[Tinycc-devel] Feature request: _Thread_local (and a possible bug)

[Robert Clausecker]

Dear tcc hackers,

It would be very nice if tcc could implement the _Thread_local (aka
__thread) storage class specified. This would make it much easier for me
to compile my C code with tcc as it is one of the few parts of C11 I am
actually relying on, the others being easily replaceable by supported
constructs.

Have a nice day,

Yours Robert Clausecker
PS: It seems like there is a bug in the x86-64 edition of tcc. If I
assemble the following assembly file:

    foo: mov 0,%eax

I get the following machine code:

    a1 00 00 00 00

Which objdump(1) and Agner Fog's objcopy(1) detect as invalid. For the
same code, gas(1) generates the following assembly:

    8b 04 25 00 00 00 00

Assembling the following assembly file

    foo: .byte 0xa1
         .zero 8

Generates the following output under objdump(1):

    a1 00 00 00 00 00 00 00 00  movabs 0x0,%eax

TL;DR I suspect tcc's assembler for amd64 is broken here. I am
compiling / assembling with tcc version 0.9.26.