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Commit 23f95cb7 by H.J. Lu Committed by H.J. Lu
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i386: Don't generate alias for function return thunk 

Function return thunks shouldn't be aliased to indirect branch thunks
since indirect branch thunks are placed in COMDAT section and a COMDAT
section with indirect branch may not have function return thunk.  This
patch generates function return thunks directly.

gcc/

	PR target/84574
	* config/i386/i386.c (indirect_thunk_needed): Update comments.
	(indirect_thunk_bnd_needed): Likewise.
	(indirect_thunks_used): Likewise.
	(indirect_thunks_bnd_used): Likewise.
	(indirect_return_needed): New.
	(indirect_return_bnd_needed): Likewise.
	(output_indirect_thunk_function): Add a bool argument for
	function return.
	(output_indirect_thunk_function): Don't generate alias for
	function return thunk.
	(ix86_code_end): Call output_indirect_thunk_function to generate
	function return thunks.
	(ix86_output_function_return): Set indirect_return_bnd_needed
	and indirect_return_needed instead of indirect_thunk_bnd_needed
	and indirect_thunk_needed.

gcc/testsuite/

	PR target/84574
	* gcc.target/i386/ret-thunk-9.c: Expect __x86_return_thunk
	label instead of __x86_indirect_thunk label.

From-SVN: r258569
parent 4a5a49b0
Showing with 61 additions and 61 deletions
gcc/ChangeLog
2018-03-15 H.J. Lu <hongjiu.lu@intel.com>
PR target/84574
* config/i386/i386.c (indirect_thunk_needed): Update comments.
(indirect_thunk_bnd_needed): Likewise.
(indirect_thunks_used): Likewise.
(indirect_thunks_bnd_used): Likewise.
(indirect_return_needed): New.
(indirect_return_bnd_needed): Likewise.
(output_indirect_thunk_function): Add a bool argument for
function return.
(output_indirect_thunk_function): Don't generate alias for
function return thunk.
(ix86_code_end): Call output_indirect_thunk_function to generate
function return thunks.
(ix86_output_function_return): Set indirect_return_bnd_needed
and indirect_return_needed instead of indirect_thunk_bnd_needed
and indirect_thunk_needed.
2018-03-15 Olga Makhotina <olga.makhotina@intel.com>
* config/i386/sgxintrin.h (_enclv_u32): New intrinsic.
......
gcc/config/i386/i386.c
......@@ -10819,19 +10819,23 @@ ix86_setup_frame_addresses (void)
labels in call and return thunks. */
static int indirectlabelno;
/* True if call and return thunk functions are needed. */
/* True if call thunk function is needed. */
static bool indirect_thunk_needed = false;
/* True if call and return thunk functions with the BND prefix are
needed. */
/* True if call thunk function with the BND prefix is needed. */
static bool indirect_thunk_bnd_needed = false;
/* Bit masks of integer registers, which contain branch target, used
by call and return thunks functions. */
by call thunk functions. */
static int indirect_thunks_used;
/* Bit masks of integer registers, which contain branch target, used
by call and return thunks functions with the BND prefix. */
by call thunk functions with the BND prefix. */
static int indirect_thunks_bnd_used;
/* True if return thunk function is needed. */
static bool indirect_return_needed = false;
/* True if return thunk function with the BND prefix is needed. */
static bool indirect_return_bnd_needed = false;
/* True if return thunk function via CX is needed. */
static bool indirect_return_via_cx;
/* True if return thunk function via CX with the BND prefix is
......@@ -11027,17 +11031,18 @@ output_indirect_thunk (enum indirect_thunk_prefix need_prefix,
/* Output a funtion with a call and return thunk for indirect branch.
If BND_P is true, the BND prefix is needed. If REGNO != UNVALID_REGNUM,
the function address is in REGNO. Otherwise, the function address is
on the top of stack. */
on the top of stack. Thunk is used for function return if RET_P is
true. */
static void
output_indirect_thunk_function (enum indirect_thunk_prefix need_prefix,
unsigned int regno)
unsigned int regno, bool ret_p)
{
char name[32];
tree decl;
/* Create __x86_indirect_thunk/__x86_indirect_thunk_bnd. */
indirect_thunk_name (name, regno, need_prefix, false);
indirect_thunk_name (name, regno, need_prefix, ret_p);
decl = build_decl (BUILTINS_LOCATION, FUNCTION_DECL,
