1. On some targets, like PowerPC, reference to ifunc function resolver
must be non-local so that compiler will properly emit PLT call. Add
TARGET_IFUNC_REF_LOCAL_OK to allow binding indirect function resolver
locally for targets which don't require special PLT call sequence.
2. Add ix86_call_use_plt_p to call local ifunc function resolvers via
PLT.
gcc/
PR target/51469
PR target/83782
* target.def (ifunc_ref_local_ok): Add a target hook.
* varasm.c (default_binds_local_p_3): Force indirect function
resolver non-local only if targetm.ifunc_ref_local_ok returns
false.
* config/i386/i386-expand.c (ix86_expand_call): Call
ix86_call_use_plt_p to check if PLT should be used.
* config/i386/i386-protos.h (ix86_call_use_plt_p): New.
* config/i386/i386.c (output_pic_addr_const): Call
ix86_call_use_plt_p to check if "@PLT" is needed.
(ix86_call_use_plt_p): New.
(TARGET_IFUNC_REF_LOCAL_OK): New.
* doc/tm.texi.in: Add TARGET_IFUNC_REF_LOCAL_OK.
* doc/tm.texi: Regenerated.
gcc/testsuite/
PR target/51469
PR target/83782
* gcc.target/i386/pr83782-1.c: New test.
* gcc.target/i386/pr83782-2.c: Likewise.
---
gcc/config/i386/i386-expand.c | 2 +-
gcc/config/i386/i386-protos.h | 1 +
gcc/config/i386/i386.c | 25 +++++++++++++++++++++-
gcc/doc/tm.texi | 5 +++++
gcc/doc/tm.texi.in | 2 ++
gcc/target.def | 8 +++++++
gcc/testsuite/gcc.target/i386/pr83782-1.c | 26 +++++++++++++++++++++++
gcc/testsuite/gcc.target/i386/pr83782-2.c | 26 +++++++++++++++++++++++
gcc/varasm.c | 3 ++-
9 files changed, 95 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr83782-1.c
create mode 100644 gcc/testsuite/gcc.target/i386/pr83782-2.c
diff --git a/gcc/config/i386/i386-expand.c b/gcc/config/i386/i386-expand.c
index 8f4e4e4d884..229a765cb40 100644
--- a/gcc/config/i386/i386-expand.c
+++ b/gcc/config/i386/i386-expand.c
@@ -8184,7 +8184,7 @@ ix86_expand_call (rtx retval, rtx fnaddr, rtx callarg1,
rtx addr = XEXP (fnaddr, 0);
if (flag_pic
&& GET_CODE (addr) == SYMBOL_REF
- && !SYMBOL_REF_LOCAL_P (addr))
+ && ix86_call_use_plt_p (addr))
{
if (flag_plt
&& (SYMBOL_REF_DECL (addr) == NULL_TREE
diff --git a/gcc/config/i386/i386-protos.h b/gcc/config/i386/i386-protos.h
index e6ac9390777..2d1cd07a215 100644
--- a/gcc/config/i386/i386-protos.h
+++ b/gcc/config/i386/i386-protos.h
@@ -152,6 +152,7 @@ extern void ix86_expand_sse_movcc (rtx, rtx, rtx, rtx);
extern void ix86_expand_sse_unpack (rtx, rtx, bool, bool);
extern bool ix86_expand_int_addcc (rtx[]);
extern rtx_insn *ix86_expand_call (rtx, rtx, rtx, rtx, rtx, bool);
+extern bool ix86_call_use_plt_p (rtx);
extern void ix86_split_call_vzeroupper (rtx, rtx);
extern void x86_initialize_trampoline (rtx, rtx, rtx);
extern rtx ix86_zero_extend_to_Pmode (rtx);
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 7d0d4143bca..731a516b516 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -11971,7 +11971,7 @@ output_pic_addr_const (FILE *file, rtx x, int code)
assemble_name (file, name);
}
if (!TARGET_MACHO && !(TARGET_64BIT && TARGET_PECOFF)
- && code == 'P' && ! SYMBOL_REF_LOCAL_P (x))
+ && code == 'P' && ix86_call_use_plt_p (x))
fputs ("@PLT", file);
break;
@@ -15678,6 +15678,26 @@ ix86_zero_extend_to_Pmode (rtx exp)
return force_reg (Pmode, convert_to_mode (Pmode, exp, 1));
}
+/* Return true if the function is called via PLT. */
+
+bool
+ix86_call_use_plt_p (rtx call_op)
+{
+ if (SYMBOL_REF_LOCAL_P (call_op))
+ {
+ if (SYMBOL_REF_DECL (call_op))
+ {
+ /* NB: All ifunc functions must be called via PLT. */
+ cgraph_node *node
+ = cgraph_node::get (SYMBOL_REF_DECL (call_op));
+ if (node && node->ifunc_resolver)
+ return true;
+ }
+ return false;
+ }
+ return true;
+}
+
/* Return true if the function being called was marked with attribute
"noplt" or using -fno-plt and we are compiling for non-PIC. We need
to handle the non-PIC case in the backend because there is no easy
@@ -24016,6 +24036,9 @@ ix86_run_selftests (void)
#define TARGET_GET_MULTILIB_ABI_NAME \
ix86_get_multilib_abi_name
+#undef TARGET_IFUNC_REF_LOCAL_OK
+#define TARGET_IFUNC_REF_LOCAL_OK hook_bool_void_true
+
static bool ix86_libc_has_fast_function (int fcode ATTRIBUTE_UNUSED)
{
#ifdef OPTION_GLIBC
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 2a41ae5fba1..d327af03c80 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -12346,6 +12346,11 @@ The support includes the assembler, linker and dynamic
linker.
