[PATCH] D144941: [m68k] Add TLS Support

[Sheng via Phabricator via llvm-commits]

0x59616e added inline comments.


================
Comment at: llvm/test/CodeGen/M68k/TLS/tlsie.ll:10
+; CHECK-NEXT:  ; %bb.0: ; %entry
+; CHECK-NEXT:    suba.l #4, %sp
+; CHECK-NEXT:    .cfi_def_cfa_offset -8
----------------
jrtc27 wrote:
> Why do we need the stack adjustment? We're not passing any arguments to __m68k_read_tp. Or is this some stack alignment issue to compensate for the implicit push of the return address?
This adjustment is the consequence of `M68kSubtarget::stackAlignment` [0]

The comment says:
```
  /// The minimum alignment known to hold of the stack frame on
  /// entry to the function and which must be maintained by every function.
  unsigned stackAlignment = 8;
```

I don't know why it is set to 8 as the ABI only requires 2.

@myhsu do you have any clue ?

[0] https://github.com/llvm/llvm-project/blob/main/llvm/lib/Target/M68k/M68kSubtarget.h#L73


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