Index: polly/trunk/lib/CodeGen/BlockGenerators.cpp
===================================================================
--- polly/trunk/lib/CodeGen/BlockGenerators.cpp
+++ polly/trunk/lib/CodeGen/BlockGenerators.cpp
@@ -222,8 +222,8 @@
   const Instruction *Inst = dyn_cast<Instruction>(Load);
   Value *NewPointer =
       generateLocationAccessed(Inst, Pointer, BBMap, GlobalMap, LTS);
-  Value *ScalarLoad =
-      Builder.CreateLoad(NewPointer, Load->getName() + "_p_scalar_");
+  Value *ScalarLoad = Builder.CreateAlignedLoad(
+      NewPointer, Load->getAlignment(), Load->getName() + "_p_scalar_");
   return ScalarLoad;
 }
 
@@ -237,7 +237,9 @@
   Value *ValueOperand = getNewValue(Store->getValueOperand(), BBMap, GlobalMap,
                                     LTS, getLoopForInst(Store));
 
-  return Builder.CreateStore(ValueOperand, NewPointer);
+  Value *NewStore = Builder.CreateAlignedStore(ValueOperand, NewPointer,
+                                               Store->getAlignment());
+  return NewStore;
 }
 
 void BlockGenerator::copyInstruction(const Instruction *Inst, ValueMapT &BBMap,
Index: polly/trunk/lib/Exchange/JSONExporter.cpp
===================================================================
--- polly/trunk/lib/Exchange/JSONExporter.cpp
+++ polly/trunk/lib/Exchange/JSONExporter.cpp
@@ -277,6 +277,21 @@
         return false;
       }
 
