Re: [PATCH v4] i386: Allow -mlarge-data-threshold with -mcmodel=large
On Tue, Aug 1, 2023 at 9:51 PM Fangrui Song wrote:
>
> When using -mcmodel=medium, large data objects larger than the
> -mlarge-data-threshold threshold are placed into large data sections
> (.lrodata, .ldata, .lbss and some variants). GNU ld and ld.lld 17 place
> .l* sections into separate output sections. If small and medium code
> model object files are mixed, the .l* sections won't exert relocation
> overflow pressure on sections in object files built with -mcmodel=small.
>
> However, when using -mcmodel=large, -mlarge-data-threshold doesn't
> apply. This means that the .rodata/.data/.bss sections may exert
> relocation overflow pressure on sections in -mcmodel=small object files.
>
> This patch allows -mcmodel=large to generate .l* sections and drops an
> unneeded documentation restriction that the value must be the same.
>
> Link: https://groups.google.com/g/x86-64-abi/c/jnQdJeabxiU
> ("Large data sections for the large code model")
>
> Signed-off-by: Fangrui Song
>
> ---
> Changes from v1
> (https://gcc.gnu.org/pipermail/gcc-patches/2023-April/616947.html):
> * Clarify commit message. Add link to
> https://groups.google.com/g/x86-64-abi/c/jnQdJeabxiU
>
> Changes from v2
> * Drop an uneeded limitation in the documentation.
>
> Changes from v3
> * Change scan-assembler directives to use \. to match literal .
> ---
> gcc/config/i386/i386.cc| 15 +--
> gcc/config/i386/i386.opt | 2 +-
> gcc/doc/invoke.texi| 6 +++---
> gcc/testsuite/gcc.target/i386/large-data.c | 13 +
> 4 files changed, 26 insertions(+), 10 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/large-data.c
>
> diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
> index eabc70011ea..37e810cc741 100644
> --- a/gcc/config/i386/i386.cc
> +++ b/gcc/config/i386/i386.cc
> @@ -647,7 +647,8 @@ ix86_can_inline_p (tree caller, tree callee)
> static bool
> ix86_in_large_data_p (tree exp)
> {
> - if (ix86_cmodel != CM_MEDIUM && ix86_cmodel != CM_MEDIUM_PIC)
> + if (ix86_cmodel != CM_MEDIUM && ix86_cmodel != CM_MEDIUM_PIC &&
> + ix86_cmodel != CM_LARGE && ix86_cmodel != CM_LARGE_PIC)
Please split multi-line expression before the operator, not after it,
as instructed in GNU Coding Standards [1] ...
[1] https://www.gnu.org/prep/standards/html_node/Formatting.html
> return false;
>
>if (exp == NULL_TREE)
> @@ -858,8 +859,9 @@ x86_elf_aligned_decl_common (FILE *file, tree decl,
> const char *name, unsigned HOST_WIDE_INT size,
> unsigned align)
> {
> - if ((ix86_cmodel == CM_MEDIUM || ix86_cmodel == CM_MEDIUM_PIC)
> - && size > (unsigned int)ix86_section_threshold)
> + if ((ix86_cmodel == CM_MEDIUM || ix86_cmodel == CM_MEDIUM_PIC ||
> + ix86_cmodel == CM_LARGE || ix86_cmodel == CM_LARGE_PIC) &&
> + size > (unsigned int)ix86_section_threshold)
... also here ...
> {
>switch_to_section (get_named_section (decl, ".lbss", 0));
>fputs (LARGECOMM_SECTION_ASM_OP, file);
> @@ -879,9 +881,10 @@ void
> x86_output_aligned_bss (FILE *file, tree decl, const char *name,
> unsigned HOST_WIDE_INT size, unsigned align)
> {
> - if ((ix86_cmodel == CM_MEDIUM || ix86_cmodel == CM_MEDIUM_PIC)
> - && size > (unsigned int)ix86_section_threshold)
> -switch_to_section (get_named_section (decl, ".lbss", 0));
> + if ((ix86_cmodel == CM_MEDIUM || ix86_cmodel == CM_MEDIUM_PIC ||
> + ix86_cmodel == CM_LARGE || ix86_cmodel == CM_LARGE_PIC) &&
> + size > (unsigned int)ix86_section_threshold)
... and here.
OK with these formatting changes.
Thanks,
Uros.
