Simplify flt_arith now that mantissa uses uint32_t.

It seems that someone wanted to build flt_arith with a compiler that
had long but not unsigned long.  This required extra code to
accomplish unsigned right shift, unsigned division, and unsigned
comparison using the signed operations.  Now that we use uint32_t, we
can simply use the unsigned operations and remove the ucmp() function.
We have similar code in mach/proto/fp/ and in
lang/cem/libcc.ansi/stdlib/ext_comp.c where we use the unsigned
operations.

Some long variables become uint32_t, and some masks with 0xFFFFFFFF
disappear because uint32_t has only 32 bits.

Update flt_arith.3 to show that mantissa uses uint32_t.

Provide a target to install modules/src/flt_arith/test.c as flt_test
so I can run the tests.

modules/src/flt_arith/b64_add.c

@@ -5,6 +5,7 @@
 
 /* $Id$ */
 
+#include <stdint.h>
 #include "flt_misc.h"
 
 int
@@ -15,16 +16,15 @@ flt_b64_add(e1,e2)
 	int	carry;
 
 	/* add higher pair of 32 bits */
-	overflow = ucmp((long)0xFFFFFFFF - e1->flt_h_32, e2->flt_h_32) < 0;
+	overflow = (0xFFFFFFFFUL - e1->flt_h_32 < e2->flt_h_32);
 	e1->flt_h_32 += e2->flt_h_32;
 
 	/* add lower pair of 32 bits */
-	carry = ucmp((long)0xFFFFFFFF - e1->flt_l_32, e2->flt_l_32) < 0;
+	carry = (0xFFFFFFFFUL - e1->flt_l_32 < e2->flt_l_32);
 	e1->flt_l_32 += e2->flt_l_32;
 
-	if ((carry) && ((++e1->flt_h_32 &~0xFFFFFFFF) || e1->flt_h_32 == 0)) {
+	if ((carry) && (++e1->flt_h_32 == 0))
-		e1->flt_h_32 = 0;
 		return(1);		/* had a 64 bit overflow */
-	}
+
 	return(overflow);	/* return status from higher add */
 }

modules/src/flt_arith/b64_sft.c

@@ -23,12 +23,10 @@ flt_b64_sft(e,n)
 		n -= 32;
 	}
 	if (n > 0) {
-		e->flt_l_32 = (e->flt_l_32 >> 1) & 0x7FFFFFFF;
+		e->flt_l_32 >>= n;
-		e->flt_l_32 >>= (n - 1);
 		if (e->flt_h_32 != 0) {
-			e->flt_l_32 |= (e->flt_h_32 << (32 - n)) & 0xFFFFFFFF;
+			e->flt_l_32 |= (e->flt_h_32 << (32 - n));
-			e->flt_h_32 = (e->flt_h_32 >> 1) & 0x7FFFFFFF;
+			e->flt_h_32 >>= n;
-			e->flt_h_32 >>= (n - 1);
 		}
 	}
 	n = -n;
@@ -38,11 +36,10 @@ flt_b64_sft(e,n)
 		n -= 32;
 	}
 	if (n > 0) {
-		e->flt_h_32 = (e->flt_h_32 << n) & 0xFFFFFFFF;
+		e->flt_h_32 <<= n;
 		if (e->flt_l_32 != 0) {
-			long l = (e->flt_l_32 >> 1) & 0x7FFFFFFF;
+			e->flt_h_32 |= (e->flt_l_32 >> (32 - n));
-			e->flt_h_32 |= (l >> (31 - n));
+			e->flt_l_32 <<= n;
-			e->flt_l_32 = (e->flt_l_32 << n) & 0xFFFFFFFF;
 		}
 	}
 }

modules/src/flt_arith/build.lua

@@ -15,7 +15,6 @@ clibrary {
 		"./flt_umin.c",
 		"./flt_chk.c",
 		"./split.c",
-		"./ucmp.c",
 	},
 	hdrs = { "./flt_arith.h" },
 	deps = {
@@ -24,4 +23,18 @@ clibrary {
 	}
 }
 
+-- The test program isn't built by default.  Here is a target
+-- modules/src/flt_arith+pkg to install it as flt_test
 
