FpSketch

lib/util/FpSketch.v3

@@ -6,8 +6,6 @@
 // words and an exponent, this class has just barely enough arithmetic
 // support to properly compute and round large bit strings.
 // Always mutable; arithmetic is done in-place.
-def trace = false; // XXX remove tracing altogether
-def XXX: Terminal;
 class FpSketch {
 	var words = Array<u32>.new(1); // base 2^32 digits.
 	var exp: int;
@@ -173,8 +171,6 @@ class FpSketch {
 	// Divide this number by {di} in place, producing at least {qmin} quotient words.
 	// Returns {true} if the divison was exact, {false} otherwise.
 	def div(di: FpSketch, qmin: u31) -> bool {
-		if (trace) XXX.put3("%q / %q, qmin=%d\n", this.render, di.render, qmin);
-
 		// Single word divisor has a faster method.
 		var dwords = di.words.length, dextra = dwords - 2;
 		if (dwords == 1) {
@@ -206,28 +202,15 @@ class FpSketch {
 		for (npos = ri.words.length -2; npos >= dextra; npos--) {
 			var q: u32;
 			var nd = ri.u64at(npos);
-			if (trace) XXX.put1("  npos=%d", npos);
-			if (trace) XXX.put3(", qi=%q, ri=%q, rlast=%d\n", qi.render, ri.render, rlast);
 			if (rlast == 0) { // 64x64 bit divide
 				var qe = nd / dh2;
 				q = u32.view(qe);
-				if (trace) TerminalBuffer.new()
-					.puts("    nd=").putd(long.view(nd))
-					.puts(" / dh2=").putd(long.view(dh2))
-					.puts(" = ").putx(q)
-					.outln();
 			} else { // 96x64 bit divide; shift in rlast bits
 				var shift = 1 + Longs.log(rlast);
-				if (trace) XXX.put2("    rlast=%d, shift=%d\n", rlast, shift);
 				var sdh2 = dh2 >> u6.view(shift);
 				var snd = nd >> u6.view(shift) | (u64.view(rlast) << u6.view(64 - shift));
 				var qe = snd / sdh2;
 				q = if(qe > 0xFFFFFFFFu, 0xFFFFFFFFu, u32.view(qe)); // +1 or +2 overestimate
-				if (trace) TerminalBuffer.new()
-					.puts("    snd=").putd(long.view(snd))
-					.puts(" / sdh2=").putd(long.view(sdh2))
-					.puts(" = ").putx(q)
-					.outln();
 			}
 			while (q > 0) {
 				var si = if(q == 1, di, di.copyInto(mi).mulAdd32(q, 0));
@@ -241,7 +224,6 @@ class FpSketch {
 			qi.words[npos] = q;
 		}
 		var exact = ri.isZero() && rlast == 0;
-		if (trace) XXX.put3("  qi=%q, ri=%q, rlast=%d\n", qi.render, ri.render, rlast);
 		return exact;
 	}
 	// Divide this number by {d} in place, producing at least {qmin} quotient words.
@@ -262,19 +244,15 @@ class FpSketch {
 		// Long-division starting at highest word; grade-school algorithm.
 		var rem = 0u;
 		for (npos = ri.words.length -1; npos >= 0; npos--) {
-			if (trace) XXX.put3("  npos=%d, qi=%q, ri=%q", npos, qi.render, ri.render);
-			if (trace) XXX.put1(", rem=%d\n", rem);
 			var nd = (u64.view(rem) << 32) | ri.words[npos];
 			rem = u32.view(nd % d);
 			qi.words[npos] = u32.view(nd / d);
 		}
-		if (trace) XXX.put2("  qi=%q, ri=%q\n", qi.render, ri.render);
 		return rem == 0;
 	}
 	// Subtract {num * 2^(32*pos)} from this number, in place, returning the borrow
 	// from the {maxPos} position.
 	def subRange(num: FpSketch, pos: int, maxPos: int) -> u32 {
-		if (trace) XXX.put3("    subRange(s=%q, pos=%d, max=%d)\n", num.render, pos, maxPos);
 		var nd = num.words, borrow = 0u;
 		for (i < nd.length) {
 			var p = pos + i;
@@ -293,7 +271,6 @@ class FpSketch {
 	// Add {num * 2^(32*pos)} to this number, in place, returning the carry
 	// out from the highest order digit of {num}.
 	def addRange(num: FpSketch, pos: int, maxPos: int) -> u32 {
-		if (trace) XXX.put2("    addRange(s=%q, pos=%d)\n", num.render, pos);
 		var nd = num.words, carry = 0u;
 		for (i < nd.length) {
 			var p = pos + i;