alloc: de-static external_pointer

Like alloc_size, this will require amplification internally.

This patch also restores performance to the status quo ante; Clang can once
again see enough to generate the same code as it did before de-static-ing
alloc_size.

src/mem/alloc.h

@@ -357,13 +357,13 @@ namespace snmalloc
     }
 
     template<Boundary location = Start>
-    static void* external_pointer(void* p)
+    void* external_pointer(void* p)
     {
 #ifdef SNMALLOC_PASS_THROUGH
       error("Unsupported");
       UNUSED(p);
 #else
-      uint8_t chunkmap_slab_kind = ChunkMap::get(address_cast(p));
+      uint8_t chunkmap_slab_kind = chunkmap().get(address_cast(p));
 
       Superslab* super = Superslab::get(p);
       if (chunkmap_slab_kind == CMSuperslab)
@@ -395,7 +395,7 @@ namespace snmalloc
           ss,
           -(static_cast<ptrdiff_t>(1)
             << (chunkmap_slab_kind - CMLargeRangeMin + SUPERSLAB_BITS)));
-        chunkmap_slab_kind = ChunkMap::get(ss);
+        chunkmap_slab_kind = chunkmap().get(ss);
       }
 
       if (chunkmap_slab_kind == CMNotOurs)

src/override/malloc.cc

@@ -27,7 +27,7 @@ extern "C"
   void SNMALLOC_NAME_MANGLE(check_start)(void* ptr)
   {
 #if !defined(NDEBUG) && !defined(SNMALLOC_PASS_THROUGH)
-    if (Alloc::external_pointer<Start>(ptr) != ptr)
+    if (ThreadAlloc::get_noncachable()->external_pointer<Start>(ptr) != ptr)
     {
       error("Using pointer that is not to the start of an allocation");
     }
@@ -38,7 +38,7 @@ extern "C"
 
   SNMALLOC_EXPORT void* SNMALLOC_NAME_MANGLE(__malloc_end_pointer)(void* ptr)
   {
-    return Alloc::external_pointer<OnePastEnd>(ptr);
+    return ThreadAlloc::get_noncachable()->external_pointer<OnePastEnd>(ptr);
   }
 
   SNMALLOC_EXPORT void* SNMALLOC_NAME_MANGLE(malloc)(size_t size)

src/test/func/memory/memory.cc

@@ -241,8 +241,8 @@ void test_external_pointer()
     for (size_t offset = 0; offset < size; offset += 17)
     {
       void* p2 = pointer_offset(p1, offset);
-      void* p3 = Alloc::external_pointer(p2);
-      void* p4 = Alloc::external_pointer<End>(p2);
+      void* p3 = alloc->external_pointer(p2);
+      void* p4 = alloc->external_pointer<End>(p2);
       UNUSED(p3);
       UNUSED(p4);
       SNMALLOC_CHECK(p1 == p3);
@@ -257,7 +257,8 @@ void test_external_pointer()
 
 void check_offset(void* base, void* interior)
 {
-  void* calced_base = Alloc::external_pointer((void*)interior);
+  auto alloc = ThreadAlloc::get();
+  void* calced_base = alloc->external_pointer((void*)interior);
   if (calced_base != (void*)base)
     abort();
 }
@@ -335,7 +336,7 @@ void test_external_pointer_dealloc_bug()
 
   for (size_t i = 0; i < count; i++)
   {
-    Alloc::external_pointer(allocs[i]);
+    alloc->external_pointer(allocs[i]);
   }
 
   alloc->dealloc(allocs[0]);
@@ -348,7 +349,7 @@ void test_alloc_16M()
   const size_t size = 16'000'000;
 
   void* p1 = alloc->alloc(size);
-  SNMALLOC_CHECK(alloc->alloc_size(Alloc::external_pointer(p1)) >= size);
+  SNMALLOC_CHECK(alloc->alloc_size(alloc->external_pointer(p1)) >= size);
   alloc->dealloc(p1);
 }
 
@@ -359,7 +360,7 @@ void test_calloc_16M()
   const size_t size = 16'000'000;
 
   void* p1 = alloc->alloc<YesZero>(size);
-  SNMALLOC_CHECK(alloc->alloc_size(Alloc::external_pointer(p1)) >= size);
+  SNMALLOC_CHECK(alloc->alloc_size(alloc->external_pointer(p1)) >= size);
   alloc->dealloc(p1);
 }
 
@@ -373,7 +374,7 @@ void test_calloc_large_bug()
   const size_t size = (SUPERSLAB_SIZE << 3) - 7;
 
   void* p1 = alloc->alloc<YesZero>(size);
-  SNMALLOC_CHECK(alloc->alloc_size(Alloc::external_pointer(p1)) >= size);
+  SNMALLOC_CHECK(alloc->alloc_size(alloc->external_pointer(p1)) >= size);
   alloc->dealloc(p1);
 }
 

src/test/perf/external_pointer/externalpointer.cc

@@ -73,7 +73,7 @@ namespace test
         size_t size = *external_ptr;
         size_t offset = (size >> 4) * (rand & 15);
         void* interior_ptr = pointer_offset(external_ptr, offset);
-        void* calced_external = Alloc::external_pointer(interior_ptr);
+        void* calced_external = alloc->external_pointer(interior_ptr);
         if (calced_external != external_ptr)
           abort();
       }