Messages in this thread | | | From | Stefan Agner <> | Subject | [PATCH 0/3] ARM: make use of UAL VFP mnemonics when possible | Date | Tue, 10 Mar 2020 23:01:18 +0100 |
| |
To build the kernel with Clang's integrated assembler the VFP code needs to make use of the unified assembler language (UAL) VFP mnemonics.
At first I tried to get rid of the co-processor instructions to access the floating point unit along with the macros completely. However, due to missing FPINST/FPINST2 argument support in older binutils versions we have to keep them around. Once we drop support for binutils 2.24 and older, the move to UAL VFP mnemonics will be straight forward with this changes applied.
Tested using Clang with integrated assembler as well as external (binutils assembler), various gcc/binutils version down to 4.7/2.23. Disassembled and compared the object files in arch/arm/vfp/ to make sure this changes leads to the same code. Besides different inlining behavior I was not able to spot a difference.
This replaces (and extends) my earlier patch "ARM: use assembly mnemonics for VFP register access" http://lore.kernel.org/r/8bb16ac4b15a7e28a8e819ef9aae20bfc3f75fbc.1582266841.git.stefan@agner.ch
-- Stefan
Stefan Agner (3): ARM: use .fpu assembler directives instead of assembler arguments ARM: use VFP assembler mnemonics in register load/store macros ARM: use VFP assembler mnemonics if available
arch/arm/include/asm/vfp.h | 2 ++ arch/arm/include/asm/vfpmacros.h | 31 ++++++++++++++++++++++--------- arch/arm/vfp/Makefile | 5 ++++- arch/arm/vfp/vfphw.S | 31 ++++++++++++++++++++----------- arch/arm/vfp/vfpinstr.h | 23 +++++++++++++++++++---- 5 files changed, 67 insertions(+), 25 deletions(-)
-- 2.25.1
| |