On 11/9/20 11:57 AM, H.J. Lu via Gcc-patches wrote: > GCC 11 supports -march=x86-64-v[234] to enable x86 micro-architecture ISA > levels: > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97250 > > Binutils has been updated to support GNU_PROPERTY_X86_ISA_1_V[234] marker: > > https://gitlab.com/x86-psABIs/x86-64-ABI/-/merge_requests/13 > > with > > commit b0ab06937385e0ae25cebf1991787d64f439bf12 > Author: H.J. Lu <hjl.to...@gmail.com> > Date: Fri Oct 30 06:49:57 2020 -0700 > > x86: Support GNU_PROPERTY_X86_ISA_1_BASELINE marker > > and > > commit 32930e4edbc06bc6f10c435dbcc63131715df678 > Author: H.J. Lu <hjl.to...@gmail.com> > Date: Fri Oct 9 05:05:57 2020 -0700 > > x86: Support GNU_PROPERTY_X86_ISA_1_V[234] marker > > in x86 ELF binaries. > > Add -mneeded to emit GNU_PROPERTY_X86_ISA_1_NEEDED property to indicate > the micro-architecture ISA level required to execute the binary. > > gcc/ > > * config.gcc: Replace cet.o with gnu-property.o. Replace > i386/t-cet with i386/t-gnu-property. > * config/i386/cet.c: Renamed to ... > * config/i386/gnu-property.c: This. > (emit_gnu_property): New function. > (file_end_indicate_exec_stack_and_cet): Renamed to ... > (file_end_indicate_exec_stack_and_gnu_property): This. Call > emit_gnu_property to generate GNU_PROPERTY_X86_FEATURE_1_AND and > GNU_PROPERTY_X86_ISA_1_NEEDED properties. > * config/i386/i386.opt (mneeded): New. > * config/i386/linux-common.h (file_end_indicate_exec_stack_and_cet): > Renamed to ... > (file_end_indicate_exec_stack_and_gnu_property): This. > (TARGET_ASM_FILE_END): Updated. > * config/i386/t-cet: Renamed to ... > * config/i386/t-gnu-property: This. > (cet.o): Renamed to ... > (gnu-property.o): This. > * doc/invoke.texi: Document -mneeded. > > gcc/testsuite/ > > * gcc.target/i386/x86-needed-1.c: New test. > * gcc.target/i386/x86-needed-2.c: Likewise. > * gcc.target/i386/x86-needed-3.c: Likewise.
Would it make sense to have -mneeded on by default if we detect a suitable assembler? The goal being that on the distro level we'd have the appropriate markup for everything in the distro without having to worry about injecting the -mneeded flag into every build. Jeff
