The RV32 emitter used an additional temporary register, as certain code
sequences required extra storage. This commit removes its usage in all
but one case, using REG_TEMP2 instead.
Signed-off-by: Alessandro Gatti <a.gatti@frob.it>
The RV32 emitter sometimes generated short load opcodes even when it
was not supposed to. This commit fixes an off-by-one error in its
offset eligibility range calculation and corrects one case of offset
calculation, operating on the raw label index number rather than its
effective offset in the stack (C.LW assumes all loads are
word-aligned).
Signed-off-by: Alessandro Gatti <a.gatti@frob.it>
The RV32 emitter always scheduled short jumps even outside the emit
compiler pass. Running the full test suite through the native emitter
instead of just the tests that depend on the emitter at runtime (as in,
`micropython/native_*` and `micropython/viper_* tests`) uncovered more
places where the invalid behaviour was still present.
Signed-off-by: Alessandro Gatti <a.gatti@frob.it>
This commit changes a few code sequences to use more compressed opcodes
where possible. The sequences in question are the ones that show up the
most in the test suite and require the least amount of code changes, namely
short offset loads from memory to RET/ARG registers, indirect calls through
the function table, register-based jumps, locals' offset calculation,
reg-is-null jumps, and register comparisons.
There are no speed losses or gains from these changes, but there is an
average 15-20% generated code size reduction.
Signed-off-by: Alessandro Gatti <a.gatti@frob.it>
This adds a native code generation backend for RISC-V RV32I CPUs, currently
limited to the I, M, and C instruction sets.
Signed-off-by: Alessandro Gatti <a.gatti@frob.it>
