* [binutils-gdb] RISC-V: Add --[no-]relax-gp to ld
@ 2023-02-24 6:11 Fangrui Song
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From: Fangrui Song @ 2023-02-24 6:11 UTC (permalink / raw)
To: bfd-cvs
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=50980ba351856dff75bb0743bfca62f4c3ab19ff
commit 50980ba351856dff75bb0743bfca62f4c3ab19ff
Author: Fangrui Song <i@maskray.me>
Date: Thu Feb 23 22:11:14 2023 -0800
RISC-V: Add --[no-]relax-gp to ld
--relax enables all relaxations. --no-relax-gp disables GP relaxation to
allow measuring its effect.
The option can test effectiveness of GP relaxation and support some ABI
variants that use GP for other purposes.
Link: https://github.com/riscv-non-isa/riscv-elf-psabi-doc/issues/298
bfd/
* elfnn-riscv.c (struct riscv_elf_link_hash_table): Add params.
(riscv_elfNN_set_options): New.
(riscv_info_to_howto_rela): Check relax_gp.
(_bfd_riscv_relax_section): Likewise.
* elfxx-riscv.h (struct riscv_elf_params): New.
(riscv_elf32_set_options): New.
(riscv_elf64_set_options): New.
ld/
* emultempl/riscvelf.em: Add option parsing.
* testsuite/ld-riscv-elf/code-model-relax-medlow-01-norelaxgp.d: New.
* testsuite/ld-riscv-elf/pcgp-relax-01-norelaxgp.d: New.
* testsuite/ld-riscv-elf/pcgp-relax-02.d: Test --relax --relax-gp can be
used together.
Diff:
---
bfd/ChangeLog | 10 ++++++
bfd/elfnn-riscv.c | 16 ++++++++--
bfd/elfxx-riscv.h | 11 +++++++
ld/ChangeLog | 8 +++++
ld/emultempl/riscvelf.em | 36 ++++++++++++++++++++++
.../code-model-relax-medlow-01-norelaxgp.d | 4 +++
ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp | 2 ++
.../ld-riscv-elf/pcgp-relax-01-norelaxgp.d | 18 +++++++++++
ld/testsuite/ld-riscv-elf/pcgp-relax-02.d | 2 +-
9 files changed, 104 insertions(+), 3 deletions(-)
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index b7c03c11678..50e1e17ef4d 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,13 @@
+2023-02-23 Fangrui Song <i@maskray.me>
+
+ * elfnn-riscv.c (struct riscv_elf_link_hash_table): Add params.
+ (riscv_elfNN_set_options): New.
+ (riscv_info_to_howto_rela): Check relax_gp.
+ (_bfd_riscv_relax_section): Likewise.
+ * elfxx-riscv.h (struct riscv_elf_params): New.
+ (riscv_elf32_set_options): New.
+ (riscv_elf64_set_options): New.
+
2023-02-23 Nick Clifton <nickc@redhat.com>
Alan Modra <amodra@gmail.com>
diff --git a/bfd/elfnn-riscv.c b/bfd/elfnn-riscv.c
index 355ddb22566..1200e6b11b5 100644
--- a/bfd/elfnn-riscv.c
+++ b/bfd/elfnn-riscv.c
@@ -118,6 +118,9 @@ struct riscv_elf_link_hash_table
{
struct elf_link_hash_table elf;
+ /* Various options and other info passed from the linker. */
+ struct riscv_elf_params *params;
+
/* Short-cuts to get to dynamic linker sections. */
asection *sdyntdata;
@@ -157,6 +160,13 @@ struct riscv_elf_link_hash_table
&& elf_hash_table_id (elf_hash_table (p)) == RISCV_ELF_DATA) \
? (struct riscv_elf_link_hash_table *) (p)->hash : NULL)
+void
+riscv_elfNN_set_options (struct bfd_link_info *link_info,
+ struct riscv_elf_params *params)
+{
