arm: incomplete support for ARMv6 systems #188
Description
as shown when building in Debian 12 using the gcc-12-arm-linux-gnueabi cross compiler and testing with qemu-user-static (not a Debian issue, but attempting to reflect what is likely happenning with at least Rasperry PI):
$ make -j CC='arm-linux-gnueabi-gcc-12 -static -march=armv6k'
$ qemu-arm-static -cpu arm1176 bin/sljit_test -v
Run executable allocator test
Run test1
Run test2
Run test3
Run test4
Run test5
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Run test93
Illegal instruction (core dumped)
Partially addressed by #187 (note that RBIT is optional in armv6, so there might be still issues yet to be reported), but still missing fixes for test93 (which requires VFP3[1] for VMOV immediate) and with an implicit base of armv6k for atomics[2]
[1] https://developer.arm.com/documentation/ddi0406/c/Application-Level-Architecture/Advanced-SIMD-and-Floating-point-Instruction-Encoding/Floating-point-data-processing-instructions
[2] https://developer.arm.com/documentation/ddi0301/h/summary-of-arm1136jf-s-and-arm1176jzf-s-processor-differences/summary-of-differences/armv6k-extensions-support