From ecef616599d5ec4fd5d42e67d0dc779a0630079b Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@keithp.com>
Date: Fri, 18 Nov 2016 21:14:47 -0800
Subject: [PATCH] altos/lisp: Use poly stashes for stacks

Saves some memory.

Signed-off-by: Keith Packard <keithp@keithp.com>
---
 src/lisp/ao_lisp.h        | 24 +++++++++++--------
 src/lisp/ao_lisp_mem.c    | 49 +++++++++++----------------------------
 src/lisp/ao_lisp_string.c |  2 +-
 3 files changed, 29 insertions(+), 46 deletions(-)

diff --git a/src/lisp/ao_lisp.h b/src/lisp/ao_lisp.h
index cea834fc..e238d4fe 100644
--- a/src/lisp/ao_lisp.h
+++ b/src/lisp/ao_lisp.h
@@ -468,22 +468,26 @@ struct ao_lisp_cons *
 ao_lisp_cons_fetch(int id);
 
 void
-ao_lisp_string_stash(int id, char *string);
+ao_lisp_poly_stash(int id, ao_poly poly);
 
-char *
-ao_lisp_string_fetch(int id);
+ao_poly
+ao_lisp_poly_fetch(int id);
 
 void
-ao_lisp_stack_stash(int id, struct ao_lisp_stack *stack);
+ao_lisp_string_stash(int id, char *string);
 
-struct ao_lisp_stack *
-ao_lisp_stack_fetch(int id);
+char *
+ao_lisp_string_fetch(int id);
 
-void
-ao_lisp_poly_stash(int id, ao_poly poly);
+static inline void
+ao_lisp_stack_stash(int id, struct ao_lisp_stack *stack) {
+	ao_lisp_poly_stash(id, ao_lisp_stack_poly(stack));
+}
 
-ao_poly
-ao_lisp_poly_fetch(int id);
+static inline struct ao_lisp_stack *
+ao_lisp_stack_fetch(int id) {
+	return ao_lisp_poly_stack(ao_lisp_poly_fetch(id));
+}
 
 /* cons */
 extern const struct ao_lisp_type ao_lisp_cons_type;
diff --git a/src/lisp/ao_lisp_mem.c b/src/lisp/ao_lisp_mem.c
index 0dfad1d7..2599f719 100644
--- a/src/lisp/ao_lisp_mem.c
+++ b/src/lisp/ao_lisp_mem.c
@@ -144,8 +144,7 @@ struct ao_lisp_root {
 
 static struct ao_lisp_cons 	*save_cons[2];
 static char			*save_string[2];
-static struct ao_lisp_stack	*save_stack[3];
-static ao_poly			save_poly[2];
+static ao_poly			save_poly[3];
 
 static const struct ao_lisp_root	ao_lisp_root[] = {
 	{
@@ -156,25 +155,13 @@ static const struct ao_lisp_root	ao_lisp_root[] = {
 		.type = &ao_lisp_cons_type,
 		.addr = (void **) &save_cons[1],
 	},
-	{
-		.type = &ao_lisp_stack_type,
-		.addr = (void **) &save_stack[0]
-	},
-	{
-		.type = &ao_lisp_stack_type,
-		.addr = (void **) &save_stack[1]
-	},
-	{
-		.type = &ao_lisp_stack_type,
-		.addr = (void **) &save_stack[2]
-	},
 	{
 		.type = &ao_lisp_string_type,
-		.addr = (void **) &save_string[0]
+		.addr = (void **) &save_string[0],
 	},
 	{
 		.type = &ao_lisp_string_type,
-		.addr = (void **) &save_string[1]
+		.addr = (void **) &save_string[1],
 	},
 	{
 		.type = NULL,
@@ -184,6 +171,10 @@ static const struct ao_lisp_root	ao_lisp_root[] = {
 		.type = NULL,
 		.addr = (void **) &save_poly[1]
 	},
+	{
+		.type = NULL,
+		.addr = (void **) &save_poly[2]
+	},
 	{
 		.type = &ao_lisp_atom_type,
 		.addr = (void **) &ao_lisp_atoms
@@ -833,17 +824,17 @@ ao_lisp_cons_fetch(int id)
 }
 
 void
-ao_lisp_stack_stash(int id, struct ao_lisp_stack *stack)
+ao_lisp_poly_stash(int id, ao_poly poly)
 {
-	save_stack[id] = stack;
+	save_poly[id] = poly;
 }
 
-struct ao_lisp_stack *
-ao_lisp_stack_fetch(int id)
+ao_poly
+ao_lisp_poly_fetch(int id)
 {
-	struct ao_lisp_stack *stack = save_stack[id];
-	save_stack[id] = NULL;
-	return stack;
+	ao_poly poly = save_poly[id];
+	save_poly[id] = AO_LISP_NIL;
+	return poly;
 }
 
 void
@@ -859,16 +850,4 @@ ao_lisp_string_fetch(int id)
 	save_string[id] = NULL;
 	return string;
 }
-void
-ao_lisp_poly_stash(int id, ao_poly poly)
-{
-	save_poly[id] = poly;
-}
 
-ao_poly
-ao_lisp_poly_fetch(int id)
-{
-	ao_poly poly = save_poly[id];
-	save_poly[id] = AO_LISP_NIL;
-	return poly;
-}
diff --git a/src/lisp/ao_lisp_string.c b/src/lisp/ao_lisp_string.c
index 207d4f3b..cd7b27a9 100644
--- a/src/lisp/ao_lisp_string.c
+++ b/src/lisp/ao_lisp_string.c
@@ -104,9 +104,9 @@ ao_lisp_string_unpack(char *a)
 		ao_lisp_cons_stash(1, tail);
 		ao_lisp_string_stash(0, a);
 		struct ao_lisp_cons	*n = ao_lisp_cons_cons(ao_lisp_int_poly(c), NULL);
+		a = ao_lisp_string_fetch(0);
 		cons = ao_lisp_cons_fetch(0);
 		tail = ao_lisp_cons_fetch(1);
-		a = ao_lisp_string_fetch(0);
 
 		if (!n) {
 			cons = NULL;
-- 
2.30.2