From 812f06b3ca425d26ea18f02dd7392a72be4f3eda Mon Sep 17 00:00:00 2001
From: Ken Thompson <ken@golang.org>
Date: Sat, 8 Aug 2009 16:53:21 -0700
Subject: [PATCH] another plateau - almost done only need to fix up certain
 denominators

R=rsc
OCL=32928
CL=32928
---
 src/cmd/6g/ggen.c    |  71 ++++++--
 test/ken/divconst.go | 376 ++++++++++++++++++++++++++++++++++++++++---
 test/ken/modconst.go | 371 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 780 insertions(+), 38 deletions(-)
 create mode 100644 test/ken/modconst.go

diff --git a/src/cmd/6g/ggen.c b/src/cmd/6g/ggen.c
index 8bbd7ec4d6..a3723738f5 100644
--- a/src/cmd/6g/ggen.c
+++ b/src/cmd/6g/ggen.c
@@ -601,16 +601,14 @@ cgen_div(int op, Node *nl, Node *nr, Node *res)
 	if(n < 0)
 		goto divbymul;
 
-	if(op == OMOD) {
-		// todo
-		goto longdiv;
-	}
-
 	switch(n) {
 	case 0:
 		// divide by 1
 		regalloc(&n1, nl->type, res);
 		cgen(nl, &n1);
+		if(op == OMOD) {
+			gins(optoas(OXOR, nl->type), &n1, &n1);
+		} else
 		if(s)
 			gins(optoas(OMINUS, nl->type), N, &n1);
 		gmove(&n1, res);
@@ -618,6 +616,17 @@ cgen_div(int op, Node *nl, Node *nr, Node *res)
 		return;
 	case 1:
 		// divide by 2
+		if(op == OMOD) {
+			if(issigned[nl->type->etype]) 
+				goto longmod;
+			regalloc(&n1, nl->type, res);
+			cgen(nl, &n1);
+			nodconst(&n2, nl->type, 1);
+			gins(optoas(OAND, nl->type), &n2, &n1);
+			gmove(&n1, res);
+			regfree(&n1);
+			return;
+		}
 		regalloc(&n1, nl->type, res);
 		cgen(nl, &n1);
 		if(!issigned[nl->type->etype])
@@ -632,6 +641,23 @@ cgen_div(int op, Node *nl, Node *nr, Node *res)
 		regfree(&n2);
 		break;
 	default:
+		if(op == OMOD) {
+			if(issigned[nl->type->etype]) 
+				goto longmod;
+			regalloc(&n1, nl->type, res);
+			cgen(nl, &n1);
+			nodconst(&n2, nl->type, mpgetfix(nr->val.u.xval)-1);
+			if(!smallintconst(&n2)) {
+				regalloc(&n3, nl->type, N);
+				gmove(&n2, &n3);
+				gins(optoas(OAND, nl->type), &n3, &n1);
+				regfree(&n3);
+			} else
+				gins(optoas(OAND, nl->type), &n2, &n1);
+			gmove(&n1, res);
+			regfree(&n1);
+			return;
+		}
 		regalloc(&n1, nl->type, res);
 		cgen(nl, &n1);
 		if(!issigned[nl->type->etype])
@@ -657,6 +683,8 @@ cgen_div(int op, Node *nl, Node *nr, Node *res)
 	return;
 
 divbymul:
+	// try to do division by multiply by (2^w)/d
+	// see hacker's delight chapter 10
 	switch(simtype[nl->type->etype]) {
 	default:
 		goto longdiv;
@@ -669,14 +697,12 @@ divbymul:
 		umagic(&m);
 		if(m.bad)
 			break;
-		if(op == OMOD) {
-			// todo
-			break;
-		}
 		if(m.ua != 0) {
 			// todo fixup
 			break;
 		}
+		if(op == OMOD)
+			goto longmod;
 
 		savex(D_AX, &ax, &oldax, res, nl->type);
