> On Mon, Feb 26, 2018 at 2:58 AM, Jan Hubicka <hubi...@ucw.cz> wrote: > >> On Mon, Feb 26, 2018 at 2:05 AM, Martin Liška <mli...@suse.cz> wrote: > >> > On 02/25/2018 02:37 AM, H.J. Lu wrote: > >> >> PR target/r84530 > >> > > >> > Just a nit I've noticed: > >> > > >> > s/r84530/84530 > >> > >> Fixed. > >> > >> -- > >> H.J. > > > >> From f08b8721ed038cefcee5a0bb1329b90a2d322269 Mon Sep 17 00:00:00 2001 > >> From: "H.J. Lu" <hjl.to...@gmail.com> > >> Date: Sat, 24 Feb 2018 05:05:49 -0800 > >> Subject: [PATCH] i386: Update -mfunction-return= for return with pop > >> > >> When -mfunction-return= is used, simple_return_pop_internal should pop > >> return address into ECX register, adjust stack by bytes to pop from stack > >> and jump to the return thunk via ECX register. > >> > >> Tested on i686 and x86-64. > >> > >> PR target/84530 > >> * config/i386/i386-protos.h (ix86_output_indirect_jmp): Remove > >> the bool argument. > >> (ix86_output_indirect_function_return): New prototype. > >> (ix86_split_simple_return_pop_internal): Likewise. > >> * config/i386/i386.c (indirect_return_via_cx): New. > >> (indirect_return_via_cx_bnd): Likewise. > >> (indirect_thunk_name): Handle return va CX_REG. > >> (output_indirect_thunk_function): Create alias for > >> __x86_return_thunk_[re]cx and __x86_return_thunk_[re]cx_bnd. > >> (ix86_output_indirect_jmp): Remove the bool argument. > >> (ix86_output_indirect_function_return): New function. > >> (ix86_split_simple_return_pop_internal): Likewise. > >> * config/i386/i386.md (*indirect_jump): Don't pass false > >> to ix86_output_indirect_jmp. > >> (*tablejump_1): Likewise. > >> (simple_return_pop_internal): Change it to define_insn_and_split. > >> Call ix86_split_simple_return_pop_internal to split it for > >> -mfunction-return=. > >> (simple_return_indirect_internal): Call > >> ix86_output_indirect_function_return instead of > >> ix86_output_indirect_jmp. > > > > It seems to make sense. Since LLVM has picked up our thunk names now, > > I wonder if they have same bug or someohow already assigned a name > > to this thunk. In the second case we probably ought to match it. Do > > you know what LLVM uses? > > > > I don't think LLVM has implemented -mfunction-return=. I disclosed > my -mindirect-branch= approach to LLVM last year. At the time, they > wanted freedom in their implementation and didn't want to be compatible > with mine. Later they added GCC compatibility so that LLVM may be > used to compile Linux kernel. I believe it will be the same case if this > option is used to compile Linux kernel.
Patch is OK then, thanks! Honza > > BTW, is my patch: > > https://gcc.gnu.org/ml/gcc-patches/2018-01/msg02233.html > > OK for trunk? The review died at > > https://gcc.gnu.org/ml/gcc-patches/2018-02/msg01355.html > > Thanks. > > -- > H.J.
