From 34ccfaec462159524c050a42af14c974008728f0 Mon Sep 17 00:00:00 2001
From: Peter Veenstra <qbix79@users.sourceforge.net>
Date: Thu, 22 Feb 2007 08:45:14 +0000
Subject: [PATCH] Add writemap. Fixes stonekeep in dynamic core.

Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@2818
---
 src/cpu/core_dyn_x86/cache.h   | 25 ++++++++++++++++++++--
 src/cpu/core_dyn_x86/decoder.h | 39 +++++++++++++++++++++++++++++++++-
 2 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/src/cpu/core_dyn_x86/cache.h b/src/cpu/core_dyn_x86/cache.h
index ce3f2556..7fe2965e 100644
--- a/src/cpu/core_dyn_x86/cache.h
+++ b/src/cpu/core_dyn_x86/cache.h
@@ -15,6 +15,9 @@ public:
 		Bit8u * start;					//Where in the cache are we
 		Bitu size;
 		CacheBlock * next;
+		Bit8u * wmapmask;
+		Bit16u maskstart;
+		Bit16u masklen;
 	} cache;
 	struct {
 		Bitu index;
@@ -222,8 +225,22 @@ public:
 			//Will crash if a block isn't found, which should never happen.
 		}
 		*where=block->hash.next;
-		for (Bitu i=block->page.start;i<=block->page.end;i++) {
-			if (write_map[i]) write_map[i]--;
+		if (GCC_UNLIKELY(block->cache.wmapmask!=NULL)) {
+			for (Bitu i=block->page.start;i<block->cache.maskstart;i++) {
+				if (write_map[i]) write_map[i]--;
+			}
+			Bitu maskct=0;
+			for (Bitu i=block->cache.maskstart;i<=block->page.end;i++,maskct++) {
+				if (write_map[i]) {
+					if ((maskct>=block->cache.masklen) || (!block->cache.wmapmask[maskct])) write_map[i]--;
+				}
+			}
+			free(block->cache.wmapmask);
+			block->cache.wmapmask=NULL;
+		} else {
+			for (Bitu i=block->page.start;i<=block->page.end;i++) {
+				if (write_map[i]) write_map[i]--;
+			}
 		}
 	}
 	void Release(void) {
@@ -324,6 +341,10 @@ void CacheBlock::Clear(void) {
 		page.handler->DelCacheBlock(this);
 		page.handler=0;
 	}
+	if (cache.wmapmask){
+		free(cache.wmapmask);
+		cache.wmapmask=NULL;
+	}
 }
 
 
diff --git a/src/cpu/core_dyn_x86/decoder.h b/src/cpu/core_dyn_x86/decoder.h
index caec4c29..ba03a074 100644
--- a/src/cpu/core_dyn_x86/decoder.h
+++ b/src/cpu/core_dyn_x86/decoder.h
@@ -140,11 +140,43 @@ static Bit32u decode_fetchd(void) {
 	return mem_readd(decode.code-4);
 }
 
+#define START_WMMEM 64
+
+static void INLINE decode_increase_wmapmask(Bitu size) {
+	Bitu mapidx;
+	CacheBlock* activecb=decode.active_block; 
+	if (GCC_UNLIKELY(!activecb->cache.wmapmask)) {
+		activecb->cache.wmapmask=(Bit8u*)malloc(START_WMMEM);
+		memset(activecb->cache.wmapmask,0,START_WMMEM);
+		activecb->cache.maskstart=decode.page.index;
+		activecb->cache.masklen=START_WMMEM;
+		mapidx=0;
+	} else {
+		mapidx=decode.page.index-activecb->cache.maskstart;
+		if (GCC_UNLIKELY(mapidx+size>=activecb->cache.masklen)) {
+			Bitu newmasklen=activecb->cache.masklen*4;
+			if (newmasklen<mapidx+size) newmasklen=((mapidx+size)&~3)*2;
+			Bit8u* tempmem=(Bit8u*)malloc(newmasklen);
+			memset(tempmem,0,newmasklen);
+			memcpy(tempmem,activecb->cache.wmapmask,activecb->cache.masklen);
+			free(activecb->cache.wmapmask);
+			activecb->cache.wmapmask=tempmem;
+			activecb->cache.masklen=newmasklen;
+		}
+	}
+	switch (size) {
+		case 1 : activecb->cache.wmapmask[mapidx]+=0x01; break;
+		case 2 : (*(Bit16u*)&activecb->cache.wmapmask[mapidx])+=0x0101; break;
+		case 4 : (*(Bit32u*)&activecb->cache.wmapmask[mapidx])+=0x01010101; break;
+	}
+}
+
 static bool decode_fetchb_imm(Bitu & val) {
 	if (decode.page.index<4096) {
 		Bitu index=(decode.code>>12);
 		if (paging.tlb.read[index]) {
 			val=(Bitu)(paging.tlb.read[index]+decode.code);
+			decode_increase_wmapmask(1);
 			decode.code++;
 			decode.page.index++;
 			return true;
@@ -158,6 +190,7 @@ static bool decode_fetchw_imm(Bitu & val) {
 		Bitu index=(decode.code>>12);
 		if (paging.tlb.read[index]) {
 			val=(Bitu)(paging.tlb.read[index]+decode.code);
+			decode_increase_wmapmask(2);
 			decode.code+=2;
 			decode.page.index+=2;
 			return true;
@@ -171,6 +204,7 @@ static bool decode_fetchd_imm(Bitu & val) {
 		Bitu index=(decode.code>>12);
 		if (paging.tlb.read[index]) {
 			val=(Bitu)(paging.tlb.read[index]+decode.code);
+			decode_increase_wmapmask(4);
 			decode.code+=4;
 			decode.page.index+=4;
 			return true;
@@ -1919,7 +1953,10 @@ restart_prefix:
 		if (!decode.page.invmap) opcode=decode_fetchb();
 		else {
 			if (decode.page.index<4096) {
-				if (GCC_UNLIKELY(decode.page.invmap[decode.page.index]>=4)) goto illegalopcode;
+				if (GCC_UNLIKELY(decode.page.invmap[decode.page.index]>=4)) {
+					decode.page.index++;
+					goto illegalopcode;
+				}
 				opcode=decode_fetchb();
 			} else {
 				opcode=decode_fetchb();