get a bunch of overrides working again

lips/Dumper.lua

@@ -6,14 +6,15 @@ local unpack = unpack or table.unpack
 local path = string.gsub(..., "[^.]+$", "")
 local data = require(path.."data")
 local util = require(path.."util")
-local overrides = require(path.."overrides")
+--local overrides = require(path.."overrides")
 local Base = require(path.."Base")
 local Token = require(path.."Token")
 local Statement = require(path.."Statement")
+local Reader = require(path.."Reader")
 
 local bitrange = util.bitrange
 
-local Dumper = Base:extend()
+local Dumper = Reader:extend()
 function Dumper:init(writer, options)
     self.writer = writer
     self.options = options or {}
@@ -23,13 +24,6 @@ function Dumper:init(writer, options)
     self.lastcommand = nil
 end
 
-function Dumper:error(msg, got)
-    if got ~= nil then
-        msg = msg..', got '..tostring(got)
-    end
-    error(('%s:%d: Error: %s'):format(self.fn, self.line, msg), 2)
-end
-
 function Dumper:export_labels(t)
     for k, v in pairs(self.labels) do
         -- only return valid labels; those that don't begin with a number
@@ -225,62 +219,6 @@ function Dumper:dump_instruction(t)
     return uw, lw
 end
 
-function Dumper:expect(tts)
-    local t = self.s[self.i]
-    if t == nil then
-        self:error("expected another argument") -- TODO: more verbose
-    end
-
-    self.fn = t.fn
-    self.line = t.line
-
-    for _, tt in pairs(tts) do
-        if t.tt == tt then
-            return t.ok
-        end
-    end
-
-    --local err = ("argument %i of %s expected type %s"):format(self.i, self.s.type, tt)
-    local err = ("unexpected type for argument %i of %s"):format(self.i, self.s.type)
-    self:error(err, t.tt)
-end
-
-function Dumper:register(registers)
-    self:expect{'REG'}
-    local t = self.s[self.i]
-    local numeric = registers[t.tok]
-    if not numeric then
-        self:error('wrong type of register')
-    end
-    return Token(t)
-end
-
-function Dumper:const(relative, no_label)
-    if no_label then
-        self:expect{'NUM'}
-    else
-        self:expect{'NUM', 'LABELSYM'}
-    end
-    local t = self.s[self.i]
-    local new = Token(t)
-    if relative then
-        if t.tt == 'LABELSYM' then
-            new.t = 'LABELREL'
-        else
-            new.t = 'REL'
-        end
-    end
-    return new
-end
-
-function Dumper:deref()
-    self:expect{'DEREF'}
-    local t = self.s[self.i]
-    local new = Token(t)
-    new.tt = 'REG'
-    return new
-end
-
 function Dumper:assemble_j(first, out)
     local w = 0
     w = w + self:valvar(first,   6) * 0x04000000
@@ -318,7 +256,7 @@ function Dumper:format_in(informat)
     local args = {}
     --if #informat ~= #s then error('mismatch') end
     for i=1, #informat do
-        self.i = i -- FIXME: do we need this?
+        self.i = i
         local c = informat:sub(i, i)
         if c == 'd' and not args.rd then
             args.rd = self:register(data.registers)
@@ -351,7 +289,7 @@ function Dumper:format_in(informat)
         elseif c == 'K' and not args.immediate then
             args.immediate = Token(self:const(nil, 'no label')):set('signed')
         elseif c == 'b' and not args.base then
-            args.base = self:deref()
+            args.base = self:deref():set('tt', 'REG')
         else
             error('Internal Error: invalid input formatting string')
         end
@@ -397,14 +335,15 @@ function Dumper:assemble(s)
     local name = s.type
     local h = data.instructions[name]
     self.s = s
-    if overrides[name] then
-        --overrides[name](self, name)
-        local s = Statement(self.fn, self.line, '!DATA') -- FIXME: dummy
-        return s
-    elseif h[2] == 'tob' then -- TODO: or h[2] == 'Tob' then
-        local s = Statement(self.fn, self.line, '!DATA') -- FIXME: dummy
-        return s
-    elseif h[2] ~= nil then
+--    if overrides[name] then
+--        --overrides[name](self, name)
+--        local s = Statement(self.fn, self.line, '!DATA') -- FIXME: dummy
+--        return s
+--    elseif h[2] == 'tob' then -- TODO: or h[2] == 'Tob' then
+--        local s = Statement(self.fn, self.line, '!DATA') -- FIXME: dummy
+--        return s
+--    elseif h[2] ~= nil then
+    if h[2] ~= nil then
         local args = self:format_in(h[2])
         return self:format_out(h, args)
     else
@@ -446,10 +385,12 @@ function Dumper:load(statements)
         if s.type:sub(1, 1) ~= '!' then
             s = self:assemble(s)
             insert(new_statements, s)
+            self.pos = self.pos + 4 -- FIXME: assumes no pseudo-ops
         elseif assembled_directives[s.type] then
             -- FIXME: check for LABELs in !DATA
             -- TODO: reimplement ALIGN and SKIP here
             insert(new_statements, s)
+            self.pos = self.pos + s:length()
         elseif s.type == '!LABEL' then
             -- noop
         else

