> Hello.
>
> The patch is small clean-up of retpoline stuff. I know that H.J. is planning
> to introduce an option driving which retpoline loop filler is selected.
> Hopefully the suggested patch clarifies current default selection of
> the filler.
>
> Patch survives make check -k -j10 RUNTESTFLAGS="i386.exp".
>
> Ready to install?
> Thanks,
> Martin
>
>
> gcc/ChangeLog:
>
> 2018-01-18 Martin Liska <mli...@suse.cz>
>
> * config/i386/i386.c (indirect_thunk_name): Document that also
> lfence is emitted.
> (output_indirect_thunk): Document why both instructions
> (pause and lfence) are generated.
OK,
thanks!
Honza
>
> gcc/testsuite/ChangeLog:
>
> 2018-01-18 Martin Liska <mli...@suse.cz>
>
> * gcc.target/i386/indirect-thunk-3.c: Remove duplicate options.
> * gcc.target/i386/indirect-thunk-4.c: Likewise.
> * gcc.target/i386/indirect-thunk-6.c: Likewise.
> * gcc.target/i386/indirect-thunk-bnd-4.c: Likewise.
> * gcc.target/i386/ret-thunk-10.c: Likewise.
> * gcc.target/i386/ret-thunk-11.c: Likewise.
> * gcc.target/i386/ret-thunk-12.c: Likewise.
> * gcc.target/i386/ret-thunk-15.c: Likewise.
> * gcc.target/i386/ret-thunk-9.c: Likewise.
> ---
> gcc/config/i386/i386.c | 5 ++++-
> gcc/testsuite/gcc.target/i386/indirect-thunk-3.c | 2 +-
> gcc/testsuite/gcc.target/i386/indirect-thunk-4.c | 2 +-
> gcc/testsuite/gcc.target/i386/indirect-thunk-6.c | 2 +-
> gcc/testsuite/gcc.target/i386/indirect-thunk-bnd-4.c | 2 +-
> gcc/testsuite/gcc.target/i386/ret-thunk-10.c | 2 +-
> gcc/testsuite/gcc.target/i386/ret-thunk-11.c | 2 +-
> gcc/testsuite/gcc.target/i386/ret-thunk-12.c | 2 +-
> gcc/testsuite/gcc.target/i386/ret-thunk-15.c | 2 +-
> gcc/testsuite/gcc.target/i386/ret-thunk-9.c | 2 +-
> 10 files changed, 13 insertions(+), 10 deletions(-)
>
>
> diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
> index cb0f4ed5e6a..72d25ae4f72 100644
> --- a/gcc/config/i386/i386.c
> +++ b/gcc/config/i386/i386.c
> @@ -10826,6 +10826,7 @@ indirect_thunk_name (char name[32], unsigned int
> regno,
> call L2
> L1:
> pause
> + lfence
> jmp L1
> L2:
> mov %REG, (%sp)
> @@ -10837,6 +10838,7 @@ indirect_thunk_name (char name[32], unsigned int
> regno,
> call L2
> L1:
> pause
> + lfence
> jmp L1
> L2:
> lea WORD_SIZE(%sp), %sp
> @@ -10864,7 +10866,8 @@ output_indirect_thunk (bool need_bnd_p, unsigned int
> regno)
>
> ASM_OUTPUT_INTERNAL_LABEL (asm_out_file, indirectlabel1);
>
> - /* Pause + lfence. */
> + /* AMD and Intel CPUs prefer each a different instruction as loop filler.
> + Usage of both pause + lfence is compromise solution. */
> fprintf (asm_out_file, "\tpause\n\tlfence\n");
>
> /* Jump. */
> diff --git a/gcc/testsuite/gcc.target/i386/indirect-thunk-3.c
> b/gcc/testsuite/gcc.target/i386/indirect-thunk-3.c
> index 9e24a385387..dab7ac2ef25 100644
> --- a/gcc/testsuite/gcc.target/i386/indirect-thunk-3.c
> +++ b/gcc/testsuite/gcc.target/i386/indirect-thunk-3.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile } */
> -/* { dg-options "-O2 -mno-indirect-branch-register
> -mno-indirect-branch-register -mno-indirect-branch-register
> -mfunction-return=keep -mindirect-branch=thunk -fno-pic" } */
> +/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep
> -mindirect-branch=thunk -fno-pic" } */
>
> typedef void (*dispatch_t)(long offset);
>
> diff --git a/gcc/testsuite/gcc.target/i386/indirect-thunk-4.c
> b/gcc/testsuite/gcc.target/i386/indirect-thunk-4.c
> index 127b5d94523..44cc5f52f45 100644
> --- a/gcc/testsuite/gcc.target/i386/indirect-thunk-4.c
> +++ b/gcc/testsuite/gcc.target/i386/indirect-thunk-4.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile } */
> -/* { dg-options "-O2 -mno-indirect-branch-register
> -mno-indirect-branch-register -mno-indirect-branch-register
> -mfunction-return=keep -mindirect-branch=thunk -fno-pic" } */
> +/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep
> -mindirect-branch=thunk -fno-pic" } */
>
> typedef void (*dispatch_t)(long offset);
>
> diff --git a/gcc/testsuite/gcc.target/i386/indirect-thunk-6.c
> b/gcc/testsuite/gcc.target/i386/indirect-thunk-6.c
> index e4649283d10..1490f5336ca 100644
> --- a/gcc/testsuite/gcc.target/i386/indirect-thunk-6.c
> +++ b/gcc/testsuite/gcc.target/i386/indirect-thunk-6.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile { target *-*-linux* } } */
