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2016-12-09py/asm: Remove need for dummy_data when doing initial assembler passes.Damien George
For all but the last pass the assembler only needs to count how much space is needed for the machine code, it doesn't actually need to emit anything. The dummy_data just uses unnecessary RAM and without it the code is not any more complex (and code size does not increase for Thumb and Xtensa archs).
2016-12-09py: Add inline Xtensa assembler.Damien George
This patch adds the MICROPY_EMIT_INLINE_XTENSA option, which, when enabled, allows the @micropython.asm_xtensa decorator to be used. The following opcodes are currently supported (ax is a register, a0-a15): ret_n() callx0(ax) j(label) jx(ax) beqz(ax, label) bnez(ax, label) mov(ax, ay) movi(ax, imm) # imm can be full 32-bit, uses l32r if needed and_(ax, ay, az) or_(ax, ay, az) xor(ax, ay, az) add(ax, ay, az) sub(ax, ay, az) mull(ax, ay, az) l8ui(ax, ay, imm) l16ui(ax, ay, imm) l32i(ax, ay, imm) s8i(ax, ay, imm) s16i(ax, ay, imm) s32i(ax, ay, imm) l16si(ax, ay, imm) addi(ax, ay, imm) ball(ax, ay, label) bany(ax, ay, label) bbc(ax, ay, label) bbs(ax, ay, label) beq(ax, ay, label) bge(ax, ay, label) bgeu(ax, ay, label) blt(ax, ay, label) bnall(ax, ay, label) bne(ax, ay, label) bnone(ax, ay, label) Upon entry to the assembly function the registers a0, a12, a13, a14 are pushed to the stack and the stack pointer (a1) decreased by 16. Upon exit, these registers and the stack pointer are restored, and ret.n is executed to return to the caller (caller address is in a0). Note that the ABI for the Xtensa emitters is non-windowing.
2016-12-09py/asmxtensa: Add low-level Xtensa assembler.Damien George