> +switch_to_section(get_named_section(decl, ".lbss", 0));
>else
> switch_to_section (bss_section);
>ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
> diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt
> index 1cc8563477a..52fad492353 100644
> --- a/gcc/config/i386/i386.opt
> +++ b/gcc/config/i386/i386.opt
> @@ -282,7 +282,7 @@ Branches are this expensive (arbitrary units).
>
> mlarge-data-threshold=
> Target RejectNegative Joined UInteger Var(ix86_section_threshold)
> Init(DEFAULT_LARGE_SECTION_THRESHOLD)
> --mlarge-data-threshold=Data greater than given threshold
> will go into .ldata section in x86-64 medium model.
> +-mlarge-data-threshold=Data greater than given threshold
> will go into a large data section in x86-64 medium and large code models.
>
> mcmodel=
> Target RejectNegative Joined Enum(cmodel) Var(ix86_cmodel) Init(CM_32)
> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> index 104766f446d..bf6fe3e1a20 100644
> --- a/gcc/doc/invoke.texi
> +++ b/gcc/doc/invoke.texi
> @@ -33207,9 +33207,9 @@ the cache line size. @samp{compat} is the default.
>
> @opindex mlarge-data-threshold
> @item -mlarge-data-threshold=@var{threshold}
> -When @option{-mcmodel=medium} is specified, data
Re: [PATCH v4] i386: Allow -mlarge-data-threshold with -mcmodel=large
On Wed, Sep 13, 2023 at 11:19 AM Fangrui Song wrote:
>
> On Tue, Aug 22, 2023 at 12:19 AM Fangrui Song wrote:
> >
> > On Tue, Aug 1, 2023 at 12:51 PM Fangrui Song wrote:
> > >
> > > When using -mcmodel=medium, large data objects larger than the
> > > -mlarge-data-threshold threshold are placed into large data sections
> > > (.lrodata, .ldata, .lbss and some variants). GNU ld and ld.lld 17 place
> > > .l* sections into separate output sections. If small and medium code
> > > model object files are mixed, the .l* sections won't exert relocation
> > > overflow pressure on sections in object files built with -mcmodel=small.
> > >
> > > However, when using -mcmodel=large, -mlarge-data-threshold doesn't
> > > apply. This means that the .rodata/.data/.bss sections may exert
> > > relocation overflow pressure on sections in -mcmodel=small object files.
> > >
> > > This patch allows -mcmodel=large to generate .l* sections and drops an
> > > unneeded documentation restriction that the value must be the same.
> > >
> > > Link: https://groups.google.com/g/x86-64-abi/c/jnQdJeabxiU
> > > ("Large data sections for the large code model")
> > >
> > > Signed-off-by: Fangrui Song
> > >
> > > ---
> > > Changes from v1
> > > (https://gcc.gnu.org/pipermail/gcc-patches/2023-April/616947.html):
> > > * Clarify commit message. Add link to
> > > https://groups.google.com/g/x86-64-abi/c/jnQdJeabxiU
> > >
> > > Changes from v2
> > > * Drop an uneeded limitation in the documentation.
> > >
> > > Changes from v3
> > > * Change scan-assembler directives to use \. to match literal .
> > > ---
> > > gcc/config/i386/i386.cc| 15 +--
> > > gcc/config/i386/i386.opt | 2 +-
> > > gcc/doc/invoke.texi| 6 +++---
> > > gcc/testsuite/gcc.target/i386/large-data.c | 13 +
> > > 4 files changed, 26 insertions(+), 10 deletions(-)
> > > create mode 100644 gcc/testsuite/gcc.target/i386/large-data.c
> > >
> > > [...]
> >
> > Ping:)
>
> Ping:) https://gcc.gnu.org/pipermail/gcc-patches/2023-August/625993.html
>
> (I don't have write access to gcc.)
>
>
> --
> 宋方睿
Ping? :) https://gcc.gnu.org/pipermail/gcc-patches/2023-August/625993.html
(I don't have write access to gcc.)
--
宋方睿
Re: [PATCH v4] i386: Allow -mlarge-data-threshold with -mcmodel=large
On Tue, Aug 22, 2023 at 12:19 AM Fangrui Song wrote:
>
> On Tue, Aug 1, 2023 at 12:51 PM Fangrui Song wrote:
> >
> > When using -mcmodel=medium, large data objects larger than the
> > -mlarge-data-threshold threshold are placed into large data sections
> > (.lrodata, .ldata, .lbss and some variants). GNU ld and ld.lld 17 place
> > .l* sections into separate output sections. If small and medium code
> > model object files are mixed, the .l* sections won't exert relocation
> > overflow pressure on sections in object files built with -mcmodel=small.