The default value of this hook is based on target's libc.
@end deftypefn
+@deftypefn {Target Hook} bool TARGET_IFUNC_REF_LOCAL_OK (void)
+Return true if it is OK to reference indirect function resolvers
+locally. The default is to return false.
+@end deftypefn
+
@deftypefn {Target Hook} {unsigned int} TARGET_ATOMIC_ALIGN_FOR_MODE
(machine_mode @var{mode})
If defined, this function returns an appropriate alignment in bits for an
atomic object of machine_mode @var{mode}. If 0 is returned then the
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index f881cdabe9e..cc6f7994cb1 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -8073,6 +8073,8 @@ and the associated definitions of those functions.
@hook TARGET_HAS_IFUNC_P
+@hook TARGET_IFUNC_REF_LOCAL_OK
+
@hook TARGET_ATOMIC_ALIGN_FOR_MODE
@hook TARGET_ATOMIC_ASSIGN_EXPAND_FENV
diff --git a/gcc/target.def b/gcc/target.def
index c009671c583..2c8aa90afac 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -2990,6 +2990,14 @@ The default value of this hook is based on target's
libc.",
bool, (void),
default_has_ifunc_p)
+/* True if it is OK to reference indirect function resolvers locally. */
+DEFHOOK
+(ifunc_ref_local_ok,
+ "Return true if it is OK to reference indirect function resolvers\n\
+locally. The default is to return false.",
+ bool, (void),
+ hook_bool_void_false)
+
/* True if it is OK to do sibling call optimization for the specified
call expression EXP. DECL will be the called function, or NULL if
this is an indirect call. */
diff --git a/gcc/testsuite/gcc.target/i386/pr83782-1.c
b/gcc/testsuite/gcc.target/i386/pr83782-1.c
new file mode 100644
index 00000000000..f4c7370142a
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr83782-1.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-require-ifunc "" } */
+/* { dg-options "-O2 -fpic" } */
+
+static void
+my_foo (void)
+{
+}
+
+static void (*resolve_foo (void)) (void)
+{
+ return my_foo;
+}
+
+extern void foo (void) __attribute__((ifunc("resolve_foo"),
visibility("hidden")));
+
+void *
+bar(void)
+{
+ return foo;
+}
+
+/* { dg-final { scan-assembler {leal[ \t]foo@GOTOFF\(%[^,]*\),[ \t]%eax} {
target ia32 } } } */
+/* { dg-final { scan-assembler {leaq[ \t]foo\(%rip\),[ \t]%rax} { target { !
ia32 } } } } */
+/* { dg-final { scan-assembler-not "foo@GOT\\\(" { target ia32 } } } */
+/* { dg-final { scan-assembler-not "foo@GOTPCREL\\\(" { target { ! ia32 } } }
} */
diff --git a/gcc/testsuite/gcc.target/i386/pr83782-2.c
b/gcc/testsuite/gcc.target/i386/pr83782-2.c
new file mode 100644
index 00000000000..6c6528fff46
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr83782-2.c
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-require-ifunc "" } */
+/* { dg-options "-O2 -fpic" } */
+
+static void
+my_foo (void)
+{
+}
+
+static void (*resolve_foo (void)) (void)
+{
+ return my_foo;
+}
+
+static void foo (void) __attribute__((ifunc("resolve_foo")));
+
+void *
+bar(void)
+{
+ return foo;
+}
+
+/* { dg-final { scan-assembler {leal[ \t]foo@GOTOFF\(%[^,]*\),[ \t]%eax} {
target ia32 } } } */
+/* { dg-final { scan-assembler {leaq[ \t]foo\(%rip\),[ \t]%rax} { target { !
ia32 } } } } */
+/* { dg-final { scan-assembler-not "foo@GOT\\\(" { target ia32 } } } */
+/* { dg-final { scan-assembler-not "foo@GOTPCREL\\\(" { target { ! ia32 } } }
} */
diff --git a/gcc/varasm.c b/gcc/varasm.c
index 53cf6dea3f3..0cba7ab0ecd 100644
--- a/gcc/varasm.c
+++ b/gcc/varasm.c
@@ -7470,7 +7470,8 @@ default_binds_local_p_3 (const_tree exp, bool shlib, bool
weak_dominate,
FIXME: We can resolve the weakref case more curefuly by looking at the
weakref alias. */
if (lookup_attribute ("weakref", DECL_ATTRIBUTES (exp))
- || (TREE_CODE (exp) == FUNCTION_DECL
+ || (!targetm.ifunc_ref_local_ok ()
+ && TREE_CODE (exp) == FUNCTION_DECL
&& cgraph_node::get (exp)
&& cgraph_node::get (exp)->ifunc_resolver))
return false;
--
2.31.1
