[Bug target/121694] New: Redundant TLSCALL

[hjl.tools at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121694

            Bug ID: 121694
           Summary: Redundant TLSCALL
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: hjl.tools at gmail dot com
  Target Milestone: ---
            Target: x86-64

[hjl@gnu-zen4-1 pr121668]$ cat x.c
typedef int caml_domain_state;
thread_local caml_domain_state caml_state;
void
caml_empty_mark_stack ()
{
  while (caml_state)
    caml_state = 0;
}
[hjl@gnu-zen4-1 pr121668]$
/export/build/gnu/tools-build/gcc-debug/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/tools-build/gcc-debug/build-x86_64-linux/gcc/ -Og -fPIC
-mtls-dialect=gnu2 -S x.c
[hjl@gnu-zen4-1 pr121668]$ cat x.s
        .file   "x.c"
        .text
        .globl  caml_empty_mark_stack
        .type   caml_empty_mark_stack, @function
caml_empty_mark_stack:
.LFB0:
        .cfi_startproc
        subq    $8, %rsp
        .cfi_def_cfa_offset 16
        jmp     .L2
        .p2align 5
.L3:
        leaq    caml_state@TLSDESC(%rip), %rax
        call    *caml_state@TLSCALL(%rax)
        movl    $0, %fs:(%rax)
.L2:
        leaq    caml_state@TLSDESC(%rip), %rax
        call    *caml_state@TLSCALL(%rax)
        cmpl    $0, %fs:(%rax)
        jne     .L3
        addq    $8, %rsp
        .cfi_def_cfa_offset 8
        ret
        .cfi_endproc
.LFE0:
        .size   caml_empty_mark_stack, .-caml_empty_mark_stack
        .globl  caml_state
        .section        .tbss,"awT",@nobits
        .align 4
        .type   caml_state, @object
        .size   caml_state, 4
caml_state:
        .zero   4
        .ident  "GCC: (GNU) 16.0.0 20250825 (experimental)"
        .section        .note.GNU-stack,"",@progbits
[hjl@gnu-zen4-1 pr121668]$ 

There are 2

        leaq    caml_state@TLSDESC(%rip), %rax
        call    *caml_state@TLSCALL(%rax)