> >
> > However, when using -mcmodel=large, -mlarge-data-threshold doesn't
> > apply. This means that the .rodata/.data/.bss sections may exert
> > relocation overflow pressure on sections in -mcmodel=small object files.
> >
> > This patch allows -mcmodel=large to generate .l* sections and drops an
> > unneeded documentation restriction that the value must be the same.
> >
> > Link: https://groups.google.com/g/x86-64-abi/c/jnQdJeabxiU
> > ("Large data sections for the large code model")
> >
> > Signed-off-by: Fangrui Song
> >
> > ---
> > Changes from v1
> > (https://gcc.gnu.org/pipermail/gcc-patches/2023-April/616947.html):
> > * Clarify commit message. Add link to
> > https://groups.google.com/g/x86-64-abi/c/jnQdJeabxiU
> >
> > Changes from v2
> > * Drop an uneeded limitation in the documentation.
> >
> > Changes from v3
> > * Change scan-assembler directives to use \. to match literal .
> > ---
> > gcc/config/i386/i386.cc| 15 +--
> > gcc/config/i386/i386.opt | 2 +-
> > gcc/doc/invoke.texi| 6 +++---
> > gcc/testsuite/gcc.target/i386/large-data.c | 13 +
> > 4 files changed, 26 insertions(+), 10 deletions(-)
> > create mode 100644 gcc/testsuite/gcc.target/i386/large-data.c
> >
> > [...]
>
> Ping:)
Ping:) https://gcc.gnu.org/pipermail/gcc-patches/2023-August/625993.html
(I don't have write access to gcc.)
--
宋方睿
Re: [PATCH v4] i386: Allow -mlarge-data-threshold with -mcmodel=large
On Tue, Aug 1, 2023 at 12:51 PM Fangrui Song wrote:
>
> When using -mcmodel=medium, large data objects larger than the
> -mlarge-data-threshold threshold are placed into large data sections
> (.lrodata, .ldata, .lbss and some variants). GNU ld and ld.lld 17 place
> .l* sections into separate output sections. If small and medium code
> model object files are mixed, the .l* sections won't exert relocation
> overflow pressure on sections in object files built with -mcmodel=small.
>
> However, when using -mcmodel=large, -mlarge-data-threshold doesn't
> apply. This means that the .rodata/.data/.bss sections may exert
> relocation overflow pressure on sections in -mcmodel=small object files.
>
> This patch allows -mcmodel=large to generate .l* sections and drops an
> unneeded documentation restriction that the value must be the same.
>
> Link: https://groups.google.com/g/x86-64-abi/c/jnQdJeabxiU
> ("Large data sections for the large code model")
>
> Signed-off-by: Fangrui Song
>
> ---
> Changes from v1
> (https://gcc.gnu.org/pipermail/gcc-patches/2023-April/616947.html):
> * Clarify commit message. Add link to
> https://groups.google.com/g/x86-64-abi/c/jnQdJeabxiU
>
> Changes from v2
> * Drop an uneeded limitation in the documentation.
>
> Changes from v3
> * Change scan-assembler directives to use \. to match literal .
> ---
> gcc/config/i386/i386.cc| 15 +--
> gcc/config/i386/i386.opt | 2 +-
> gcc/doc/invoke.texi| 6 +++---
> gcc/testsuite/gcc.target/i386/large-data.c | 13 +
> 4 files changed, 26 insertions(+), 10 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/large-data.c
>
> [...]
Ping:)
[PATCH v4] i386: Allow -mlarge-data-threshold with -mcmodel=large
When using -mcmodel=medium, large data objects larger than the
-mlarge-data-threshold threshold are placed into large data sections
(.lrodata, .ldata, .lbss and some variants). GNU ld and ld.lld 17 place
.l* sections into separate output sections. If small and medium code
model object files are mixed, the .l* sections won't exert relocation
overflow pressure on sections in object files built with -mcmodel=small.
However, when using -mcmodel=large, -mlarge-data-threshold doesn't
apply. This means that the .rodata/.data/.bss sections may exert
relocation overflow pressure on sections in -mcmodel=small object files.
This patch allows -mcmodel=large to generate .l* sections and drops an
unneeded documentation restriction that the value must be the same.
Link: https://groups.google.com/g/x86-64-abi/c/jnQdJeabxiU
("Large data sections for the large code model")
Signed-off-by: Fangrui Song
---
Changes from v1
(https://gcc.gnu.org/pipermail/gcc-patches/2023-April/616947.html):
* Clarify commit message. Add link to
https://groups.google.com/g/x86-64-abi/c/jnQdJeabxiU
Changes from v2
* Drop an uneeded limitation in the documentation.
