Merge branch 'typed-cmp'

* give an explicit type to compare's operands

7 files changed, 75 insertions, 5 deletions

diff --git a/Documentation/IR.rst b/Documentation/IR.rst
index ff5af1c5..6330ee9c 100644
--- a/Documentation/IR.rst
+++ b/Documentation/IR.rst
@@ -134,6 +134,7 @@ They all have the following signature:
 	* .src1, .src2: operands (types must be compatible)
 	* .target: result of the operation (0/1 valued integer)
 	* .type: type of .target, must be an integral type
+	* .itype: type of the input operands
 
 .. op:: OP_SET_EQ
 	Compare equal.
diff --git a/linearize.c b/linearize.c
index def6cf34..c1e3455a 100644
--- a/linearize.c
+++ b/linearize.c
@@ -1080,6 +1080,13 @@ static pseudo_t add_binary_op(struct entrypoint *ep, struct symbol *ctype, int o
 	return target;
 }
 
+static pseudo_t add_cmp_op(struct entrypoint *ep, struct symbol *ctype, int op, struct symbol *itype, pseudo_t left, pseudo_t right)
+{
+	pseudo_t target = add_binary_op(ep, ctype, op, left, right);
+	target->def->itype = itype;
+	return target;
+}
+
 static pseudo_t add_setval(struct entrypoint *ep, struct symbol *ctype, struct expression *val)
 {
 	struct instruction *insn = alloc_typed_instruction(OP_SETVAL, ctype);
@@ -1217,7 +1224,7 @@ static pseudo_t linearize_regular_preop(struct entrypoint *ep, struct expression
 		return pre;
 	case '!': {
 		pseudo_t zero = value_pseudo(0);
-		return add_binary_op(ep, ctype, OP_SET_EQ, pre, zero);
+		return add_cmp_op(ep, ctype, OP_SET_EQ, expr->unop->ctype, pre, zero);
 	}
 	case '~':
 		return add_unop(ep, ctype, OP_NOT, pre);
@@ -1444,7 +1451,7 @@ static inline pseudo_t add_convert_to_bool(struct entrypoint *ep, pseudo_t src,
 		zero = value_pseudo(0);
 		op = OP_SET_NE;
 	}
-	return add_binary_op(ep, &bool_ctype, op, src, zero);
+	return add_cmp_op(ep, &bool_ctype, op, type, src, zero);
 }
 
 static pseudo_t linearize_expression_to_bool(struct entrypoint *ep, struct expression *expr)
@@ -1773,10 +1780,11 @@ static pseudo_t linearize_compare(struct entrypoint *ep, struct expression *expr
 		[SPECIAL_UNSIGNED_LTE] = OP_SET_BE,
 		[SPECIAL_UNSIGNED_GTE] = OP_SET_AE,
 	};
-	int op = opcode_float(cmpop[expr->op], expr->right->ctype);
+	struct symbol *itype = expr->right->ctype;
+	int op = opcode_float(cmpop[expr->op], itype);
 	pseudo_t src1 = linearize_expression(ep, expr->left);
 	pseudo_t src2 = linearize_expression(ep, expr->right);
-	pseudo_t dst = add_binary_op(ep, expr->ctype, op, src1, src2);
+	pseudo_t dst = add_cmp_op(ep, expr->ctype, op, itype, src1, src2);
 	return dst;
 }
 
diff --git a/linearize.h b/linearize.h
index 57fe2035..77ae7c9a 100644
--- a/linearize.h
+++ b/linearize.h
@@ -123,6 +123,10 @@ struct instruction {
 		struct /* binops and sel */ {
 			pseudo_t src1, src2, src3;
 		};
+		struct /* compare */ {
+			pseudo_t _src1, _src2;		// alias .src[12]
+			struct symbol *itype;		// input operands' type
+		};
 		struct /* slice */ {
 			pseudo_t base;
 			unsigned from, len;
diff --git a/simplify.c b/simplify.c
index 6f75b1ae..f2aaa52d 100644
--- a/simplify.c
+++ b/simplify.c
@@ -635,6 +635,11 @@ static pseudo_t eval_op(int op, unsigned size, pseudo_t src1, pseudo_t src2)
 	default:
 		return NULL;
 	}
+
+	// Warning: this should be done with the output size which may
+	// be different than the input size used here. But it differs
+	// only for compares which are not concerned since only returning
+	// 0 or 1 and for casts which are not handled here.
 	res &= bits;
 
