From d83b994da62f88d9bee5ab62702cb560e9c3ad48 Mon Sep 17 00:00:00 2001
From: Ken Thompson <ken@golang.org>
Date: Fri, 6 Jun 2008 20:43:29 -0700
Subject: [PATCH] div and mod operators

SVN=121576
---
 src/cmd/6g/cgen.c  |  7 ++++--
 src/cmd/6g/gen.c   | 53 ++++++++++++++++++++++++++++++++++++++++++++++
 src/cmd/6g/gg.h    |  1 +
 src/cmd/6g/gsubr.c | 10 +++++++++
 4 files changed, 69 insertions(+), 2 deletions(-)

diff --git a/src/cmd/6g/cgen.c b/src/cmd/6g/cgen.c
index ef77fa19fd..07bb11c3b2 100644
--- a/src/cmd/6g/cgen.c
+++ b/src/cmd/6g/cgen.c
@@ -112,9 +112,7 @@ cgen(Node *n, Node *res)
 		goto sbop;
 
 	// asymmetric binary
-	case OMOD:
 	case OSUB:
-	case ODIV:
 	case OLSH:
 	case ORSH:
 		a = optoas(n->op, nl->type);
@@ -237,6 +235,11 @@ cgen(Node *n, Node *res)
 		cgen_call(n);
 		cgen_callret(n, res);
 		break;
+
+	case OMOD:
+	case ODIV:
+		cgen_div(n->op, nl, nr, res);
+		break;
 	}
 	goto ret;
 
diff --git a/src/cmd/6g/gen.c b/src/cmd/6g/gen.c
index 47e5037640..165a91a83f 100644
--- a/src/cmd/6g/gen.c
+++ b/src/cmd/6g/gen.c
@@ -826,3 +826,56 @@ cgen_as(Node *nl, Node *nr, int op)
 	}
 	cgen(nr, nl);
 }
+
+void
+cgen_div(int op, Node *nl, Node *nr, Node *res)
+{
+	Node n1, n2, n3;
+	int a;
+
+	if(reg[D_AX] || reg[D_DX]) {
+		fatal("registers occupide");
+	}
+
+	a = optoas(op, nl->type);
+
+	// hold down the DX:AX registers
+	nodreg(&n1, types[TINT64], D_AX);
+	nodreg(&n2, types[TINT64], D_DX);
+	regalloc(&n1, nr->type, &n1);
+	regalloc(&n2, nr->type, &n2);
+
+	if(!issigned[nl->type->etype]) {
+		nodconst(&n3, nl->type, 0);
+		gmove(&n3, &n2);
+	}
+
+	if(nl->ullman >= nr->ullman) {
+		cgen(nl, &n1);
+		if(issigned[nl->type->etype])
+			gins(ACDQ, N, N);
+		if(!nr->addable) {
+			regalloc(&n3, nr->type, res);
+			cgen(nr, &n3);
+			gins(a, &n3, N);
+			regfree(&n3);
+		} else
+			gins(a, nr, N);
+	} else {
+		regalloc(&n3, nr->type, res);
+		cgen(nr, &n3);
+		cgen(nl, &n1);
+		if(issigned[nl->type->etype])
+			gins(ACDQ, N, N);
+		gins(a, &n3, N);
+		regfree(&n3);
+	}
+
+	if(op == ODIV)
+		gmove(&n1, res);
+	else
+		gmove(&n2, res);
+
+	regfree(&n1);
+	regfree(&n2);
+}
diff --git a/src/cmd/6g/gg.h b/src/cmd/6g/gg.h
index 5cd31b4aeb..290b10114b 100644
--- a/src/cmd/6g/gg.h
+++ b/src/cmd/6g/gg.h
@@ -117,6 +117,7 @@ void	cgen_call(Node*);
 void	cgen_callmeth(Node*);
 void	cgen_callinter(Node*, Node*);
 void	cgen_callret(Node*, Node*);
+void	cgen_div(int, Node*, Node*, Node*);
 void	genpanic(void);
 int	needconvert(Type*, Type*);
 void	genconv(Type*, Type*);
diff --git a/src/cmd/6g/gsubr.c b/src/cmd/6g/gsubr.c
index 9ced8fe2f5..125e4c8323 100644
--- a/src/cmd/6g/gsubr.c
+++ b/src/cmd/6g/gsubr.c
@@ -1397,36 +1397,46 @@ optoas(int op, Type *t)
 		break;
 
 	case CASE(ODIV, TINT8):
+	case CASE(OMOD, TINT8):
 		a = AIDIVB;
 		break;
 
 	case CASE(ODIV, TUINT8):
+	case CASE(OMOD, TUINT8):
 		a = ADIVB;
 		break;
 
 	case CASE(ODIV, TINT16):
+	case CASE(OMOD, TINT16):
 		a = AIDIVW;
 		break;
 
 	case CASE(ODIV, TUINT16):
+	case CASE(OMOD, TUINT16):
 		a = ADIVW;
 		break;
 
 	case CASE(ODIV, TINT32):
+	case CASE(OMOD, TINT32):
 		a = AIDIVL;
 		break;
 
 	case CASE(ODIV, TUINT32):
 	case CASE(ODIV, TPTR32):
+	case CASE(OMOD, TUINT32):
+	case CASE(OMOD, TPTR32):
 		a = ADIVL;
 		break;
 
 	case CASE(ODIV, TINT64):
+	case CASE(OMOD, TINT64):
 		a = AIDIVQ;
 		break;
 
 	case CASE(ODIV, TUINT64):
 	case CASE(ODIV, TPTR64):
+	case CASE(OMOD, TUINT64):
+	case CASE(OMOD, TPTR64):
 		a = ADIVQ;
 		break;
 
-- 
2.48.1