf2out_inline_entry ignore the inline entry note if
> debug_inline_points is not set while the compiler is in LTO mode. This
> is effectively relaxing the assertion condition by allowing an exception
> for LTO.
>
> Bootstrapped on x86_64, and tested using GCN as an offload accelerator.
> Okay for trunk?
The stream-in code has
/* If we're recompiling LTO objects with debug stmts but
we're not supposed to have debug stmts, remove them now.
We can't remove them earlier because this would cause uid
mismatches in fixups, but we can do it at this point, as
long as debug stmts don't require fixups.
Similarly remove all IFN_*SAN_* internal calls */
if (!flag_wpa)
{
if (is_gimple_debug (stmt)
&& (gimple_debug_nonbind_marker_p (stmt)
? !MAY_HAVE_DEBUG_MARKER_STMTS
: !MAY_HAVE_DEBUG_BIND_STMTS))
remove = true;
/* In case the linemap overflows locations can be dropped
to zero. Thus do not keep nonsensical inline entry markers
we'd later ICE on. */
tree block;
if (gimple_debug_inline_entry_p (stmt)
&& (block = gimple_block (stmt))
&& !inlined_function_outer_scope_p (block))
remove = true;
so can you please instead amend that or figure why it doesn't work?
Thanks,
Richard.
> Kwok
>
>
> It is possible for the host compiler to emit entry point markers in the
> GIMPLE code while the accelerator compiler has them disabled, causing an
> assertion to fire where processed by the accelerator compiler. This is
> fixed by allowing the markers to be ignored in LTO mode only.
>
> 2019-12-06 Kwok Cheung Yeung <k...@codesourcery.com>
>
> gcc/
> * dwarf2out.c (dwarf2out_inline_entry): Return early if in LTO and
> debug_inline_points not set.
> ---
> gcc/dwarf2out.c | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
> index 6fb345b..44fa071 100644
> --- a/gcc/dwarf2out.c
> +++ b/gcc/dwarf2out.c
> @@ -27679,6 +27679,13 @@ block_within_block_p (tree block, tree outer,
> bool bothways)
> static void
> dwarf2out_inline_entry (tree block)
> {
> + /* In an offloading configuration, it is possible for the host
> toolchain but
> + not the offload toolchain to support extended debug information
> for inlined
> + functions. In that case, we can just ignore any entry point markers
> + read from the LTO stream. */
> + if (in_lto_p && !debug_inline_points)
> + return;
> +
> gcc_assert (debug_inline_points);
>
> /* If we can't represent it, don't bother. */
> --
> 2.8.1
>
