From: ceriel <none@none>
Date: Wed, 3 Aug 1988 23:31:40 +0000 (+0000)
Subject: some modifications to improve speed (sorry, I mean, make a bit less slow)
X-Git-Tag: release-5-5~2956
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=2a9fe2a774ec95a45932fe14b77fd3305180b437;p=ack.git

some modifications to improve speed (sorry, I mean, make a bit less slow)
---

diff --git a/mach/proto/fp/FP.script b/mach/proto/fp/FP.script
index e77da5f37..38213b181 100644
--- a/mach/proto/fp/FP.script
+++ b/mach/proto/fp/FP.script
@@ -34,10 +34,10 @@ g/_sub_ext/s//.sub_ext/g
 g/_zrf_ext/s//.zrf_ext/g
 g/_compact/s//.compact/g
 g/_extend/s//.extend/g
-g/_load4/s//.load4/g
-g/_store4/s//.store4/g
 g/_b32_add/s//.b32_add/g
 g/_b64_add/s//.b64_add/g
 g/_b64_sft/s//.b64_sft/g
+g/_b64_rsft/s//.b64_rsft/g
+g/_b64_lsft/s//.b64_lsft/g
 w
 q
diff --git a/mach/proto/fp/add_ext.c b/mach/proto/fp/add_ext.c
index 9671da36e..11783ecf2 100644
--- a/mach/proto/fp/add_ext.c
+++ b/mach/proto/fp/add_ext.c
@@ -15,7 +15,7 @@ add_ext(e1,e2)
 register EXTEND	*e1,*e2;
 {
 	if (b64_add(&e1->m1,&e2->m1)) {	/* addition carry */
-		b64_sft(&e1->m1,1);	/* shift mantissa one bit RIGHT */
+		b64_rsft(&e1->m1);	/* shift mantissa one bit RIGHT */
 		e1->m1 |= 0x80000000L;	/* set max bit	*/
 		e1->exp++;		/* increase the exponent */
 	}
diff --git a/mach/proto/fp/adder.c b/mach/proto/fp/adder.c
index d116d7d65..af5396546 100644
--- a/mach/proto/fp/adder.c
+++ b/mach/proto/fp/adder.c
@@ -55,34 +55,8 @@ register	B64	*e1,*e2;
 b32_add(e1,e2)
 register	unsigned long	*e1,*e2;
 {
-	register	int	carry;
-
-	if (*e1 & *e2 & MAXBIT) /* both max_bits are set */
-		carry = TRUE;	 /* so there is a carry	*/
-	else 
-		carry = ((*e1 | *e2) & MAXBIT)
-				/* only one is set - might be a carry */
-			? UNKNOWN
-				/* both are clear - no carry */
-			: FALSE;
-# ifdef EXT_DEBUG
-	fflush(stdout);
-	printf("\t\t\t\t\tb32_add: overflow before add(%d) test(%d)\n",
-				carry,(*e1&MAXBIT)?FALSE:TRUE);
-	printf("%08X\n%08X\n",*e1,*e2);
-# endif
+	int	carry = ((unsigned long) 0xFFFFFFFF - *e1 < *e2);
 
 	*e1 += *e2;
-# ifdef EXT_DEBUG
-	printf("%08X\n",*e1);
-	fflush(stdout);
-# endif
-	if (carry != UNKNOWN)
-		return(carry);
-	else
-		/*
-		 * if maxbit in answer is set there is no carry
-		 * return the NAND of this bit
-		 */
-		return((*e1&MAXBIT)?FALSE:TRUE);
+	return carry;
 }
diff --git a/mach/proto/fp/div_ext.c b/mach/proto/fp/div_ext.c
index b75599d8c..883bd5497 100644
--- a/mach/proto/fp/div_ext.c
+++ b/mach/proto/fp/div_ext.c
@@ -40,8 +40,8 @@ EXTEND	*e1,*e2;
 	 * that m1 is quaranteed to be larger if its
 	 * maximum bit is set
 	 */
-	b64_sft(&e1->m1,1);	/* 64 bit shift right */
-	b64_sft(&e2->m1,1);	/* 64 bit shift right */
+	b64_rsft(&e1->m1);	/* 64 bit shift right */
+	b64_rsft(&e2->m1);	/* 64 bit shift right */
 	e1->exp++;
 	e2->exp++;
 	/*	check for underflow, divide by zero, etc	*/
@@ -92,7 +92,7 @@ EXTEND	*e1,*e2;
 		/* first left shift result 1 bit	*/
 		/* this is ALWAYS done			*/
 
-		b64_sft(result,-1);
+		b64_lsft(result);
 
 		/* compare dividend and divisor		*/
 		/* if dividend >= divisor add a bit	*/
@@ -124,7 +124,7 @@ EXTEND	*e1,*e2;
 		error = ((*lp | *(lp+1)) != 0L) ? 1 : 0;
 		if (error)	{	/* more work */
 			/*	assume max bit == 0 (see above)	*/
-			b64_sft(&e1->m1,-1);
+			b64_lsft(&e1->m1);
 			continue;
 		}
 		else
diff --git a/mach/proto/fp/fif4.c b/mach/proto/fp/fif4.c
index c1093dc0d..1142dbb73 100644
--- a/mach/proto/fp/fif4.c
+++ b/mach/proto/fp/fif4.c
@@ -12,29 +12,33 @@
 #include "FP_types.h"
 #include "FP_shift.h"
 
-_float mlf4();
 _float sbf4();
 
 fif4(x,y)
 _float	x,y;
 {
-	EXTEND e;
 
