From: Lulu Cheng <chenglulu@loongson.cn>
To: Xi Ruoyao <xry111@xry111.site>, gcc-patches@gcc.gnu.org
Cc: Chenghua Xu <xuchenghua@loongson.cn>,
Youling Tang <tangyouling@loongson.cn>,
Huacai Chen <chenhuacai@kernel.org>,
Jinyang He <hejinyang@loongson.cn>, Wang Xuerui <i@xen0n.name>
Subject: Re: [PATCH v2 2/2 resend] LoongArch: add model attribute
Date: Thu, 25 Aug 2022 16:53:34 +0800 [thread overview]
Message-ID: <f8ec502a-fd8e-0235-fe47-8bac4a2da9c8@loongson.cn> (raw)
Message-ID: <20220825085334.dK-Z2AD2cb2Ks7NvFMwUq51cZbvW8vrnkRtL_Q4QdKI@z> (raw)
In-Reply-To: <7a57979ed30cdb47b51b24c7af80ad2b79be401c.camel@xry111.site>
[-- Attachment #1: Type: text/plain, Size: 16840 bytes --]
在 2022/8/24 下午10:12, Xi Ruoyao 写道:
> On Wed, 2022-08-24 at 22:08 +0800, Xi Ruoyao wrote:
>> v1 -> v2:
>>
>> * Avoid introduce of SYMBOL_PCREL32, use SYMBOL_PCREL for 32-bit PC
>> relative.
>> * Rebase onto a bug fix ([1/2] in the series) to avoid merge conflict.
>> * Fix missed ChangeLog entries.
> Resend because my mail client has done some stupid thing to the patch :(
>
> -- >8 --
>
> A linker script and/or a section attribute may locate some object
> specially, so we need to handle the code model for such objects
> differently than the -mcmodel setting. This happens when the Linux
> kernel loads a module with per-CPU variables.
>
> Add an attribute to override the code model for a specific variable.
>
> gcc/ChangeLog:
>
> * config/loongarch/loongarch-protos.h (loongarch_symbol_type):
> Add SYMBOL_PCREL64 and change the description for SYMBOL_PCREL.
> * config/loongarch/loongarch.cc (loongarch_attribute_table):
> New attribute table.
> (TARGET_ATTRIBUTE_TABLE): Define the target hook.
> (loongarch_handle_model_attribute): New static function.
> (loongarch_classify_symbol): Take TARGET_CMODEL_EXTREME and the
> model attribute of SYMBOL_REF_DECL into account returning
> SYMBOL_PCREL or SYMBOL_PCREL64.
> (loongarch_use_anchors_for_symbol_p): New static function.
> (TARGET_USE_ANCHORS_FOR_SYMBOL_P): Define the target hook.
> (loongarch_symbol_extreme_p): New static function.
> (loongarch_symbolic_constant_p): Handle SYMBOL_PCREL64.
> (loongarch_symbol_insns): Likewise.
> (loongarch_split_symbol_type): Likewise.
> (loongarch_split_symbol): Check SYMBOL_PCREL64 instead of
> TARGET_CMODEL_EXTREME for PC-relative addressing.
> (loongarch_print_operand_reloc): Likewise.
> * doc/extend.texi (Variable Attributes): Document new
> LoongArch specific attribute.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/loongarch/attr-model-test.c: New test.
> * gcc.target/loongarch/attr-model-1.c: New test.
> * gcc.target/loongarch/attr-model-2.c: New test.
> * gcc.target/loongarch/attr-model-diag.c: New test.
> ---
> gcc/config/loongarch/loongarch-protos.h | 8 +-
> gcc/config/loongarch/loongarch.cc | 190 ++++++++++++++++--
> gcc/doc/extend.texi | 16 ++
> .../gcc.target/loongarch/attr-model-1.c | 6 +
> .../gcc.target/loongarch/attr-model-2.c | 6 +
> .../gcc.target/loongarch/attr-model-diag.c | 7 +
> .../gcc.target/loongarch/attr-model-test.c | 25 +++
> 7 files changed, 237 insertions(+), 21 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/loongarch/attr-model-1.c
> create mode 100644 gcc/testsuite/gcc.target/loongarch/attr-model-2.c
> create mode 100644 gcc/testsuite/gcc.target/loongarch/attr-model-diag.c
> create mode 100644 gcc/testsuite/gcc.target/loongarch/attr-model-test.c
>
> diff --git a/gcc/config/loongarch/loongarch-protos.h b/gcc/config/loongarch/loongarch-protos.h
> index cadaad7519c..77b2217247d 100644
> --- a/gcc/config/loongarch/loongarch-protos.h
> +++ b/gcc/config/loongarch/loongarch-protos.h
> @@ -28,7 +28,12 @@ along with GCC; see the file COPYING3. If not see
> The symbol's value will be loaded directly from the GOT.