 		savex(D_DX, &dx, &olddx, res, nl->type);
@@ -709,14 +735,12 @@ divbymul:
 		smagic(&m);
 		if(m.bad)
 			break;
-		if(op == OMOD) {
-			// todo
-			break;
-		}
 		if(m.sm < 0) {
 			// todo fixup
 			break;
 		}
+		if(op == OMOD)
+			goto longmod;
 
 		savex(D_AX, &ax, &oldax, res, nl->type);
 		savex(D_DX, &dx, &olddx, res, nl->type);
@@ -751,11 +775,32 @@ divbymul:
 	goto longdiv;
 
 longdiv:
+	// division and mod using (slow) hardware instruction
 	savex(D_AX, &ax, &oldax, res, nl->type);
 	savex(D_DX, &dx, &olddx, res, nl->type);
 	dodiv(op, nl, nr, res, &ax, &dx);
 	restx(&ax, &oldax);
 	restx(&dx, &olddx);
+	return;
+
+longmod:
+	// mod using formula A%B = A-(A/B*B) but
+	// we know that there is a fast algorithm for A/B
+	regalloc(&n1, nl->type, res);
+	cgen(nl, &n1);
+	regalloc(&n2, nl->type, N);
+	cgen_div(ODIV, &n1, nr, &n2);
+	if(!smallintconst(nr)) {
+		regalloc(&n3, nl->type, N);
+		cgen(nr, &n3);
+		gins(optoas(OMUL, nl->type), &n3, &n2);
+		regfree(&n3);
+	} else
+		gins(optoas(OMUL, nl->type), nr, &n2);
+	gins(optoas(OSUB, nl->type), &n2, &n1);
+	gmove(&n1, res);
+	regfree(&n1);
+	regfree(&n2);
 }
 
 /*
diff --git a/test/ken/divconst.go b/test/ken/divconst.go
index 9042b1e962..d0cbbbedcd 100644
--- a/test/ken/divconst.go
+++ b/test/ken/divconst.go
@@ -9,37 +9,363 @@ package main
 
 import	"rand"
 
-func	test(a,b,c int64);
+const	Count	= 1e6
+
+func
+i64rand() int64
+{
+	for {
+		a := int64(rand.Uint32());
+		a = (a<<32) | int64(rand.Uint32());
+		a >>= uint(rand.Intn(64));
+		if -a != a {
+			return a;
+		}
+	}
+	return 0;	// impossible
+}
+
+func
+i64test(a,b,c int64)
+{
+	d := a/c;
+	if d != b {
+		panicln("i64", a, b, c, d);
+	}
+}
+
+func
+i64run()
+{
+	var a, b int64;
+
+	for i:=0; i<Count; i++ {
+		a = i64rand();
+
+		b = a/1;	i64test(a,b,1);
+		b = a/2;	i64test(a,b,2);
+		b = a/3;	i64test(a,b,3);
+		b = a/4;	i64test(a,b,4);
+		b = a/5;	i64test(a,b,5);
+		b = a/6;	i64test(a,b,6);
+		b = a/7;	i64test(a,b,7);
+		b = a/8;	i64test(a,b,8);
+		b = a/10;	i64test(a,b,10);
+		b = a/16;	i64test(a,b,16);
+		b = a/20;	i64test(a,b,20);
+		b = a/32;	i64test(a,b,32);
+		b = a/60;	i64test(a,b,60);
+		b = a/64;	i64test(a,b,64);
+		b = a/128;	i64test(a,b,128);
+		b = a/256;	i64test(a,b,256);
+		b = a/16384;	i64test(a,b,16384);
+
+		b = a/-1;	i64test(a,b,-1);
+		b = a/-2;	i64test(a,b,-2);
+		b = a/-3;	i64test(a,b,-3);
+		b = a/-4;	i64test(a,b,-4);
+		b = a/-5;	i64test(a,b,-5);
+		b = a/-6;	i64test(a,b,-6);
+		b = a/-7;	i64test(a,b,-7);
+		b = a/-8;	i64test(a,b,-8);
+		b = a/-10;	i64test(a,b,-10);
+		b = a/-16;	i64test(a,b,-16);
+		b = a/-20;	i64test(a,b,-20);