lips/Parser.lua

@@ -103,12 +103,7 @@ function Parser:parse(asm)
 
     local preproc = Preproc(self.options)
     self.statements = preproc:process(self.statements)
-
-    --[[ process:
-- inline labels? how do you know how far they are?
-                 i guess you can just offset on statements instead
-- assemble? dumper gets passed .org .base
---]]
+    self.statements = preproc:expand(self.statements)
 
     -- DEBUG
     for i, s in ipairs(self.statements) do

lips/Preproc.lua

@@ -2,9 +2,11 @@ local insert = table.insert
 
 local path = string.gsub(..., "[^.]+$", "")
 local data = require(path.."data")
+local overrides = require(path.."overrides")
 local Base = require(path.."Base")
 local Token = require(path.."Token")
 local Statement = require(path.."Statement")
+local Reader = require(path.."Reader")
 
 local abs = math.abs
 
@@ -37,18 +39,11 @@ local function RelativeLabel(index, name)
     }
 end
 
-local Preproc = Base:extend()
+local Preproc = Reader:extend()
 function Preproc:init(options)
     self.options = options or {}
 end
 
-function Preproc:error(msg, got)
-    if got ~= nil then
-        msg = msg..', got '..tostring(got)
-    end
-    error(('%s:%d: Error: %s'):format(self.fn, self.line, msg), 2)
-end
-
 function Preproc:lookup(t)
     if t.tt == 'VARSYM' then
         local name = t.tok
@@ -110,6 +105,8 @@ function Preproc:lookup(t)
 end
 
 function Preproc:check(s, i, tt)
+    s = s or self.s
+    i = i or self.i
     local t = s[i]
     if t == nil then
         self:error("expected another argument")
@@ -187,7 +184,77 @@ function Preproc:process(statements)
         end
     end
 
-    self.statements = new_statements
+    return new_statements
+end
+
+function Preproc:statement(...)
+    self.fn = self.s.fn
+    self.line = self.s.line
+    local s = Statement(self.fn, self.line, ...)
+    return s
+end
+
+function Preproc:push(s)
+    s:validate()
+    insert(self.statements, s)
+end
+
+function Preproc:push_new(...)
+    self:push(self:statement(...))
+end
+
+function Preproc:pop(kind)
+    local ret
+    if kind == nil then
+        -- noop
+    elseif kind == 'CPU' then
+        ret = self:register(data.registers)
+    elseif kind == 'DEREF' then
+        ret = self:deref()
+    elseif kind == 'CONST' then
+        ret = self:const()
+    elseif kind == 'REL' then
+        ret = self:const('REL')
+    elseif kind == 'END' then
+        if self.s[self.i + 1] ~= nil then
+            self:error('too many arguments')
+        end
+        return -- don't increment self.i past end of arguments
+    else
+        error('Internal Error: unknown kind, got '..tostring(kind))
+    end
+    self.i = self.i + 1
+    return ret
+end
+
+function Preproc:expand(statements)
+    -- third pass: expand pseudo-instructions
+    self.statements = {}
+    for i=1, #statements do
+        local s = statements[i]
+        self.s = s
+        self.fn = s.fn
+        self.line = s.line
+        if s.type:sub(1, 1) == '!' then
+            -- TODO
+            self:push(s)
+        else
+            local name = s.type
+            local h = data.instructions[name]
+            if h == nil then
+                error('Internal Error: unknown instruction')
+            end
+
+            if overrides[name] then
+                self.i = 1
+                overrides[name](self, name)
+                self:pop('END')
+            else
+                self:push(s)
+            end
+        end
+    end
+
     return self.statements
 end
 