> -/* { dg-options "-O2 -mno-indirect-branch-register
> -mno-indirect-branch-register -mno-indirect-branch-register
> -mfunction-return=keep -fpic -fno-plt -mindirect-branch=thunk" } */
> +/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep
> -fpic -fno-plt -mindirect-branch=thunk" } */
>
> extern void bar (void);
>
> diff --git a/gcc/testsuite/gcc.target/i386/indirect-thunk-bnd-4.c
> b/gcc/testsuite/gcc.target/i386/indirect-thunk-bnd-4.c
> index 0e19830de4d..a5fc4a23351 100644
> --- a/gcc/testsuite/gcc.target/i386/indirect-thunk-bnd-4.c
> +++ b/gcc/testsuite/gcc.target/i386/indirect-thunk-bnd-4.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile { target { *-*-linux* && { ! x32 } } } } */
> -/* { dg-options "-O2 -mno-indirect-branch-register
> -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk
> -fcheck-pointer-bounds -mmpx -fpic -fno-plt" } */
> +/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep
> -mindirect-branch=thunk -fcheck-pointer-bounds -mmpx -fpic -fno-plt" } */
>
> void bar (char *);
> char buf[10];
> diff --git a/gcc/testsuite/gcc.target/i386/ret-thunk-10.c
> b/gcc/testsuite/gcc.target/i386/ret-thunk-10.c
> index e6fea84a4d9..6de9b8c9f4f 100644
> --- a/gcc/testsuite/gcc.target/i386/ret-thunk-10.c
> +++ b/gcc/testsuite/gcc.target/i386/ret-thunk-10.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile } */
> -/* { dg-options "-O2 -mno-indirect-branch-register
> -mno-indirect-branch-register -mfunction-return=thunk-inline
> -mindirect-branch=thunk -fno-pic" } */
> +/* { dg-options "-O2 -mno-indirect-branch-register
> -mfunction-return=thunk-inline -mindirect-branch=thunk -fno-pic" } */
>
> extern void (*bar) (void);
>
> diff --git a/gcc/testsuite/gcc.target/i386/ret-thunk-11.c
> b/gcc/testsuite/gcc.target/i386/ret-thunk-11.c
> index e239ec4542f..36598037541 100644
> --- a/gcc/testsuite/gcc.target/i386/ret-thunk-11.c
> +++ b/gcc/testsuite/gcc.target/i386/ret-thunk-11.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile } */
> -/* { dg-options "-O2 -mno-indirect-branch-register
> -mno-indirect-branch-register -mno-indirect-branch-register
> -mno-indirect-branch-register -mfunction-return=thunk-extern
> -mindirect-branch=thunk -fno-pic" } */
> +/* { dg-options "-O2 -mno-indirect-branch-register
> -mfunction-return=thunk-extern -mindirect-branch=thunk -fno-pic" } */
>
> extern void (*bar) (void);
>
> diff --git a/gcc/testsuite/gcc.target/i386/ret-thunk-12.c
> b/gcc/testsuite/gcc.target/i386/ret-thunk-12.c
> index fa3181303c9..5fb1a4de776 100644
> --- a/gcc/testsuite/gcc.target/i386/ret-thunk-12.c
> +++ b/gcc/testsuite/gcc.target/i386/ret-thunk-12.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile } */
> -/* { dg-options "-O2 -mno-indirect-branch-register
> -mno-indirect-branch-register -mno-indirect-branch-register
> -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=thunk
> -fno-pic" } */
> +/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep
> -mindirect-branch=thunk -fno-pic" } */
>
> extern void (*bar) (void);
>
> diff --git a/gcc/testsuite/gcc.target/i386/ret-thunk-15.c
> b/gcc/testsuite/gcc.target/i386/ret-thunk-15.c
> index 75e45e226b8..2038644aa59 100644
> --- a/gcc/testsuite/gcc.target/i386/ret-thunk-15.c
> +++ b/gcc/testsuite/gcc.target/i386/ret-thunk-15.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile } */
> -/* { dg-options "-O2 -mno-indirect-branch-register
> -mno-indirect-branch-register -mno-indirect-branch-register
> -mno-indirect-branch-register -mfunction-return=keep -mindirect-branch=keep
> -fno-pic" } */
> +/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=keep
> -mindirect-branch=keep -fno-pic" } */
>
> extern void (*bar) (void);
>
> diff --git a/gcc/testsuite/gcc.target/i386/ret-thunk-9.c
> b/gcc/testsuite/gcc.target/i386/ret-thunk-9.c
> index d1db41cc128..d34dd4e6dc7 100644
> --- a/gcc/testsuite/gcc.target/i386/ret-thunk-9.c
> +++ b/gcc/testsuite/gcc.target/i386/ret-thunk-9.c
> @@ -1,5 +1,5 @@
> /* { dg-do compile } */
> -/* { dg-options "-O2 -mno-indirect-branch-register
> -mno-indirect-branch-register -mfunction-return=thunk -mindirect-branch=thunk
> -fno-pic" } */
> +/* { dg-options "-O2 -mno-indirect-branch-register -mfunction-return=thunk
> -mindirect-branch=thunk -fno-pic" } */
>
> extern void (*bar) (void);
>
>