+		b = a/-32;	i64test(a,b,-32);
+		b = a/-60;	i64test(a,b,-60);
+		b = a/-64;	i64test(a,b,-64);
+		b = a/-128;	i64test(a,b,-128);
+		b = a/-256;	i64test(a,b,-256);
+		b = a/-16384;	i64test(a,b,-16384);
+	}
+}
+
+func
+u64rand() uint64
+{
+	a := uint64(rand.Uint32());
+	a = (a<<32) | uint64(rand.Uint32());
+	a >>= uint(rand.Intn(64));
+	return a;
+}
+
+func
+u64test(a,b,c uint64)
+{
+	d := a/c;
+	if d != b {
+		panicln("u64", a, b, c, d);
+	}
+}
+
+func
+u64run()
+{
+	var a, b uint64;
+
+	for i:=0; i<Count; i++ {
+		a = u64rand();
+
+		b = a/1;	u64test(a,b,1);
+		b = a/2;	u64test(a,b,2);
+		b = a/3;	u64test(a,b,3);
+		b = a/4;	u64test(a,b,4);
+		b = a/5;	u64test(a,b,5);
+		b = a/6;	u64test(a,b,6);
+		b = a/7;	u64test(a,b,7);
+		b = a/8;	u64test(a,b,8);
+		b = a/10;	u64test(a,b,10);
+		b = a/16;	u64test(a,b,16);
+		b = a/20;	u64test(a,b,20);
+		b = a/32;	u64test(a,b,32);
+		b = a/60;	u64test(a,b,60);
+		b = a/64;	u64test(a,b,64);
+		b = a/128;	u64test(a,b,128);
+		b = a/256;	u64test(a,b,256);
+		b = a/16384;	u64test(a,b,16384);
+	}
+}
+
+func
+i32rand() int32
+{
+	for {
+		a := int32(rand.Uint32());
+		a >>= uint(rand.Intn(32));
+		if -a != a {
+			return a;
+		}
+	}
+	return 0;	// impossible
+}
+
+func
+i32test(a,b,c int32)
+{
+	d := a/c;
+	if d != b {
+		panicln("i32", a, b, c, d);
+	}
+}
+
+func
+i32run()
+{
+	var a, b int32;
+
+	for i:=0; i<Count; i++ {
+		a = i32rand();
+
+		b = a/1;	i32test(a,b,1);
+		b = a/2;	i32test(a,b,2);
+		b = a/3;	i32test(a,b,3);
+		b = a/4;	i32test(a,b,4);
+		b = a/5;	i32test(a,b,5);
+		b = a/6;	i32test(a,b,6);
+		b = a/7;	i32test(a,b,7);
+		b = a/8;	i32test(a,b,8);
+		b = a/10;	i32test(a,b,10);
+		b = a/16;	i32test(a,b,16);
+		b = a/20;	i32test(a,b,20);
+		b = a/32;	i32test(a,b,32);
+		b = a/60;	i32test(a,b,60);
+		b = a/64;	i32test(a,b,64);
+		b = a/128;	i32test(a,b,128);
+		b = a/256;	i32test(a,b,256);
+		b = a/16384;	i32test(a,b,16384);
+
+		b = a/-1;	i32test(a,b,-1);
+		b = a/-2;	i32test(a,b,-2);
+		b = a/-3;	i32test(a,b,-3);
+		b = a/-4;	i32test(a,b,-4);
+		b = a/-5;	i32test(a,b,-5);
+		b = a/-6;	i32test(a,b,-6);
+		b = a/-7;	i32test(a,b,-7);
+		b = a/-8;	i32test(a,b,-8);
+		b = a/-10;	i32test(a,b,-10);
+		b = a/-16;	i32test(a,b,-16);
+		b = a/-20;	i32test(a,b,-20);
+		b = a/-32;	i32test(a,b,-32);
+		b = a/-60;	i32test(a,b,-60);
+		b = a/-64;	i32test(a,b,-64);
+		b = a/-128;	i32test(a,b,-128);
+		b = a/-256;	i32test(a,b,-256);
+	}
+}
+
+func
+u32rand() uint32
+{
+	a := uint32(rand.Uint32());
+	a >>= uint(rand.Intn(32));
+	return a;
+}
+
+func
+u32test(a,b,c uint32)
+{
+	d := a/c;
+	if d != b {
+		panicln("u32", a, b, c, d);
+	}
+}
+
+func
+u32run()
+{
+	var a, b uint32;
