[PATCH v2] RISC-V: Optimize relax of GP/call with max_alignment.
Lifang Xia
lifang_xia@linux.alibaba.com
Wed Nov 9 02:52:06 GMT 2022
ping.
On 2022/10/27 11:19, lifang_xia@linux.alibaba.com wrote:
> From: Lifang Xia <lifang_xia@linux.alibaba.com>
>
> The max_alignment defined out of [gp-2K, gp+2k), the max_alignment
> shouldn't affect the relax of gp.
> If the symbol is in [gp-2K, gp+2k), the max_alignment would be
> replaced with the max_alignment of the section in [gp-2k, gp+2k).
>
> Likewise, the max_alignment defined out of [call-1M, call+1M),
> the max_alignment shouldn't affect the relax of call.
> If the symbol is in [call-1M, call+1M), the max_alignment would be
> replaced with the max_alignment of the section in [call-1M, call+1M).
>
> bfd/
> * elfnn-riscv.c (_bfd_riscv_get_max_alignment_in_jtype): New.
> (_bfd_riscv_relax_call): The max_alignment of sections is from
> [base-1M, base+1M).
> (_bfd_riscv_get_max_alignment_in_itype): New.
> (_bfd_riscv_relax_lui): The max_alignment of sections is from
> [gp-2K, gp+2K).
> (_bfd_riscv_relax_pc): Likewise.
> ld/
> * ld/testsuite/ld-riscv-elf/relax-max-align-call.*: New tests.
> * ld/testsuite/ld-riscv-elf/relax-max-align-gp.*: New tests.
> ---
> bfd/elfnn-riscv.c | 67 +++++++++++++++++++
> ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp | 2 +
> .../ld-riscv-elf/relax-max-align-call.d | 18 +++++
> .../ld-riscv-elf/relax-max-align-call.ld | 22 ++++++
> .../ld-riscv-elf/relax-max-align-call.s | 23 +++++++
> .../ld-riscv-elf/relax-max-align-gp.d | 46 +++++++++++++
> .../ld-riscv-elf/relax-max-align-gp.s | 29 ++++++++
> 7 files changed, 207 insertions(+)
> create mode 100644 ld/testsuite/ld-riscv-elf/relax-max-align-call.d
> create mode 100644 ld/testsuite/ld-riscv-elf/relax-max-align-call.ld
> create mode 100644 ld/testsuite/ld-riscv-elf/relax-max-align-call.s
> create mode 100644 ld/testsuite/ld-riscv-elf/relax-max-align-gp.d
> create mode 100644 ld/testsuite/ld-riscv-elf/relax-max-align-gp.s
>
> diff --git a/bfd/elfnn-riscv.c b/bfd/elfnn-riscv.c
> index cf852636c9c..ed72704bd80 100644
> --- a/bfd/elfnn-riscv.c
> +++ b/bfd/elfnn-riscv.c
> @@ -4266,6 +4266,28 @@ typedef bool (*relax_func_t) (bfd *, asection *, asection *,
> riscv_pcgp_relocs *,
> bool undefined_weak);
>
> +/* Traverse all output sections in jtype, and return the max alignment. */
> +
> +static bfd_vma
> +_bfd_riscv_get_max_alignment_in_jtype (asection *sec, bfd_vma base)
> +{
> + unsigned int max_alignment_power = 0;
> + asection *o;
> +
> + if (sec == NULL)
> + return 0;
> +
> + for (o = sec->owner->sections; o != NULL; o = o->next)
> + {
> + if (VALID_JTYPE_IMM (sec_addr(o) - base)
> + || VALID_ITYPE_IMM (sec_addr(o) + o->size - base))
