Some small changes to simplify the generated IR.

+ mark the alloc routines as no alias (=attribute(malloc)).
  This marks every alloc call as noalias in the IR.
  (While I felt somewhat frightened by the malloc attribute AFAIK the generated IR looks reasonable.)
+ inline the trivial Box constructor
+ fix dead allocs pass: we will now remove the useless list creation inside f2 in speculation_test.py

src/codegen/opt/dead_allocs.cpp

@@ -18,6 +18,7 @@
 
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/MemoryBuiltins.h"
 #include "llvm/Analysis/Passes.h"
 #include "llvm/Analysis/PostDominators.h"
@@ -402,11 +403,12 @@ private:
 
         std::unordered_map<BasicBlock*, Value*> seen;
         Value* new_v = getLoadValFromPrevious(li->getPointerOperand(), li->getParent(), seen, chain);
-        assert(new_v);
+        if (!new_v) {
+            new_v = llvm::UndefValue::get(li->getType());
+        }
         if (VERBOSITY("opt") >= 1)
             errs() << "Remapped to: " << *new_v << '\n';
-        li->replaceAllUsesWith(new_v);
-        li->eraseFromParent();
+        llvm::replaceAndRecursivelySimplify(li, new_v);
     }
 
 public:

src/core/types.h

@@ -398,7 +398,19 @@ public:
 
     llvm::iterator_range<BoxIterator> pyElements();
 
-    Box(BoxedClass* cls);
+    Box(BoxedClass* cls) : cls(cls) {
+        // if (TRACK_ALLOCATIONS) {
+        // int id = Stats::getStatId("allocated_" + *getNameOfClass(c));
+        // Stats::log(id);
+        //}
+
+        // the only way cls should be NULL is if we're creating the type_cls
+        // object itself:
+        if (cls == NULL) {
+            ASSERT(type_cls == NULL, "should pass a non-null cls here");
+        } else {
+        }
+    }
 
     HCAttrs* getAttrsPtr();
 

src/gc/heap.h

@@ -108,8 +108,8 @@ private:
     Block* full_heads[NUM_BUCKETS];
     LargeObj* large_head = NULL;
 
-    GCAllocation* allocSmall(size_t rounded_size, int bucket_idx);
-    GCAllocation* allocLarge(size_t bytes);
+    GCAllocation* __attribute__((__malloc__)) allocSmall(size_t rounded_size, int bucket_idx);
+    GCAllocation* __attribute__((__malloc__)) allocLarge(size_t bytes);
 
     // DS_DEFINE_MUTEX(lock);
     DS_DEFINE_SPINLOCK(lock);
@@ -134,7 +134,7 @@ public:
 
     GCAllocation* realloc(GCAllocation* alloc, size_t bytes);
 
-    GCAllocation* alloc(size_t bytes) {
+    GCAllocation* __attribute__((__malloc__)) alloc(size_t bytes) {
         GCAllocation* rtn;
         // assert(bytes >= 16);
         if (bytes <= 16)

src/runtime/objmodel.cpp

@@ -494,21 +494,6 @@ HiddenClass* HiddenClass::delAttrToMakeHC(const std::string& attr) {
     return cur;
 }
 
-Box::Box(BoxedClass* cls) : cls(cls) {
-    // if (TRACK_ALLOCATIONS) {
-    // int id = Stats::getStatId("allocated_" + *getNameOfClass(c));
-    // Stats::log(id);
-    //}
-
-    // the only way cls should be NULL is if we're creating the type_cls
-    // object itself:
-    if (cls == NULL) {
-        ASSERT(type_cls == NULL, "should pass a non-null cls here");
-    } else {
-    }
-}
-
-
 HCAttrs* Box::getAttrsPtr() {
     assert(cls->instancesHaveAttrs());