+
+	for i:=0; i<Count; i++ {
+		a = u32rand();
+
+		b = a/1;	u32test(a,b,1);
+		b = a/2;	u32test(a,b,2);
+		b = a/3;	u32test(a,b,3);
+		b = a/4;	u32test(a,b,4);
+		b = a/5;	u32test(a,b,5);
+		b = a/6;	u32test(a,b,6);
+		b = a/7;	u32test(a,b,7);
+		b = a/8;	u32test(a,b,8);
+		b = a/10;	u32test(a,b,10);
+		b = a/16;	u32test(a,b,16);
+		b = a/20;	u32test(a,b,20);
+		b = a/32;	u32test(a,b,32);
+		b = a/60;	u32test(a,b,60);
+		b = a/64;	u32test(a,b,64);
+		b = a/128;	u32test(a,b,128);
+		b = a/256;	u32test(a,b,256);
+		b = a/16384;	u32test(a,b,16384);
+	}
+}
+
+func
+i16rand() int16
+{
+	for {
+		a := int16(rand.Uint32());
+		a >>= uint(rand.Intn(16));
+		if -a != a {
+			return a;
+		}
+	}
+	return 0;	// impossible
+}
+
+func
+i16test(a,b,c int16)
+{
+	d := a/c;
+	if d != b {
+		panicln("i16", a, b, c, d);
+	}
+}
+
+func
+i16run()
+{
+	var a, b int16;
+
+	for i:=0; i<Count; i++ {
+		a = i16rand();
+
+		b = a/1;	i16test(a,b,1);
+		b = a/2;	i16test(a,b,2);
+		b = a/3;	i16test(a,b,3);
+		b = a/4;	i16test(a,b,4);
+		b = a/5;	i16test(a,b,5);
+		b = a/6;	i16test(a,b,6);
+		b = a/7;	i16test(a,b,7);
+		b = a/8;	i16test(a,b,8);
+		b = a/10;	i16test(a,b,10);
+		b = a/16;	i16test(a,b,16);
+		b = a/20;	i16test(a,b,20);
+		b = a/32;	i16test(a,b,32);
+		b = a/60;	i16test(a,b,60);
+		b = a/64;	i16test(a,b,64);
+		b = a/128;	i16test(a,b,128);
+		b = a/256;	i16test(a,b,256);
+		b = a/16384;	i16test(a,b,16384);
+
+		b = a/-1;	i16test(a,b,-1);
+		b = a/-2;	i16test(a,b,-2);
+		b = a/-3;	i16test(a,b,-3);
+		b = a/-4;	i16test(a,b,-4);
+		b = a/-5;	i16test(a,b,-5);
+		b = a/-6;	i16test(a,b,-6);
+		b = a/-7;	i16test(a,b,-7);
+		b = a/-8;	i16test(a,b,-8);
+		b = a/-10;	i16test(a,b,-10);
+		b = a/-16;	i16test(a,b,-16);
+		b = a/-20;	i16test(a,b,-20);
+		b = a/-32;	i16test(a,b,-32);
+		b = a/-60;	i16test(a,b,-60);
+		b = a/-64;	i16test(a,b,-64);
+		b = a/-128;	i16test(a,b,-128);
+		b = a/-256;	i16test(a,b,-256);
+		b = a/-16384;	i16test(a,b,-16384);
+	}
+}
+
+func
+u16rand() uint16
+{
+	a := uint16(rand.Uint32());
+	a >>= uint(rand.Intn(16));
+	return a;
+}
+
+func
+u16test(a,b,c uint16)
+{
+	d := a/c;
+	if d != b {
+		panicln("u16", a, b, c, d);
+	}
+}
+
+func
+u16run()
+{
+	var a, b uint16;
+
+	for i:=0; i<Count; i++ {
+		a = u16rand();
+
+		b = a/1;	u16test(a,b,1);
+		b = a/2;	u16test(a,b,2);
+		b = a/3;	u16test(a,b,3);
+		b = a/4;	u16test(a,b,4);
+		b = a/5;	u16test(a,b,5);
+		b = a/6;	u16test(a,b,6);
+		b = a/7;	u16test(a,b,7);
+		b = a/8;	u16test(a,b,8);
+		b = a/10;	u16test(a,b,10);
+		b = a/16;	u16test(a,b,16);
+		b = a/20;	u16test(a,b,20);
+		b = a/32;	u16test(a,b,32);
+		b = a/60;	u16test(a,b,60);
