From 560667eef61691d0935bd990c61291f8baaa2b6f Mon Sep 17 00:00:00 2001
From: Justin Ethier <justin.ethier@gmail.com>
Date: Wed, 3 Aug 2016 03:23:16 -0400
Subject: [PATCH] Only use 96-byte object heap on 64-bit platforms

---
 gc.c                    | 31 +++++++++----------------------
 include/cyclone/types.h |  2 --
 runtime.c               |  6 +++---
 3 files changed, 12 insertions(+), 27 deletions(-)

diff --git a/gc.c b/gc.c
index f3169258..8ba2514e 100644
--- a/gc.c
+++ b/gc.c
@@ -572,23 +572,12 @@ void *gc_alloc(gc_heap_root * hrt, size_t size, char *obj, gc_thread_data * thd,
     heap_type = HEAP_SM;
   } else if (size <= 64) {
     heap_type = HEAP_64;
-/*
-TODO:
-from http://stackoverflow.com/a/32717129/101258
+// Only use this heap on 64-bit platforms, where larger objs are used more often
+// Code from http://stackoverflow.com/a/32717129/101258
 #if INTPTR_MAX == INT64_MAX
-// 64-bit
-#elif INTPTR_MAX == INT32_MAX
-// 32-bit
-#else
-#error Unknown pointer size or missing size macros!
-#endif
-*/
   } else if (size <= 96) {
     heap_type = HEAP_96;
-//  } else if (size <= 128) {
-//    heap_type = HEAP_128;
-//  } else if (size <= 160) {
-//    heap_type = HEAP_160;
+#endif
   } else if (size >= MAX_STACK_OBJ) {
     heap_type = HEAP_HUGE;
   } else {
@@ -1066,12 +1055,10 @@ void gc_mut_cooperate(gc_thread_data * thd, int buf_len)
         cached_heap_total_sizes[HEAP_SM] * GC_COLLECTION_THRESHOLD) ||
        (cached_heap_free_sizes[HEAP_64] <
         cached_heap_total_sizes[HEAP_64] * GC_COLLECTION_THRESHOLD) ||
+#if INTPTR_MAX == INT64_MAX
        (cached_heap_free_sizes[HEAP_96] <
         cached_heap_total_sizes[HEAP_96] * GC_COLLECTION_THRESHOLD) ||
-//       (cached_heap_free_sizes[HEAP_128] <
-//        cached_heap_total_sizes[HEAP_128] * GC_COLLECTION_THRESHOLD) ||
-//       (cached_heap_free_sizes[HEAP_160] <
-//        cached_heap_total_sizes[HEAP_160] * GC_COLLECTION_THRESHOLD) ||
+#endif
        (cached_heap_free_sizes[HEAP_REST] <
         cached_heap_total_sizes[HEAP_REST] * GC_COLLECTION_THRESHOLD))) {
 #if GC_DEBUG_TRACE
@@ -1438,15 +1425,15 @@ void gc_collector()
 #if GC_DEBUG_TRACE
   total_size = cached_heap_total_sizes[HEAP_SM] +
                cached_heap_total_sizes[HEAP_64] + 
+#if INTPTR_MAX == INT64_MAX
                cached_heap_total_sizes[HEAP_96] + 
-//               cached_heap_total_sizes[HEAP_128] + 
-//               cached_heap_total_sizes[HEAP_160] + 
+#endif
                cached_heap_total_sizes[HEAP_REST];
   total_free = cached_heap_free_sizes[HEAP_SM] +
                cached_heap_free_sizes[HEAP_64] + 
+#if INTPTR_MAX == INT64_MAX
                cached_heap_free_sizes[HEAP_96] + 
-//               cached_heap_free_sizes[HEAP_128] + 
-//               cached_heap_free_sizes[HEAP_160] + 
+#endif
                cached_heap_free_sizes[HEAP_REST];
   fprintf(stderr,
           "sweep done, total_size = %zu, total_free = %zu, freed = %zu, elapsed = %ld\n",
diff --git a/include/cyclone/types.h b/include/cyclone/types.h
index 7c10b47a..2ad5c3b1 100644
--- a/include/cyclone/types.h
+++ b/include/cyclone/types.h
@@ -172,8 +172,6 @@ typedef enum {
     HEAP_SM = 0  // 32 byte objects (min gc_heap_align)
   , HEAP_64
   , HEAP_96
-//  , HEAP_128
-//  , HEAP_160
   , HEAP_REST    // Everything else
   , HEAP_HUGE    // Huge objects, 1 per page
 } gc_heap_type;
diff --git a/runtime.c b/runtime.c
index b914c004..06d72a48 100644
--- a/runtime.c
+++ b/runtime.c
@@ -214,9 +214,9 @@ void gc_init_heap(long heap_size)
   Cyc_heap->heap[HEAP_REST] = gc_heap_create(HEAP_REST, initial_heap_size, 0, 0);
   Cyc_heap->heap[HEAP_SM] = gc_heap_create(HEAP_SM, initial_heap_size, 0, 0);
   Cyc_heap->heap[HEAP_64] = gc_heap_create(HEAP_64, initial_heap_size, 0, 0);
-  Cyc_heap->heap[HEAP_96] = gc_heap_create(HEAP_96, initial_heap_size, 0, 0);
-//  Cyc_heap->heap[HEAP_128] = gc_heap_create(HEAP_128, initial_heap_size, 0, 0);
-//  Cyc_heap->heap[HEAP_160] = gc_heap_create(HEAP_160, initial_heap_size, 0, 0);
+  if (sizeof(void *) == 8) { // Only use this heap on 64-bit platforms
+    Cyc_heap->heap[HEAP_96] = gc_heap_create(HEAP_96, initial_heap_size, 0, 0);
+  }
   Cyc_heap->heap[HEAP_HUGE] = gc_heap_create(HEAP_HUGE, 1024, 0, 0);
 
   if (!ck_hs_init(&symbol_table,