From 22bd4fbc93a08613a2f7423159d76a0bad45435c Mon Sep 17 00:00:00 2001
From: Ulya Trofimovich <skvadrik@gmail.com>
Date: Wed, 11 Mar 2015 10:52:05 +0000
Subject: [PATCH] Simplify handling of high/low spans.

Spans are already ordered, so to get high (wide) spans,
all we need is to find first span with upper bound >0x100
and point at it.
---
 re2c/code.cc | 60 ++++++++++++++++++++++------------------------------
 re2c/dfa.h   |  6 ++++--
 2 files changed, 29 insertions(+), 37 deletions(-)

diff --git a/re2c/code.cc b/re2c/code.cc
index 9387c0d2..97e0552e 100644
--- a/re2c/code.cc
+++ b/re2c/code.cc
@@ -819,7 +819,7 @@ void Go::genSwitchD (OutputFile & o, const State *from) const
 
 void Go::genSwitch(OutputFile & o, uint ind, const State *from, const State *next, bool &readCh, uint mask) const
 {
-	if ((mask ? wSpans : nSpans) <= 2)
+	if ((mask ? hSpans : nSpans) <= 2)
 	{
 		genLinear(o, ind, from, next, readCh, mask);
 	}
@@ -880,19 +880,7 @@ void Go::genBinary(OutputFile & o, uint ind, const State *from, const State *nex
 {
 	if (mask)
 	{
-		Span * sc = new Span[wSpans];
-		
-		for (uint i = 0, j = 0; i < nSpans; i++)
-		{
-			if (span[i].ub > 0x100)
-			{
-				sc[j++] = span[i];
-			}
-		}
-
-		doBinary(o, ind, sc, wSpans, from, next, readCh, mask);
-
-		delete[] sc;
+		doBinary(o, ind, hspan, hSpans, from, next, readCh, mask);
 	}
 	else
 	{
@@ -902,7 +890,7 @@ void Go::genBinary(OutputFile & o, uint ind, const State *from, const State *nex
 
 void Go::genBase(OutputFile & o, uint ind, const State *from, const State *next, bool &readCh, uint mask) const
 {
-	if ((mask ? wSpans : nSpans) == 0)
+	if ((mask ? hSpans : nSpans) == 0)
 	{
 		return ;
 	}
@@ -913,7 +901,7 @@ void Go::genBase(OutputFile & o, uint ind, const State *from, const State *next,
 		return ;
 	}
 
-	if ((mask ? wSpans : nSpans) > 8)
+	if ((mask ? hSpans : nSpans) > 8)
 	{
 		Span *bot = &span[0], *top = &span[nSpans - 1];
 		uint util;
@@ -942,7 +930,7 @@ void Go::genBase(OutputFile & o, uint ind, const State *from, const State *next,
 		}
 	}
 
-	if ((mask ? wSpans : nSpans) > 5)
+	if ((mask ? hSpans : nSpans) > 5)
 	{
 		genBinary(o, ind, from, next, readCh, mask);
 	}
@@ -959,7 +947,7 @@ std::string Go::genGotoProlog(OutputFile & o, uint ind, const State *from, const
 		: mapCodeName["yych"];
 	readCh = false;
 
-	if (encoding.szCodeUnit() > 1) // wSpans > 0
+	if (encoding.szCodeUnit() > 1) // hSpans > 0
 	{
 		o << indent(ind) << "if (" << sYych <<" & ~0xFF) {\n";
 		genBase(o, ind + 1, from, next, readCh, 1);
@@ -1018,37 +1006,39 @@ void Go::genGoto(OutputFile & o, uint ind, const State *from, const State *next,
 		return;
 	}
 
-	uint dSpans = 0;
-	uint nBitmaps = 0;
-	wSpans = 0;
 	for (uint i = 0; i < nSpans; ++i)
 	{
 		if (span[i].ub > 0x100)
 		{
-			wSpans++;
+			hspan = &span[i];
+			hSpans = nSpans - i;
+			break;
 		}
-		else
+	}
+
+	uint dSpans = 0;
+	uint nBitmaps = 0;
+	for (uint i = 0; i < nSpans - hSpans; ++i)
+	{
+		State *to = span[i].to;
+
+		if (to && to->isBase)
 		{
-			State *to = span[i].to;
+			const BitMap *b = BitMap::find(to);
 
-			if (to && to->isBase)
+			if (b && matches(b->go, b->on, this, to))
 			{
-				const BitMap *b = BitMap::find(to);
-
-				if (b && matches(b->go, b->on, this, to))
-				{
-					nBitmaps++;
-				}
-				else
-				{
-					dSpans++;
-				}
+				nBitmaps++;
 			}
 			else
 			{
 				dSpans++;
 			}
 		}
+		else
+		{
+			dSpans++;
+		}
 	}
 
 	if (gFlag && (dSpans >= cGotoThreshold))
diff --git a/re2c/dfa.h b/re2c/dfa.h
index 1c6e91de..e61d129b 100644
--- a/re2c/dfa.h
+++ b/re2c/dfa.h
@@ -168,15 +168,17 @@ class Go
 public:
 	Go()
 		: nSpans(0)
-		, wSpans(~0u)
+		, hSpans(0)
 		, span(NULL)
+		, hspan(NULL)
 	{
 	}
 
 public:
 	uint	nSpans; // number of spans
-	uint    wSpans; // number of spans in wide mode
+	uint	hSpans; // number of spans with upper bound > 0x100
 	Span	*span;
+	Span	*hspan;
 
 public:
 	void genGoto(OutputFile &, uint ind, const State *from, const State *next, bool &readCh);
-- 
2.40.0