+		b = a/64;	u16test(a,b,64);
+		b = a/128;	u16test(a,b,128);
+		b = a/256;	u16test(a,b,256);
+		b = a/16384;	u16test(a,b,16384);
+	}
+}
+
+func	xtest()
 
 func
 main()
 {
-	var a, b int64;
-
-	for i:=0; i<1e6; i++ {
-		a := rand.Int63() - 1<<62;
-		b = a/1;	test(a,b,1);
-		b = a/2;	test(a,b,2);
-		b = a/3;	test(a,b,3);
-		b = a/4;	test(a,b,4);
-		b = a/5;	test(a,b,5);
-		b = a/6;	test(a,b,6);
-		b = a/7;	test(a,b,7);
-		b = a/8;	test(a,b,8);
-		b = a/16;	test(a,b,16);
-		b = a/32;	test(a,b,32);
-		b = a/64;	test(a,b,64);
-		b = a/128;	test(a,b,128);
-		b = a/256;	test(a,b,256);
-		b = a/16384;	test(a,b,16384);
-	}
+	xtest();
+	i64run();
+	u64run();
+	i32run();
+	u32run();
+	i16run();
+	u16run();
 }
 
 func
-test(a,b,c int64)
+xtest()
 {
-	d := a/c;
-	if d != b {
-		panicln(a, b, c, d);
-	}
 }
diff --git a/test/ken/modconst.go b/test/ken/modconst.go
new file mode 100644
index 0000000000..812a13ca82
--- /dev/null
+++ b/test/ken/modconst.go
@@ -0,0 +1,371 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out
+
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+
+package main
+
+import	"rand"
+
+const	Count	= 1e6
+
+func
+i64rand() int64
+{
+	for {
+		a := int64(rand.Uint32());
+		a = (a<<32) | int64(rand.Uint32());
+		a >>= uint(rand.Intn(64));
+		if -a != a {
+			return a;
+		}
+	}
+	return 0;	// impossible
+}
+
+func
+i64test(a,b,c int64)
+{
+	d := a%c;
+	if d != b {
+		panicln("i64", a, b, c, d);
+	}
+}
+
+func
+i64run()
+{
+	var a, b int64;
+
+	for i:=0; i<Count; i++ {
+		a = i64rand();
+
+		b = a%1;	i64test(a,b,1);
+		b = a%2;	i64test(a,b,2);
+		b = a%3;	i64test(a,b,3);
+		b = a%4;	i64test(a,b,4);
+		b = a%5;	i64test(a,b,5);
+		b = a%6;	i64test(a,b,6);
+		b = a%7;	i64test(a,b,7);
+		b = a%8;	i64test(a,b,8);
+		b = a%10;	i64test(a,b,10);
+		b = a%16;	i64test(a,b,16);
+		b = a%20;	i64test(a,b,20);
+		b = a%32;	i64test(a,b,32);
+		b = a%60;	i64test(a,b,60);
+		b = a%64;	i64test(a,b,64);
+		b = a%128;	i64test(a,b,128);
+		b = a%256;	i64test(a,b,256);
+		b = a%16384;	i64test(a,b,16384);
+
+		b = a%-1;	i64test(a,b,-1);
+		b = a%-2;	i64test(a,b,-2);
+		b = a%-3;	i64test(a,b,-3);
+		b = a%-4;	i64test(a,b,-4);
+		b = a%-5;	i64test(a,b,-5);
+		b = a%-6;	i64test(a,b,-6);
+		b = a%-7;	i64test(a,b,-7);
+		b = a%-8;	i64test(a,b,-8);
+		b = a%-10;	i64test(a,b,-10);
+		b = a%-16;	i64test(a,b,-16);
+		b = a%-20;	i64test(a,b,-20);
+		b = a%-32;	i64test(a,b,-32);
+		b = a%-60;	i64test(a,b,-60);
+		b = a%-64;	i64test(a,b,-64);
+		b = a%-128;	i64test(a,b,-128);
+		b = a%-256;	i64test(a,b,-256);
+		b = a%-16384;	i64test(a,b,-16384);
+	}
+}
+
+func
+u64rand() uint64
+{
+	a := uint64(rand.Uint32());
