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-rw-r--r--src/file_system.c255
1 files changed, 132 insertions, 123 deletions
diff --git a/src/file_system.c b/src/file_system.c
index b10b207..c709b45 100644
--- a/src/file_system.c
+++ b/src/file_system.c
@@ -252,13 +252,13 @@ u32 DecompressAT(char *result, u32 resultLength, const char *compressedData)
char c13;
const char *p;
int command;
- int resultIndex;
+ int bytesWritten;
int v16;
int cmdBit;
int currentByte;
compressedLength = compressedData[5] + (compressedData[6] << 8);
- resultIndex = 0;
+ bytesWritten = 0;
currentByte = 0;
cmdBit = 8;
@@ -284,7 +284,7 @@ u32 DecompressAT(char *result, u32 resultLength, const char *compressedData)
return 0;
}
- if (compressedData[5] == 'N') {
+ if (compressedData[4] == 'N') {
// uncompressed mode, unused
int i;
for (i = 0; i < compressedLength; i++)
@@ -304,13 +304,13 @@ u32 DecompressAT(char *result, u32 resultLength, const char *compressedData)
// Some mismatches regarding the signedness of these two conditionals, extremely fragile
if (curIndex < compressedLength) {
- while (resultLength == 0 || resultIndex < resultLength) {
+ while (resultLength == 0 || bytesWritten < resultLength) {
if (cmdBit == 8) {
currentByte = compressedData[curIndex++];
cmdBit = 0;
}
if (currentByte & 0x80) { // some weird reordering happens here, couldn't figure it out
- result[resultIndex++] = compressedData[curIndex++];
+ result[bytesWritten++] = compressedData[curIndex++];
goto end_800AE08;
}
p = &compressedData[curIndex];
@@ -329,8 +329,8 @@ u32 DecompressAT(char *result, u32 resultLength, const char *compressedData)
case 0x1f:
c10 = *p & 0xf;
c10 = c10 | (c10 << 4);
- result[resultIndex++] = c10;
- result[resultIndex++] = c10;
+ result[bytesWritten++] = c10;
+ result[bytesWritten++] = c10;
curIndex++;
// if curIndex is incremented inside each case, the compiler leaves them inside, but if curIndex is moved after the switch
// then it moves the second result assignment (just the 'strb' instruction) after the switch.
@@ -340,22 +340,22 @@ u32 DecompressAT(char *result, u32 resultLength, const char *compressedData)
v12 = *p & 0xf;
v12 = (v12 + 1) & 0xf;
c10 = v12;
- result[resultIndex++] = ((*p & 0xf) << 4) | c10;
- result[resultIndex++] = (v12 << 4) | c10;
+ result[bytesWritten++] = ((*p & 0xf) << 4) | c10;
+ result[bytesWritten++] = (v12 << 4) | c10;
curIndex++;
break;
case 0x1d:
c11 = *p & 0xf;
c10 = c11 << 4;
- result[resultIndex++] = ((c11 - 1) & 0xf) | c10;
- result[resultIndex++] = c10 | c11;
+ result[bytesWritten++] = ((c11 - 1) & 0xf) | c10;
+ result[bytesWritten++] = c10 | c11;
curIndex++;
break;
case 0x1c:
v12 = *p & 0xf;
c10 = v12;
- result[resultIndex++] = (v12 << 4) | c10;
- result[resultIndex++] = ((v12 & 0xf) << 4) | c10;
+ result[bytesWritten++] = (v12 << 4) | c10;
+ result[bytesWritten++] = ((v12 & 0xf) << 4) | c10;
v12--;
curIndex++;
break;
@@ -363,48 +363,48 @@ u32 DecompressAT(char *result, u32 resultLength, const char *compressedData)
c10 = *p;
c11 = c10 & 0xf;
c13 = c11 << 4;
- result[resultIndex++] = c13 | c11;
+ result[bytesWritten++] = c13 | c11;
c10 = (c10 & 0xf) - 1;
- result[resultIndex++] = c13 | (c10 & 0xf);
+ result[bytesWritten++] = c13 | (c10 & 0xf);
curIndex++;
break;
case 0x1a:
v12 = ((*p & 0xf) - 1) & 0xf;
c10 = v12;
- result[resultIndex++] = ((*p & 0xf) << 4) | c10;
