On Wed, Nov 8, 2023 at 5:37 PM Alexandre Oliva <[email protected]> wrote:
>
> Ping?
> https://gcc.gnu.org/pipermail/gcc-patches/2022-July/598872.html
>
> Looking at the code generated for sse2-{load,store}-multi.c with PIE,
> I realized we could use UNSPEC_GOTOFF as a base address, and that this
> would enable the test to use the vector insns expected by the tests
> even with PIC, so I extended the base + offset logic used by the SSE2
> multi-load/store peepholes to accept reg + symbolic base + offset too,
> so that the test generated the expected insns even with PIE.
>
> Regstrapped on x86_64-linux-gnu, also tested with gcc-13 on i686- and
> x86_64-. Ok to install?
>
>
> for gcc/ChangeLog
>
> * config/i386/i386.cc (symbolic_base_address_p,
> base_address_p): New, factored out from...
> (extract_base_offset_in_addr): ... here and extended to
> recognize REG+GOTOFF, as in gcc.target/i386/sse2-load-multi.c
> and sse2-store-multi.c with PIE enabled by default.
LGTM.
Thanks,
Uros.
> ---
> gcc/config/i386/i386.cc | 89
> ++++++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 75 insertions(+), 14 deletions(-)
>
> diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
> index c2bd07fced7b1..eec9b42396e0a 100644
> --- a/gcc/config/i386/i386.cc
> +++ b/gcc/config/i386/i386.cc
> @@ -25198,11 +25198,40 @@ ix86_reloc_rw_mask (void)
> }
> #endif
>
> -/* If MEM is in the form of [base+offset], extract the two parts
> - of address and set to BASE and OFFSET, otherwise return false. */
> +/* Return true iff ADDR can be used as a symbolic base address. */
>
> static bool
> -extract_base_offset_in_addr (rtx mem, rtx *base, rtx *offset)
> +symbolic_base_address_p (rtx addr)
> +{
> + if (GET_CODE (addr) == SYMBOL_REF)
> + return true;
> +
> + if (GET_CODE (addr) == UNSPEC && XINT (addr, 1) == UNSPEC_GOTOFF)
> + return true;
> +
> + return false;
> +}
> +
> +/* Return true iff ADDR can be used as a base address. */
> +
> +static bool
> +base_address_p (rtx addr)
> +{
> + if (REG_P (addr))
> + return true;
> +
> + if (symbolic_base_address_p (addr))
> + return true;
> +
> + return false;
> +}
> +
> +/* If MEM is in the form of [(base+symbase)+offset], extract the three
> + parts of address and set to BASE, SYMBASE and OFFSET, otherwise
> + return false. */
> +
> +static bool
> +extract_base_offset_in_addr (rtx mem, rtx *base, rtx *symbase, rtx *offset)
> {
> rtx addr;
>
> @@ -25213,21 +25242,52 @@ extract_base_offset_in_addr (rtx mem, rtx *base,
> rtx *offset)
> if (GET_CODE (addr) == CONST)
> addr = XEXP (addr, 0);
>
> - if (REG_P (addr) || GET_CODE (addr) == SYMBOL_REF)
> + if (base_address_p (addr))
> {
> *base = addr;
> + *symbase = const0_rtx;
> *offset = const0_rtx;
> return true;
> }
>
> if (GET_CODE (addr) == PLUS
> - && (REG_P (XEXP (addr, 0))
> - || GET_CODE (XEXP (addr, 0)) == SYMBOL_REF)
> - && CONST_INT_P (XEXP (addr, 1)))
> + && base_address_p (XEXP (addr, 0)))
> {
> - *base = XEXP (addr, 0);
> - *offset = XEXP (addr, 1);
> - return true;
> + rtx addend = XEXP (addr, 1);
> +
> + if (GET_CODE (addend) == CONST)
> + addend = XEXP (addend, 0);
> +
> + if (CONST_INT_P (addend))
> + {
> + *base = XEXP (addr, 0);
> + *symbase = const0_rtx;
> + *offset = addend;
> + return true;
> + }
> +
> + /* Also accept REG + symbolic ref, with or without a CONST_INT
> + offset. */
> + if (REG_P (XEXP (addr, 0)))
> + {
> + if (symbolic_base_address_p (addend))
> + {
> + *base = XEXP (addr, 0);
> + *symbase = addend;
> + *offset = const0_rtx;
> + return true;
> + }
> +
> + if (GET_CODE (addend) == PLUS
> + && symbolic_base_address_p (XEXP (addend, 0))
> + && CONST_INT_P (XEXP (addend, 1)))
> + {
> + *base = XEXP (addr, 0);
> + *symbase = XEXP (addend, 0);
> + *offset = XEXP (addend, 1);
> + return true;
> + }
> + }
> }
>
> return false;
> @@ -25242,7 +25302,8 @@ ix86_operands_ok_for_move_multiple (rtx *operands,
> bool load,
> machine_mode mode)
> {
> HOST_WIDE_INT offval_1, offval_2, msize;
> - rtx mem_1, mem_2, reg_1, reg_2, base_1, base_2, offset_1, offset_2;
> + rtx mem_1, mem_2, reg_1, reg_2, base_1, base_2,
> + symbase_1, symbase_2, offset_1, offset_2;
>
> if (load)
> {
> @@ -25265,13 +25326,13 @@ ix86_operands_ok_for_move_multiple (rtx *operands,
> bool load,
> return false;
>
> /* Check if the addresses are in the form of [base+offset]. */
> - if (!extract_base_offset_in_addr (mem_1, &base_1, &offset_1))
> + if (!extract_base_offset_in_addr (mem_1, &base_1, &symbase_1, &offset_1))
> return false;
> - if (!extract_base_offset_in_addr (mem_2, &base_2, &offset_2))
> + if (!extract_base_offset_in_addr (mem_2, &base_2, &symbase_2, &offset_2))
> return false;
>
> /* Check if the bases are the same. */
> - if (!rtx_equal_p (base_1, base_2))
> + if (!rtx_equal_p (base_1, base_2) || !rtx_equal_p (symbase_1, symbase_2))
> return false;
>
> offval_1 = INTVAL (offset_1);
>
>
> --
> Alexandre Oliva, happy hacker https://FSFLA.org/blogs/lxo/
> Free Software Activist GNU Toolchain Engineer
> More tolerance and less prejudice are key for inclusion and diversity
> Excluding neuro-others for not behaving ""normal"" is *not* inclusive