+	a = (a<<32) | uint64(rand.Uint32());
+	a >>= uint(rand.Intn(64));
+	return a;
+}
+
+func
+u64test(a,b,c uint64)
+{
+	d := a%c;
+	if d != b {
+		panicln("u64", a, b, c, d);
+	}
+}
+
+func
+u64run()
+{
+	var a, b uint64;
+
+	for i:=0; i<Count; i++ {
+		a = u64rand();
+
+		b = a%1;	u64test(a,b,1);
+		b = a%2;	u64test(a,b,2);
+		b = a%3;	u64test(a,b,3);
+		b = a%4;	u64test(a,b,4);
+		b = a%5;	u64test(a,b,5);
+		b = a%6;	u64test(a,b,6);
+		b = a%7;	u64test(a,b,7);
+		b = a%8;	u64test(a,b,8);
+		b = a%10;	u64test(a,b,10);
+		b = a%16;	u64test(a,b,16);
+		b = a%20;	u64test(a,b,20);
+		b = a%32;	u64test(a,b,32);
+		b = a%60;	u64test(a,b,60);
+		b = a%64;	u64test(a,b,64);
+		b = a%128;	u64test(a,b,128);
+		b = a%256;	u64test(a,b,256);
+		b = a%16384;	u64test(a,b,16384);
+	}
+}
+
+func
+i32rand() int32
+{
+	for {
+		a := int32(rand.Uint32());
+		a >>= uint(rand.Intn(32));
+		if -a != a {
+			return a;
+		}
+	}
+	return 0;	// impossible
+}
+
+func
+i32test(a,b,c int32)
+{
+	d := a%c;
+	if d != b {
+		panicln("i32", a, b, c, d);
+	}
+}
+
+func
+i32run()
+{
+	var a, b int32;
+
+	for i:=0; i<Count; i++ {
+		a = i32rand();
+
+		b = a%1;	i32test(a,b,1);
+		b = a%2;	i32test(a,b,2);
+		b = a%3;	i32test(a,b,3);
+		b = a%4;	i32test(a,b,4);
+		b = a%5;	i32test(a,b,5);
+		b = a%6;	i32test(a,b,6);
+		b = a%7;	i32test(a,b,7);
+		b = a%8;	i32test(a,b,8);
+		b = a%10;	i32test(a,b,10);
+		b = a%16;	i32test(a,b,16);
+		b = a%20;	i32test(a,b,20);
+		b = a%32;	i32test(a,b,32);
+		b = a%60;	i32test(a,b,60);
+		b = a%64;	i32test(a,b,64);
+		b = a%128;	i32test(a,b,128);
+		b = a%256;	i32test(a,b,256);
+		b = a%16384;	i32test(a,b,16384);
+
+		b = a%-1;	i32test(a,b,-1);
+		b = a%-2;	i32test(a,b,-2);
+		b = a%-3;	i32test(a,b,-3);
+		b = a%-4;	i32test(a,b,-4);
+		b = a%-5;	i32test(a,b,-5);
+		b = a%-6;	i32test(a,b,-6);
+		b = a%-7;	i32test(a,b,-7);
+		b = a%-8;	i32test(a,b,-8);
+		b = a%-10;	i32test(a,b,-10);
+		b = a%-16;	i32test(a,b,-16);
+		b = a%-20;	i32test(a,b,-20);
+		b = a%-32;	i32test(a,b,-32);
+		b = a%-60;	i32test(a,b,-60);
+		b = a%-64;	i32test(a,b,-64);
+		b = a%-128;	i32test(a,b,-128);
+		b = a%-256;	i32test(a,b,-256);
+	}
+}
+
+func
+u32rand() uint32
+{
+	a := uint32(rand.Uint32());
+	a >>= uint(rand.Intn(32));
+	return a;
+}
+
+func
+u32test(a,b,c uint32)
+{
+	d := a%c;
+	if d != b {
+		panicln("u32", a, b, c, d);
+	}
+}
+
+func
+u32run()
+{
+	var a, b uint32;
+
+	for i:=0; i<Count; i++ {
+		a = u32rand();
+
+		b = a%1;	u32test(a,b,1);
+		b = a%2;	u32test(a,b,2);
+		b = a%3;	u32test(a,b,3);
+		b = a%4;	u32test(a,b,4);
+		b = a%5;	u32test(a,b,5);
+		b = a%6;	u32test(a,b,6);
+		b = a%7;	u32test(a,b,7);
+		b = a%8;	u32test(a,b,8);