>
> SYMBOL_PCREL
> - The symbol's value will be loaded directly from data section.
> + The symbol's value will be loaded directly from data section within
> + +/- 2GiB range.
> +
> + SYMBOL_PCREL64
> + The symbol's value will be loaded directly from data section within
> + +/- 8EiB range.
>
> SYMBOL_TLS
> A thread-local symbol.
> @@ -42,6 +47,7 @@ along with GCC; see the file COPYING3. If not see
> enum loongarch_symbol_type {
> SYMBOL_GOT_DISP,
> SYMBOL_PCREL,
> + SYMBOL_PCREL64,
> SYMBOL_TLS,
> SYMBOL_TLS_IE,
> SYMBOL_TLS_LE,
> diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc
> index 41d9cca6d31..d9061cdeee3 100644
> --- a/gcc/config/loongarch/loongarch.cc
> +++ b/gcc/config/loongarch/loongarch.cc
> @@ -1633,8 +1633,11 @@ loongarch_rtx_constant_in_small_data_p (machine_mode mode)
> static enum loongarch_symbol_type
> loongarch_classify_symbol (const_rtx x)
> {
> + enum loongarch_symbol_type pcrel =
> + TARGET_CMODEL_EXTREME ? SYMBOL_PCREL64 : SYMBOL_PCREL;
> +
> if (!SYMBOL_REF_P (x))
> - return SYMBOL_PCREL;
> + return pcrel;
>
> if (SYMBOL_REF_TLS_MODEL (x))
> return SYMBOL_TLS;
> @@ -1642,7 +1645,28 @@ loongarch_classify_symbol (const_rtx x)
> if (!loongarch_symbol_binds_local_p (x))
> return SYMBOL_GOT_DISP;
>
> - return SYMBOL_PCREL;
> + tree t = SYMBOL_REF_DECL (x);
> + if (!t)
> + return pcrel;
> +
> + t = lookup_attribute ("model", DECL_ATTRIBUTES (t));
> + if (!t)
> + return pcrel;
> +
> + t = TREE_VALUE (TREE_VALUE (t));
> +
> + /* loongarch_handle_model_attribute should reject other values. */
> + gcc_assert (TREE_CODE (t) == STRING_CST);
> +
> + const char *model = TREE_STRING_POINTER (t);
> + if (strcmp (model, "normal") == 0)
> + return SYMBOL_PCREL;
> + if (strcmp (model, "extreme") == 0)
> + return SYMBOL_PCREL64;
> +
> + /* loongarch_handle_model_attribute should reject unknown model
> + name. */
> + gcc_unreachable ();
> }
>
> /* Classify the base of symbolic expression X, given that X appears in
> @@ -1695,6 +1719,7 @@ loongarch_symbolic_constant_p (rtx x, enum loongarch_symbol_type *symbol_type)
> case SYMBOL_TLSGD:
> case SYMBOL_TLSLDM:
> case SYMBOL_PCREL:
> + case SYMBOL_PCREL64:
> /* GAS rejects offsets outside the range [-2^31, 2^31-1]. */
> return sext_hwi (INTVAL (offset), 32) == INTVAL (offset);
>
> @@ -1729,6 +1754,9 @@ loongarch_symbol_insns (enum loongarch_symbol_type type, machine_mode mode)
> case SYMBOL_TLSLDM:
> return 3;
>
> + case SYMBOL_PCREL64:
> + return 5;
> +
> case SYMBOL_TLS:
> /* We don't treat a bare TLS symbol as a constant. */
> return 0;
> @@ -1833,7 +1861,7 @@ loongarch_valid_offset_p (rtx x, machine_mode mode)
> return true;
> }
>
> -/* Should a symbol of type SYMBOL_TYPE should be split in two? */
> +/* Should a symbol of type SYMBOL_TYPE should be split in two or more? */
>
> bool
> loongarch_split_symbol_type (enum loongarch_symbol_type symbol_type)
> @@ -1841,6 +1869,7 @@ loongarch_split_symbol_type (enum loongarch_symbol_type symbol_type)
> switch (symbol_type)
> {
> case SYMBOL_PCREL:
> + case SYMBOL_PCREL64:
> case SYMBOL_GOT_DISP:
> case SYMBOL_TLS_IE:
> case SYMBOL_TLS_LE:
> @@ -2718,6 +2747,20 @@ loongarch_force_address (rtx x, machine_mode mode)
> return x;
> }
>
> +static bool
> +loongarch_symbol_extreme_p (enum loongarch_symbol_type type)
> +{
> + switch (type)
> + {
> + case SYMBOL_PCREL:
> + return false;
> + case SYMBOL_PCREL64:
> + return true;
> + default:
> + return TARGET_CMODEL_EXTREME;
> + }
> +}
> +
> /* If MODE is MAX_MACHINE_MODE, ADDR appears as a move operand, otherwise
> it appears in a MEM of that mode. Return true if ADDR is a legitimate
> constant in that context and can be split into high and low parts.
