Merge branch 'margnus1/hipe/refactor-rtl/PR-1243'

* margnus1/hipe/refactor-rtl/PR-1243:
  hipe_x86: Fix encoding of test instr w/ neg imm
  hipe_tagscheme: Simplify test_two_fixnums with imm
  hipe_icode: Always const-propagate if&call args
  hipe_tagscheme: x86 lea+test for mask_and_compare
  hipe_tagscheme: Improve fixnum_addsub with imm
  hipe: Make realloc_binary fast case true branch
  hipe_x86_postpass: Negate conditions in goto elim
  hipe_tagscheme: Improve fixnum add on x86
  hipe_rtl_to_x86: Use LEA only for immediate adds
  hipe_x86: LeaToAdd peephole rule
  hipe_sparc: move coalescing
  hipe_ppc: better rlwinm pp
  hipe_ppc: move coalescing
  hipe_rtl: drop alub dest when unused
  hipe_rtl: unify branch and alub
  hipe_x86: Fix&activate ElimCmp0 peephole rule
  hipe_{x86,amd64}: Finish test instr implementation

1 files changed, 17 insertions, 0 deletions

diff --git a/lib/hipe/icode/hipe_icode.erl b/lib/hipe/icode/hipe_icode.erl
index 78508dff22..d2d08e0253 100644
--- a/lib/hipe/icode/hipe_icode.erl
+++ b/lib/hipe/icode/hipe_icode.erl
@@ -438,6 +438,7 @@
 	 if_true_label/1,
 	 if_false_label/1,
 	 if_args/1,
+	 if_args_update/2,
 	 if_pred/1,
 	 %% is_if/1,
 	 
@@ -594,6 +595,7 @@
 	 uses/1,
 	 defines/1,
 	 is_safe/1,
+	 reduce_unused/1,
 	 strip_comments/1,
 	 subst/2,
 	 subst_uses/2,
@@ -713,6 +715,9 @@ if_op_update(IF, NewOp) -> IF#icode_if{op=NewOp}.
 -spec if_args(#icode_if{}) -> [icode_term_arg()].
 if_args(#icode_if{args=Args}) -> Args.
 
+-spec if_args_update(#icode_if{}, [icode_term_arg()]) -> #icode_if{}.
+if_args_update(IF, Args) -> IF#icode_if{args=Args}.
+
 -spec if_true_label(#icode_if{}) -> icode_lbl().
 if_true_label(#icode_if{true_label=TrueLbl}) -> TrueLbl.
 
@@ -1765,6 +1770,18 @@ is_safe(Instr) ->
     #icode_end_try{} -> false
   end.
 
+%% @doc Produces a simplified instruction sequence that is equivalent to [Instr]
+%% under the assumption that all results of Instr are unused, or 'false' if
+%% there is no such sequence (other than [Instr] itself).
+
+-spec reduce_unused(icode_instr()) -> false | [icode_instr()].
+
+reduce_unused(Instr) ->
+  case is_safe(Instr) of
+    true -> [];
+    false -> false
+  end.
+
 %%-----------------------------------------------------------------------
 
 -spec highest_var(icode_instrs()) -> non_neg_integer().