procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

LoongArch: Use explicit relocs for TLS access with -mexplicit-relocs=auto

Browse source 
The linker does not know how to relax TLS access for LoongArch, so let's
emit machine instructions with explicit relocs for TLS.

gcc/ChangeLog:

	* config/loongarch/loongarch.cc (loongarch_explicit_relocs_p):
	Return true for TLS symbol types if -mexplicit-relocs=auto.
	(loongarch_call_tls_get_addr): Replace TARGET_EXPLICIT_RELOCS
	with la_opt_explicit_relocs != EXPLICIT_RELOCS_NONE.
	(loongarch_legitimize_tls_address): Likewise.
	* config/loongarch/loongarch.md (@tls_low<mode>): Remove
	TARGET_EXPLICIT_RELOCS from insn condition.

gcc/testsuite/ChangeLog:

	* gcc.target/loongarch/explicit-relocs-auto-tls-ld-gd.c: New
	test.
	* gcc.target/loongarch/explicit-relocs-auto-tls-le-ie.c: New
	test.
This commit is contained in:
Xi Ruoyao 2023-10-02 13:00:18 +08:00
parent 8811630df8
commit 95db62f4ad
No known key found for this signature in database
GPG key ID: ACAAD20E19E710E3
4 changed files with 40 additions and 14 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

37
gcc/config/loongarch/loongarch.cc
View file

@ -1936,16 +1936,27 @@ loongarch_explicit_relocs_p (enum loongarch_symbol_type type)
if (la_opt_explicit_relocs != EXPLICIT_RELOCS_AUTO)
return la_opt_explicit_relocs == EXPLICIT_RELOCS_ALWAYS;
/* If we are performing LTO for a final link, and we have the linker
plugin so we know the resolution of the symbols, then all GOT
references are binding to external symbols or preemptable symbols.
So the linker cannot relax them. */
return (in_lto_p
&& !flag_incremental_link
&& HAVE_LTO_PLUGIN == 2
&& (!global_options_set.x_flag_use_linker_plugin
|| global_options.x_flag_use_linker_plugin)
&& type == SYMBOL_GOT_DISP);
switch (type)
{
case SYMBOL_TLS_IE:
case SYMBOL_TLS_LE:
case SYMBOL_TLSGD:
case SYMBOL_TLSLDM:
/* The linker don't know how to relax TLS accesses. */
return true;
case SYMBOL_GOT_DISP:
/* If we are performing LTO for a final link, and we have the
linker plugin so we know the resolution of the symbols, then
all GOT references are binding to external symbols or
preemptable symbols. So the linker cannot relax them. */
return (in_lto_p
&& !flag_incremental_link
&& HAVE_LTO_PLUGIN == 2
&& (!global_options_set.x_flag_use_linker_plugin
|| global_options.x_flag_use_linker_plugin));
default:
return false;
}
}
/* Returns the number of instructions necessary to reference a symbol. */
@ -2753,7 +2764,7 @@ loongarch_call_tls_get_addr (rtx sym, enum loongarch_symbol_type type, rtx v0)
start_sequence ();
if (TARGET_EXPLICIT_RELOCS)
if (la_opt_explicit_relocs != EXPLICIT_RELOCS_NONE)
{
/* Split tls symbol to high and low. */
rtx high = gen_rtx_HIGH (Pmode, copy_rtx (loc));
@ -2918,7 +2929,7 @@ loongarch_legitimize_tls_address (rtx loc)
tp = gen_rtx_REG (Pmode, THREAD_POINTER_REGNUM);
tmp1 = gen_reg_rtx (Pmode);
dest = gen_reg_rtx (Pmode);
if (TARGET_EXPLICIT_RELOCS)
if (la_opt_explicit_relocs != EXPLICIT_RELOCS_NONE)
{
tmp2 = loongarch_unspec_address (loc, SYMBOL_TLS_IE);
tmp3 = gen_reg_rtx (Pmode);
@ -2955,7 +2966,7 @@ loongarch_legitimize_tls_address (rtx loc)
tmp1 = gen_reg_rtx (Pmode);
dest = gen_reg_rtx (Pmode);
if (TARGET_EXPLICIT_RELOCS)
if (la_opt_explicit_relocs != EXPLICIT_RELOCS_NONE)
{
tmp2 = loongarch_unspec_address (loc, SYMBOL_TLS_LE);
tmp3 = gen_reg_rtx (Pmode);

2
gcc/config/loongarch/loongarch.md
View file

@ -2257,7 +2257,7 @@
(unspec:P [(mem:P (lo_sum:P (match_operand:P 1 "register_operand" "r")
(match_operand:P 2 "symbolic_operand" "")))]
UNSPEC_TLS_LOW))]
"TARGET_EXPLICIT_RELOCS"
""
"addi.<d>\t%0,%1,%L2"
[(set_attr "type" "arith")
(set_attr "mode" "<MODE>")])

9
gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-tls-ld-gd.c Normal file
View file

@ -0,0 +1,9 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fPIC -mexplicit-relocs=auto" } */
__thread int a __attribute__((visibility("hidden")));
extern __thread int b __attribute__((visibility("default")));
int test() { return a + b; }
/* { dg-final { scan-assembler-not "la.tls" { target tls_native } } } */

6
gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-tls-le-ie.c Normal file
View file

@ -0,0 +1,6 @@
/* { dg-do compile } */
/* { dg-options "-O2 -mexplicit-relocs=auto" } */
#include "explicit-relocs-auto-tls-ld-gd.c"
/* { dg-final { scan-assembler-not "la.tls" { target tls_native } } } */