> @@ -2757,7 +2800,7 @@ loongarch_split_symbol (rtx temp, rtx addr, machine_mode mode, rtx *low_out)
> high = gen_rtx_HIGH (Pmode, copy_rtx (addr));
> high = loongarch_force_temporary (temp, high);
>
> - if (TARGET_CMODEL_EXTREME && can_create_pseudo_p ())
> + if (loongarch_symbol_extreme_p (symbol_type) && can_create_pseudo_p ())
> {
> gcc_assert (TARGET_EXPLICIT_RELOCS);
>
> @@ -2771,14 +2814,16 @@ loongarch_split_symbol (rtx temp, rtx addr, machine_mode mode, rtx *low_out)
> if (low_out)
> switch (symbol_type)
> {
> - case SYMBOL_PCREL:
> - {
> - if (TARGET_CMODEL_EXTREME && can_create_pseudo_p ())
> + case SYMBOL_PCREL64:
> + if (can_create_pseudo_p ())
> + {
> *low_out = gen_rtx_PLUS (Pmode, high, temp1);
> - else
> - *low_out = gen_rtx_LO_SUM (Pmode, high, addr);
> - break;
> - }
> + break;
> + }
> + /* fall through */
> + case SYMBOL_PCREL:
> + *low_out = gen_rtx_LO_SUM (Pmode, high, addr);
> + break;
>
> case SYMBOL_GOT_DISP:
> /* SYMBOL_GOT_DISP symbols are loaded from the GOT. */
> @@ -4745,22 +4790,23 @@ loongarch_print_operand_reloc (FILE *file, rtx op, bool hi64_part,
> bool hi_reloc)
> {
> const char *reloc;
> + enum loongarch_symbol_type symbol_type =
> + loongarch_classify_symbolic_expression (op);
>
> - if (TARGET_CMODEL_EXTREME)
> + if (loongarch_symbol_extreme_p (symbol_type))
> gcc_assert (TARGET_EXPLICIT_RELOCS);
>
> - switch (loongarch_classify_symbolic_expression (op))
> + switch (symbol_type)
> {
> - case SYMBOL_PCREL:
> + case SYMBOL_PCREL64:
> if (hi64_part)
> {
> - if (TARGET_CMODEL_EXTREME)
> - reloc = hi_reloc ? "%pc64_hi12" : "%pc64_lo20";
> - else
> - gcc_unreachable ();
> + reloc = hi_reloc ? "%pc64_hi12" : "%pc64_lo20";
> + break;
> }
> - else
> - reloc = hi_reloc ? "%pc_hi20" : "%pc_lo12";
> + /* fall through */
> + case SYMBOL_PCREL:
> + reloc = hi_reloc ? "%pc_hi20" : "%pc_lo12";
> break;
>
> case SYMBOL_GOT_DISP:
> @@ -6316,6 +6362,104 @@ loongarch_starting_frame_offset (void)
> return crtl->outgoing_args_size;
> }
>
> +static tree
> +loongarch_handle_model_attribute (tree *node, tree name, tree arg, int,
> + bool *no_add_attrs)
> +{
> + tree decl = *node;
> + if (TREE_CODE (decl) == VAR_DECL)
> + {
> + if (DECL_THREAD_LOCAL_P (decl))
> + {
> + error_at (DECL_SOURCE_LOCATION (decl),
> + "%qE attribute cannot be specified for thread-local "
> + "variables", name);
> + *no_add_attrs = true;
> + return NULL_TREE;
> + }
> + if (DECL_CONTEXT (decl)
> + && TREE_CODE (DECL_CONTEXT (decl)) == FUNCTION_DECL
> + && !TREE_STATIC (decl))
> + {
> + error_at (DECL_SOURCE_LOCATION (decl),
> + "%qE attribute cannot be specified for local "
> + "variables", name);
> + *no_add_attrs = true;
> + return NULL_TREE;
> + }
> + if (DECL_REGISTER (decl))
> + {
> + error_at (DECL_SOURCE_LOCATION (decl),
> + "%qE attribute cannot be specified for register "
> + "variables", name);
> + *no_add_attrs = true;
> + return NULL_TREE;
> + }
> + if (!TARGET_EXPLICIT_RELOCS)
> + {