lips/Reader.lua

@@ -0,0 +1,93 @@
+local path = string.gsub(..., "[^.]+$", "")
+local Base = require(path.."Base")
+local Token = require(path.."Token")
+
+local Reader = Base:extend()
+-- no init method
+
+-- Reader expects self.s to be set to a statement, and self.i to a token index
+
+function Reader:error(msg, got)
+    if got ~= nil then
+        msg = msg..', got '..tostring(got)
+    end
+    error(('%s:%d: Error: %s'):format(self.fn, self.line, msg), 2)
+end
+
+function Reader:token(t, ...)
+    local new
+    if type(t) == 'table' then
+        new = Token(t, ...)
+    else
+        new = Token(self.fn, self.line, t, ...)
+    end
+    return new
+end
+
+function Reader:expect(tts)
+    local t = self.s[self.i]
+    if t == nil then
+        self:error("expected another argument") -- TODO: more verbose
+    end
+
+    self.fn = t.fn
+    self.line = t.line
+
+    for _, tt in pairs(tts) do
+        if t.tt == tt then
+            return t.ok
+        end
+    end
+
+    --local err = ("argument %i of %s expected type %s"):format(self.i, self.s.type, tt)
+    local err = ("unexpected type for argument %i of %s"):format(self.i, self.s.type)
+    self:error(err, t.tt)
+end
+
+function Reader:register(registers)
+    self:expect{'REG'}
+    local t = self.s[self.i]
+    local numeric = registers[t.tok]
+    if not numeric then
+        self:error('wrong type of register')
+    end
+    local new = Token(t)
+    return new
+end
+
+function Reader:const(relative, no_label)
+    if no_label then
+        self:expect{'NUM'}
+    else
+        self:expect{'NUM', 'LABELSYM'}
+    end
+    local t = self.s[self.i]
+    local new = Token(t)
+    if relative then
+        if t.tt == 'LABELSYM' then
+            new.t = 'LABELREL'
+        else
+            new.t = 'REL'
+        end
+    end
+    return new
+end
+
+function Reader:deref()
+    self:expect{'DEREF'}
+    local t = self.s[self.i]
+    local new = Token(t)
+    --new.tt = 'REG'
+    return new
+end
+
+function Reader:peek(tt)
+    local t = self.s[self.i]
+    local seen = t and t.tt or nil
+    if tt ~= nil then
+        return seen == tt
+    end
+    return t
+end
+
+return Reader

lips/Statement.lua

@@ -45,7 +45,8 @@ function Statement:validate(n)
     end
     for i, v in ipairs(self) do
         if util.parent(v) ~= Token then
-            error(('Internal Error: Statement[%i] is not a Token'):format(i), n)
+            self[i] = Token(self.fn, self.line, v)
+            --error(('Internal Error: Statement[%i] is not a Token'):format(i), n)
         end
     end
 end

lips/overrides.lua

@@ -3,19 +3,52 @@ local insert = table.insert
 local path = string.gsub(..., "[^.]+$", "")
 local data = require(path.."data")
 
