https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96955
Bug ID: 96955
Summary: Implement __builtin_thread_pointer
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: hjl.tools at gmail dot com
CC: crazylht at gmail dot com, wwwhhhyyy333 at gmail dot com
Blocks: 96200
Target Milestone: ---
Target: i386,x86-64
On Linux/x86-64, The %fs segment register is used to implement the thread
pointer. The linear address of the thread pointer is stored at offset 0
relative to the %fs segment register. The following code loads the thread
pointer in the %rax register:
movq %fs:0, %rax
On Linux/i386, the %gs segment register is used:
movl %gs:0, %eax
We need to
1. Implement __builtin_thread_pointer for Linux/x86.
2. Document its behavior.
Referenced Bugs:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96200
[Bug 96200] Implement __builtin_thread_pointer() and
__builtin_set_thread_pointer() if TLS is supported