Changes from v3
* Change scan-assembler directives to use \. to match literal .
---
gcc/config/i386/i386.cc| 15 +--
gcc/config/i386/i386.opt | 2 +-
gcc/doc/invoke.texi| 6 +++---
gcc/testsuite/gcc.target/i386/large-data.c | 13 +
4 files changed, 26 insertions(+), 10 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/large-data.c
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index eabc70011ea..37e810cc741 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -647,7 +647,8 @@ ix86_can_inline_p (tree caller, tree callee)
static bool
ix86_in_large_data_p (tree exp)
{
- if (ix86_cmodel != CM_MEDIUM && ix86_cmodel != CM_MEDIUM_PIC)
+ if (ix86_cmodel != CM_MEDIUM && ix86_cmodel != CM_MEDIUM_PIC &&
+ ix86_cmodel != CM_LARGE && ix86_cmodel != CM_LARGE_PIC)
return false;
if (exp == NULL_TREE)
@@ -858,8 +859,9 @@ x86_elf_aligned_decl_common (FILE *file, tree decl,
const char *name, unsigned HOST_WIDE_INT size,
unsigned align)
{
- if ((ix86_cmodel == CM_MEDIUM || ix86_cmodel == CM_MEDIUM_PIC)
- && size > (unsigned int)ix86_section_threshold)
+ if ((ix86_cmodel == CM_MEDIUM || ix86_cmodel == CM_MEDIUM_PIC ||
+ ix86_cmodel == CM_LARGE || ix86_cmodel == CM_LARGE_PIC) &&
+ size > (unsigned int)ix86_section_threshold)
{
switch_to_section (get_named_section (decl, ".lbss", 0));
fputs (LARGECOMM_SECTION_ASM_OP, file);
@@ -879,9 +881,10 @@ void
x86_output_aligned_bss (FILE *file, tree decl, const char *name,
unsigned HOST_WIDE_INT size, unsigned align)
{
- if ((ix86_cmodel == CM_MEDIUM || ix86_cmodel == CM_MEDIUM_PIC)
- && size > (unsigned int)ix86_section_threshold)
-switch_to_section (get_named_section (decl, ".lbss", 0));
+ if ((ix86_cmodel == CM_MEDIUM || ix86_cmodel == CM_MEDIUM_PIC ||
+ ix86_cmodel == CM_LARGE || ix86_cmodel == CM_LARGE_PIC) &&
+ size > (unsigned int)ix86_section_threshold)
+switch_to_section(get_named_section(decl, ".lbss", 0));
else
switch_to_section (bss_section);
ASM_OUTPUT_ALIGN (file, floor_log2 (align / BITS_PER_UNIT));
diff --git a/gcc/config/i386/i386.opt b/gcc/config/i386/i386.opt
index 1cc8563477a..52fad492353 100644
--- a/gcc/config/i386/i386.opt
+++ b/gcc/config/i386/i386.opt
@@ -282,7 +282,7 @@ Branches are this expensive (arbitrary units).
mlarge-data-threshold=
Target RejectNegative Joined UInteger Var(ix86_section_threshold)
Init(DEFAULT_LARGE_SECTION_THRESHOLD)
--mlarge-data-threshold=Data greater than given threshold will
go into .ldata section in x86-64 medium model.
+-mlarge-data-threshold=Data greater than given threshold will
go into a large data section in x86-64 medium and large code models.
mcmodel=
Target RejectNegative Joined Enum(cmodel) Var(ix86_cmodel) Init(CM_32)
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 104766f446d..bf6fe3e1a20 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -33207,9 +33207,9 @@ the cache line size. @samp{compat} is the default.
@opindex mlarge-data-threshold
@item -mlarge-data-threshold=@var{threshold}
-When @option{-mcmodel=medium} is specified, data objects larger than
-@var{threshold} are placed in the large data section. This value must be the
-same across all objects linked into the binary, and defaults to 65535.
+When @option{-mcmodel=medium} or @option{-mcmodel=large} is specified, data
+objects larger than @var{threshold} are placed in large data sections. The
+default is 65535.
@opindex mrtd
@item -mrtd
diff --git a/gcc/testsuite/gcc.target/i386/large-data.c
b/gcc/testsuite/gcc.target/i386/large-data.c
new file mode 100644
index
