remove duplicate BranchLoop class

slothy/targets/arm_v7m/arch_v7m.py

@@ -514,96 +514,6 @@ def end(self, other, indentation=0):
             yield f'{indent}subs {other["cnt"]}, {other["reg1"]}, {other["imm"]}'  # `subs` sets flags
         yield f'{indent}bne {lbl_start}'
 
-class BranchLoop(Loop):
-    def __init__(self, lbl="lbl", lbl_start="1", lbl_end="2", loop_init="lr") -> None:
-        super().__init__(lbl_start=lbl_start, lbl_end=lbl_end, loop_init=loop_init)
-        self.lbl = lbl
-        self.lbl_regex = r"^\s*(?P<label>\w+)\s*:(?P<remainder>.*)$"
-        self.end_regex = (rf"^\s*(cbnz|cbz|bne)(?:\.w)?\s+{lbl}",)
-
-    def start(self, loop_cnt, indentation=0, fixup=0, unroll=1, jump_if_empty=None, preamble_code=None, body_code=None, postamble_code=None, register_aliases=None):
-        """Emit starting instruction(s) and jump label for loop"""
-        indent = ' ' * indentation
-        if body_code is None:
-            logging.debug(f"No body code in loop start: Just printing label.")
-            yield f"{self.lbl}:"
-            return
-        # Identify the register that is used as a loop counter
-        body_code = [l for l in body_code if l.text != ""]
-        for l in body_code:
-            inst = Instruction.parser(l)
-            # Flags are set through cmp 
-            # LIMITATION: By convention, we require the first argument to be the
-            # "counter" and the second the one marking the iteration end.
-            if isinstance(inst[0], cmp):
-                # Assume this mapping
-                loop_cnt_reg = inst[0].args_in[0]
-                loop_end_reg = inst[0].args_in[1]
-                logging.debug(f"Assuming {loop_cnt_reg} as counter register and {loop_end_reg} as end register.")
-                break
-            # Flags are set through subs
-            elif isinstance(inst[0], subs_imm_short):
-                loop_cnt_reg = inst[0].args_in_out[0]
-                loop_end_reg = inst[0].args_in_out[0]
-                break
-
-        # Find FPR that is used to stash the loop end incase it's vmov loop
-        loop_end_reg_fpr = None
-        for li, l in enumerate(body_code):
-            inst = Instruction.parser(l)
-            # Flags are set through cmp 
-            if isinstance(inst[0], vmov_gpr):
-                if loop_end_reg in inst[0].args_out:
-                    logging.debug(f"Copying from {inst[0].args_in} to {loop_end_reg}")
-                    loop_end_reg_fpr = inst[0].args_in[0]
-
-            # The last vmov occurance before the cmp that writes to the register
-            # we compare to will be the right one. The same GPR could be written
-            # previously due to renaming, before it becomes the value used in
-            # the cmp.
-            if isinstance(inst[0], cmp):
-                break
-
-        if unroll > 1:
-            assert unroll in [1,2,4,8,16,32]
-            yield f"{indent}lsr {loop_end_reg}, {loop_end_reg}, #{int(math.log2(unroll))}"
-
-        inc_per_iter = 0
-        for l in body_code:
-            inst = Instruction.parser(l)
-            # Increment happens through pointer modification
-            if loop_cnt_reg.lower() == inst[0].addr and inst[0].increment is not None:
-                inc_per_iter = inc_per_iter + simplify(inst[0].increment)
-            # Increment through explicit modification
-            elif loop_cnt_reg.lower() in (inst[0].args_out + inst[0].args_in_out) and inst[0].immediate is not None:
-                # TODO: subtract if we have a subtraction
-                inc_per_iter = inc_per_iter + simplify(inst[0].immediate)
-        logging.debug(f"Loop counter {loop_cnt_reg} is incremented by {inc_per_iter} per iteration.")
-
-        if fixup != 0 and loop_end_reg_fpr is not None:
-            yield f"{indent}push {{{loop_end_reg}}}"
-            yield f"{indent}vmov {loop_end_reg}, {loop_end_reg_fpr}"
-
-        if fixup != 0:
-            yield f"{indent}sub {loop_end_reg}, {loop_end_reg}, #{fixup*inc_per_iter}"
-
-        if fixup != 0 and loop_end_reg_fpr is not None:
-            yield f"{indent}vmov {loop_end_reg_fpr}, {loop_end_reg}"
-            yield f"{indent}pop {{{loop_end_reg}}}"
-
-        if jump_if_empty is not None:
-            yield f"cbz {loop_cnt}, {jump_if_empty}"
-        yield f"{self.lbl}:"
-
-    def end(self, other, indentation=0):
-        """Emit compare-and-branch at the end of the loop"""
-        indent = ' ' * indentation
-        lbl_start = self.lbl
-        if lbl_start.isdigit():
-            lbl_start += "b"
-
-        yield f'{indent}bne {lbl_start}'
-
 class FatalParsingException(Exception):
     """A fatal error happened during instruction parsing"""