-local instructions = data.instructions
-
 local overrides = {}
--- note: "self" is an instance of Parser
+-- note: "self" is an instance of Preproc
+
+local function tob_override(self, name)
+    -- handle all the addressing modes for lw/sw-like instructions
+    local rt = self:pop('CPU')
+    local offset, base
+    if self:peek('DEREF') then
+        offset = 0
+        base = self:pop('DEREF')
+    else -- NUM or LABELSYM
+        local o = self:pop('CONST')
+        if self:peek('NUM') then
+            o:set('offset', self:pop('CONST').tok)
+        end
+        offset = self:token(o)
+        if not o.portion then
+            offset:set('portion', 'lower')
+        end
+        -- attempt to use the fewest possible instructions for this offset
+        if not o.portion and (o.tt == 'LABELSYM' or o.tok >= 0x80000000) then
+            local immediate = self:token(o):set('portion', 'upperoff')
+            self:push_new('LUI', 'AT', immediate)
+            if self.s[self.i] ~= nil then
+                local reg = self:pop('DEREF'):set('tt', 'REG')
+                if reg.tok ~= 'R0' then
+                    self:push_new('ADDU', 'AT', 'AT', 'R0')
+                end
+            end
+            base = self:token('DEREF', 'AT')
+        else
+            base = self:pop('DEREF')
+        end
+    end
+    self:push_new(name, rt, offset, base)
+end
+
+for k, v in pairs(data.instructions) do
+    if v[2] == 'tob' then
+        overrides[k] = tob_override
+    end
+end
 
 function overrides.LI(self, name)
-    local lui = instructions['LUI']
-    local ori = instructions['ORI']
-    local addiu = instructions['ADDIU']
-    local args = {}
-    args.rt = self:register()
-    self:optional_comma()
-    local im = self:const()
+    local rt = self:pop('CPU')
+    local im = self:pop('CONST')
 
     -- for us, this is just semantics. for a "real" assembler,
     -- LA could add appropriate RELO LUI/ADDIU directives.
@@ -24,272 +57,180 @@ function overrides.LI(self, name)
     end
 
     if im.portion then
-        args.rs = 'R0'
-        args.immediate = im
-        self:format_out(addiu, args)
+        -- FIXME: use appropriate instruction based on portion?
+        self:push_new('ADDIU', rt, 'R0', im)
         return
     end
 
     im.tok = im.tok % 0x100000000
     if im.tok >= 0x10000 and im.tok <= 0xFFFF8000 then
-        args.rs = args.rt
-        args.immediate = self:token(im):set('portion', 'upper')
-        self:format_out(lui, args)
+        local rs = rt
+        local immediate = self:token(im):set('portion', 'upper')
+        self:push_new('LUI', rt, immediate)
         if im.tok % 0x10000 ~= 0 then
-            args.immediate = self:token(im):set('portion', 'lower')
-            self:format_out(ori, args)
+            local immediate = self:token(im):set('portion', 'lower')
+            self:push_new('ORI', rt, rs, immediate)
         end
     elseif im.tok >= 0x8000 and im.tok < 0x10000 then
-        args.rs = 'R0'
-        args.immediate = self:token(im):set('portion', 'lower')
-        self:format_out(ori, args)
+        local immediate = self:token(im):set('portion', 'lower')
+        self:push_new('ORI', rt, 'R0', immediate)
     else
-        args.rs = 'R0'
-        args.immediate = self:token(im):set('portion', 'lower')
-        self:format_out(addiu, args)
+        local immediate = self:token(im):set('portion', 'lower')
+        self:push_new('ADDIU', rt, 'R0', immediate)
     end
 end
 
 function overrides.LA(self, name)
-    local lui = instructions['LUI']
-    local addiu = instructions['ADDIU']
-    local args = {}
-    args.rt = self:register()
-    self:optional_comma()
-    local im = self:const()
+    local rt = self:pop('CPU')
+    local im = self:pop('CONST')
 
