From: Moritz Kroll <Moritz.Kroll@gmx.de>
Date: Mon, 3 Nov 2008 19:39:38 +0000 (+0000)
Subject: Added new storage class for pointer constants
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;h=e3e0e94d6bcf4257ff00c8bc173d13fd279932b1;p=libfirm

Added new storage class for pointer constants

[r23420]
---

diff --git a/include/libfirm/irmemory.h b/include/libfirm/irmemory.h
index c99764a27..fbc22461c 100644
--- a/include/libfirm/irmemory.h
+++ b/include/libfirm/irmemory.h
@@ -64,6 +64,7 @@ typedef enum {
 	ir_sc_argument          = 0x3,  /**< an method argument */
 	ir_sc_tls               = 0x4,  /**< an address of a thread local storage variable */
 	ir_sc_malloced          = 0x5,  /**< an allocated heap address */
+	ir_sc_globaladdr        = 0x6,  /**< a constant address of something, said to be alias free */
 
 	ir_sc_modifier_nottaken = 0x80  /**< if set, the address of the variable was not taken */
 } ir_storage_class_class_t;
diff --git a/ir/ana/irmemory.c b/ir/ana/irmemory.c
index 850326627..2c2965997 100644
--- a/ir/ana/irmemory.c
+++ b/ir/ana/irmemory.c
@@ -438,6 +438,8 @@ ir_storage_class_class_t classify_pointer(ir_graph *irg, ir_node *irn, ir_entity
 			res |= ir_sc_modifier_nottaken;
 	} else if (is_Proj(irn) && is_malloc_Result(irn)) {
 		return ir_sc_malloced;
+	} else if (is_Const(irn)) {
+		return ir_sc_globaladdr;
 	}
 
 	return res;
@@ -603,6 +605,16 @@ static ir_alias_relation _get_alias_relation(
 
 			/* for some reason CSE didn't happen yet for the 2 SymConsts... */
 			return ir_may_alias;
+		} else if (class1 == ir_sc_globaladdr) {
+			tarval *tv  = get_Const_tarval(base1);
+			offset1    += get_tarval_long(tv);
+			tv          = get_Const_tarval(base2);
+			offset2    += get_tarval_long(tv);
+
+			if ((unsigned long)labs(offset2 - offset1) >= mode_size)
+				return ir_no_alias;
+			else
+				return ir_sure_alias;
 		}
 	}