On 9/20/22 06:39, Xi Ruoyao via Gcc-help wrote:
On Mon, 2022-09-19 at 21:47 -0700, mike wrote:
/* snip */
I am having a problem using ldrexb and strexb using inline assembler. The
code is running on a RPi4 on ubuntu 20.04LTS.
I get an error message "Error: unknown mnemonic `ldrexb' -- `ldrexb
x0,[[sp,8]]'"
ldrexb and strexb are Thumb-2 instructions, but RPi4 uses an AArch64
CPU. AArch64 is an extension of the classic ARM instruction set, not an
extension of Thumb-2. So you can't use them on AArch64.
The AArch64 name of that instruction is LDAXRB. I'm assuming you're running
a 64-bit kernel: you don't say.
--
Andrew Haley (he/him)
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
https://keybase.io/andrewhaley
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