+cprogram {
+	name = "test",
+	srcs = { "./test.c" },
+	deps = { "+lib" },
+}
+
+installable {
+	name = "pkg",
+	map = {
+		["$(INSDIR)/bin/flt_test"] = "+test",
+	},
+}

modules/src/flt_arith/flt_add.c

@@ -44,11 +44,10 @@ flt_add(e1,e2,e3)
 	}
 	if (e1->flt_sign != e2->flt_sign) {
 		/* e2 + e1 = e2 - (-e1) */
-		int tmp = ucmp(e1->m1, e2->m1);
+		if (e1->m1 > e2->m1 ||
-		int tmp2 = ucmp(e1->m2, e2->m2);
+		    (e1->m1 == e2->m1 && e1->m2 > e2->m2)) {
-		if (tmp > 0 || (tmp == 0 && tmp2 > 0)) {
                 	/*      abs(e1) > abs(e2) */
-                	if (tmp2 < 0) {
+			if (e1->m2 < e2->m2) {
                         	e1->m1 -= 1;    /* carry in */
                 	}
                 	e1->m1 -= e2->m1;
@@ -56,7 +55,7 @@ flt_add(e1,e2,e3)
                 	*e3 = *e1;
         	}
         	else {
-                	if (tmp2 > 0)
+			if (e1->m2 > e2->m2)
                         	e2->m1 -= 1;    /* carry in */
                 	e2->m1 -= e1->m1;
                 	e2->m2 -= e1->m2;

modules/src/flt_arith/flt_arith.3

@@ -9,8 +9,8 @@ flt_arith \- high precision floating point arithmetic
 .if t .ta 3m 13m 22m
 .if n .ta 5m 25m 40m
 struct flt_mantissa {
-	long	flt_h_32;	/* high order 32 bits of mantissa */
+	uint32_t flt_h_32;	/* high order 32 bits of mantissa */
-	long	flt_l_32;	/* low order 32 bits of mantissa */
+	uint32_t flt_l_32;	/* low order 32 bits of mantissa */
 };
 
 typedef struct {

modules/src/flt_arith/flt_div.c

@@ -5,14 +5,15 @@
 
 /* $Id$ */
 
+#include <stdint.h>
 #include "flt_misc.h"
 
 void
 flt_div(e1,e2,e3)
 	register flt_arith *e1,*e2,*e3;
 {
-	long	result[2];
+	uint32_t result[2];
-	register long	*lp;
+	register uint32_t *rp;
 	unsigned short u[9], v[5];
 	register int j;
 	register unsigned short *u_p = u;
@@ -44,7 +45,7 @@ flt_div(e1,e2,e3)
 	while (! v[maxv]) maxv--;
 	result[0] = 0;
 	result[1] = 0;
-	lp = result;
+	rp = result;
 
 	/*
 	 * Use an algorithm of Knuth (The art of programming, Seminumerical
@@ -52,35 +53,25 @@ flt_div(e1,e2,e3)
 	 * with base 65536. 
 	 */
 	for (j = 0; j <= 3; j++, u_p++) {
-		long q_est, temp;
+		uint32_t q_est, temp;
-		long v1 = v[1];
 
-		if (j == 2) lp++;
+		if (j == 2) rp++;
 		if (u_p[0] == 0 && u_p[1] < v[1]) continue;
-		temp = ((long)u_p[0] << 16) + u_p[1];
+		temp = ((uint32_t)u_p[0] << 16) + u_p[1];
 		if (u_p[0] >= v[1]) {
-			q_est = 0x0000FFFFL;
+			q_est = 0x0000FFFFUL;
 		}
 		else if (v[1] == 1) {
 			q_est = temp;
 		}
-		else if (temp >= 0) {
-			q_est = temp / v1;
-		}
 		else {
-			long rem;
+			q_est = temp / v[1];
-			q_est = (0x7FFFFFFF/v1)+((temp&0x7FFFFFFF)/v1);
-			rem = (0x7FFFFFFF%v1)+((temp&0x7FFFFFFF)%v1)+1;
-			while (rem >= v1) {
-				q_est++;
-				rem -= v1;
-			}
 		}
-		temp -= q_est * v1;
+		temp -= q_est * v[1];
 		while (!(temp&0xFFFF0000) &&
-		       ucmp((long)v[2]*q_est,(temp<<16)+(long)u_p[2]) > 0) {
+		       v[2]*q_est > (temp<<16)+u_p[2]) {
 			q_est--;
-			temp += v1;
+			temp += v[1];
 		}
 		/*	Now, according to Knuth, we have an estimate of the
 			quotient, that is either correct or one too big, but
@@ -88,11 +79,11 @@ flt_div(e1,e2,e3)
 		*/
 		if (q_est != 0)  {
 			int i;
-			long k = 0;
+			uint32_t k = 0;
 			int borrow = 0;
 
 			for (i = maxv; i > 0; i--) {
-				long tmp = q_est * (long)v[i] + k + borrow;
+				uint32_t tmp = q_est * v[i] + k + borrow;
 				unsigned short md = tmp & 0xFFFF;
 
 				borrow = (md > u_p[i]);
@@ -100,7 +91,7 @@ flt_div(e1,e2,e3)
 				k = (tmp >> 16) & 0xFFFF;
 			}
 			k += borrow;
-			borrow = (long)u_p[0] < k;
+			borrow = u_p[0] < k;
 			u_p[0] -= k;
 
