Avoid some operator new null checks

diff --git a/src/jit/compiler.hpp b/src/jit/compiler.hpp
index 190cc2e..07b264e 100644 (file)
--- a/src/jit/compiler.hpp
+++ b/src/jit/compiler.hpp
@@ -872,7 +872,13 @@ void* GenTree::operator new(size_t sz, Compiler* comp, genTreeOps oper)
 #endif // MEASURE_NODE_SIZE
 
     assert(size >= sz);
-    return comp->compGetMem(size, CMK_ASTNode);
+    void* mem = comp->compGetMem(size, CMK_ASTNode);
+#ifdef _MSC_VER
+    // MSVC assumes that a user defined operator new may return nullptr and inserts
+    // a null check before invoking the constructor. This can be avoided using __assume.
+    __assume(mem != nullptr);
+#endif
+    return mem;
 }
 
 // GenTree constructor

diff --git a/src/jit/jit.h b/src/jit/jit.h
index 4315f94..5939013 100644 (file)
--- a/src/jit/jit.h
+++ b/src/jit/jit.h
@@ -864,12 +864,24 @@ public:
 
 inline void* __cdecl operator new(size_t n, CompAllocator* alloc)
 {
-    return alloc->Alloc(n);
+    void* mem = alloc->Alloc(n);
+#ifdef _MSC_VER
+    // MSVC assumes that a user defined operator new may return nullptr and inserts
+    // a null check before invoking the constructor. This can be avoided using __assume.
+    __assume(mem != nullptr);
+#endif
+    return mem;
 }
 
 inline void* __cdecl operator new[](size_t n, CompAllocator* alloc)
 {
-    return alloc->Alloc(n);
+    void* mem = alloc->Alloc(n);
+#ifdef _MSC_VER
+    // MSVC assumes that a user defined operator new may return nullptr and inserts
+    // a null check before invoking the constructor. This can be avoided using __assume.
+    __assume(mem != nullptr);
+#endif
+    return mem;
 }
 
 class JitTls