From 5a8e6c4183a30f3b10de22fa5ba80950dfb2adea Mon Sep 17 00:00:00 2001
From: Patrik Nyblom <pan@erlang.org>
Date: Mon, 7 Dec 2009 15:25:32 +0100
Subject: Fit all heap data into the 32-bit address range

This is the first step in the implementation of the half-word emulator,
a 64-bit emulator where all pointers to heap data will be stored
in 32-bit words. Code specific for this emulator variant is
conditionally compiled when the HALFWORD_HEAP define has
a non-zero value.

First force all pointers to heap data to fall into a single 32-bit range,
but still store them in 64-bit words.

Temporary term data stored on C stack is moved into scheduler specific
storage (allocated as heaps) and macros are added to make this
happen only in emulators where this is needed. For a vanilla VM the
temporary terms are still stored on the C stack.
---
 erts/emulator/beam/global.h | 57 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

(limited to 'erts/emulator/beam/global.h')

diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index cab249a53f..03e97a0ce4 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -1839,4 +1839,61 @@ erts_alloc_message_heap(Uint size,
 
 #endif /* #if ERTS_GLB_INLINE_INCL_FUNC_DEF */
 
+#if !HEAP_ON_C_STACK
+#  if defined(DEBUG)
+#    define DeclareTmpHeap(VariableName,Size,Process) \
+       Eterm *VariableName = erts_debug_allocate_tmp_heap(Size,Process)
+#    define DeclareTmpHeapNoproc(VariableName,Size) \
+       Eterm *VariableName = erts_debug_allocate_tmp_heap(Size,NULL)
+#    define UseTmpHeap(Size,Proc) \
+       do { \
+         erts_debug_use_tmp_heap((Size),(Proc)); \
+       } while (0)
+#    define UnUseTmpHeap(Size,Proc) \
+       do { \
+         erts_debug_unuse_tmp_heap((Size),(Proc)); \
+       } while (0)
+#    define UseTmpHeapNoproc(Size) \
+       do { \
+         erts_debug_use_tmp_heap(Size,NULL); \
+       } while (0)
+#    define UnUseTmpHeapNoproc(Size) \
+       do { \
+         erts_debug_unuse_tmp_heap(Size,NULL); \
+       } while (0)
+#  else
+#    define DeclareTmpHeap(VariableName,Size,Process) \
+       Eterm *VariableName = (ERTS_PROC_GET_SCHDATA(Process)->tmp_heap)+(ERTS_PROC_GET_SCHDATA(Process)->num_tmp_heap_used)
+#    define DeclareTmpHeapNoproc(VariableName,Size) \
+       Eterm *VariableName = (erts_get_scheduler_data()->tmp_heap)+(erts_get_scheduler_data()->num_tmp_heap_used)
+#    define UseTmpHeap(Size,Proc) \
+       do { \
+         ERTS_PROC_GET_SCHDATA(Proc)->num_tmp_heap_used += (Size); \
+       } while (0)
+#    define UnUseTmpHeap(Size,Proc) \
+       do { \
+         ERTS_PROC_GET_SCHDATA(Proc)->num_tmp_heap_used -= (Size); \
+       } while (0)
+#    define UseTmpHeapNoproc(Size) \
+       do { \
+         erts_get_scheduler_data()->num_tmp_heap_used += (Size); \
+       } while (0)
+#    define UnUseTmpHeapNoproc(Size) \
+       do { \
+         erts_get_scheduler_data()->num_tmp_heap_used -= (Size); \
+       } while (0)
+
+
+#  endif
+
+#else
+#  define DeclareTmpHeap(VariableName,Size,Process) \
+     Eterm VariableName[Size]
+#  define DeclareTmpHeapNoproc(VariableName,Size) \
+     Eterm VariableName[Size]
+#  define UseTmpHeap(Size,Proc) /* Nothing */
+#  define UnUseTmpHeap(Size,Proc) /* Nothing */
+#  define UseTmpHeapNoproc(Size) /* Nothing */
+#  define UnUseTmpHeapNoproc(Size) /* Nothing */
+#endif
 #endif
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