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.
+@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;
--
2.37.2