> + if (o->alignment_power > max_alignment_power)
> + max_alignment_power = o->alignment_power;
> + }
> +
> + return (bfd_vma) 1 << max_alignment_power;
> +}
> +
> /* Relax AUIPC + JALR into JAL. */
>
> static bool
> @@ -4294,6 +4316,15 @@ _bfd_riscv_relax_call (bfd *abfd, asection *sec, asection *sym_sec,
> if (sym_sec->output_section == sec->output_section
> && sym_sec->output_section != bfd_abs_section_ptr)
> max_alignment = (bfd_vma) 1 << sym_sec->output_section->alignment_power;
> + else
> + {
> + bfd_vma new_max_alignment =
> + _bfd_riscv_get_max_alignment_in_jtype (sec,
> + (sec_addr (sec)
> + + rel->r_offset));
> + if (new_max_alignment)
> + max_alignment = new_max_alignment;
> + }
> foff += ((bfd_signed_vma) foff < 0 ? -max_alignment : max_alignment);
> }
>
> @@ -4360,6 +4391,28 @@ _bfd_riscv_get_max_alignment (asection *sec)
> return (bfd_vma) 1 << max_alignment_power;
> }
>
> +/* Traverse all output sections in [gp-2K, gp+2K) and return the max alignment. */
> +
> +static bfd_vma
> +_bfd_riscv_get_max_alignment_in_itype (asection *sec, bfd_vma gp)
> +{
> + unsigned int max_alignment_power = 0;
> + asection *o;
> +
> + if (sec == NULL)
> + return 0;
> +
> + for (o = sec->owner->sections; o != NULL; o = o->next)
> + {
> + if (VALID_ITYPE_IMM (sec_addr(o) - gp)
> + || VALID_ITYPE_IMM (sec_addr(o) + o->size - gp))
> + if (o->alignment_power > max_alignment_power)
> + max_alignment_power = o->alignment_power;
> + }
> +
> + return (bfd_vma) 1 << max_alignment_power;
> +}
> +
> /* Relax non-PIC global variable references to GP-relative references. */
>
> static bool
> @@ -4391,6 +4444,13 @@ _bfd_riscv_relax_lui (bfd *abfd,
> if (h->u.def.section->output_section == sym_sec->output_section
> && sym_sec->output_section != bfd_abs_section_ptr)
> max_alignment = (bfd_vma) 1 << sym_sec->output_section->alignment_power;
> + else
> + {
> + /* Otherwise, consider the alignment of sections in [gp-2K,gp+2K). */
> + bfd_vma new_max_alignment = _bfd_riscv_get_max_alignment_in_itype (sec, gp);
> + if (new_max_alignment)
> + max_alignment = new_max_alignment;
> + }
> }
>
> /* Is the reference in range of x0 or gp?
> @@ -4656,6 +4716,13 @@ _bfd_riscv_relax_pc (bfd *abfd ATTRIBUTE_UNUSED,
> if (h->u.def.section->output_section == sym_sec->output_section
> && sym_sec->output_section != bfd_abs_section_ptr)
> max_alignment = (bfd_vma) 1 << sym_sec->output_section->alignment_power;
> + else if (!undefined_weak)
> + {
> + /* Otherwise, consider the alignment of sections in [gp-2K,gp+2K). */
> + bfd_vma new_max_alignment = _bfd_riscv_get_max_alignment_in_itype (sec, gp);
> + if (new_max_alignment)
> + max_alignment = new_max_alignment;
> + }
> }
>
> /* Is the reference in range of x0 or gp?
