* Claudiu Zissulescu <claz...@gmail.com> [2018-11-12 13:25:11 +0200]:
> Our ABI says the blink is pushed first on stack followed by an unknown
> number of register saves, and finally by fp. Hence we cannot use the
> EH_RETURN_ADDRESS macro as the stack is not finalized at that moment.
> The alternative is to use the eh_return pattern and to initialize all
> the bits after register allocation when the stack layout is finalized.
>
> gcc/
> xxxx-xx-xx Claudiu Zissulescu <claz...@synopsys.com>
>
> * config/arc/arc.c (arc_eh_return_address_location): Repurpose it
> to fit the eh_return pattern.
> * config/arc/arc.md (eh_return): Define.
> (VUNSPEC_ARC_EH_RETURN): Likewise.
> * config/arc/arc-protos.h (arc_eh_return_address_location): Match
> new implementation.
> * config/arc/arc.h (EH_RETURN_HANDLER_RTX): Remove it.
Looks good.
Thanks,
Andrew
>
> testsuite/
> xxxx-xx-xx Claudiu Zissulescu <claz...@synopsys.com>
>
> * gcc.target/arc/builtin_eh.c: New test.
> ---
> gcc/config/arc/arc-protos.h | 2 +-
> gcc/config/arc/arc.c | 13 ++++++++-----
> gcc/config/arc/arc.h | 2 --
> gcc/config/arc/arc.md | 15 +++++++++++++++
> gcc/testsuite/gcc.target/arc/builtin_eh.c | 22 ++++++++++++++++++++++
> 5 files changed, 46 insertions(+), 8 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/arc/builtin_eh.c
>
> diff --git a/gcc/config/arc/arc-protos.h b/gcc/config/arc/arc-protos.h
> index 6450b6a014e..4f72a06e3dc 100644
> --- a/gcc/config/arc/arc-protos.h
> +++ b/gcc/config/arc/arc-protos.h
> @@ -110,7 +110,7 @@ extern bool arc_legitimize_reload_address (rtx *,
> machine_mode, int, int);
> extern void arc_secondary_reload_conv (rtx, rtx, rtx, bool);
> extern void arc_cpu_cpp_builtins (cpp_reader *);
> extern bool arc_store_addr_hazard_p (rtx_insn *, rtx_insn *);
> -extern rtx arc_eh_return_address_location (void);
> +extern void arc_eh_return_address_location (rtx);
> extern bool arc_is_jli_call_p (rtx);
> extern void arc_file_end (void);
> extern bool arc_is_secure_call_p (rtx);
> diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c
> index 6802ca66554..a92456b457d 100644
> --- a/gcc/config/arc/arc.c
> +++ b/gcc/config/arc/arc.c
> @@ -3858,10 +3858,13 @@ arc_check_multi (rtx op, bool push_p)
> /* Return rtx for the location of the return address on the stack,
> suitable for use in __builtin_eh_return. The new return address
> will be written to this location in order to redirect the return to
> - the exception handler. */
> + the exception handler. Our ABI says the blink is pushed first on
> + stack followed by an unknown number of register saves, and finally
> + by fp. Hence we cannot use the EH_RETURN_ADDRESS macro as the
> + stack is not finalized. */
>
> -rtx
> -arc_eh_return_address_location (void)
> +void
> +arc_eh_return_address_location (rtx source)
> {
> rtx mem;
> int offset;
> @@ -3889,8 +3892,8 @@ arc_eh_return_address_location (void)
> remove this store seems perfectly sensible. Marking the memory
> address as volatile obviously has the effect of preventing DSE
> from removing the store. */
> - MEM_VOLATILE_P (mem) = 1;
> - return mem;
> + MEM_VOLATILE_P (mem) = true;
> + emit_move_insn (mem, source);
> }
>
> /* PIC */
> diff --git a/gcc/config/arc/arc.h b/gcc/config/arc/arc.h
> index afd6d7681cf..a0a84900917 100644
> --- a/gcc/config/arc/arc.h
> +++ b/gcc/config/arc/arc.h
> @@ -1355,8 +1355,6 @@ do { \
>
> #define EH_RETURN_STACKADJ_RTX gen_rtx_REG (Pmode, 2)
>
> -#define EH_RETURN_HANDLER_RTX arc_eh_return_address_location ()
> -
> /* Turn off splitting of long stabs. */
> #define DBX_CONTIN_LENGTH 0
>
> diff --git a/gcc/config/arc/arc.md b/gcc/config/arc/arc.md
> index a28c67ac184..a6bac0e8bee 100644
> --- a/gcc/config/arc/arc.md
> +++ b/gcc/config/arc/arc.md
> @@ -163,6 +163,7 @@
> VUNSPEC_ARC_SC
> VUNSPEC_ARC_LL
> VUNSPEC_ARC_BLOCKAGE
> + VUNSPEC_ARC_EH_RETURN
> ])
>
> (define_constants
> @@ -6627,6 +6628,20 @@ core_3, archs4x, archs4xd, archs4xd_slow"
> [(set_attr "type" "call_no_delay_slot")
> (set_attr "length" "2")])
>
> +;; Patterns for exception handling
> +(define_insn_and_split "eh_return"
> + [(unspec_volatile [(match_operand:SI 0 "register_operand" "r")]
> + VUNSPEC_ARC_EH_RETURN)]
> + ""
> + "#"
> + "reload_completed"
> + [(const_int 0)]
> + "
> + {
> + arc_eh_return_address_location (operands[0]);
> + DONE;
> + }"
> +)
> ;; include the arc-FPX instructions
> (include "fpx.md")
>
> diff --git a/gcc/testsuite/gcc.target/arc/builtin_eh.c
> b/gcc/testsuite/gcc.target/arc/builtin_eh.c
> new file mode 100644
> index 00000000000..717a54bb084
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/arc/builtin_eh.c
> @@ -0,0 +1,22 @@
> +/* Check if we have the right offset for @bar function. */
> +/* { dg-options "-O1" } */
> +
> +void bar (void);
> +
> +void
> +foo (int x)
> +{
> + __builtin_unwind_init ();
> + __builtin_eh_return (x, bar);
> +}
> +
> +/* { dg-final { scan-assembler "r24" } } */
> +/* { dg-final { scan-assembler "r22" } } */
> +/* { dg-final { scan-assembler "r20" } } */
> +/* { dg-final { scan-assembler "r18" } } */
> +/* { dg-final { scan-assembler "r16" } } */
> +/* { dg-final { scan-assembler "r14" } } */
> +/* { dg-final { scan-assembler "r13" } } */
> +/* { dg-final { scan-assembler "r0" } } */
> +/* { dg-final { scan-assembler "fp" } } */
> +/* { dg-final { scan-assembler "fp,64" } } */
> --
> 2.19.1
>
