On Mon, Feb 26, 2018 at 7:06 AM, Jan Hubicka <hubi...@ucw.cz> wrote: >> 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! >
Checked into trunk. OK for backport to GCC 7 branch after a few days? -- H.J.