+ riscv_elf_hash_table (link_info)->params = params;
+}
+
static bool
riscv_info_to_howto_rela (bfd *abfd,
arelent *cache_ptr,
@@ -4389,7 +4399,9 @@ _bfd_riscv_relax_lui (bfd *abfd,
bool undefined_weak)
{
bfd_byte *contents = elf_section_data (sec)->this_hdr.contents;
- bfd_vma gp = riscv_global_pointer_value (link_info);
+ bfd_vma gp = riscv_elf_hash_table (link_info)->params->relax_gp
+ ? riscv_global_pointer_value (link_info)
+ : 0;
int use_rvc = elf_elfheader (abfd)->e_flags & EF_RISCV_RVC;
BFD_ASSERT (rel->r_offset + 4 <= sec->size);
@@ -4834,7 +4846,7 @@ _bfd_riscv_relax_section (bfd *abfd, asection *sec,
|| type == R_RISCV_TPREL_LO12_I
|| type == R_RISCV_TPREL_LO12_S)
relax_func = _bfd_riscv_relax_tls_le;
- else if (!bfd_link_pic (info)
+ else if (!bfd_link_pic (info) && htab->params->relax_gp
&& (type == R_RISCV_PCREL_HI20
|| type == R_RISCV_PCREL_LO12_I
|| type == R_RISCV_PCREL_LO12_S))
diff --git a/bfd/elfxx-riscv.h b/bfd/elfxx-riscv.h
index 5e1bdae9b2a..abcb409bd78 100644
--- a/bfd/elfxx-riscv.h
+++ b/bfd/elfxx-riscv.h
@@ -27,6 +27,17 @@
#define RISCV_UNKNOWN_VERSION -1
+struct riscv_elf_params
+{
+ /* Whether to relax code sequences to GP-relative addressing. */
+ bool relax_gp;
+};
+
+extern void riscv_elf32_set_options (struct bfd_link_info *,
+ struct riscv_elf_params *);
+extern void riscv_elf64_set_options (struct bfd_link_info *,
+ struct riscv_elf_params *);
+
extern reloc_howto_type *
riscv_reloc_name_lookup (bfd *, const char *);
diff --git a/ld/ChangeLog b/ld/ChangeLog
index de9ed2753bc..9f4ad7cbf25 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,11 @@
+2023-02-23 Fangrui Song <i@maskray.me>
+
+ * emultempl/riscvelf.em: Add option parsing.
+ * testsuite/ld-riscv-elf/code-model-relax-medlow-01-norelaxgp.d: New.
+ * testsuite/ld-riscv-elf/pcgp-relax-01-norelaxgp.d: New.
+ * testsuite/ld-riscv-elf/pcgp-relax-02.d: Test --relax --relax-gp can be
+ used together.
+
2023-02-20 Nick Clifton <nickc@redhat.com>
PR 30004
diff --git a/ld/emultempl/riscvelf.em b/ld/emultempl/riscvelf.em
index b12d15065c4..bb6298d3e8d 100644
--- a/ld/emultempl/riscvelf.em
+++ b/ld/emultempl/riscvelf.em
@@ -25,6 +25,40 @@ fragment <<EOF
#include "elf/riscv.h"
#include "elfxx-riscv.h"
+static struct riscv_elf_params params = { .relax_gp = 1 };
+EOF
+
+# Define some shell vars to insert bits of code into the standard elf
+# parse_args and list_options functions. */
+PARSE_AND_LIST_PROLOGUE=${PARSE_AND_LIST_PROLOGUE}'
+enum risccv_opt
+{
+ OPTION_RELAX_GP = 321,
+ OPTION_NO_RELAX_GP,
+};
+'
+
+PARSE_AND_LIST_LONGOPTS=${PARSE_AND_LIST_LONGOPTS}'
+ { "relax-gp", no_argument, NULL, OPTION_RELAX_GP },
+ { "no-relax-gp", no_argument, NULL, OPTION_NO_RELAX_GP },
+'
+
+PARSE_AND_LIST_OPTIONS=${PARSE_AND_LIST_OPTIONS}'
+ fprintf (file, _(" --relax-gp Perform GP relaxation\n"));
+ fprintf (file, _(" --no-relax-gp Don'\''t perform GP relaxation\n"));
+'
+
+PARSE_AND_LIST_ARGS_CASES=${PARSE_AND_LIST_ARGS_CASES}'
+ case OPTION_RELAX_GP:
+ params.relax_gp = 1;
+ break;
