On Wed, May 18, 2022 at 9:32 AM Hongyu Wang <hongyu.w...@intel.com> wrote:
>
> Hi,
>
> This patch adds a constraint "Ws" to allow absolute symbolic address for
> either
> function or variable. This also works under -mcmodel=large.
>
> Bootstrapped/regtested on x86_64-pc-linux-gnu{-m32,}
>
> Ok for master?
Maybe you should use:
asm ("%p0" :: "X"(addr));
asm ("%p0" :: "X"(&var));
instead.
Uros.
> gcc/ChangeLog:
>
> PR target/105576
> * config/i386/constraints.md (Ws): New constraint.
> * config/i386/i386-protos.h (ix86_symbolic_address_p):
> New proto type.
> * config/i386/i386.cc (ix86_symbolic_address_p):
> New function to ensure a rtx is a symbolic address.
>
> gcc/testsuite/ChangeLog:
>
> PR target/105576
> * gcc.target/i386/pr105576.c: New test.
> ---
> gcc/config/i386/constraints.md | 4 ++++
> gcc/config/i386/i386-protos.h | 1 +
> gcc/config/i386/i386.cc | 7 +++++++
> gcc/testsuite/gcc.target/i386/pr105576.c | 11 +++++++++++
> 4 files changed, 23 insertions(+)
> create mode 100644 gcc/testsuite/gcc.target/i386/pr105576.c
>
> diff --git a/gcc/config/i386/constraints.md b/gcc/config/i386/constraints.md
> index 7361687632f..ec0702be368 100644
> --- a/gcc/config/i386/constraints.md
> +++ b/gcc/config/i386/constraints.md
> @@ -348,6 +348,10 @@ (define_constraint "Z"
> instructions)."
> (match_operand 0 "x86_64_zext_immediate_operand"))
>
> +(define_constraint "Ws"
> + "A constraint that matches an absolute symbolic address."
> + (match_test "ix86_symbolic_address_p (op)"))
> +
> ;; T prefix is used for different address constraints
> ;; v - VSIB address
> ;; s - address with no segment register
> diff --git a/gcc/config/i386/i386-protos.h b/gcc/config/i386/i386-protos.h
> index 3596ce81ecf..2b8d063850f 100644
> --- a/gcc/config/i386/i386-protos.h
> +++ b/gcc/config/i386/i386-protos.h
> @@ -337,6 +337,7 @@ extern void x86_output_aligned_bss (FILE *, tree, const
> char *,
> unsigned HOST_WIDE_INT, unsigned);
> extern void x86_elf_aligned_decl_common (FILE *, tree, const char *,
> unsigned HOST_WIDE_INT, unsigned);
> +extern bool ix86_symbolic_address_p (rtx x);
>
> #ifdef RTX_CODE
> extern void ix86_fp_comparison_codes (enum rtx_code code, enum rtx_code *,
> diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
> index 86752a6516a..76728d10c8d 100644
> --- a/gcc/config/i386/i386.cc
> +++ b/gcc/config/i386/i386.cc
> @@ -23956,6 +23956,13 @@ ix86_push_rounding (poly_int64 bytes)
> return ROUND_UP (bytes, UNITS_PER_WORD);
> }
>
> +bool ix86_symbolic_address_p (rtx x)
> +{
> + poly_int64 offset;
> + x = strip_offset (x, &offset);
> + return SYMBOL_REF_P (x) || LABEL_REF_P (x);
> +}
> +
> /* Target-specific selftests. */
>
> #if CHECKING_P
> diff --git a/gcc/testsuite/gcc.target/i386/pr105576.c
> b/gcc/testsuite/gcc.target/i386/pr105576.c
> new file mode 100644
> index 00000000000..06dd860d3f3
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/pr105576.c
> @@ -0,0 +1,11 @@
> +/* PR target/105576 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -mcmodel=large" } */
> +
> +extern int var;
> +void *addr(void) { return &var; }
> +void addr_via_asm(void)
> +{
> + asm (".pushsection .xxx,\"aw\"\n\t .dc.a %0\n\t .popsection" ::
> "Ws"(addr));
> + asm (".pushsection .xxx,\"aw\"\n\t .dc.a %0\n\t .popsection" ::
> "Ws"(&var));
> +}
> --
> 2.18.1
>