 			if (borrow) {
@@ -110,15 +101,15 @@ flt_div(e1,e2,e3)
 				q_est--;
 				borrow = 0;
 				for (i = maxv; i > 0; i--) {
-					long tmp 
+					uint32_t tmp
-					    = v[i]+(long)u_p[i]+borrow;
+					    = v[i]+(uint32_t)u_p[i]+borrow;
-					
+
 					u_p[i] = tmp & 0xFFFF;
 					borrow = (tmp >> 16) & 0xFFFF;
 				}
 				u_p[0] += borrow;
 			}
-			*lp |= (j & 1) ? q_est : (q_est<<16);
+			*rp |= (j & 1) ? q_est : (q_est<<16);
 		}
 	}
 	e3->m1 = result[0];

modules/src/flt_arith/flt_misc.h

@@ -15,13 +15,11 @@
 #define EXT_MIN		(-16384)	/* min exponent */
 
 /* hiding of names: */
-#define ucmp		_flt_ucmp
 #define flt_nrm		_flt_nrm
 #define flt_chk		_flt_chk
 #define flt_b64_add	_flt_64add
 #define flt_split	_flt_split
 
-int ucmp(long, long);
 void flt_nrm(flt_arith *);
 void flt_chk(flt_arith *);
 int flt_b64_add(struct flt_mantissa *, struct flt_mantissa *);

modules/src/flt_arith/flt_mul.c

@@ -5,6 +5,7 @@
 
 /* $Id$ */
 
+#include <stdint.h>
 #include "flt_misc.h"
 
 void
@@ -43,9 +44,9 @@ flt_mul(e1,e2,e3)
 	 */
 	for(i=4, pres = &result[4];i--;pres--) if (mp[i]) {
 		unsigned short k = 0;
-		long mpi = mp[i];
+		uint32_t mpi = mp[i];
 		for(j=4;j--;) {
-			long tmp = (long)pres[j] + k;
+			long tmp = (uint32_t)pres[j] + k;
 			if (mc[j]) tmp += mpi * mc[j];
 			pres[j] = tmp & 0xFFFF;
 			k = (tmp >> 16) & 0xFFFF;
@@ -64,12 +65,12 @@ flt_mul(e1,e2,e3)
 	/*
 	 *	combine the registers to a total
 	 */
-	e3->m1 = ((long)result[0] << 16) + result[1];
+	e3->m1 = ((uint32_t)result[0] << 16) + result[1];
-	e3->m2 = ((long)result[2] << 16) + result[3];
+	e3->m2 = ((uint32_t)result[2] << 16) + result[3];
 	if (result[4] & 0x8000) {
-		if (++e3->m2 == 0 || (e3->m2 & ~ 0xFFFFFFFF)) {
+		if (++e3->m2 == 0) {
 			e3->m2 = 0;
-			if (++e3->m1 == 0 || (e3->m1 & ~ 0xFFFFFFFF)) {
+			if (++e3->m1 == 0) {
 				e3->m1 = 0x80000000;
 				e3->flt_exp++;
 			}

modules/src/flt_arith/flt_nrm.c

@@ -5,6 +5,7 @@
 
 /* $Id$ */
 
+#include <stdint.h>
 #include "flt_misc.h"
 
 void
@@ -24,8 +25,8 @@ flt_nrm(e)
 		e->m2 = 0L;
 		e->flt_exp -= 32;
 	}
-	if ((e->m1 & 0x80000000) == 0) {
+	if ((e->m1 & 0x80000000UL) == 0) {
-		long l = 0x40000000;
+		uint32_t l = 0x40000000UL;
 		int cnt = -1;
 
 		while (! (l & e->m1)) {

modules/src/flt_arith/test.c

@@ -1,3 +1,5 @@
+#include <stdio.h>
+#include <string.h>
 #include "flt_arith.h"
 
 struct tests {
@@ -22,6 +24,7 @@ struct tests {
 	{ 0, 0, 0, 0}
 };
 
+int
 main()
 {
 	register struct tests *p = tests;
@@ -31,7 +34,7 @@ main()
 		if (! dotest(p)) exit_status = 1;
 		p++;
 	}
-	exit(exit_status);
+	return exit_status;
 }
 
 int

modules/src/flt_arith/ucmp.c

@@ -1,21 +0,0 @@
-/*
-  (c) copyright 1989 by the Vrije Universiteit, Amsterdam, The Netherlands.
-  See the copyright notice in the ACK home directory, in the file "Copyright".
-*/
-
-/* $Id$ */
-
-#include "flt_misc.h"
-
-int
-ucmp(l1,l2)
-	long l1,l2;
-{
-	if (l1 == l2) return 0;
-	if (l2 >= 0) {
-		if (l1 > l2 || l1 < 0) return 1;
-		return -1;
-	}
-	if (l1 >= 0 || l1 < l2) return -1;
-	return 1;
-}