+      // We keep the old alignment, thus we cannot allow accesses to memory
+      // locations that were not accessed before.
+      isl_set *newAccessSet = isl_map_range(isl_map_copy(newAccessMap));
+      isl_set *currentAccessSet = isl_map_range(isl_map_copy(currentAccessMap));
+      bool isSubset = isl_set_is_subset(newAccessSet, currentAccessSet);
+      isl_set_free(newAccessSet);
+      isl_set_free(currentAccessSet);
+
+      if (!isSubset) {
+        errs() << "JScop file changes the accessed memory\n";
+        isl_map_free(currentAccessMap);
+        isl_map_free(newAccessMap);
+        return false;
+      }
+
       // We need to copy the isl_ids for the parameter dimensions to the new
       // map. Without doing this the current map would have different
       // ids then the new one, even though both are named identically.
Index: polly/trunk/test/Isl/CodeGen/MemAccess/bad_alignment.ll
===================================================================
--- polly/trunk/test/Isl/CodeGen/MemAccess/bad_alignment.ll
+++ polly/trunk/test/Isl/CodeGen/MemAccess/bad_alignment.ll
@@ -0,0 +1,36 @@
+; RUN: opt %loadPolly -polly-codegen-scev -polly-import-jscop -polly-import-jscop-dir=%S -analyze 2>&1 < %s | FileCheck %s
+;
+; Check that we do not allow to access elements not accessed before because the
+; alignment information would become invalid.
+;
+; CHECK: JScop file changes the accessed memory
+;
+;    void bad_alignment(int *A) {
+;      for (int i = 0; i < 1024; i += 2)
+;        A[i] = i;
+;    }
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @bad_alignment(i32* %A) {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ]
+  %cmp = icmp slt i64 %indvars.iv, 1024
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %arrayidx = getelementptr inbounds i32* %A, i64 %indvars.iv
+  %tmp = trunc i64 %indvars.iv to i32
+  store i32 %tmp, i32* %arrayidx, align 8
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 2
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  ret void
+}
Index: polly/trunk/test/Isl/CodeGen/MemAccess/bad_alignment___%for.cond---%for.end.jscop
===================================================================
--- polly/trunk/test/Isl/CodeGen/MemAccess/bad_alignment___%for.cond---%for.end.jscop
+++ polly/trunk/test/Isl/CodeGen/MemAccess/bad_alignment___%for.cond---%for.end.jscop
@@ -0,0 +1,17 @@
+{
+   "context" : "{  :  }",
+   "name" : "for.cond => polly.merge_new_and_old",
+   "statements" : [
+      {
+         "accesses" : [
+            {
+               "kind" : "write",
+               "relation" : "{ Stmt_for_body[i0] -> MemRef_A[1] }"
+            }
+         ],
+         "domain" : "{ Stmt_for_body[i0] : i0 >= 0 and i0 <= 511 }",
+         "name" : "Stmt_for_body",
+         "schedule" : "{ Stmt_for_body[i0] -> scattering[0, i0, 0] }"
+      }
+   ]
+}
Index: polly/trunk/test/Isl/CodeGen/alignment.ll
===================================================================
--- polly/trunk/test/Isl/CodeGen/alignment.ll
+++ polly/trunk/test/Isl/CodeGen/alignment.ll
@@ -0,0 +1,36 @@
+; RUN: opt %loadPolly -polly-codegen-scev -polly-codegen-isl -S < %s | FileCheck %s
+;
+; Check that the special alignment information is kept
+;
+; CHECK: align 8
+; CHECK: align 8
+;
+;    void jd(int *A) {
+;      for (int i = 0; i < 1024; i += 2)
+;        A[i] = i;
+;    }
+;
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @jd(i32* %A) {
+entry:
+  br label %for.cond
+
+for.cond:                                         ; preds = %for.inc, %entry
+  %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ]
+  %cmp = icmp slt i64 %indvars.iv, 1024
+  br i1 %cmp, label %for.body, label %for.end
+
+for.body:                                         ; preds = %for.cond
+  %arrayidx = getelementptr inbounds i32* %A, i64 %indvars.iv
+  %tmp = trunc i64 %indvars.iv to i32
+  store i32 %tmp, i32* %arrayidx, align 8
+  br label %for.inc
+
+for.inc:                                          ; preds = %for.body
+  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 2
+  br label %for.cond
+
+for.end:                                          ; preds = %for.cond
+  ret void
+}
Index: polly/trunk/test/Isl/CodeGen/annotated_alias_scopes.ll
===================================================================
--- polly/trunk/test/Isl/CodeGen/annotated_alias_scopes.ll
+++ polly/trunk/test/Isl/CodeGen/annotated_alias_scopes.ll
@@ -4,11 +4,11 @@
 ; Check that we create alias scopes that indicate the accesses to A, B and C cannot alias in any way.
 ;
 ; SCOPES:      %[[BIdx:[._a-zA-Z0-9]*]] = getelementptr inbounds i32* %B, i64 %polly.indvar
-; SCOPES:      load i32* %[[BIdx]], !alias.scope ![[AliasScopeB:[0-9]*]], !noalias ![[NoAliasB:[0-9]*]]
+; SCOPES:      load i32* %[[BIdx]], align 4, !alias.scope ![[AliasScopeB:[0-9]*]], !noalias ![[NoAliasB:[0-9]*]]
 ; SCOPES:      %[[CIdx:[._a-zA-Z0-9]*]] = getelementptr inbounds float* %C, i64 %polly.indvar
-; SCOPES:      load float* %[[CIdx]], !alias.scope ![[AliasScopeC:[0-9]*]], !noalias ![[NoAliasC:[0-9]*]]
+; SCOPES:      load float* %[[CIdx]], align 4, !alias.scope ![[AliasScopeC:[0-9]*]], !noalias ![[NoAliasC:[0-9]*]]
 ; SCOPES:      %[[AIdx:[._a-zA-Z0-9]*]] = getelementptr inbounds i32* %A, i64 %polly.indvar
-; SCOPES:      store i32 %{{[._a-zA-Z0-9]*}}, i32* %[[AIdx]], !alias.scope ![[AliasScopeA:[0-9]*]], !noalias ![[NoAliasA:[0-9]*]]
+; SCOPES:      store i32 %{{[._a-zA-Z0-9]*}}, i32* %[[AIdx]], align 4, !alias.scope ![[AliasScopeA:[0-9]*]], !noalias ![[NoAliasA:[0-9]*]]
 ;
 ; SCOPES:      ![[AliasScopeB]] = metadata !{metadata ![[AliasScopeB]], metadata !{{[0-9]*}}, metadata !"polly.alias.scope.B"}
 ; SCOPES:      ![[NoAliasB]] = metadata !{