From 4a961e0a8921d62a0c6ddf8c34a7597bfc3c4ecd Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Mon, 21 Nov 2011 22:41:54 +0100
Subject: [PATCH] allow boolean expressions where an affine expression is
 expected

For a boolean expression "cond", return the affine expression "cond ? 1 : 0".

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---
 scan.cc               | 27 +++++++++++++++++++++++++++
 scan.h                |  1 +
 tests/piecewise2.c    | 10 ++++++++++
 tests/piecewise2.scop | 23 +++++++++++++++++++++++
 4 files changed, 61 insertions(+)
 create mode 100644 tests/piecewise2.c
 create mode 100644 tests/piecewise2.scop

diff --git a/scan.cc b/scan.cc
index 9838868..b797c80 100644
--- a/scan.cc
+++ b/scan.cc
@@ -459,6 +459,21 @@ static __isl_give isl_pw_aff *wrap(__isl_take isl_pw_aff *pwaff,
 	return pwaff;
 }
 
+/* Extract an affine expression from a boolean expression.
+ * In particular, return the expression "expr ? 1 : 0".
+ */
+__isl_give isl_pw_aff *PetScan::extract_implicit_affine(Expr *expr)
+{
+	isl_set *cond = extract_condition(expr);
+	isl_space *space = isl_set_get_space(cond);
+	isl_local_space *ls = isl_local_space_from_space(space);
+	isl_aff *zero = isl_aff_zero_on_domain(isl_local_space_copy(ls));
+	isl_aff *one = isl_aff_zero_on_domain(ls);
+	one = isl_aff_add_constant_si(one, 1);
+	return isl_pw_aff_cond(cond, isl_pw_aff_from_aff(one),
+					isl_pw_aff_from_aff(zero));
+}
+
 /* Extract an affine expression from some binary operations.
  * If the result of the expression is unsigned, then we wrap it
  * based on the size of the type.
@@ -481,6 +496,16 @@ __isl_give isl_pw_aff *PetScan::extract_affine(BinaryOperator *expr)
 	case BO_Mul:
 		res = extract_affine_mul(expr);
 		break;
+	case BO_LT:
+	case BO_LE:
+	case BO_GT:
+	case BO_GE:
+	case BO_EQ:
+	case BO_NE:
+	case BO_LAnd:
+	case BO_LOr:
+		res = extract_implicit_affine(expr);
+		break;
 	default:
 		unsupported(expr);
 		return NULL;
@@ -498,6 +523,8 @@ __isl_give isl_pw_aff *PetScan::extract_affine(UnaryOperator *expr)
 {
 	if (expr->getOpcode() == UO_Minus)
 		return isl_pw_aff_neg(extract_affine(expr->getSubExpr()));
+	if (expr->getOpcode() == UO_LNot)
+		return extract_implicit_affine(expr);
 
 	unsupported(expr);
 	return NULL;
diff --git a/scan.h b/scan.h
index 7a3efd3..a6610a8 100644
--- a/scan.h
+++ b/scan.h
@@ -159,6 +159,7 @@ private:
 	__isl_give isl_pw_aff *extract_affine(clang::ArraySubscriptExpr *expr);
 	__isl_give isl_pw_aff *extract_affine(clang::ConditionalOperator *expr);
 
+	__isl_give isl_pw_aff *extract_implicit_affine(clang::Expr *expr);
 	__isl_give isl_set *extract_implicit_condition(clang::Expr *expr);
 
 	__isl_give isl_set *extract_condition(clang::UnaryOperator *expr);
diff --git a/tests/piecewise2.c b/tests/piecewise2.c
new file mode 100644
index 0000000..7ff7b40
--- /dev/null
+++ b/tests/piecewise2.c
@@ -0,0 +1,10 @@
+void bar(int N, int a[N][N], int b[5][5])
+{
+	int i, j;
+
+#pragma scop
+	for (i = 0; i < N; ++i)
+		for (j = i; j < N; ++j)
+			a[i][j] = a[i - (i > 0)][0];
+#pragma endscop
+}
diff --git a/tests/piecewise2.scop b/tests/piecewise2.scop
new file mode 100644
index 0000000..bffe60a
--- /dev/null
+++ b/tests/piecewise2.scop
@@ -0,0 +1,23 @@
+context: '[N] -> {  : N >= 0 }'
+arrays:
+- context: '[N] -> {  : N >= 0 }'
+  extent: '[N] -> { a[i0, i1] : i0 >= 0 and i1 >= 0 and i1 <= -1 + N }'
+  element_type: int
+statements:
+- line: 8
+  domain: '[N] -> { S_0[i, j] : i >= 0 and i <= -1 + N and j >= i and j <= -1 + N
+    }'
+  schedule: '[N] -> { S_0[i, j] -> [0, i, j] }'
+  body:
+    type: binary
+    operation: =
+    arguments:
+    - type: access
+      relation: '[N] -> { S_0[i, j] -> a[i, j] }'
+      read: 0
+      write: 1
+    - type: access
+      relation: '[N] -> { S_0[i, j] -> a[i, 0] : i <= 0; S_0[i, j] -> a[-1 + i, 0]
+        : i >= 1 }'
+      read: 1
+      write: 0
-- 
2.11.4.GIT