> + error_at (DECL_SOURCE_LOCATION (decl),
> + "%qE attribute requires %s", name, "-mexplicit-relocs");
> + *no_add_attrs = true;
> + return NULL_TREE;
> + }
> +
> + arg = TREE_VALUE (arg);
> + if (TREE_CODE (arg) != STRING_CST)
> + {
> + error_at (DECL_SOURCE_LOCATION (decl),
> + "invalid argument of %qE attribute", name);
> + *no_add_attrs = true;
> + return NULL_TREE;
> + }
> +
> + const char *model = TREE_STRING_POINTER (arg);
> + if (strcmp (model, "normal") != 0
> + && strcmp (model, "extreme") != 0)
> + {
> + error_at (DECL_SOURCE_LOCATION (decl),
> + "invalid argument of %qE attribute", name);
> + *no_add_attrs = true;
> + return NULL_TREE;
> + }
> +
> + if (lookup_attribute ("model", DECL_ATTRIBUTES (decl)))
> + {
> + error_at (DECL_SOURCE_LOCATION (decl),
> + "multiple %qE attribute", name);
> + *no_add_attrs = true;
> + return NULL_TREE;
> + }
> + }
> + else
> + {
> + warning (OPT_Wattributes, "%qE attribute ignored", name);
> + *no_add_attrs = true;
> + }
> + return NULL_TREE;
> +}
> +
> +static const struct attribute_spec loongarch_attribute_table[] =
> +{
> + /* { name, min_len, max_len, decl_req, type_req, fn_type_req,
> + affects_type_identity, handler, exclude } */
> + { "model", 1, 1, true, false, false, false,
> + loongarch_handle_model_attribute, NULL },
> + /* The last attribute spec is set to be NULL. */
> + {}
> +};
> +
> +bool
> +loongarch_use_anchors_for_symbol_p (const_rtx symbol)
> +{
> + tree decl = SYMBOL_REF_DECL (symbol);
> +
> + /* The section anchor optimization may break custom address model. */
> + if (decl && lookup_attribute ("model", DECL_ATTRIBUTES (decl)))
> + return false;
> +
> + return default_use_anchors_for_symbol_p (symbol);
> +}
> +
> /* Initialize the GCC target structure. */
> #undef TARGET_ASM_ALIGNED_HI_OP
> #define TARGET_ASM_ALIGNED_HI_OP "\t.half\t"
> @@ -6504,6 +6648,12 @@ loongarch_starting_frame_offset (void)
> #undef TARGET_HAVE_SPECULATION_SAFE_VALUE
> #define TARGET_HAVE_SPECULATION_SAFE_VALUE speculation_safe_value_not_needed
>
> +#undef TARGET_ATTRIBUTE_TABLE
> +#define TARGET_ATTRIBUTE_TABLE loongarch_attribute_table
> +
> +#undef TARGET_USE_ANCHORS_FOR_SYMBOL_P
> +#define TARGET_USE_ANCHORS_FOR_SYMBOL_P loongarch_use_anchors_for_symbol_p
> +
> struct gcc_target targetm = TARGET_INITIALIZER;
>
> #include "gt-loongarch.h"
> diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
> index 7fe7f8817cd..431811c7b26 100644
> --- a/gcc/doc/extend.texi
> +++ b/gcc/doc/extend.texi
> @@ -7314,6 +7314,7 @@ attributes.
> * Blackfin Variable Attributes::
> * H8/300 Variable Attributes::
> * IA-64 Variable Attributes::
> +* LoongArch Variable Attributes::
> * M32R/D Variable Attributes::
> * MeP Variable Attributes::
> * Microsoft Windows Variable Attributes::
> @@ -8098,6 +8099,21 @@ defined by shared libraries.
>
> @end table
>
> +@node LoongArch Variable Attributes
> +@subsection LoongArch Variable Attributes
> +
> +One attribute is currently defined for the LoongArch.
