[PATCH] LoongArch: Update comment about bottom bit usage in TLS GOT construction

[Tatsuyuki Ishi]

The GOT assignment logic, likely copied from another backend, does not in
fact require multiple flags to construct multiple type of slots. Instead,
all slots are initialized on the first relocation encountered. Update
comment to avoid confusion.
---
 bfd/elfnn-loongarch.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c
index 64c34e99261..d66dcee1100 100644
--- a/bfd/elfnn-loongarch.c
+++ b/bfd/elfnn-loongarch.c
@@ -3656,16 +3656,13 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
 	  relocation -= elf_hash_table (info)->tls_sec->vma;
 	  break;
 
-	/* TLS IE LD/GD process separately is troublesome.
-	   When a symbol is both ie and LD/GD, h->got.off |= 1
-	   make only one type be relocated.  We must use
-	   h->got.offset |= 1 and h->got.offset |= 2
-	   diff IE and LD/GD.  And all (got_off & (~(bfd_vma)1))
-	   (IE LD/GD and reusable GOT reloc) must change to
-	   (got_off & (~(bfd_vma)3)), beause we use lowest 2 bits
-	   as a tag.
-	   Now, LD and GD is both GOT_TLS_GD type, LD seems to
-	   can be omitted.  */
+	/* The bottom bit of h->got.offset is (ab)used as a flag.
+	   Upon encountering the first TLS relocation, we initialize all GOT
+	   slots for the corresponding symbol and set the bottom bit to 1.
+
+	   The second and subsequent relocations will check the flag, see that
+	   the slot is already initialized, and move on to just relocating the
+	   entry.  */
 	case R_LARCH_TLS_IE_PC_HI20:
 	case R_LARCH_TLS_IE_HI20:
 	case R_LARCH_TLS_LD_PC_HI20:
-- 
2.40.1