hipe: Add hipe_regalloc_prepass

hipe_regalloc_prepass speeds up register allocation by spilling any temp
that is live over a call (which clobbers all register).

In order to detect these, a new function was added to the target
interface; defines_all_alloc/1, that takes an instruction and returns a
boolean.

2 files changed, 9 insertions, 0 deletions

diff --git a/lib/hipe/arm/hipe_arm_defuse.erl b/lib/hipe/arm/hipe_arm_defuse.erl
index f57b0e601c..f92cf4f82a 100644
--- a/lib/hipe/arm/hipe_arm_defuse.erl
+++ b/lib/hipe/arm/hipe_arm_defuse.erl
@@ -22,6 +22,7 @@
 -module(hipe_arm_defuse).
 -export([insn_def_all/1, insn_use_all/1]).
 -export([insn_def_gpr/1, insn_use_gpr/1]).
+-export([insn_defs_all_gpr/1]).
 -include("hipe_arm.hrl").
 
 %%%
@@ -55,6 +56,12 @@ insn_def_gpr(I) ->
     _ -> []
   end.
 
+insn_defs_all_gpr(I) ->
+  case I of
+    #pseudo_call{} -> true;
+    _ -> false
+  end.
+
 call_clobbered_gpr() ->
   [hipe_arm:mk_temp(R, T)
    || {R,T} <- hipe_arm_registers:call_clobbered() ++ all_fp_pseudos()].
diff --git a/lib/hipe/arm/hipe_arm_registers.erl b/lib/hipe/arm/hipe_arm_registers.erl
index dcf039676b..3ecf2f2fdb 100644
--- a/lib/hipe/arm/hipe_arm_registers.erl
+++ b/lib/hipe/arm/hipe_arm_registers.erl
@@ -180,6 +180,8 @@ is_arg(R) ->
     _ -> false
   end.
 
+%% Note: the fact that allocatable_gpr() is a subset of call_clobbered() is
+%% hard-coded in hipe_arm_defuse:insn_defs_all_gpr/1
 call_clobbered() ->		% does the RA strip the type or not?
   [{?R0,tagged},{?R0,untagged},
    {?R1,tagged},{?R1,untagged},