-	y = mlf4(x,y);
-	extend((_double *)&y,&e,sizeof(SINGLE));
-	e.exp--;			/* additional bias correction */
-	if (e.exp < 1) {
+	EXTEND	e1,e2;
+
+	extend((_double *)&y,&e1,sizeof(_float));
+	extend((_double *)&x,&e2,sizeof(_float));
+		/* do a multiply */
+	mul_ext(&e1,&e2);
+	e2 = e1;
+	compact(&e2, (_double *)&y, sizeof(_float));
+	e1.exp--;			/* additional bias correction */
+	if (e1.exp < 1) {
 		x = 0;
 		return;
 	}
-	if (e.exp > 31 - SGL_M1LEFT) {
+	if (e1.exp > 31 - SGL_M1LEFT) {
 		x = y;
 		y = 0;
 		return;
 	}
-	b64_sft(&e.m1, 64 - e.exp);
-	b64_sft(&e.m1, e.exp - 64);	/* "loose" low order bits */
-	e.exp++;
-	compact(&e,(_double *) &x, sizeof(SINGLE));
+	b64_sft(&e1.m1, 64 - e1.exp);
+	b64_sft(&e1.m1, e1.exp - 64);	/* "loose" low order bits */
+	e1.exp++;
+	compact(&e1,(_double *) &x, sizeof(SINGLE));
 	y = sbf4(x, y);
 }
diff --git a/mach/proto/fp/fif8.c b/mach/proto/fp/fif8.c
index 9fe768020..6a938cc2e 100644
--- a/mach/proto/fp/fif8.c
+++ b/mach/proto/fp/fif8.c
@@ -12,32 +12,36 @@
 #include "FP_types.h"
 #include "FP_shift.h"
 
-_double mlf8();
 _double sbf8();
 
 fif8(x,y)
 _double	x,y;
 {
-	EXTEND e;
 
-	y = mlf8(x,y);
-	extend((_double *)&y,&e,sizeof(DOUBLE));
-	e.exp--;			/* additional bias correction */
-	if (e.exp < 1) {
+	EXTEND	e1,e2;
+
+	extend(&y,&e1,sizeof(_double));
+	extend(&x,&e2,sizeof(_double));
+		/* do a multiply */
+	mul_ext(&e1,&e2);
+	e2 = e1;
+	compact(&e2, &y, sizeof(_double));
+	e1.exp--;			/* additional bias correction */
+	if (e1.exp < 1) {
 		x.__double[0] = 0;
 		x.__double[1] = 0;
 		return;
 	}
-	if (e.exp > 63 - DBL_M1LEFT) {
+	if (e1.exp > 63 - DBL_M1LEFT) {
 		x.__double[0] = y.__double[0];
 		x.__double[1] = y.__double[1];
 		y.__double[0] = 0;
 		y.__double[1] = 0;
 		return;
 	}
-	b64_sft(&e.m1, 64 - e.exp);
-	b64_sft(&e.m1, e.exp - 64);	/* "loose" low order bits */
-	e.exp++;
-	compact(&e, &x, sizeof(DOUBLE));
+	b64_sft(&e1.m1, 64 - e1.exp);
+	b64_sft(&e1.m1, e1.exp - 64);	/* "loose" low order bits */
+	e1.exp++;
+	compact(&e1, &x, sizeof(DOUBLE));
 	y = sbf8(x, y);
 }
diff --git a/mach/proto/fp/shifter.c b/mach/proto/fp/shifter.c
index 5f47f8c4a..086df3338 100644
--- a/mach/proto/fp/shifter.c
+++ b/mach/proto/fp/shifter.c
@@ -11,17 +11,42 @@ b64_sft(e1,n)
 B64	*e1;
 int	n;
 {
-	if (n>0) do	{	/* RIGHT shift n bits */
-		e1->l_32 >>= 1;		/* shift 64 bits	*/
-		if (e1->h_32 & 1)
-			e1->l_32 |= 0x80000000L;
-		e1->h_32 >>= 1;
-	} while	(--n);
-	else			/* LEFT shift n bits	*/
-		while (n++)	{
-		e1->h_32 <<= 1;		/* shift 64 bits	*/
-		if (e1->l_32 & 0x80000000L)
-			e1->h_32 |= 1;
-		e1->l_32 <<= 1;
+	if (n >= 32) {
+		e1->l_32 = e1->h_32;
+		e1->h_32 = 0;
+		n -= 32;
 	}
+	if (n > 0) {
+		e1->l_32 = (e1->l_32 >> n) | (e1->h_32 << (32 - n));
+		e1->h_32 >>= n;
+		return;
+	}
+	n = -n;
+	if (n >= 32) {
+		e1->h_32 = e1->l_32;
+		e1->l_32 = 0;
+		n -= 32;
+	}
+	if (n > 0) {
+		e1->h_32 = (e1->h_32 << n) | (e1->l_32 >> (32 - n));
+		e1->l_32 <<= n;
+	}
+}
+
+b64_lsft(e1)
+B64	*e1;
+{
+	/*	shift left 1 bit */
+	e1->h_32 <<= 1;
+	if (e1->l_32 & 0x80000000L) e1->h_32 |= 1;
+	e1->l_32 <<= 1;
+}
+
+b64_rsft(e1)
+B64	*e1;
+{
+	/*	shift right 1 bit */
+	e1->l_32 >>= 1;
+	if (e1->h_32 & 1) e1->l_32 |= 0x80000000L;
+	e1->h_32 >>= 1;
 }