-    args.rs = args.rt
-    args.immediate = self:token(im):set('portion', 'upperoff')
-    self:format_out(lui, args)
-    args.immediate = self:token(im):set('portion', 'lower')
-    self:format_out(addiu, args)
+    local rs = rt
+    local immediate = self:token(im):set('portion', 'upperoff')
+    self:push_new('LUI', rt, immediate)
+    local immediate = self:token(im):set('portion', 'lower')
+    self:push_new('ADDIU', rt, immediate)
 end
 
 function overrides.PUSH(self, name)
-    local addi = instructions['ADDI']
-    local w = instructions[name == 'PUSH' and 'SW' or 'LW']
-    local jr = instructions['JR']
+    local w = name == 'PUSH' and 'SW' or 'LW'
     local stack = {}
-    while not self:is_EOL() do
-        if self.tt == 'NUM' then
-            if self.tok < 0 then
-                self:error("can't push a negative number of spaces")
+    for _, t in ipairs(self.s) do
+        if t.tt == 'NUM' then
+            if t.tok < 0 then
+                self:error("can't push a negative number of spaces", t.tok)
             end
-            for i=1,self.tok do
+            for i=1, t.tok do
                 insert(stack, '')
             end
-            self:advance()
+            self:pop()
         else
-            insert(stack, self:register())
-        end
-        if not self:is_EOL() then
-            self:optional_comma()
+            insert(stack, self:pop('CPU'))
         end
     end
     if #stack == 0 then
         self:error(name..' requires at least one argument')
     end
-    local args = {}
     if name == 'PUSH' then
-        args.rt = 'SP'
-        args.rs = 'SP'
-        args.immediate = self:token(#stack*4):set('negate')
-        self:format_out(addi, args)
+        local immediate = self:token(#stack*4):set('negate')
+        self:push_new('ADDIU', 'SP', 'SP', immediate)
     end
-    args.base = 'SP'
     for i, r in ipairs(stack) do
-        args.rt = r
         if r ~= '' then
-            args.offset = (i - 1)*4
-            self:format_out(w, args)
+            local offset = (i - 1)*4
+            self:push_new(w, r, offset, self:token('DEREF', 'SP'))
         end
     end
     if name == 'JPOP' then
-        args.rs = 'RA'
-        self:format_out(jr, args)
+        self:push_new('JR', 'RA')
     end
     if name == 'POP' or name == 'JPOP' then
-        args.rt = 'SP'
-        args.rs = 'SP'
-        args.immediate = #stack*4
-        self:format_out(addi, args)
+        local immediate = #stack * 4
+        self:push_new('ADDIU', 'SP', 'SP', immediate)
     end
 end
 overrides.POP = overrides.PUSH
 overrides.JPOP = overrides.PUSH
 
 function overrides.NAND(self, name)
-    local and_ = instructions['AND']
-    local nor = instructions['NOR']
-    local args = {}
-    args.rd = self:register()
-    self:optional_comma()
-    args.rs = self:register()
-    self:optional_comma()
-    args.rt = self:register()
-    self:format_out(and_, args)
-    args.rs = args.rd
-    args.rt = 'R0'
-    self:format_out(nor, args)
+    local rd = self:pop('CPU')
+    local rs = self:pop('CPU')
+    local rt = self:pop('CPU')
+    self:push_new('AND', rd, rs, rt)
+    local rs = rd
+    local rt = 'R0'
+    self:push_new('NOR', rd, rs, rt)
 end
 
 function overrides.NANDI(self, name)
-    local andi = instructions['ANDI']
-    local nor = instructions['NOR']
-    local args = {}
-    args.rt = self:register()
-    self:optional_comma()
-    args.rs = self:register()
-    self:optional_comma()
-    args.immediate = self:const()
-    self:format_out(andi[3], andi[1], args, andi[4], andi[5])
-    args.rd = args.rt
-    args.rs = args.rt
-    args.rt = 'R0'
-    self:format_out(nor[3], nor[1], args, nor[4], nor[5])
+    local rt = self:pop('CPU')
+    local rs = self:pop('CPU')
+    local immediate = self:pop('CONST')
+    self:push_new('ANDI', rt, rs, immediate)
+    local rd = rt
+    local rs = rt
+    local rt = 'R0'
+    self:push_new('NOR', rd, rs, rt)
 end
 
