Added elimination of maps:is_key/2 calls to HiPE

 * Implemented removal of maps:is_key/2 calls of which the result is
   known in a new pass during the typed phase, called
   hipe_icode_call_elim.
 * Added the option icode_call_elim that enables the
   hipe_icode_call_elim pass, and made it default for o2.

3 files changed, 19 insertions, 3 deletions

diff --git a/lib/hipe/main/hipe.app.src b/lib/hipe/main/hipe.app.src
index aa86b6dc5b..f8487151d7 100644
--- a/lib/hipe/main/hipe.app.src
+++ b/lib/hipe/main/hipe.app.src
@@ -88,6 +88,7 @@
 	     hipe_icode2rtl,
 	     hipe_icode_bincomp,
 	     hipe_icode_callgraph,
+	     hipe_icode_call_elim,
 	     hipe_icode_cfg,
 	     hipe_icode_coordinator,
 	     hipe_icode_ebb,
diff --git a/lib/hipe/main/hipe.erl b/lib/hipe/main/hipe.erl
index 0e32da1d36..c026329276 100644
--- a/lib/hipe/main/hipe.erl
+++ b/lib/hipe/main/hipe.erl
@@ -1165,6 +1165,9 @@ option_text(caller_save_spill_restore) ->
   "Activates caller save register spills and restores";
 option_text(debug) ->
   "Outputs internal debugging information during compilation";
+option_text(icode_call_elim) ->
+  "Performs call elimination of BIFs that are side-effect free\n" ++
+  "only on some argument types";
 option_text(icode_range) ->
   "Performs integer range analysis on the Icode level";
 option_text(icode_ssa_check) ->
@@ -1318,6 +1321,7 @@ opt_keys() ->
      get_called_modules,
      split_arith,
      split_arith_unsafe,
+     icode_call_elim,
      icode_inline_bifs,
      icode_ssa_check,
      icode_ssa_copy_prop,
@@ -1399,7 +1403,7 @@ o1_opts(TargetArch) ->
 
 o2_opts(TargetArch) ->
   Common = [icode_ssa_const_prop, icode_ssa_copy_prop, % icode_ssa_struct_reuse,
-	    icode_type, icode_inline_bifs, rtl_lcm,
+	    icode_type, icode_inline_bifs, icode_call_elim, rtl_lcm,
 	    rtl_ssa, rtl_ssa_const_prop,
 	    spillmin_color, use_indexing, remove_comments,
 	    concurrent_comp, binary_opt | o1_opts(TargetArch)],
@@ -1429,6 +1433,7 @@ opt_negations() ->
    {no_icode_inline_bifs, icode_inline_bifs},
    {no_icode_range, icode_range},
    {no_icode_split_arith, icode_split_arith},
+   {no_icode_call_elim, icode_call_elim},
    {no_icode_ssa_check, icode_ssa_check},
    {no_icode_ssa_copy_prop, icode_ssa_copy_prop},
    {no_icode_ssa_const_prop, icode_ssa_const_prop},
diff --git a/lib/hipe/main/hipe_main.erl b/lib/hipe/main/hipe_main.erl
index be5050e155..b9d783d20a 100644
--- a/lib/hipe/main/hipe_main.erl
+++ b/lib/hipe/main/hipe_main.erl
@@ -284,8 +284,9 @@ icode_ssa_type(IcodeSSA, MFA, Options, Servers) ->
 	  false -> AnnIcode1
 	end,
       AnnIcode3 = icode_range_analysis(AnnIcode2, MFA, Options, Servers),
-      pp(AnnIcode3, MFA, icode, pp_range_icode, Options, Servers),
-      hipe_icode_type:unannotate_cfg(AnnIcode3)
+      AnnIcode4 = icode_eliminate_safe_calls(AnnIcode3, Options),
+      pp(AnnIcode4, MFA, icode, pp_range_icode, Options, Servers),
+      hipe_icode_type:unannotate_cfg(AnnIcode4)
   end.
 
 icode_ssa_convert(IcodeCfg, Options) ->
@@ -334,6 +335,15 @@ icode_range_analysis(IcodeSSA, MFA, Options, Servers) ->
      IcodeSSA
   end.
 
+icode_eliminate_safe_calls(IcodeSSA, Options) ->
+  case proplists:get_bool(icode_call_elim, Options) of
+    true ->
+      ?option_time(hipe_icode_call_elim:cfg(IcodeSSA),
+		   "Icode SSA safe call elimination", Options);
+    false ->
+     IcodeSSA
+  end.
+
 icode_ssa_dead_code_elimination(IcodeSSA, Options) ->
   IcodeSSA1 = ?option_time(hipe_icode_ssa:remove_dead_code(IcodeSSA),
 			   "Icode SSA dead code elimination pass 2",