> diff --git a/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp b/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
> index df89e0ee68b..f38807b991e 100644
> --- a/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
> +++ b/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
> @@ -169,6 +169,8 @@ if [istarget "riscv*-*-*"] {
> run_dump_test "attr-merge-priv-spec-failed-05"
> run_dump_test "attr-merge-priv-spec-failed-06"
> run_dump_test "attr-phdr"
> + run_dump_test "relax-max-align-gp"
> + run_dump_test "relax-max-align-call"
> run_ld_link_tests [list \
> [list "Weak reference 32" "-T weakref.ld -m[riscv_choose_ilp32_emul]" "" \
> "-march=rv32i -mabi=ilp32" {weakref32.s} \
> diff --git a/ld/testsuite/ld-riscv-elf/relax-max-align-call.d b/ld/testsuite/ld-riscv-elf/relax-max-align-call.d
> new file mode 100644
> index 00000000000..490ad8c865e
> --- /dev/null
> +++ b/ld/testsuite/ld-riscv-elf/relax-max-align-call.d
> @@ -0,0 +1,18 @@
> +#source: relax-max-align-call.s
> +#as: -march=rv64gc
> +#ld: -Trelax-max-align-call.ld
> +#objdump: -d
> +
> +.*:[ ]+file format .*
> +
> +
> +Disassembly of section .text1:
> +
> +0000000000100000 <_start>:
> +[ ]+100000:[ ]+79dff0ef[ ]+jal[ ]+1fff9c <foo>
> +[ ]+100004:[ ]+a001[ ]+j[ ]+100004 <_start\+0x4>
> +
> +Disassembly of section .text2:
> +
> +00000000001fff9c <foo>:
> +[ ]+1fff9c:[ ]+8082[ ]+ret
> diff --git a/ld/testsuite/ld-riscv-elf/relax-max-align-call.ld b/ld/testsuite/ld-riscv-elf/relax-max-align-call.ld
> new file mode 100644
> index 00000000000..91991ed0f41
> --- /dev/null
> +++ b/ld/testsuite/ld-riscv-elf/relax-max-align-call.ld
> @@ -0,0 +1,22 @@
> +
> +ENTRY(_start)
> +
> +SECTIONS
> +{
> + . = 0x100000;
> +
> + .text1 : {
> + *(.text1)
> + }
> +
> + . = 0x200000 - 100;
> +
> + .text2 : {
> + *(.text2)
> + }
> +
> + . = 0x300000;
> + .data : {
> + *(.data)
> + }
> +}
> diff --git a/ld/testsuite/ld-riscv-elf/relax-max-align-call.s b/ld/testsuite/ld-riscv-elf/relax-max-align-call.s
> new file mode 100644
> index 00000000000..3335c0970e7
> --- /dev/null
> +++ b/ld/testsuite/ld-riscv-elf/relax-max-align-call.s
> @@ -0,0 +1,23 @@
> +
> +.section .text1, "ax"
> +.global _start
> +.align 2
> +_start:
> + call foo
> + j .
> + .size _start, . - _start
> +
> +.section .text2, "ax"
> +.align 2
> +.global foo
> +.type foo, @function
> +foo:
> + ret
> + .size foo, . - foo
> +
> +.data
> +.global gdata
> +.align 10
> +gdata:
> + .long 0
> + .size gdata, . - gdata
> diff --git a/ld/testsuite/ld-riscv-elf/relax-max-align-gp.d b/ld/testsuite/ld-riscv-elf/relax-max-align-gp.d
> new file mode 100644
> index 00000000000..637de426ee4
> --- /dev/null
> +++ b/ld/testsuite/ld-riscv-elf/relax-max-align-gp.d
> @@ -0,0 +1,46 @@
> +#source: relax-max-align-gp.s
> +#ld:
> +#objdump: -d
> +
> +.*:[ ]+file format .*
> +
> +
> +Disassembly of section .text:
> +
> +0+[0-9a-f]+ <_start>:
> +.*:[ ]+[0-9a-f]+[ ]+add[ ]+.*<gdata>
> +.*:[ ]+[0-9a-f]+[ ]+jal[ ]+.*
> +.*:[ ]+[0-9a-f]+[ ]+j[ ]+.*
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +.*:[ ]+[0-9a-f]+[ ]+nop
> +
> +0+[0-9a-f]+ <func>:
> +.*:[ ]+[0-9a-f]+[ ]+ret
> +[ ]+...
> diff --git a/ld/testsuite/ld-riscv-elf/relax-max-align-gp.s b/ld/testsuite/ld-riscv-elf/relax-max-align-gp.s
> new file mode 100644
> index 00000000000..0d162ff4d93
> --- /dev/null
> +++ b/ld/testsuite/ld-riscv-elf/relax-max-align-gp.s
> @@ -0,0 +1,29 @@
> +
> +.global _start
> +_start:
> + lui a0, %hi(gdata)
> + addi a0, a0, %lo(gdata)
> + call func
> + j .
> + .size _start, . - _start
> +
> +.global func
> +.align 7
> +func:
> + ret
> + .size func, . - func
> +
> +.data
> +padding:
> + .long 0
> + .long 0
> + .long 0
> + .long 0
> + .size padding, . - padding
> +
> +.global gdata
> +.type gdata, object
> +gdata:
> + .zero 4
> + .size gdata, . - gdata
> +
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