arm: provide emulation for SLJIT_CTZ in ARMv6#187
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zherczeg merged 1 commit intozherczeg:masterfrom Aug 23, 2023
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There was a code for this when armv5 support was removed, maybe it can be restored.
Since 3499aba (Set armv6 as the minimum arm version, 2023-04-07) the fallback code in use for ARMv5 was removed, but the RBIT instruction is not supported in ARMv6 so bring it back. A similar problem in the Thumb2 code is suspected as it should affect at least armv6t2 but a solution for it has been punted.
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According to my documentation, RBIT is ARMv6T2, ARMv7 instruction, so Thumb code should not be affected. |
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Avoids SIGILL when running in older CPUs than armv7 (ex: Raspberry PI < 2)
Tested with QEMU using a softfp userland, but would work as well with hardfp (FPU is optional but common with those CPUs, even if it is not NEON).
Thumb2 with
march=armv6t2not addressed yet