[gcc r14-8348] LoongArch: Disable explicit reloc for TLS LD/GD with -mexplicit-relocs=auto

[gcc r14-8348] LoongArch: Disable explicit reloc for TLS LD/GD with -mexplicit-relocs=auto

[Xi Ruoyao]

https://gcc.gnu.org/g:f12317306ee714aed0ca7ed01cafa520296b4c4c

commit r14-8348-gf12317306ee714aed0ca7ed01cafa520296b4c4c
Author: Xi Ruoyao <xry111@xry111.site>
Date:   Mon Jan 22 18:07:42 2024 +0800

    LoongArch: Disable explicit reloc for TLS LD/GD with -mexplicit-relocs=auto
    
    Binutils 2.42 supports TLS LD/GD relaxation which requires the assembler
    macro.
    
    gcc/ChangeLog:
    
            * config/loongarch/loongarch.cc (loongarch_explicit_relocs_p):
            If la_opt_explicit_relocs is EXPLICIT_RELOCS_AUTO, return false
            for SYMBOL_TLS_LDM and SYMBOL_TLS_GD.
            (loongarch_call_tls_get_addr): Do not split symbols of
            SYMBOL_TLS_LDM or SYMBOL_TLS_GD if la_opt_explicit_relocs is
            EXPLICIT_RELOCS_AUTO.
    
    gcc/testsuite/ChangeLog:
    
            * gcc.target/loongarch/explicit-relocs-auto-tls-ld-gd.c: Check
            for la.tls.ld and la.tls.gd.

Diff:
---
 gcc/config/loongarch/loongarch.cc                              | 10 +++++-----
 .../gcc.target/loongarch/explicit-relocs-auto-tls-ld-gd.c      |  3 ++-
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc
index 82467474288..072c68d97e3 100644
--- a/gcc/config/loongarch/loongarch.cc
+++ b/gcc/config/loongarch/loongarch.cc
@@ -1970,11 +1970,11 @@ loongarch_explicit_relocs_p (enum loongarch_symbol_type type)
     {
       case SYMBOL_TLS_IE:
       case SYMBOL_TLS_LE:
-      case SYMBOL_TLSGD:
-      case SYMBOL_TLSLDM:
       case SYMBOL_PCREL64:
-	/* The linker don't know how to relax TLS accesses or 64-bit
-	   pc-relative accesses.  */
+	/* TLS IE cannot be relaxed.  TLS LE relaxation is different from
+	   the normal R_LARCH_RELAX-based relaxation and it **requires**
+	   using the explicit %le_{lo12,hi20,add}_r relocs.  The linker
+	   does not relax 64-bit pc-relative accesses as at now.  */
 	return true;
       case SYMBOL_GOT_DISP:
 	/* The linker don't know how to relax GOT accesses in extreme
@@ -2789,7 +2789,7 @@ loongarch_call_tls_get_addr (rtx sym, enum loongarch_symbol_type type, rtx v0)
 
   start_sequence ();
 
-  if (la_opt_explicit_relocs != EXPLICIT_RELOCS_NONE)
+  if (la_opt_explicit_relocs == EXPLICIT_RELOCS_ALWAYS)
     {
       /* Split tls symbol to high and low.  */
       rtx high = gen_rtx_HIGH (Pmode, copy_rtx (loc));
diff --git a/gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-tls-ld-gd.c b/gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-tls-ld-gd.c
index 957ff98df62..ca55fcfc53e 100644
--- a/gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-tls-ld-gd.c
+++ b/gcc/testsuite/gcc.target/loongarch/explicit-relocs-auto-tls-ld-gd.c
@@ -6,4 +6,5 @@ extern __thread int b __attribute__((visibility("default")));
 
 int test() { return a + b; }
 
-/* { dg-final { scan-assembler-not "la.tls" { target tls_native } } } */
+/* { dg-final { scan-assembler "la\\.tls\\.ld" { target tls_native } } } */
+/* { dg-final { scan-assembler "la\\.tls\\.gd" { target tls_native } } } */