first stub for softfloats, intercepts float instructions and skips

        them in the stream.

R=rsc
https://golang.org/cl/174052

1 files changed, 70 insertions, 0 deletions

diff --git a/src/cmd/5l/softfloat.c b/src/cmd/5l/softfloat.c
new file mode 100644
index 0000000000..f5a146feb0
--- /dev/null
+++ b/src/cmd/5l/softfloat.c
@@ -0,0 +1,70 @@
+// 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.
+
+#define	EXTERN
+#include	"l.h"
+
+void
+softfloat()
+{
+	Prog *p, *prev, *psfloat;
+	Sym *symsfloat;
+	int wasfloat;
+	
+	symsfloat = lookup("_sfloat", 0);
+	psfloat = P;
+	if(symsfloat->type == STEXT)
+	for(p = firstp; p != P; p = p->link) {
+		if(p->as == ATEXT) {
+			if(p->from.sym == symsfloat) {
+				psfloat = p;
+				break;
+			}
+		}
+	}
+
+	wasfloat = 0;
+	p = firstp;
+	prev = P;
+	for(p = firstp; p != P; p = p->link) {
+		switch(p->as) {
+		case AMOVWD:
+		case AMOVWF:
+		case AMOVDW:
+		case AMOVFW:
+		case AMOVFD:
+		case AMOVDF:
+		case AMOVF:
+		case AMOVD:
+		case ACMPF:
+		case ACMPD:
+		case AADDF:
+		case AADDD:
+		case ASUBF:
+		case ASUBD:
+		case AMULF:
+		case AMULD:
+		case ADIVF:
+		case ADIVD:
+			if (psfloat == P)
+				diag("floats used with _sfloat not defined");
+			if (!wasfloat) {
+				if (prev == P)
+					diag("float instruction without predecessor TEXT");
+				// BL		_sfloat(SB)
+				prev = appendp(prev);
+				prev->as = ABL;
+ 				prev->to.type = D_BRANCH;
+				prev->to.sym = symsfloat;
+				prev->cond = psfloat;
+				
+				wasfloat = 1;
+			}
+			break;
+		default:
+			wasfloat = 0;
+		}
+		prev = p;
+	}
+}