 function overrides.NORI(self, name)
-    local ori = instructions['ORI']
-    local nor = instructions['NOR']
-    local args = {}
-    args.rt = self:register()
-    self:optional_comma()
-    args.rs = self:register()
-    self:optional_comma()
-    args.immediate = self:const()
-    self:format_out(ori, args)
-    args.rd = args.rt
-    args.rs = args.rt
-    args.rt = 'R0'
-    self:format_out(nor, args)
+    local rt = self:pop('CPU')
+    local rs = self:pop('CPU')
+    local immediate = self:pop('CONST')
+    self:push_new('ORI', rt, rs, immediate)
+    local rd = rt
+    local rs = rt
+    local rt = 'R0'
+    self:push_new('NOR', rd, rs, rt)
 end
 
 function overrides.ROL(self, name)
-    local sll = instructions['SLL']
-    local srl = instructions['SRL']
-    local or_ = instructions['OR']
-    local args = {}
-    local left = self:register()
-    self:optional_comma()
-    args.rt = self:register()
-    self:optional_comma()
-    args.immediate = self:const()
-    args.rd = left
-    if args.rd == 'AT' or args.rt == 'AT' then
-        self:error('registers cannot be AT in this pseudo-instruction')
-    end
-    if args.rd == args.rt and args.rd ~= 'R0' then
-        self:error('registers cannot be the same')
-    end
-    self:format_out(sll, args)
-    args.rd = 'AT'
-    args.immediate = 32 - args.immediate[2]
-    self:format_out(srl, args)
-    args.rd = left
-    args.rs = left
-    args.rt = 'AT'
-    self:format_out(or_, args)
+    -- FIXME
+    local rd, rs, rt
+    local left = self:pop('CPU')
+    rt = self:pop('CPU')
+    local immediate = self:pop('CONST')
+    error('Internal Error: unimplemented')
 end
 
 function overrides.ROR(self, name)
-    local sll = instructions['SLL']
-    local srl = instructions['SRL']
-    local or_ = instructions['OR']
-    local args = {}
-    local right = self:register()
-    self:optional_comma()
-    args.rt = self:register()
-    self:optional_comma()
-    args.immediate = self:const()
-    args.rd = right
-    if args.rt == 'AT' or args.rd == 'AT' then
-        self:error('registers cannot be AT in a pseudo-instruction that uses AT')
-    end
-    if args.rd == args.rt and args.rd ~= 'R0' then
-        self:error('registers cannot be the same')
-    end
-    self:format_out(srl, args)
-    args.rd = 'AT'
-    args.immediate = 32 - args.immediate[2]
-    self:format_out(sll, args)
-    args.rd = right
-    args.rs = right
-    args.rt = 'AT'
-    self:format_out(or_, args)
+    -- FIXME
+    local right = self:pop('CPU')
+    local rt = self:pop('CPU')
+    local immediate = self:pop('CONST')
+    error('Internal Error: unimplemented')
 end
 
 function overrides.JR(self, name)
-    local jr = instructions['JR']
-    local args = {}
-    if self:is_EOL() then
-        args.rs = 'RA'
-    else
-        args.rs = self:register()
-    end
-    self:format_out(jr, args)
+    local rs = self:peek() and self:pop('CPU') or 'RA'
+    self:push_new('JR', rs)
 end
 
 local branch_basics = {
-    BEQI = "BEQ",
-    BGEI = "BEQ",
-    BGTI = "BEQ",
-    BLEI = "BNE",
-    BLTI = "BNE",
-    BNEI = "BNE",
-    BEQIL = "BEQL",
-    BGEIL = "BEQL",
-    BGTIL = "BEQL",
-    BLEIL = "BNEL",
-    BLTIL = "BNEL",
-    BNEIL = "BNEL",
+    BEQI = 'BEQ',
+    BGEI = 'BEQ',
+    BGTI = 'BEQ',
+    BLEI = 'BNE',
+    BLTI = 'BNE',
+    BNEI = 'BNE',
+    BEQIL = 'BEQL',
+    BGEIL = 'BEQL',
+    BGTIL = 'BEQL',
+    BLEIL = 'BNEL',
+    BLTIL = 'BNEL',
+    BNEIL = 'BNEL',
 }
 
 function overrides.BEQI(self, name)
-    local addiu = instructions['ADDIU']
-    local branch = instructions[branch_basics[name]]
-    local args = {}
-    local reg = self:register()
-    self:optional_comma()
-    args.immediate = self:const()
-    self:optional_comma()
-    args.offset = self:token(self:const('relative')):set('signed')
+    local branch = branch_basics[name]
+    local reg = self:pop('CPU')
+    local immediate = self:pop('CONST')
+    local offset = self:pop('REL'):set('signed')
 
     if reg == 'AT' then
         self:error('register cannot be AT in this pseudo-instruction')
     end
 
-    args.rt = 'AT'
-    args.rs = 'R0'
-    self:format_out(addiu, args)
+    self:push_new('ADDIU', 'AT', 'R0', immediate)
 
-    args.rs = reg
-    self:format_out(branch, args)
+    self:push_new(branch, reg, 'AT', offset)
 end
 overrides.BNEI = overrides.BEQI
 overrides.BEQIL = overrides.BEQI
 overrides.BNEIL = overrides.BEQI
 
 function overrides.BLTI(self, name)
-    local slti = instructions['SLTI']
-    local branch = instructions[branch_basics[name]]
-    local args = {}
-    args.rs = self:register()
-    self:optional_comma()
-    args.immediate = self:const()
-    self:optional_comma()
-    args.offset = self:token(self:const('relative')):set('signed')
+    local branch = branch_basics[name]
+    local rs = self:pop('CPU')
+    local immediate = self:pop('CONST')
+    local offset = self:pop('REL'):set('signed')
 
-    if args.rs == 'AT' then
+    if rs == 'AT' then
         self:error('register cannot be AT in this pseudo-instruction')
     end
 
-    args.rt = 'AT'
-    self:format_out(slti, args)
+    self:push_new('SLTI', 'AT', reg)
 
-    args.rs = 'AT'
-    args.rt = 'R0'
-    self:format_out(branch, args)
+    self:push_new(branch, 'R0', 'AT', offset)
 end
 overrides.BGEI = overrides.BLTI
 overrides.BLTIL = overrides.BLTI
@@ -297,40 +238,28 @@ overrides.BGEIL = overrides.BLTI
 
 function overrides.BLEI(self, name)
     -- TODO: this can probably be optimized
-    local addiu = instructions['ADDIU']
-    local slt = instructions['SLT']
-    local branch = instructions[branch_basics[name]]
-    local beq = instructions['BEQ']
-    local args = {}
-    local reg = self:register()
-    self:optional_comma()
-    args.immediate = self:const()
-    self:optional_comma()
-    local offset = self:token(self:const('relative')):set('signed')
+    local branch = branch_basics[name]
+    local reg = self:pop('CPU')
+    local immediate = self:pop('CONST')
+    local offset = self:pop('REL'):set('signed')
 
     if reg == 'AT' then
         self:error('register cannot be AT in this pseudo-instruction')
     end
 
-    args.rt = 'AT'
-    args.rs = 'R0'
-    self:format_out(addiu, args)
+    self:push_new('ADDIU', 'AT', 'R0', immediate)
 
+    local beq_offset
     if name == 'BLEI' then
-        args.offset = offset
+        beq_offset = offset
     else
-        args.offset = 2 -- branch to delay slot of the next branch
+        beq_offset = 2 -- branch to delay slot of the next branch
     end
-    args.rs = reg
-    self:format_out(beq, args)
+    self:push_new('BEQ', reg, 'R0', beq_offset)
 
-    args.rd = 'AT'
-    self:format_out(slt, args)
+    self:push_new('SLT', 'AT', reg)
 
-    args.rs = 'AT'
-    args.rt = 'R0'
-    args.offset = offset
-    self:format_out(branch, args)
+    self:push_new(branch, 'AT', 'R0', offset)
 end
 overrides.BGTI = overrides.BLEI
 overrides.BLEIL = overrides.BLEI