+		b = a%10;	u32test(a,b,10);
+		b = a%16;	u32test(a,b,16);
+		b = a%20;	u32test(a,b,20);
+		b = a%32;	u32test(a,b,32);
+		b = a%60;	u32test(a,b,60);
+		b = a%64;	u32test(a,b,64);
+		b = a%128;	u32test(a,b,128);
+		b = a%256;	u32test(a,b,256);
+		b = a%16384;	u32test(a,b,16384);
+	}
+}
+
+func
+i16rand() int16
+{
+	for {
+		a := int16(rand.Uint32());
+		a >>= uint(rand.Intn(16));
+		if -a != a {
+			return a;
+		}
+	}
+	return 0;	// impossible
+}
+
+func
+i16test(a,b,c int16)
+{
+	d := a%c;
+	if d != b {
+		panicln("i16", a, b, c, d);
+	}
+}
+
+func
+i16run()
+{
+	var a, b int16;
+
+	for i:=0; i<Count; i++ {
+		a = i16rand();
+
+		b = a%1;	i16test(a,b,1);
+		b = a%2;	i16test(a,b,2);
+		b = a%3;	i16test(a,b,3);
+		b = a%4;	i16test(a,b,4);
+		b = a%5;	i16test(a,b,5);
+		b = a%6;	i16test(a,b,6);
+		b = a%7;	i16test(a,b,7);
+		b = a%8;	i16test(a,b,8);
+		b = a%10;	i16test(a,b,10);
+		b = a%16;	i16test(a,b,16);
+		b = a%20;	i16test(a,b,20);
+		b = a%32;	i16test(a,b,32);
+		b = a%60;	i16test(a,b,60);
+		b = a%64;	i16test(a,b,64);
+		b = a%128;	i16test(a,b,128);
+		b = a%256;	i16test(a,b,256);
+		b = a%16384;	i16test(a,b,16384);
+
+		b = a%-1;	i16test(a,b,-1);
+		b = a%-2;	i16test(a,b,-2);
+		b = a%-3;	i16test(a,b,-3);
+		b = a%-4;	i16test(a,b,-4);
+		b = a%-5;	i16test(a,b,-5);
+		b = a%-6;	i16test(a,b,-6);
+		b = a%-7;	i16test(a,b,-7);
+		b = a%-8;	i16test(a,b,-8);
+		b = a%-10;	i16test(a,b,-10);
+		b = a%-16;	i16test(a,b,-16);
+		b = a%-20;	i16test(a,b,-20);
+		b = a%-32;	i16test(a,b,-32);
+		b = a%-60;	i16test(a,b,-60);
+		b = a%-64;	i16test(a,b,-64);
+		b = a%-128;	i16test(a,b,-128);
+		b = a%-256;	i16test(a,b,-256);
+		b = a%-16384;	i16test(a,b,-16384);
+	}
+}
+
+func
+u16rand() uint16
+{
+	a := uint16(rand.Uint32());
+	a >>= uint(rand.Intn(16));
+	return a;
+}
+
+func
+u16test(a,b,c uint16)
+{
+	d := a%c;
+	if d != b {
+		panicln("u16", a, b, c, d);
+	}
+}
+
+func
+u16run()
+{
+	var a, b uint16;
+
+	for i:=0; i<Count; i++ {
+		a = u16rand();
+
+		b = a%1;	u16test(a,b,1);
+		b = a%2;	u16test(a,b,2);
+		b = a%3;	u16test(a,b,3);
+		b = a%4;	u16test(a,b,4);
+		b = a%5;	u16test(a,b,5);
+		b = a%6;	u16test(a,b,6);
+		b = a%7;	u16test(a,b,7);
+		b = a%8;	u16test(a,b,8);
+		b = a%10;	u16test(a,b,10);
+		b = a%16;	u16test(a,b,16);
+		b = a%20;	u16test(a,b,20);
+		b = a%32;	u16test(a,b,32);
+		b = a%60;	u16test(a,b,60);
+		b = a%64;	u16test(a,b,64);
+		b = a%128;	u16test(a,b,128);
+		b = a%256;	u16test(a,b,256);
+		b = a%16384;	u16test(a,b,16384);
+	}
+}
+
+func	xtest()
+
+func
+main()
+{
+	xtest();
+	i64run();
+	u64run();
+	i32run();
+	u32run();
+	i16run();
+	u16run();
+}
+
+func
+xtest()
+{
+}