On Thu, Aug 21, 2025 at 3:46 AM H.J. Lu <hjl.to...@gmail.com> wrote:
>
> For a basic block with only a label:
>
> (code_label 78 11 77 3 14 (nil) [1 uses])
> (note 77 78 54 3 [bb 3] NOTE_INSN_BASIC_BLOCK)
>
> emit the TLS call after NOTE_INSN_BASIC_BLOCK, instead of before
> NOTE_INSN_BASIC_BLOCK, to avoid
>
> x.c: In function ‘aout_16_write_syms’:
> x.c:54:1: error: NOTE_INSN_BASIC_BLOCK is missing for block 3
> 54 | }
> | ^
> x.c:54:1: error: NOTE_INSN_BASIC_BLOCK 77 in middle of basic block 3
> during RTL pass: x86_cse
> x.c:54:1: internal compiler error: verify_flow_info failed
Ok.
>
> gcc/
>
> PR target/121607
> * config/i386/i386-features.cc (ix86_emit_tls_call): Emit the
> TLS call after NOTE_INSN_BASIC_BLOCK in a basic block with only
> a label.
>
> gcc/testsuite/
>
> PR target/121607
> * gcc.target/i386/pr121607-1a.c: New test.
> * gcc.target/i386/pr121607-1b.c: Likewise.
>
> Signed-off-by: H.J. Lu <hjl.to...@gmail.com>
> ---
> gcc/config/i386/i386-features.cc | 24 +++++++--
> gcc/testsuite/gcc.target/i386/pr121607-1a.c | 59 +++++++++++++++++++++
> gcc/testsuite/gcc.target/i386/pr121607-1b.c | 6 +++
> 3 files changed, 86 insertions(+), 3 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/pr121607-1a.c
> create mode 100644 gcc/testsuite/gcc.target/i386/pr121607-1b.c
>
> diff --git a/gcc/config/i386/i386-features.cc
> b/gcc/config/i386/i386-features.cc
> index 7869ee22b67..514d2a5d378 100644
> --- a/gcc/config/i386/i386-features.cc
> +++ b/gcc/config/i386/i386-features.cc
> @@ -3795,7 +3795,18 @@ ix86_emit_tls_call (rtx tls_set, x86_cse_kind kind,
> basic_block bb,
> while (insn && !NONDEBUG_INSN_P (insn))
> {
> if (insn == BB_END (bb))
> - break;
> + {
> + /* This must be a basic block with only a label:
> +
> + (code_label 78 11 77 3 14 (nil) [1 uses])
> + (note 77 78 54 3 [bb 3] NOTE_INSN_BASIC_BLOCK)
> +
> + */
> + gcc_assert (NOTE_P (insn)
> + && NOTE_KIND (insn) == NOTE_INSN_BASIC_BLOCK);
> + insn = NULL;
> + break;
> + }
> insn = NEXT_INSN (insn);
> }
>
> @@ -3824,14 +3835,21 @@ ix86_emit_tls_call (rtx tls_set, x86_cse_kind kind,
> basic_block bb,
>
> if (bitmap_empty_p (live_caller_saved_regs))
> {
> - if (insn == BB_HEAD (bb) || insn == BB_END (bb))
> + if (insn == BB_HEAD (bb))
> {
> *before_p = insn;
> tls_insn = emit_insn_before (tls_set, insn);
> }
> else
> {
> - insn = PREV_INSN (insn);
> + /* Emit the TLS call after NOTE_INSN_BASIC_BLOCK in a
> + basic block with only a label:
> +
> + (code_label 78 11 77 3 14 (nil) [1 uses])
> + (note 77 78 54 3 [bb 3] NOTE_INSN_BASIC_BLOCK)
> +
> + */
> + insn = insn ? PREV_INSN (insn) : BB_END (bb);
> *after_p = insn;
> tls_insn = emit_insn_after (tls_set, insn);
> }
> diff --git a/gcc/testsuite/gcc.target/i386/pr121607-1a.c
> b/gcc/testsuite/gcc.target/i386/pr121607-1a.c
> new file mode 100644
> index 00000000000..4c047068e3a
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr121607-1a.c
> @@ -0,0 +1,59 @@
> +/* { dg-do compile { target *-*-linux* } } */
> +/* { dg-options "-O2 -fpic -fplt -mtls-dialect=gnu
> -fno-semantic-interposition -fstack-protector" } */
> +
> +typedef enum
> +{
> + bfd_error_invalid_error_code
> +} bfd_error_type;
> +thread_local bfd_error_type bfd_error;
> +int aout_16_write_syms___trans_tmp_1;
> +short aout_16_write_syms_g_0_0;
> +void xvec_0 (long, void *);
> +
> +typedef struct
> +{
> + int output_section;
> +} asection;
> +
> +void bfd_asymbol_section ();
> +
> +struct pdp11_external_nlist
> +{
> + char e_desc[2];
> + char e_type[1];
> + char e_ovly[10];
> +} translate_to_native_sym_flags (struct pdp11_external_nlist *sym_pointer)
> +{
> + asection *sec;
> + sym_pointer->e_type[0] &= 5;
> + bfd_asymbol_section ();
> + if (sec == 0)
> + {
> + bfd_error_type error_tag;
> + bfd_error = error_tag;
> + }
> + if (sec->output_section)
> + {
> + bfd_error_type error_tag;
> + bfd_error = error_tag;
> + }
> +}
> +
> +bool
> +aout_16_write_syms (void *abfd)
> +{
> + for (; aout_16_write_syms___trans_tmp_1;)
> + {
> + struct pdp11_external_nlist nsp;
> + if (abfd)
> + {
> + xvec_0 (aout_16_write_syms_g_0_0, nsp.e_desc);
> + nsp.e_ovly[0] = 0;
> + }
> + else
> + nsp.e_type[0] = 0;
> + translate_to_native_sym_flags (&nsp);
> + }
> +}
> +
> +/* { dg-final { scan-assembler-times "call\[ \t\]__tls_get_addr@PLT" 2 {
> target { ! ia32 } } } } */
> diff --git a/gcc/testsuite/gcc.target/i386/pr121607-1b.c
> b/gcc/testsuite/gcc.target/i386/pr121607-1b.c
> new file mode 100644
> index 00000000000..366306702c7
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr121607-1b.c
> @@ -0,0 +1,6 @@
> +/* { dg-do compile { target *-*-linux* } } */
> +/* { dg-options "-O2 -fpic -fplt -mtls-dialect=gnu2
> -fno-semantic-interposition -fstack-protector" } */
> +
> +#include "pr121607-1a.c"
> +
> +/* { dg-final { scan-assembler-times "call\[
> \t\]\\*bfd_error@TLSCALL\\(%(?:r|e)ax\\)" 2 { target { ! ia32 } } } } */
> --
> 2.50.1
>
--
BR,
Hongtao
