add EQ condition for JUMPR and support for opcodes emitting >1 instruction

Author: wnienhaus

esp32_ulp/assemble.py

@@ -263,16 +263,22 @@ def assembler_pass(self, lines):
                         continue
                 else:
                     # machine instruction
-                    func = getattr(opcodes, 'i_' + opcode.lower(), None)
+                    opcode_lower = opcode.lower()
+                    func = getattr(opcodes, 'i_' + opcode_lower, None)
                     if func is not None:
-                        # during the first pass, symbols are not all known yet.
-                        # so some expressions may not evaluate to something (yet).
-                        # instruction building requires sane arguments however.
-                        # since all instructions are 4 bytes long, we simply skip
-                        # building instructions during pass 1, and append an "empty
-                        # instruction" to the section to get the right section size.
-                        instruction = 0 if self.a_pass == 1 else func(*args)
-                        self.append_section(instruction.to_bytes(4, 'little'), TEXT)
+                        if self.a_pass == 1:
+                            # during the first pass, symbols are not all known yet.
+                            # so we add empty instructions to the section, to determine
+                            # section sizes and symbol offsets for pass 2.
+                            result = (0,) * opcodes.no_of_instr(opcode_lower, args)
+                        else:
+                            result = func(*args)
+
+                        if not isinstance(result, tuple):
+                            result = (result,)
+
+                        for instruction in result:
+                            self.append_section(instruction.to_bytes(4, 'little'), TEXT)
                         continue
                 raise ValueError('Unknown opcode or directive: %s' % opcode)
         self.finalize_sections()

esp32_ulp/opcodes.py

@@ -636,6 +636,19 @@ def i_jump(target, condition='--'):
     raise TypeError('unsupported operand: %s' % target.raw)
 
 
+def _jump_relr(threshold, cond, offset):
+    """
+    Equivalent of I_JUMP_RELR macro in binutils-esp32ulp
+    """
+    _br.imm = threshold
+    _br.cmp = cond
+    _br.offset = abs(offset)
+    _br.sign = 0 if offset >= 0 else 1
+    _br.sub_opcode = SUB_OPCODE_BR
+    _br.opcode = OPCODE_BRANCH
+    return _br.all
+
+
 def i_jumpr(offset, threshold, condition):
     offset = get_rel(offset)
     threshold = get_imm(threshold)
@@ -650,15 +663,16 @@ def i_jumpr(offset, threshold, condition):
     elif condition == 'gt':  # gt == ge(threshold+1)
         threshold += 1
         cmp_op = BRCOND_GE
+    elif condition == 'eq':  # eq == ge(threshold) but not ge(threshold+1)
+        # jump over next JUMPR
+        skip_ins = _jump_relr(threshold + 1, BRCOND_GE, 2)
+        # jump to target
+        offset -= 1  # adjust for the additional JUMPR instruction
+        jump_ins = _jump_relr(threshold, BRCOND_GE, offset)
+        return (skip_ins, jump_ins)
     else:
         raise ValueError("invalid comparison condition")
-    _br.imm = threshold
-    _br.cmp = cmp_op
-    _br.offset = abs(offset)
-    _br.sign = 0 if offset >= 0 else 1
-    _br.sub_opcode = SUB_OPCODE_BR
-    _br.opcode = OPCODE_BRANCH
-    return _br.all
+    return _jump_relr(threshold, cmp_op, offset)
 
 
 def i_jumps(offset, threshold, condition):
@@ -680,3 +694,10 @@ def i_jumps(offset, threshold, condition):
     _bs.sub_opcode = SUB_OPCODE_BS
     _bs.opcode = OPCODE_BRANCH
     return _bs.all
+
+
+def no_of_instr(opcode, args):
+    if opcode == 'jumpr' and get_cond(args[2]) == 'eq':
+        return 2
+
+    return 1

tests/compat/jumps.S

@@ -19,6 +19,8 @@ entry:
   jumpr later, 42, le
   jumpr entry, 42, gt
   jumpr later, 42, gt
+  jumpr entry, 42, eq
+  jumpr later, 42, eq
 
   nop
   nop