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authorChristoph Müllner <christoph.muellner@vrull.eu>2024-04-18 23:58:58 +0200
committerAndreas K. Hüttel <dilfridge@gentoo.org>2024-06-24 21:36:49 +0200
commit81c7f6193ce66480b2a29a5b2c66a7356e743308 (patch)
treea4337e4852e0a1042250783985cb2fe5f720fd2c /sysdeps/x86/tst-cpu-features-cpuinfo.c
parent9e06e4a43b58519991acbed1d7f33abc40249226 (diff)
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RISC-V: Execute a PAUSE hint in spin loops
The atomic_spin_nop() macro can be used to run arch-specific
code in the body of a spin loop to potentially improve efficiency.
RISC-V's Zihintpause extension includes a PAUSE instruction for
this use-case, which is encoded as a HINT, which means that it
behaves like a NOP on systems that don't implement Zihintpause.

Binutils supports Zihintpause since 2.36, so this patch uses
the ".insn" directive to keep the code compatible with older
toolchains.

Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'sysdeps/x86/tst-cpu-features-cpuinfo.c')
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