x86: Add ix86_ifunc_ref_local_ok

We can't always use the PLT entry as the function address for local IFUNC
functions.  When the PIC register is needed for PLT call, indirect call
via the PLT entry will fail since the PIC register may not be set up
properly for indirect call.  Add ix86_ifunc_ref_local_ok to return false
when the PLT entry can't be used as local IFUNC function pointers.

gcc/

	PR target/83782
	* config/i386/i386.cc (ix86_ifunc_ref_local_ok): New.
	(TARGET_IFUNC_REF_LOCAL_OK): Use it.

gcc/testsuite/

	PR target/83782
	* gcc.target/i386/pr83782-1.c: Require non-ia32.
	* gcc.target/i386/pr83782-2.c: Likewise.
	* gcc.target/i386/pr83782-3.c: New test.
This commit is contained in:
H.J. Lu 2022-07-20 16:57:32 -07:00
parent 32566720f3
commit 8092892014
4 changed files with 50 additions and 9 deletions

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@ -16070,6 +16070,19 @@ ix86_call_use_plt_p (rtx call_op)
return true; return true;
} }
/* Implement TARGET_IFUNC_REF_LOCAL_OK. If this hook returns true,
the PLT entry will be used as the function address for local IFUNC
functions. When the PIC register is needed for PLT call, indirect
call via the PLT entry will fail since the PIC register may not be
set up properly for indirect call. In this case, we should return
false. */
static bool
ix86_ifunc_ref_local_ok (void)
{
return !flag_pic || (TARGET_64BIT && ix86_cmodel != CM_LARGE_PIC);
}
/* Return true if the function being called was marked with attribute /* 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 "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 to handle the non-PIC case in the backend because there is no easy
@ -24953,7 +24966,7 @@ ix86_libgcc_floating_mode_supported_p
ix86_get_multilib_abi_name ix86_get_multilib_abi_name
#undef TARGET_IFUNC_REF_LOCAL_OK #undef TARGET_IFUNC_REF_LOCAL_OK
#define TARGET_IFUNC_REF_LOCAL_OK hook_bool_void_true #define TARGET_IFUNC_REF_LOCAL_OK ix86_ifunc_ref_local_ok
#if !TARGET_MACHO && !TARGET_DLLIMPORT_DECL_ATTRIBUTES #if !TARGET_MACHO && !TARGET_DLLIMPORT_DECL_ATTRIBUTES
# undef TARGET_ASM_RELOC_RW_MASK # undef TARGET_ASM_RELOC_RW_MASK

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@ -1,4 +1,4 @@
/* { dg-do compile } */ /* { dg-do compile { target { ! ia32 } } } */
/* { dg-require-ifunc "" } */ /* { dg-require-ifunc "" } */
/* { dg-options "-O2 -fpic" } */ /* { dg-options "-O2 -fpic" } */
@ -20,7 +20,5 @@ bar(void)
return foo; return foo;
} }
/* { dg-final { scan-assembler {leal[ \t]foo@GOTOFF\(%[^,]*\),[ \t]%eax} { target ia32 } } } */ /* { dg-final { scan-assembler {lea(?:l|q)[ \t]foo\(%rip\),[ \t]%(?:e|r)ax} } } */
/* { dg-final { scan-assembler {lea(?:l|q)[ \t]foo\(%rip\),[ \t]%(?:e|r)ax} { target { ! ia32 } } } } */ /* { dg-final { scan-assembler-not "foo@GOTPCREL\\\(" } } */
/* { dg-final { scan-assembler-not "foo@GOT\\\(" { target ia32 } } } */
/* { dg-final { scan-assembler-not "foo@GOTPCREL\\\(" { target { ! ia32 } } } } */

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@ -1,4 +1,4 @@
/* { dg-do compile } */ /* { dg-do compile { target { ! ia32 } } } */
/* { dg-require-ifunc "" } */ /* { dg-require-ifunc "" } */
/* { dg-options "-O2 -fpic" } */ /* { dg-options "-O2 -fpic" } */
@ -20,7 +20,5 @@ bar(void)
return foo; return foo;
} }
/* { dg-final { scan-assembler {leal[ \t]foo@GOTOFF\(%[^,]*\),[ \t]%eax} { target ia32 } } } */
/* { dg-final { scan-assembler {lea(?:l|q)[ \t]foo\(%rip\),[ \t]%(?:e|r)ax} { target { ! ia32 } } } } */ /* { dg-final { scan-assembler {lea(?:l|q)[ \t]foo\(%rip\),[ \t]%(?:e|r)ax} { target { ! ia32 } } } } */
/* { dg-final { scan-assembler-not "foo@GOT\\\(" { target ia32 } } } */
/* { dg-final { scan-assembler-not "foo@GOTPCREL\\\(" { target { ! ia32 } } } } */ /* { dg-final { scan-assembler-not "foo@GOTPCREL\\\(" { target { ! ia32 } } } } */

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@ -0,0 +1,32 @@
/* { dg-do run } */
/* { dg-require-ifunc "" } */
/* { dg-require-effective-target pie } */
/* { dg-options "-fpie -pie" } */
#include <stdio.h>
static int __attribute__((noinline))
implementation (void)
{
printf ("'ere I am JH\n");
return 0;
}
static __typeof__ (implementation) *resolver (void)
{
return (void *)implementation;
}
extern int magic (void) __attribute__ ((ifunc ("resolver")));
__attribute__ ((weak))
int
call_magic (int (*ptr) (void))
{
return ptr ();
}
int main ()
{
return call_magic (magic);
}