From 02fc5395a0f9e32140154370566f88c08907f2c4 Mon Sep 17 00:00:00 2001
From: Connor Olding <cloningdonor@gmail.com>
Date: Sat, 2 Jan 2016 06:00:05 -0800
Subject: [PATCH] implement some basic branch pseudo-instructions

---
 Lua/inject/lips.lua  | 71 +++++++++++++++++++++++++-------------------
 Lua/inject/spawn.asm | 23 +++++++-------
 2 files changed, 52 insertions(+), 42 deletions(-)

diff --git a/Lua/inject/lips.lua b/Lua/inject/lips.lua
index d96ee45..b8c2cea 100644
--- a/Lua/inject/lips.lua
+++ b/Lua/inject/lips.lua
@@ -409,6 +409,8 @@ local instructions = {
     -- pseudo-instructions
     B       = {4, 'r', '00o'},          -- BEQ R0, R0, offset
     BAL     = {1, 'r', '0Co', 17},      -- BGEZAL R0, offset
+    BEQZ    = {4, 'sr', 's0o'},         -- BEQ RS, R0, offset
+    BNEZ    = {5, 'sr', 's0o'},         -- BNE RS, R0, offset
     CL      = {0, 'd', '00d0C', 37},    -- OR RD, R0, R0
     MOV     = {0, 'ds', 's0d0C', 37},   -- OR RD, RS, R0
     NEG     = {0, 'dt', '0td0C', 34},   -- SUB RD, R0, RT
@@ -437,37 +439,18 @@ local instructions = {
     ROL     = {}, -- SLL, SRL, OR
     ROR     = {}, -- SRL, SLL, OR
 
-    SEQ     = {},
-    SEQI    = {},
-    SEQIU   = {},
-    SEQU    = {},
-    SGE     = {},
-    SGEI    = {},
-    SGEIU   = {},
-    SGEU    = {},
-    SGT     = {},
-    SGTI    = {},
-    SGTIU   = {},
-    SGTU    = {},
-    SLE     = {},
-    SLEI    = {},
-    SLEIU   = {},
-    SLEU    = {},
-    SNE     = {},
-    SNEI    = {},
-    SNEIU   = {},
-    SNEU    = {},
+    SEQ     = {}, SEQI    = {}, SEQIU   = {}, SEQU    = {},
+    SGE     = {}, SGEI    = {}, SGEIU   = {}, SGEU    = {},
+    SGT     = {}, SGTI    = {}, SGTIU   = {}, SGTU    = {},
+    SLE     = {}, SLEI    = {}, SLEIU   = {}, SLEU    = {},
+    SNE     = {}, SNEI    = {}, SNEIU   = {}, SNEU    = {},
 
-    BEQI    = {},
-    BNEI    = {},
-    BGE     = {},
-    BGEI    = {},
-    BLE     = {},
-    BLEI    = {},
-    BLT     = {},
-    BLTI    = {},
-    BGT     = {},
-    BGTI    = {},
+                  BEQI    = {},
+                  BNEI    = {},
+    BGE     = {}, BGEI    = {},
+    BLE     = {}, BLEI    = {},
+    BLT     = {}, BLTI    = {},
+    BGT     = {}, BGTI    = {},
 }
 
 local all_instructions = {}
@@ -1263,6 +1246,34 @@ function overrides.JR(self, name)
     self:format_out(jr[3], jr[1], args, jr[4], jr[5])
 end
 
+local branch_basics = {
+    BEQI = "BEQ",
+    BNEI = "BNE",
+}
+
+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 = {'SIGNED', self:const('relative')}
+
+    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[3], addiu[1], args, addiu[4], addiu[5])
+
+    args.rs = reg
+    self:format_out(branch[3], branch[1], args, branch[4], branch[5])
+end
+overrides.BNEI = overrides.BEQI
+
 function Parser:instruction()
     local name = self.tok
     local h = instructions[name]
diff --git a/Lua/inject/spawn.asm b/Lua/inject/spawn.asm
index 10c792d..4cd4d0c 100644
--- a/Lua/inject/spawn.asm
+++ b/Lua/inject/spawn.asm
@@ -20,34 +20,33 @@
     lhu     t9, @rupees_offset(t0)
     lw      s1, hold_delay
     andi    t4, t2, @button_any
-    bne     t4, r0, +
+    bnez    t4, +
     addi    s1, s1, 1
     li      s1, 0
 +:
-    subi    t4, s1, 1
-    beq     t4, r0, +
+    beqi    s1, 1, +
     nop
     subi    t4, s1, @hold_delay_amount
     bltz    t4, return
     nop
 +:
     andi    t3, t2, @button_D_up
-    beq     t3, r0, +
+    beqz    t3, +
     nop
     addi    t9, t9, 1
 +:
     andi    t3, t2, @button_D_down
-    beq     t3, r0, +
+    beqz    t3, +
     nop
     subi    t9, t9, 1
 +:
     andi    t3, t2, @button_D_right
-    beq     t3, r0, +
+    beqz    t3, +
     nop
     addi    t9, t9, 10
 +:
     andi    t3, t2, @button_D_left
-    beq     t3, r0, +
+    beqz    t3, +
     nop
     subi    t9, t9, 10
 +:
@@ -63,7 +62,7 @@
 +:
     sh      t9, @rupees_offset(t0)
     andi    t3, t2, @button_L
-    beq     t3, r0, return
+    beqz    t3, return
     nop
     mov     a0, t9
     bal     simple_spawn
@@ -76,7 +75,7 @@ simple_spawn: // args: a0 (actor to spawn)
     push    4, 9, ra
     jal     load_object
     sw      a0, 56(sp) // keep me updated!
-    bne     v0, r0, simple_spawn_return
+    bnez    v0, simple_spawn_return
     lw      a2, 56(sp) // keep me updated!
     li      a1, @global_context
     addi    a0, a1, @actor_spawn_offset
@@ -122,11 +121,11 @@ load_object:
     sll     t1, a0, 1
     addu    t0, t0, t1
     lhu     s0, 0(t0) // object number
-    beq     s0, r0, +
+    beqz    s0, +
     nop
     bal     is_object_loaded
     mov     a0, s0
-    bne     v0, r0, +
+    bnez    v0, +
     cl      v0
     li      t8, @global_context
     li      t9, @object_spawn_offset
@@ -167,7 +166,7 @@ is_object_loaded:
     beq     a0, t2, +
     subi    t1, t1, 1 // TODO: double check there's no off-by-one error
     addi    t0, t0, 68
-    bne     t1, r0, -
+    bnez    t1, -
     nop
     cl      v0
 +: