From 05795807194fad22cb7dcc0d0be36577bd31b836 Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Sat, 1 Jun 2013 20:09:23 +0200
Subject: [PATCH] isl_input.c: accept_div: accept floor/ceil of rational affine
 expression

We may want to print interger divisions as floor(...) instead of [...]
in the future, so we might as well start parsing such expressions.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---
 include/isl/stream.h |  1 +
 isl_input.c          | 23 +++++++++++++++++++++--
 isl_stream.c         |  4 ++++
 isl_test.c           |  4 ++++
 4 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/include/isl/stream.h b/include/isl/stream.h
index 7484af1..d3f65e4 100644
--- a/include/isl/stream.h
+++ b/include/isl/stream.h
@@ -35,6 +35,7 @@ enum isl_token_type { ISL_TOKEN_ERROR = -1,
 			ISL_TOKEN_CEILD, ISL_TOKEN_FLOORD, ISL_TOKEN_MOD,
 			ISL_TOKEN_STRING,
 			ISL_TOKEN_MAP, ISL_TOKEN_AFF,
+			ISL_TOKEN_CEIL, ISL_TOKEN_FLOOR,
 			ISL_TOKEN_LAST };
 
 struct isl_token {
diff --git a/isl_input.c b/isl_input.c
index ba10ce8..480d60d 100644
--- a/isl_input.c
+++ b/isl_input.c
@@ -350,6 +350,10 @@ static int is_start_of_div(struct isl_token *tok)
 		return 0;
 	if (tok->type == '[')
 		return 1;
+	if (tok->type == ISL_TOKEN_FLOOR)
+		return 1;
+	if (tok->type == ISL_TOKEN_CEIL)
+		return 1;
 	if (tok->type == ISL_TOKEN_FLOORD)
 		return 1;
 	if (tok->type == ISL_TOKEN_CEILD)
@@ -357,17 +361,32 @@ static int is_start_of_div(struct isl_token *tok)
 	return 0;
 }
 
+/* Read an integer division from "s" and return it as an isl_pw_aff.
+ *
+ * The integer division can be of the form
+ *
+ *	[<affine expression>]
+ *	floor(<affine expression>)
+ *	ceil(<affine expression>)
+ *	floord(<affine expression>,<denominator>)
+ *	ceild(<affine expression>,<denominator>)
+ */
 static __isl_give isl_pw_aff *accept_div(struct isl_stream *s,
 	__isl_take isl_space *dim, struct vars *v)
 {
 	struct isl_token *tok;
 	int f = 0;
 	int c = 0;
+	int extra = 0;
 	isl_pw_aff *pwaff = NULL;
 
 	if (isl_stream_eat_if_available(s, ISL_TOKEN_FLOORD))
-		f = 1;
+		extra = f = 1;
 	else if (isl_stream_eat_if_available(s, ISL_TOKEN_CEILD))
+		extra = c = 1;
+	else if (isl_stream_eat_if_available(s, ISL_TOKEN_FLOOR))
+		f = 1;
+	else if (isl_stream_eat_if_available(s, ISL_TOKEN_CEIL))
 		c = 1;
 	if (f || c) {
 		if (isl_stream_eat(s, '('))
@@ -379,7 +398,7 @@ static __isl_give isl_pw_aff *accept_div(struct isl_stream *s,
 
 	pwaff = accept_affine(s, isl_space_copy(dim), v);
 
-	if (f || c) {
+	if (extra) {
 		if (isl_stream_eat(s, ','))
 			goto error;
 
diff --git a/isl_stream.c b/isl_stream.c
index c40756d..de69f45 100644
--- a/isl_stream.c
+++ b/isl_stream.c
@@ -323,6 +323,10 @@ static enum isl_token_type check_keywords(struct isl_stream *s)
 		return ISL_TOKEN_FLOORD;
 	if (!strcasecmp(s->buffer, "mod"))
 		return ISL_TOKEN_MOD;
+	if (!strcasecmp(s->buffer, "ceil"))
+		return ISL_TOKEN_CEIL;
+	if (!strcasecmp(s->buffer, "floor"))
+		return ISL_TOKEN_FLOOR;
 
 	if (!s->keywords)
 		return ISL_TOKEN_IDENT;
diff --git a/isl_test.c b/isl_test.c
index eeb2fc3..5d3e4aa 100644
--- a/isl_test.c
+++ b/isl_test.c
@@ -209,6 +209,10 @@ int test_parse(struct isl_ctx *ctx)
 	if (test_parse_map_equal(ctx, "{ [*] }", "{ [a] }") < 0)
 		return -1;
 
+	if (test_parse_map_equal(ctx, "{ [i] : 2*floor(i/2) = i }",
+				      "{ [i] : exists a : i = 2 a }") < 0)
+		return -1;
+
 	return 0;
 }
 
-- 
2.7.4