get_identifier (name),
build_function_type_list (void_type_node, NULL_TREE));
......@@ -11080,50 +11085,6 @@ output_indirect_thunk_function (enum indirect_thunk_prefix need_prefix,
ASM_OUTPUT_LABEL (asm_out_file, name);
}
/* Create alias for __x86_return_thunk/__x86_return_thunk_bnd or
__x86_return_thunk_ecx/__x86_return_thunk_ecx_bnd. */
bool need_alias;
if (regno == INVALID_REGNUM)
need_alias = true;
else if (regno == CX_REG)
{
if (need_prefix == indirect_thunk_prefix_bnd)
need_alias = indirect_return_via_cx_bnd;
else
need_alias = indirect_return_via_cx;
}
else
need_alias = false;
if (need_alias)
{
char alias[32];
indirect_thunk_name (alias, regno, need_prefix, true);
#if TARGET_MACHO
if (TARGET_MACHO)
{
fputs ("\t.weak_definition\t", asm_out_file);
assemble_name (asm_out_file, alias);
fputs ("\n\t.private_extern\t", asm_out_file);
assemble_name (asm_out_file, alias);
putc ('\n', asm_out_file);
ASM_OUTPUT_LABEL (asm_out_file, alias);
}
#else
ASM_OUTPUT_DEF (asm_out_file, alias, name);
if (USE_HIDDEN_LINKONCE)
{
fputs ("\t.globl\t", asm_out_file);
assemble_name (asm_out_file, alias);
putc ('\n', asm_out_file);
fputs ("\t.hidden\t", asm_out_file);
assemble_name (asm_out_file, alias);
putc ('\n', asm_out_file);
}
#endif
}
DECL_INITIAL (decl) = make_node (BLOCK);
current_function_decl = decl;
allocate_struct_function (decl, false);
......@@ -11170,23 +11131,37 @@ ix86_code_end (void)
rtx xops[2];
unsigned int regno;
if (indirect_return_needed)
output_indirect_thunk_function (indirect_thunk_prefix_none,
INVALID_REGNUM, true);
if (indirect_return_bnd_needed)
output_indirect_thunk_function (indirect_thunk_prefix_bnd,
INVALID_REGNUM, true);
if (indirect_return_via_cx)
output_indirect_thunk_function (indirect_thunk_prefix_none,
CX_REG, true);
if (indirect_return_via_cx_bnd)
output_indirect_thunk_function (indirect_thunk_prefix_bnd,
CX_REG, true);
if (indirect_thunk_needed)
output_indirect_thunk_function (indirect_thunk_prefix_none,
INVALID_REGNUM);
INVALID_REGNUM, false);
if (indirect_thunk_bnd_needed)
output_indirect_thunk_function (indirect_thunk_prefix_bnd,
INVALID_REGNUM);
INVALID_REGNUM, false);
for (regno = FIRST_REX_INT_REG; regno <= LAST_REX_INT_REG; regno++)
{
unsigned int i = regno - FIRST_REX_INT_REG + LAST_INT_REG + 1;
if ((indirect_thunks_used & (1 << i)))
output_indirect_thunk_function (indirect_thunk_prefix_none,
regno);
regno, false);
if ((indirect_thunks_bnd_used & (1 << i)))
output_indirect_thunk_function (indirect_thunk_prefix_bnd,
regno);
regno, false);
}
for (regno = FIRST_INT_REG; regno <= LAST_INT_REG; regno++)
......@@ -11196,11 +11171,11 @@ ix86_code_end (void)
if ((indirect_thunks_used & (1 << regno)))
output_indirect_thunk_function (indirect_thunk_prefix_none,
regno);
regno, false);
if ((indirect_thunks_bnd_used & (1 << regno)))
output_indirect_thunk_function (indirect_thunk_prefix_bnd,
regno);
regno, false);
if (!(pic_labels_used & (1 << regno)))
continue;
......@@ -29060,12 +29035,12 @@ ix86_output_function_return (bool long_p)
true);
if (need_prefix == indirect_thunk_prefix_bnd)
{
indirect_thunk_bnd_needed |= need_thunk;
indirect_return_bnd_needed |= need_thunk;
fprintf (asm_out_file, "\tbnd jmp\t%s\n", thunk_name);
}
else
{
indirect_thunk_needed |= need_thunk;
indirect_return_needed |= need_thunk;
fprintf (asm_out_file, "\tjmp\t%s\n", thunk_name);
}
}
gcc/testsuite/ChangeLog
2018-03-15 H.J. Lu <hongjiu.lu@intel.com>
PR target/84574
* gcc.target/i386/ret-thunk-9.c: Expect __x86_return_thunk
label instead of __x86_indirect_thunk label.
2018-03-15 Jakub Jelinek <jakub@redhat.com>
PR c++/84222
......
gcc/testsuite/gcc.target/i386/ret-thunk-9.c
......@@ -13,7 +13,7 @@ foo (void)
/* { dg-final { scan-assembler "jmp\[ \t\]*__x86_return_thunk" } } */
/* { dg-final { scan-assembler "jmp\[ \t\]*\.LIND" } } */
/* { dg-final { scan-assembler "call\[ \t\]*\.LIND" } } */
/* { dg-final { scan-assembler "__x86_indirect_thunk:" } } */
/* { dg-final { scan-assembler "__x86_return_thunk:" } } */
/* { dg-final { scan-assembler "mov(?:l|q)\[ \t\]*_?bar" { target *-*-linux* } } } */
/* { dg-final { scan-assembler-times {\tpause} 2 } } */
/* { dg-final { scan-assembler-times {\tlfence} 2 } } */
......
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