> +
> +@table @code
> +@item model("@var{name}")
> +@cindex @code{model} variable attribute, LoongArch
> +Use this attribute on the LoongArch to use a different code model for
> +addressing this variable, than the code model specified by the global
> +@option{-mcmodel} option.This attribute is mostly useful if a
> +@code{section} attribute and/or a linker script will locate this object
> +specially.
I think this should add a sentence:
"Currently, the identifier name can only be one of small or extreme."
Others I think are ok.
> +@end table
> +
> @node M32R/D Variable Attributes
> @subsection M32R/D Variable Attributes
>
> diff --git a/gcc/testsuite/gcc.target/loongarch/attr-model-1.c b/gcc/testsuite/gcc.target/loongarch/attr-model-1.c
> new file mode 100644
> index 00000000000..916d715b98b
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/loongarch/attr-model-1.c
> @@ -0,0 +1,6 @@
> +/* { dg-do compile } */
> +/* { dg-options "-mexplicit-relocs -mcmodel=normal -O2" } */
> +/* { dg-final { scan-assembler-times "%pc64_hi12" 2 } } */
> +
> +#define ATTR_MODEL_TEST
> +#include "attr-model-test.c"
> diff --git a/gcc/testsuite/gcc.target/loongarch/attr-model-2.c b/gcc/testsuite/gcc.target/loongarch/attr-model-2.c
> new file mode 100644
> index 00000000000..a74c795ac3e
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/loongarch/attr-model-2.c
> @@ -0,0 +1,6 @@
> +/* { dg-do compile } */
> +/* { dg-options "-mexplicit-relocs -mcmodel=extreme -O2" } */
> +/* { dg-final { scan-assembler-times "%pc64_hi12" 3 } } */
> +
> +#define ATTR_MODEL_TEST
> +#include "attr-model-test.c"
> diff --git a/gcc/testsuite/gcc.target/loongarch/attr-model-diag.c b/gcc/testsuite/gcc.target/loongarch/attr-model-diag.c
> new file mode 100644
> index 00000000000..88beede74df
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/loongarch/attr-model-diag.c
> @@ -0,0 +1,7 @@
> +/* { dg-do compile } */
> +/* { dg-options "-mexplicit-relocs" } */
> +
> +__thread int x __attribute__((model("extreme"))); /* { dg-error "attribute cannot be specified for thread-local variables" } */
> +register int y __asm__("tp") __attribute__((model("extreme"))); /* { dg-error "attribute cannot be specified for register variables" } */
> +int z __attribute__((model(114))); /* { dg-error "invalid argument" } */
> +int t __attribute__((model("good"))); /* { dg-error "invalid argument" } */
> diff --git a/gcc/testsuite/gcc.target/loongarch/attr-model-test.c b/gcc/testsuite/gcc.target/loongarch/attr-model-test.c
> new file mode 100644
> index 00000000000..5b61a7af9c3
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/loongarch/attr-model-test.c
> @@ -0,0 +1,25 @@
> +#ifdef ATTR_MODEL_TEST
> +int x __attribute__((model("extreme")));
> +int y __attribute__((model("normal")));
> +int z;
> +
> +int
> +test(void)
> +{
> + return x + y + z;
> +}
> +
> +/* The following will be used for kernel per-cpu storage implemention. */
> +
> +register char *per_cpu_base __asm__("r21");
> +static int counter __attribute__((section(".data..percpu"), model("extreme")));
> +
> +void
> +inc_counter(void)
> +{
> + int *ptr = (int *)(per_cpu_base + (long)&counter);
> + (*ptr)++;
> +}
> +#endif
> +
> +int dummy;
next prev parent reply other threads:[~2022-08-25 8:53 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-24 14:03 [PATCH 1/2] LoongArch: Avoid RTL flag check failure in loongarch_classify_symbol Xi Ruoyao
2022-08-24 14:08 ` [PATCH v2 2/2] LoongArch: add model attribute Xi Ruoyao
2022-08-24 14:12 ` [PATCH v2 2/2 resend] " Xi Ruoyao
2022-08-25 8:53 ` Lulu Cheng [this message]
2022-08-25 8:53 ` Lulu Cheng
2022-08-25 9:12 ` Xi Ruoyao
2022-08-25 11:41 ` Xi Ruoyao
2022-08-25 11:53 ` Lulu Cheng
2022-08-25 8:29 ` [PATCH 1/2] LoongArch: Avoid RTL flag check failure in loongarch_classify_symbol Lulu Cheng
2022-08-25 8:29 ` Lulu Cheng
2022-08-25 10:53 ` Xi Ruoyao
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