[llvm-branch-commits] [lld] [lld][LoongArch] Relax TLS LE/GD/LD (PR #123600)

[WÁNG Xuěruì via llvm-branch-commits]

================
@@ -1015,8 +1063,20 @@ void LoongArch::finalizeRelax(int passes) const {
             r.expr = r.sym->hasFlag(NEEDS_PLT) ? R_PLT_PC : R_PC;
             break;
           case R_LARCH_B26:
+          case R_LARCH_TLS_LE_LO12_R:
+            skip = 4;
+            write32le(p, aux.writes[writesIdx++]);
+            break;
+          case R_LARCH_TLS_GD_PCREL20_S2:
+            // Note: R_LARCH_TLS_LD_PCREL20_S2 must also use R_TLSGD_PC instead
+            // of R_TLSLD_PC because the processing of relocation
+            // R_LARCH_TLS_LD_PC_HI20 is the same as R_LARCH_TLS_GD_PC_HI20. If
----------------
xen0n wrote:

> Thanks for your review. I will revise it to the following description. Do you think it is clear?
> 
> ```
> Note: R_LARCH_TLS_LD_PCREL20_S2 must also use R_TLSGD_PC instead
> of R_TLSLD_PC due to historical reasons. In fact, TLSLD is not fully supported
> on LoongArch. We need to handle relocation of R_LARCH_TLS_LD_PC_HI20
> as equivalent to R_LARCH_TLS_GD_PC_HI20.
> 
> This reason has also been mentioned in mold commit:
> https://github.com/rui314/mold/commit/5dfa1cf07c03bd57cb3d493b652ef22441bcd71c
> ```

"In fact, right now TLS LD behaves exactly like GD on LoongArch." is enough, and the "We need to ..." sentence can be omitted this way.

https://github.com/llvm/llvm-project/pull/123600