- result[resultIndex++] = (v12 << 4) | c10;
+ result[bytesWritten++] = ((*p & 0xf) << 4) | c10;
+ result[bytesWritten++] = (v12 << 4) | c10;
curIndex++;
break;
case 0x19:
c11 = *p & 0xf;
c10 = c11 << 4;
- result[resultIndex++] = ((c11 + 1) & 0xf) | c10;
- result[resultIndex++] = c10 | c11;
+ result[bytesWritten++] = ((c11 + 1) & 0xf) | c10;
+ result[bytesWritten++] = c10 | c11;
curIndex++;
break;
case 0x18:
v12 = *p & 0xf;
c10 = v12;
- result[resultIndex++] = (v12 << 4) | c10;
+ result[bytesWritten++] = (v12 << 4) | c10;
v12++;
curIndex++;
- result[resultIndex++] = ((v12 & 0xf) << 4) | c10;
+ result[bytesWritten++] = ((v12 & 0xf) << 4) | c10;
break;
case 0x17:
c10 = *p;
c11 = c10 & 0xf;
c13 = c11 << 4;
- result[resultIndex++] = c11 | c13;
+ result[bytesWritten++] = c11 | c13;
c10 = (c10 & 0xf) + 1;
- result[resultIndex++] = c13 | (c10 & 0xf);
+ result[bytesWritten++] = c13 | (c10 & 0xf);
curIndex++;
break;
default:
v16 = curIndex + 1;
curIndex += 2;
- v16 = ((*p & 0xf) << 8) + compressedData[v16] + (-0x1000) + resultIndex;
+ v16 = ((*p & 0xf) << 8) + compressedData[v16] + (-0x1000) + bytesWritten;
while (command) {
- result[resultIndex++] = result[v16++];
+ result[bytesWritten++] = result[v16++];
command--;
}
break;
@@ -413,7 +413,7 @@ end_800AE08:
cmdBit++;
currentByte <<= 1;
if (curIndex > compressedLength)
- return resultIndex;
+ return bytesWritten;
}
}
@@ -921,13 +921,9 @@ u32 DecompressATGlobal(u32 *result, u32 resultLength, const char *compressedData
int flags8;
int flags9;
int compressedLength;
- u32 c10;
- char c11;
- u32 curIndex;
- const char *p;
+ int curIndex;
int command;
int bytesWritten;
- int v16;
int cmdBit;
int currentByte;
@@ -942,6 +938,7 @@ u32 DecompressATGlobal(u32 *result, u32 resultLength, const char *compressedData
&& compressedData[1] == 'T'
&& compressedData[2] == '4'
&& compressedData[3] == 'P') {
+ // compiler swaps comparison order somehow
if (resultLength != compressedData[0x10] + (compressedData[0x11] << 8) && resultLength != 0)
return 0;
curIndex = 0x12;
@@ -954,13 +951,13 @@ u32 DecompressATGlobal(u32 *result, u32 resultLength, const char *compressedData
return 0;
}
- if (compressedData[5] == 'N') {
+ if (compressedData[4] == 'N') {
// uncompressed mode, unused
- int i;
- for (i = 0; i < compressedLength; i++)
- DecompressAT_AppendByte(compressedData[i + 7]);
+ for (bytesWritten = 0; bytesWritten < compressedLength; bytesWritten++) {
+ DecompressAT_AppendByte(compressedData[bytesWritten + 7]);
+ }
DecompressAT_Finish();
- return i;
+ return bytesWritten;
}
flags1 = compressedData[0x7] + 3;
@@ -973,106 +970,118 @@ u32 DecompressATGlobal(u32 *result, u32 resultLength, const char *compressedData
flags8 = compressedData[0xe] + 3;
flags9 = compressedData[0xf] + 3;
- // Some mismatches regarding the signedness of these two conditionals, extremely fragile
- if (curIndex < compressedLength) {
- while (resultLength == 0 || bytesWritten < resultLength) {
+ // Some mismatches regarding the signedness of these two conditionals, extremely fragile without explicit casts
+ // TODO: clean this up later
+ if ((int)curIndex < (int)compressedLength) {
+ // '<' comparison compiles to wrong branch, but if I add another 'return bytesWritten;'
+ // after the while loop, the compiler merges it with the earlier uncompressed case which breaks stuff.
