match the final non-matching in boot!

1 files changed, 13 insertions, 18 deletions

diff --git a/src/boot/yaz0.c b/src/boot/yaz0.c
index 5954e28aa..379d4ca46 100644
--- a/src/boot/yaz0.c
+++ b/src/boot/yaz0.c
@@ -51,10 +51,6 @@ void* Yaz0_NextDMA(void* curSrcPos) {
     return dst;
 }
 
-#ifdef NON_MATCHING
-// has an extra check at the start of the small compressed loop
-// along with an extra move instruction
-// maybe some regalloc differences besides these issues
 void Yaz0_DecompressImpl(Yaz0Header* hdr, u8* dst) {
     u32 bitIdx;
     u8* src;
@@ -63,46 +59,45 @@ void Yaz0_DecompressImpl(Yaz0Header* hdr, u8* dst) {
     u32 nibble;
     u8* backPtr;
     s32 chunkSize;
-    u32 curDecBit;
     u32 off;
 
     bitIdx = 0;
-    src = hdr->data;
+    src = (u8*)hdr->data;
     dstEnd = dst + hdr->decSize;
 
     do {
         if (bitIdx == 0) {
-            if ((sYaz0MaxPtr < (u32)src) && (sYaz0CurSize != 0))
+            if ((sYaz0MaxPtr < (u32)src) && (sYaz0CurSize != 0)) {
                 src = Yaz0_NextDMA(src);
+            }
 
             chunkHeader = *src++;
             bitIdx = 8;
         }
 
-        curDecBit = chunkHeader & (1 << 7);
-        chunkHeader <<= 1;
-
-        if (curDecBit) { // uncompressed
-            *dst++ = *src++;
+        if (chunkHeader & (1 << 7)) { // uncompressed
+            *dst = *src;
+            dst++;
+            src++;
         } else { // compressed
+            off = ((*src & 0xF) << 8 | *(src + 1));
             nibble = *src >> 4;
-            backPtr = dst - (*(src + 1) | (*src & 0xF) << 8);
+            backPtr = dst - off;
             src += 2;
 
             chunkSize = (nibble == 0)       // N = chunkSize; B = back offset
                             ? *src++ + 0x12 // 3 bytes 0B BB NN
                             : nibble + 2;   // 2 bytes NB BB
 
-            for (off = chunkSize; off > 0; off--)
+            do {
                 *dst++ = *(backPtr++ - 1);
+                chunkSize--;
+            } while (chunkSize != 0);
         }
-
+        chunkHeader <<= 1;
         bitIdx--;
     } while (dst != dstEnd);
 }
-#else
-#pragma GLOBAL_ASM("asm/non_matchings/boot/yaz0/Yaz0_DecompressImpl.s")
-#endif
 
 void Yaz0_Decompress(u32 romStart, void* dst, u32 size) {
     sYaz0CurRomStart = romStart;