Improve the state of handwritten assembly files (#865)

* Format all handwritten asm and document some

* Use c preprocessor for constants

* Fix

* Fix PI_STATUS_ERROR, some label improvements

* Avoid hi/lo for constants

* Some more comments

* Properly mark functions as functions and their sizes

* Fix merge

* Improvements

* Review suggestions, rework procedure start/end macros to be more like libreultra

* Move IPL3 symbol definitions into ipl3.s

* Fix undefined_syms, add include and language guards to asm.h and fix the comment in gbi.h

* Consistent hex capitalization, add some MIPS builtin defines to CC_CHECK to behave properly

* Add -no-pad-sections assembler option and clean up alignment in gu files and bzero

* Further suggestions and improvements

* Matrix conversion function clarifications

* Fix passing AVOID_UB to gcc

* Suggestions

* Suggestions, global interrupt mask improvements

* Further suggestions, interrupt mask comments

* Comments fixes, rdb.h

* Switch from # comments to // comments, remove unnecesary .set gp=64 directives

* Further review suggestions

* Missed one

asm/osInvalICache.s

@@ -1,46 +1,52 @@
-.include "macro.inc"
+#include "ultra64/asm.h"
+#include "ultra64/r4300.h"
 
-# assembler directives
-.set noat      # allow manual use of $at
-.set noreorder # don't insert nops after branches
-.set gp=64     # allow use of 64-bit general purpose registers
+.set noat
+.set noreorder
 
 .section .text
 
 .balign 16
-  
-glabel osInvalICache
-/* 006D50 80006150 18A00011 */  blez  $a1, .L80006198
-/* 006D54 80006154 00000000 */   nop   
-/* 006D58 80006158 240B4000 */  li    $t3, 16384
-/* 006D5C 8000615C 00AB082B */  sltu  $at, $a1, $t3
-/* 006D60 80006160 1020000F */  beqz  $at, .L800061A0
-/* 006D64 80006164 00000000 */   nop   
-/* 006D68 80006168 00804025 */  move  $t0, $a0
-/* 006D6C 8000616C 00854821 */  addu  $t1, $a0, $a1
-/* 006D70 80006170 0109082B */  sltu  $at, $t0, $t1
-/* 006D74 80006174 10200008 */  beqz  $at, .L80006198
-/* 006D78 80006178 00000000 */   nop   
-/* 006D7C 8000617C 310A001F */  andi  $t2, $t0, 0x1f
-/* 006D80 80006180 2529FFE0 */  addiu $t1, $t1, -0x20
-/* 006D84 80006184 010A4023 */  subu  $t0, $t0, $t2
-.L80006188:
-/* 006D88 80006188 BD100000 */  cache 0x10, ($t0)
-/* 006D8C 8000618C 0109082B */  sltu  $at, $t0, $t1
-/* 006D90 80006190 1420FFFD */  bnez  $at, .L80006188
-/* 006D94 80006194 25080020 */   addiu $t0, $t0, 0x20
-.L80006198:
-/* 006D98 80006198 03E00008 */  jr    $ra
-/* 006D9C 8000619C 00000000 */   nop   
 
-.L800061A0:
-/* 006DA0 800061A0 3C088000 */  lui   $t0, 0x8000
-/* 006DA4 800061A4 010B4821 */  addu  $t1, $t0, $t3
-/* 006DA8 800061A8 2529FFE0 */  addiu $t1, $t1, -0x20
-.L800061AC:
-/* 006DAC 800061AC BD000000 */  cache 0, ($t0)
-/* 006DB0 800061B0 0109082B */  sltu  $at, $t0, $t1
-/* 006DB4 800061B4 1420FFFD */  bnez  $at, .L800061AC
-/* 006DB8 800061B8 25080020 */   addiu $t0, 0x20
-/* 006DBC 800061BC 03E00008 */  jr    $ra
-/* 006DC0 800061C0 00000000 */   nop   
+LEAF(osInvalICache)
+    // If the amount to invalidate is less than or equal to 0, return immediately
+    blez    $a1, 2f
+     nop
+    // If the amount to invalidate is as large as or larger than
+    // the instruction cache size, invalidate all
+    li      $t3, ICACHE_SIZE
+    sltu    $at, $a1, $t3
+    beqz    $at, 3f
+     nop
+    // ensure end address doesn't wrap around and end up smaller
+    // than the start address
+    move    $t0, $a0
+    addu    $t1, $a0, $a1
+    sltu    $at, $t0, $t1
+    beqz    $at, 2f
+     nop
+    // Mask and subtract to align to cache line
+    andi    $t2, $t0, ICACHE_LINEMASK
+    addiu   $t1, $t1, -ICACHE_LINESIZE
+    subu    $t0, $t0, $t2
+1:
+    cache   (CACH_PI | C_HINV), ($t0)
+    sltu    $at, $t0, $t1
+    bnez    $at, 1b
+     addiu  $t0, $t0, ICACHE_LINESIZE
+2:
+    jr      $ra
+     nop
+
+3:
+    li      $t0, K0BASE
+    addu    $t1, $t0, $t3
+    addiu   $t1, $t1, -ICACHE_LINESIZE
+4:
+    cache   (CACH_PI | C_IINV), ($t0)
+    sltu    $at, $t0, $t1
+    bnez    $at, 4b
+     addiu  $t0, ICACHE_LINESIZE
+    jr      $ra
+     nop
+END(osInvalICache)