(attempt to) abide to calling conventions

i haven't checked if i need double-word alignment

Lua/README.md

@@ -40,6 +40,9 @@ which produces [a large csv file.][csv]
 Tests the fastest form of basic movement in Majora's Mask.
 Run it in the Clock Town Great Fairy's Fountain.
 
+#### inject.lua
+Assembles and injects an assembly subroutine into the game.
+
 #### oneshot.lua
 Instantly gives you all the items in the game, etc.
 

Lua/inject.lua

@@ -37,14 +37,16 @@ local ow_before_addr = (ow_before % 0x4000000)*4
 
 local header = ("[overwritten]: 0x%08X\n"):format(ow_before_addr)
 header = header..[[
-        sw      ra, -4(sp)
+        // TODO: optimize for size
+        // TODO: fix case where overwritten function takes 5+ args
+        push    ra
+        push    a0, a1, a2, a3
         bal     start
-        subi    sp, sp, 4
+        nop
+        pop     a0, a1, a2, a3
         jal     @overwritten
         nop
-        lw      ra, 0(sp)
+        jpop    ra
-        jr
-        addi    sp, sp, 4
 start:
 ]]
 

Lua/inject/crap.asm

@@ -24,7 +24,7 @@
 [cosf]: 0x80091F40
 
 main:
-        push    ra, a0, s1, s3, s4
+        push    4, s1, s3, s4, ra
         // s1: current actor ptr
         // s3: current actor type ptr
         // s4: current actor type index
@@ -70,12 +70,11 @@ continue:
         bne     s4, t0, typeloop
         addi    s3, s3, @actorlist_dead_space
 
-        jpop    ra, a0, s1, s3, s4
+        jpop    4, s1, s3, s4, ra
 
 process_actor: // args: a0. returns nothing.
         // TODO: ignore bomb explosions, they share the same type
-        push    r0, ra, s0, s1
+        push    4, s0, s1, ra
-        // 0(sp) reserved for sinf/cosf
         // s0: result of sin
         // s1: result of cos
         lh      t0, 0(a0)
@@ -128,7 +127,7 @@ process_actor: // args: a0. returns nothing.
         sw      t5, current_rotation
 
 process_actor_return:
-        jpop    r0, ra, s0, s1
+        jpop    4, s0, s1, ra
 
 rotations:
         .word 0x00000000 // pi*0/6

Lua/inject/lips.lua

@@ -1034,31 +1034,37 @@ function Parser:instruction()
         local addi = instructions['ADDI']
         local w = instructions[h == 'PUSH' and 'SW' or 'LW']
         local jr = instructions['JR']
-        local registers = {}
+        local stack = {}
         while not self:is_EOL() do
-            local r = self:register()
+            if self.tt == 'NUM' then
-            table.insert(registers, r)
+                if self.tok < 0 then
+                    self:error("can't push a negative number of spaces")
+                end
+                for i=1,self.tok do
+                    table.insert(stack, '')
+                end
+                self:advance()
+            else
+                table.insert(stack, self:register())
+            end
             if not self:is_EOL() then
                 self:optional_comma()
             end
         end
-        if #registers == 0 then
+        if #stack == 0 then
             self:error(h..' requires at least one argument')
         end
-        if #registers >= 0x8000/4 then
-            self:error("that's way too many registers bub")
-        end
         local args = {}
         if h == 'PUSH' then
             args.rt = 'SP'
             args.rs = 'SP'
-            args.immediate = {'NEGATE', {'NUM', #registers*4}}
+            args.immediate = {'NEGATE', {'NUM', #stack*4}}
             self:format_out(addi[3], addi[1], args, addi[4], addi[5])
         end
         args.base = 'SP'
-        for i, r in ipairs(registers) do
+        for i, r in ipairs(stack) do
             args.rt = r
-            if r ~= 'R0' then
+            if r ~= '' then
                 args.offset = {'NUM', (i - 1)*4}
                 self:format_out(w[3], w[1], args, w[4], w[5])
             end
@@ -1070,7 +1076,7 @@ function Parser:instruction()
         if h == 'POP' or h == 'JPOP' then
             args.rt = 'SP'
             args.rs = 'SP'
-            args.immediate = {'NUM', #registers*4}
+            args.immediate = {'NUM', #stack*4}
             self:format_out(addi[3], addi[1], args, addi[4], addi[5])
         end
     elseif h == 'NAND' then