From 5053f2a183e02fadae48814c6bd297d752a4903c Mon Sep 17 00:00:00 2001
From: ceriel <none@none>
Date: Thu, 14 May 1987 14:58:21 +0000
Subject: [PATCH] generate code for ACK assembler, including floats

---
 mach/pdp/cg/mach.c | 44 +++++++++++++++++++++++++++++++++++---------
 mach/pdp/cg/mach.h |  2 +-
 2 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/mach/pdp/cg/mach.c b/mach/pdp/cg/mach.c
index 37d4bf5ee..b15dbfc93 100644
--- a/mach/pdp/cg/mach.c
+++ b/mach/pdp/cg/mach.c
@@ -50,24 +50,50 @@ con_mult(sz) word sz; {
  * The next function is difficult to do when not running on a PDP 11 or VAX
  * The strategy followed is to assume the code generator is running on a PDP 11
  * unless the ACK_ASS define  is on.
- * In the last case floating point constants are simply not handled
  */
 
 con_float() {
 #ifdef ACK_ASS
-	static int been_here;
+	double f, f1;
+	double atof(), frexp(), modf();
+	int i, j;
+	int sign = 0;
+	int fraction ;
 
 	if (argval != 4 && argval != 8)
 		fatal("bad fcon size");
-	fprintf(codefile,".data4\t");
-	if (argval == 8)
-		fprintf(codefile,"F_DUM,");
-	fprintf(codefile,"F_DUM\n");
-	if ( !been_here++)
-		fprintf(stderr,"Warning : dummy float-constant(s)\n");
+	f = atof(str);
+	f = frexp(f, &i);
+	if (f < 0) {
+		f = -f;
+		sign = 1;
+	}
+	while (f < 0.5) {
+		f += f;
+		i --;
+	}
+	f = modf(2 * f, &f1); /* hidden bit */
+	i = (i + 128) & 0377;
+	fraction = (sign << 15) | (i << 7);
+	for (j = 6; j>= 0; j--) {
+		if (f >= 0.5) fraction |= (1 << j);
+		f = modf(2*f, &f1);
+	}
+	fprintf(codefile, ".data2 0%o", fraction);
+	for (i = argval / 2 - 1; i; i--) {
+		fraction = 0;
+		for (j = 15; j>= 0; j--) {
+			if (f >= 0.5) fraction |= (1 << j);
+			f = modf(2*f, &f1);
+		}
+		fprintf(codefile, ", 0%o", fraction);
+	}
+	putc('\n', codefile);
 #else
 	double f;
-	register short *p,i;
+	double atof();
+	int i;
+	short *p;
 
 	if (argval != 4 && argval != 8)
 		fatal("bad fcon size");
diff --git a/mach/pdp/cg/mach.h b/mach/pdp/cg/mach.h
index 64bddd106..4c2395f18 100644
--- a/mach/pdp/cg/mach.h
+++ b/mach/pdp/cg/mach.h
@@ -8,7 +8,7 @@
  * or for the standard UNIX V7 assembler.
  * If on code is generated for the ACK assembler.
  */
-/* #define ACK_ASS	/* code for ACK assembler */
+#define ACK_ASS	/* code for ACK assembler */
 
 #ifdef ACK_ASS
 #define COMMENTCHAR '!'
-- 
2.34.1