diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6329243a864..5e410297e92 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2000-03-05  Mark Mitchell  <mark@codesourcery.com>
+
+	* basic-block.h (ALLOCA_REG_SET): Remove.
+	(INITIALIZE_REG_SET): New macro.
+	* flow.c (update_life_info): Use it.
+	(calculate_global_regs_live): Likewise.
+	(propagate_block): Likewise.
+	* global.c (build_insn_chain): Likewise.
+	* haifa-sched.c (schedule_region): Likewise.
+
 2000-03-05  Stephane Carrez  <stcarrez@worldnet.fr>
 
 	* dwarf2out.c (UNALIGNED_WORD_ASM_OP): Support 2 bytes pointer.
diff --git a/gcc/basic-block.h b/gcc/basic-block.h
index 50cc28e0dc1..0aef32b2353 100644
--- a/gcc/basic-block.h
+++ b/gcc/basic-block.h
@@ -98,8 +98,8 @@ do {									\
 /* Allocate a register set with oballoc.  */
 #define OBSTACK_ALLOC_REG_SET(OBSTACK) BITMAP_OBSTACK_ALLOC (OBSTACK)
 
-/* Allocate a register set with alloca.  */
-#define ALLOCA_REG_SET() BITMAP_ALLOCA ()
+/* Initialize a register set.  Returns the new register set.  */
+#define INITIALIZE_REG_SET(HEAD) bitmap_initialize (&HEAD)
 
 /* Do any cleanup needed on a regset when it is no longer used.  */
 #define FREE_REG_SET(REGSET) BITMAP_FREE(REGSET)
diff --git a/gcc/flow.c b/gcc/flow.c
index 6cdda708fe1..e134794f38c 100644
--- a/gcc/flow.c
+++ b/gcc/flow.c
@@ -2643,9 +2643,10 @@ update_life_info (blocks, extent, prop_flags)
      int prop_flags;
 {
   regset tmp;
+  regset_head tmp_head;
   int i;
 
-  tmp = ALLOCA_REG_SET ();
+  tmp = INITIALIZE_REG_SET (tmp_head);
 
   /* For a global update, we go through the relaxation process again.  */
   if (extent != UPDATE_LIFE_LOCAL)
@@ -2949,10 +2950,12 @@ calculate_global_regs_live (blocks_in, blocks_out, flags)
 {
   basic_block *queue, *qhead, *qtail, *qend;
   regset tmp, new_live_at_end;
+  regset_head tmp_head;
+  regset_head new_live_at_end_head;
   int i;
 
-  tmp = ALLOCA_REG_SET ();
-  new_live_at_end = ALLOCA_REG_SET ();
+  tmp = INITIALIZE_REG_SET (tmp_head);
+  new_live_at_end = INITIALIZE_REG_SET (new_live_at_end_head);
 
   /* Create a worklist.  Allocate an extra slot for ENTRY_BLOCK, and one
      because the `head == tail' style test for an empty queue doesn't 
@@ -3177,7 +3180,9 @@ propagate_block (bb, old, significant, flags)
   register rtx insn;
   rtx prev;
   regset live;
+  regset_head live_head;
   regset dead;
+  regset_head dead_head;
 
   /* Find the loop depth for this block.  Ignore loop level changes in the
      middle of the basic block -- for register allocation purposes, the 
@@ -3185,8 +3190,8 @@ propagate_block (bb, old, significant, flags)
      not in the loop pre-header or post-trailer.  */
   loop_depth = bb->loop_depth;
 
-  dead = ALLOCA_REG_SET ();
-  live = ALLOCA_REG_SET ();
+  dead = INITIALIZE_REG_SET (live_head);
+  live = INITIALIZE_REG_SET (dead_head);
 
   cc0_live = 0;
 
diff --git a/gcc/global.c b/gcc/global.c
index 571320c3e33..74d9fd2a6b7 100644
--- a/gcc/global.c
+++ b/gcc/global.c
@@ -1764,8 +1764,9 @@ build_insn_chain (first)
   struct insn_chain **p = &reload_insn_chain;
   struct insn_chain *prev = 0;
   int b = 0;
+  regset_head live_relevant_regs_head;
 
-  live_relevant_regs = ALLOCA_REG_SET ();
+  live_relevant_regs = INITIALIZE_REG_SET (live_relevant_regs_head);
 
   for (; first; first = NEXT_INSN (first))
     {
diff --git a/gcc/haifa-sched.c b/gcc/haifa-sched.c
index 430abaf429c..eb6f121d0b7 100644
--- a/gcc/haifa-sched.c
+++ b/gcc/haifa-sched.c
@@ -6631,13 +6631,15 @@ schedule_region (rgn)
   int bb;
   int rgn_n_insns = 0;
   int sched_rgn_n_insns = 0;
+  regset_head reg_pending_sets_head;
+  regset_head reg_pending_clobbers_head;
 
   /* Set variables for the current region.  */
   current_nr_blocks = RGN_NR_BLOCKS (rgn);
   current_blocks = RGN_BLOCKS (rgn);
 
-  reg_pending_sets = ALLOCA_REG_SET ();
-  reg_pending_clobbers = ALLOCA_REG_SET ();
+  reg_pending_sets = INITIALIZE_REG_SET (reg_pending_sets_head);
+  reg_pending_clobbers = INITIALIZE_REG_SET (reg_pending_clobbers_head);
   reg_pending_sets_all = 0;
 
   /* Initializations for region data dependence analyisis.  */