+ if (resultLength == 0 || (int)bytesWritten < (int)resultLength) return 0;
+ do {
if (cmdBit == 8) {
currentByte = compressedData[curIndex++];
cmdBit = 0;
}
if (currentByte & 0x80) { // some weird reordering happens here, couldn't figure it out
+ // do NOT try inverting the above condition and moving this to the bottom
+ // it really won't end well
DecompressAT_AppendByte(compressedData[curIndex++]);
- goto end_800B198;
- }
- p = &compressedData[curIndex];
- command = (*p >> 4) + 3;
- if (command == flags1) command = 0x1f;
- if (command == flags2) command = 0x1e;
- if (command == flags3) command = 0x1d;
- if (command == flags4) command = 0x1c;
- if (command == flags5) command = 0x1b;
- if (command == flags6) command = 0x1a;
- if (command == flags7) command = 0x19;
- if (command == flags8) command = 0x18;
- if (command == flags9) command = 0x17;
-
- switch (command) {
- case 0x1f:
- c10 = *p & 0xf;
- c10 = c10 | (c10 << 4);
- DecompressAT_AppendByte(c10);
- break;
- case 0x1e:
- c10 = ((*p & 0xf) + 1) & 0xf;
- DecompressAT_AppendByte(((*p & 0xf) << 4) | c10);
- c10 |= c10 << 4;
- break;
- case 0x1d:
- c10 = *p & 0xf;
- DecompressAT_AppendByte(((c10 - 1) & 0xf) | (c10 << 4));
- c10 |= c10 << 4;
- break;
- case 0x1c:
- c10 = *p & 0xf;
- DecompressAT_AppendByte((c10 << 4) | c10);
- c10 |= ((c10 - 1) & 0xf) << 4;
- break;
- case 0x1b:
- c11 = *p & 0xf;
- c10 = c11 << 4;
- DecompressAT_AppendByte(c10 | c11);
- c11--;
- c10 |= c11 & 0xf;
- break;
- case 0x1a:
- c10 = ((*p & 0xf) - 1) & 0xf;
- DecompressAT_AppendByte(((*p & 0xf) << 4) | c10);
- c10 |= c10 << 4;
- break;
- case 0x19:
- c10 = *p & 0xf;
- DecompressAT_AppendByte(((c10 + 1) & 0xf) | (c10 << 4));
- c10 |= c10 << 4;
- break;
- case 0x18:
- c10 = *p & 0xf;
- DecompressAT_AppendByte((c10 << 4) | c10);
- c10 |= ((c10 + 1) & 0xf) << 4;
- break;
- case 0x17:
- c11 = *p & 0xf;
- c10 = c11 << 4;
- DecompressAT_AppendByte(c10 | c11);
- c11++;
- c10 |= c11 & 0xf;
- break;
- default:
- v16 = curIndex + 1;
- curIndex += 2;
- v16 = ((*p & 0xf) << 8) + compressedData[v16] + (-0x1000) + bytesWritten;
- while (command) {
- char c = DecompressAT_GetByte(v16);
- DecompressAT_AppendByte(c);
- bytesWritten++;
- v16++;
- command--;
+ bytesWritten++;
+ } else {
+ command = (compressedData[curIndex] >> 4) + 3;
+ if (command == flags1) command = 0x1f;
+ if (command == flags2) command = 0x1e;
+ if (command == flags3) command = 0x1d;
+ if (command == flags4) command = 0x1c;
+ if (command == flags5) command = 0x1b;
+ if (command == flags6) command = 0x1a;
+ if (command == flags7) command = 0x19;
+ if (command == flags8) command = 0x18;
+ if (command == flags9) command = 0x17;
+
+ switch (command) {
+ case 0x1f: {
+ char c = compressedData[curIndex++] & 0xf;
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c + 0) & 0xf)); bytesWritten++;
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c + 0) & 0xf)); bytesWritten++;
+ break;
+ }
+ case 0x1e: {
+ char c = compressedData[curIndex++] & 0xf;