 	return value_pseudo(res);
@@ -767,7 +772,11 @@ static int simplify_mask_shift(struct instruction *sh, unsigned long long mask)
 
 static pseudo_t eval_insn(struct instruction *insn)
 {
-	return eval_op(insn->opcode, insn->size, insn->src1, insn->src2);
+	unsigned size = insn->size;
+
+	if (opcode_table[insn->opcode].flags & OPF_COMPARE)
+		size = insn->itype->bit_size;
+	return eval_op(insn->opcode, size, insn->src1, insn->src2);
 }
 
 static long long check_shift_count(struct instruction *insn, unsigned long long uval)
@@ -1009,6 +1018,7 @@ static int simplify_seteq_setne(struct instruction *insn, long long value)
 		//	setcc.m %r <- %a, $b
 		// and similar for setne/eq ... 0/1
 		insn->opcode = inverse ? opcode_table[opcode].negate : opcode;
+		insn->itype = def->itype;
 		use_pseudo(insn, def->src1, &insn->src1);
 		use_pseudo(insn, def->src2, &insn->src2);
 		remove_usage(old, &insn->src1);
@@ -1025,6 +1035,7 @@ static int simplify_seteq_setne(struct instruction *insn, long long value)
 		// into:
 		//	setne.1 %s <- %a, $0
 		// and same for setne/eq ... 0/1
+		insn->itype = def->orig_type;
 		return replace_pseudo(insn, &insn->src1, def->src);
 	case OP_TRUNC:
 		if (!one_use(old))
@@ -1671,6 +1682,7 @@ static int simplify_cast(struct instruction *insn)
 			//	setcc.m	%r <- %a, %b
 			// and same for s/zext/trunc/
 			insn->opcode = def->opcode;
+			insn->itype = def->itype;
 			use_pseudo(insn, def->src2, &insn->src2);
 			return replace_pseudo(insn, &insn->src1, def->src1);
 		}
diff --git a/validation/optim/cmp-op-type.c b/validation/optim/cmp-op-type.c
new file mode 100644
index 00000000..037272f8
--- /dev/null
+++ b/validation/optim/cmp-op-type.c
@@ -0,0 +1,18 @@
+extern int get(void);
+
+static int array[8192];
+
+static int foo(void)
+{
+	int n = -1;
+	if (n < 0)
+		n = get();
+	return array[n];
+}
+
+/*
+ * check-name: cmp-op-type
+ * check-command: test-linearize -Wno-decl $file
+ *
+ * check-output-ignore
+ */
diff --git a/validation/optim/cmp-type0.c b/validation/optim/cmp-type0.c
new file mode 100644
index 00000000..15115b9f
--- /dev/null
+++ b/validation/optim/cmp-type0.c
@@ -0,0 +1,12 @@
+static int foo(long long a)
+{
+	return 0LL < (0x80000000LL + (a - a));
+}
+
+/*
+ * check-name: cmp-type0
+ * check-command: test-linearize $file
+ *
+ * check-output-ignore
+ * check-output-returns: 1
+ */
diff --git a/validation/optim/cmp-type1.c b/validation/optim/cmp-type1.c
new file mode 100644
index 00000000..6df6376b
--- /dev/null
+++ b/validation/optim/cmp-type1.c
@@ -0,0 +1,15 @@
+int foo(void)
+{
+	int r;
+	long n;
+	n = 0;
+	return n < 2147483648U;
+}
+
+/*
+ * check-name: cmp-type1
+ * check-command: test-linearize -Wno-decl $file
+ *
+ * check-output-ignore
+ * check-output-returns: 1
+ */