https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125436
--- Comment #12 from H.J. Lu <hjl.tools at gmail dot com> ---
The fixed GCC generates:
ms_tls_access:
.LFB0:
.cfi_startproc
pushq %rdi
.cfi_def_cfa_offset 16
.cfi_offset 5, -16
pushq %rsi
.cfi_def_cfa_offset 24
.cfi_offset 4, -24
pushq %rbx
.cfi_def_cfa_offset 32
.cfi_offset 3, -32
subq $160, %rsp
.cfi_def_cfa_offset 192
movaps %xmm6, (%rsp)
movaps %xmm7, 16(%rsp)
movaps %xmm8, 32(%rsp)
movaps %xmm9, 48(%rsp)
movaps %xmm10, 64(%rsp)
movaps %xmm11, 80(%rsp)
movaps %xmm12, 96(%rsp)
movaps %xmm13, 112(%rsp)
movaps %xmm14, 128(%rsp)
movaps %xmm15, 144(%rsp)
.cfi_offset 23, -192
.cfi_offset 24, -176
.cfi_offset 25, -160
.cfi_offset 26, -144
.cfi_offset 27, -128
.cfi_offset 28, -112
.cfi_offset 29, -96
.cfi_offset 30, -80
.cfi_offset 31, -64
.cfi_offset 32, -48
movl %ecx, %ebx
leaq tls_instance@tlsld(%rip), %rdi
call __tls_get_addr@PLT
addl %ebx, tls_instance@dtpoff(%rax)
movaps (%rsp), %xmm6
movaps 16(%rsp), %xmm7
movaps 32(%rsp), %xmm8
movaps 48(%rsp), %xmm9
movaps 64(%rsp), %xmm10
movaps 80(%rsp), %xmm11
movaps 96(%rsp), %xmm12
movaps 112(%rsp), %xmm13
movaps 128(%rsp), %xmm14
movaps 144(%rsp), %xmm15
addq $160, %rsp
.cfi_restore 32
.cfi_restore 31
.cfi_restore 30
.cfi_restore 29
.cfi_restore 28
.cfi_restore 27
.cfi_restore 26
.cfi_restore 25
.cfi_restore 24
.cfi_restore 23
.cfi_def_cfa_offset 32
popq %rbx
.cfi_restore 3
.cfi_def_cfa_offset 24
popq %rsi
.cfi_restore 4
.cfi_def_cfa_offset 16
popq %rdi
.cfi_restore 5
.cfi_def_cfa_offset 8
ret
.cfi_endproc
instead of
ms_tls_access:
.LFB0:
.cfi_startproc
pushq %rbx
.cfi_def_cfa_offset 16
.cfi_offset 3, -16
movl %edi, %ebx
leaq tls_instance@tlsld(%rip), %rdi
call __tls_get_addr@PLT
addl %ebx, tls_instance@dtpoff(%rax)
popq %rbx
.cfi_def_cfa_offset 8
ret
.cfi_endproc