+
+ case OPTION_NO_RELAX_GP:
+ params.relax_gp = 0;
+ break;
+'
+
+fragment <<EOF
static void
riscv_elf_before_allocation (void)
{
@@ -96,6 +130,8 @@ riscv_create_output_section_statements (void)
" whilst linking %s binaries\n"), "RISC-V");
return;
}
+
+ riscv_elf${ELFSIZE}_set_options (&link_info, ¶ms);
}
EOF
diff --git a/ld/testsuite/ld-riscv-elf/code-model-relax-medlow-01-norelaxgp.d b/ld/testsuite/ld-riscv-elf/code-model-relax-medlow-01-norelaxgp.d
new file mode 100644
index 00000000000..8e40cc5f32d
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/code-model-relax-medlow-01-norelaxgp.d
@@ -0,0 +1,4 @@
+#source: code-model.s
+#as: -march=rv64i -mabi=lp64 --defsym __medlow__=1
+#ld: -Tcode-model-01.ld -melf64lriscv --no-relax-gp --relax
+#error: .*relocation truncated to fit: R_RISCV_HI20 against `symbolL'
diff --git a/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp b/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
index 0f7ccd92ed5..5dd6144efd3 100644
--- a/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
+++ b/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
@@ -122,6 +122,7 @@ if [istarget "riscv*-*-*"] {
run_dump_test "align-small-region"
run_dump_test "call-relax"
run_dump_test "pcgp-relax-01"
+ run_dump_test "pcgp-relax-01-norelaxgp"
run_dump_test "pcgp-relax-02"
run_dump_test "c-lui"
run_dump_test "c-lui-2"
@@ -141,6 +142,7 @@ if [istarget "riscv*-*-*"] {
run_dump_test "code-model-medany-weakref-01"
run_dump_test "code-model-medany-weakref-02"
run_dump_test "code-model-relax-medlow-01"
+ run_dump_test "code-model-relax-medlow-01-norelaxgp"
run_dump_test "code-model-relax-medlow-02"
run_dump_test "code-model-relax-medlow-weakref-01"
run_dump_test "code-model-relax-medlow-weakref-02"
diff --git a/ld/testsuite/ld-riscv-elf/pcgp-relax-01-norelaxgp.d b/ld/testsuite/ld-riscv-elf/pcgp-relax-01-norelaxgp.d
new file mode 100644
index 00000000000..d1344576ff3
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/pcgp-relax-01-norelaxgp.d
@@ -0,0 +1,18 @@
+#source: pcgp-relax-01.s
+#ld: --no-relax-gp --relax
+#objdump: -d -Mno-aliases
+
+.*:[ ]+file format .*
+
+
+Disassembly of section \.text:
+
+0+[0-9a-f]+ <_start>:
+.*:[ ]+[0-9a-f]+[ ]+addi[ ]+a0,a0,[0-9]+
+.*:[ ]+[0-9a-f]+[ ]+jal[ ]+ra,[0-9a-f]+ <_start>
+.*:[ ]+[0-9a-f]+[ ]+auipc[ ]+a1,0x[0-9a-f]+
+.*:[ ]+[0-9a-f]+[ ]+addi[ ]+a1,a1,[0-9]+ # [0-9a-f]+ <data_g>
+.*:[ ]+[0-9a-f]+[ ]+lui[ ]+a2,0x[0-9a-f]+
+.*:[ ]+[0-9a-f]+[ ]+addi[ ]+a2,a2,[0-9]+ # [0-9a-f]+ <data_g>
+.*:[ ]+[0-9a-f]+[ ]+addi[ ]+a3,tp,0 # 0 <data_t>
+.*:[ ]+[0-9a-f]+[ ]+auipc[ ]+a0,0x[0-9a-f]+
diff --git a/ld/testsuite/ld-riscv-elf/pcgp-relax-02.d b/ld/testsuite/ld-riscv-elf/pcgp-relax-02.d
index 1248132ab42..055f03e57f2 100644
--- a/ld/testsuite/ld-riscv-elf/pcgp-relax-02.d
+++ b/ld/testsuite/ld-riscv-elf/pcgp-relax-02.d
@@ -1,6 +1,6 @@
#source: pcgp-relax-02.s
#as:
-#ld: --relax
+#ld: --relax --relax-gp
#objdump: -d
.*:[ ]+file format .*
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