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c + 1) & 0xf)); bytesWritten++;
+ DecompressAT_AppendByte((((c + 1) & 0xf) << 4) | ((c + 1) & 0xf)); bytesWritten++;
+ break; // rather large mismatch
+ }
+ case 0x1d: {
+ char c = compressedData[curIndex] & 0xf;
+ curIndex++;
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c - 1) & 0xf)); bytesWritten++;
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c + 0) & 0xf)); bytesWritten++;
+ break;
+ }
+ case 0x1c: {
+ char c = compressedData[curIndex] & 0xf;
+ curIndex++;
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c + 0) & 0xf)); bytesWritten++;
+ DecompressAT_AppendByte((((c - 1) & 0xf) << 4) | ((c + 0) & 0xf)); bytesWritten++;
+ break;
+ }
+ case 0x1b: {
+ char c = compressedData[curIndex] & 0xf;
+ curIndex++;
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c + 0) & 0xf)); bytesWritten++;
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c - 1) & 0xf)); bytesWritten++;
+ break;
+ }
+ case 0x1a: {
+ char c = compressedData[curIndex] & 0xf;
+ // weird movs/adds here - possibly regalloc
+ curIndex++;
+ // missing u8 cast for argument, twice
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c - 1) & 0xf)); bytesWritten++;
+ DecompressAT_AppendByte((((c - 1) & 0xf) << 4) | ((c - 1) & 0xf)); bytesWritten++;
+ break; // second call is inlined! Should end up after switch code
+ // and yes, I tried extracting (c-1)&0xf into its own variable, and in 0x1e as well
+ // which had little effect
+ }
+ case 0x19: {
+ char c = compressedData[curIndex] & 0xf;
+ curIndex++;
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c + 1) & 0xf)); bytesWritten++;
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c + 0) & 0xf)); bytesWritten++;
+ break;
+ }
+ case 0x18: {
+ char c = compressedData[curIndex] & 0xf;
+ curIndex++;
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c + 0) & 0xf)); bytesWritten++;
+ DecompressAT_AppendByte((((c + 1) & 0xf) << 4) | ((c + 0) & 0xf)); bytesWritten++;
+ break;
+ }
+ case 0x17: {
+ char c = compressedData[curIndex] & 0xf;
+ curIndex++;
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c + 0) & 0xf)); bytesWritten++;
+ DecompressAT_AppendByte((((c + 0) & 0xf) << 4) | ((c + 1) & 0xf)); bytesWritten++;
+ break;
+ }
+ default: {
+ unsigned tmp = curIndex + 1;
+ tmp = bytesWritten - 0x1000 + ((compressedData[curIndex++] & 0xf) << 8) + compressedData[tmp];
+ curIndex++;
+ for (; command != 0; tmp++, command--) {
+ char c = DecompressAT_GetByte(tmp);
+ DecompressAT_AppendByte(c); bytesWritten++;
+ }
+ }
}
- goto end_800B198;
}
- curIndex++;
- DecompressAT_AppendByte(c10);
- bytesWritten += 2;
-end_800B198:
cmdBit++;
currentByte <<= 1;
- if (curIndex > compressedLength)
- break;
- }
+ } while ((int)curIndex < (int)compressedLength);
DecompressAT_Finish();
- return bytesWritten;
}
- return 0;
+ return bytesWritten;
#else
asm_unified(
"DecompressATGlobal:\n"
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