Merge pull request #2242 from bjorng/bjorn/add-swap-instruction

Make the swap instruction known to the compiler

3 files changed, 9 insertions, 100 deletions

diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index 941c3ebbbe..0de694f449 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -3131,27 +3131,6 @@ mixed_types(LoaderState* stp, GenOpArg Size, GenOpArg* Rest)
     return 0;
 }
 
-static int
-is_killed_apply(LoaderState* stp, GenOpArg Reg, GenOpArg Live)
-{
-    return Reg.type == TAG_x && Live.type == TAG_u &&
-	Live.val+2 <= Reg.val;
-}
-
-static int
-is_killed(LoaderState* stp, GenOpArg Reg, GenOpArg Live)
-{
-    return Reg.type == TAG_x && Live.type == TAG_u &&
-	Live.val <= Reg.val;
-}
-
-static int
-is_killed_by_call_fun(LoaderState* stp, GenOpArg Reg, GenOpArg Live)
-{
-    return Reg.type == TAG_x && Live.type == TAG_u &&
-	Live.val+1 <= Reg.val;
-}
-
 /*
  * Test whether register Reg is killed by make_fun instruction that
  * creates the fun given by index idx.
@@ -3172,16 +3151,6 @@ is_killed_by_make_fun(LoaderState* stp, GenOpArg Reg, GenOpArg idx)
 }
 
 /*
- * Test whether register Reg is killed by the send instruction that follows.
- */
-
-static int
-is_killed_by_send(LoaderState* stp, GenOpArg Reg)
-{
-    return Reg.type == TAG_x && 2 <= Reg.val;
-}
-
-/*
  * Generate an instruction for element/2.
  */
 
diff --git a/erts/emulator/beam/instrs.tab b/erts/emulator/beam/instrs.tab
index 462ee77e6f..c77e5eae58 100644
--- a/erts/emulator/beam/instrs.tab
+++ b/erts/emulator/beam/instrs.tab
@@ -683,10 +683,11 @@ swap(R1, R2) {
     $R2 = V;
 }
 
-swap_temp(R1, R2, Tmp) {
-    Eterm V = $R1;
-    $R1 = $R2;
-    $R2 = $Tmp = V;
+swap2(R1, R2, R3) {
+    Eterm V = $R2;
+    $R2 = $R1;
+    $R1 = $R3;
+    $R3 = V;
 }
 
 test_heap(Nh, Live) {
diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab
index 10ca74cd60..1beeb67c1f 100644
--- a/erts/emulator/beam/ops.tab
+++ b/erts/emulator/beam/ops.tab
@@ -324,76 +324,15 @@ move_src_window2 y x x
 move_src_window3 y x x x
 move_src_window4 y x x x x
 
-# Swap registers.
-move R1=xy Tmp=x | move R2=xy R1 | move Tmp R2 => swap_temp R1 R2 Tmp
-
-# The compiler uses x(1022) when swapping registers. It will definitely
-# not be used again.
-swap_temp R1 R2 Tmp=x==1022 => swap R1 R2
-
-swap_temp R1 R2 Tmp | move Src Tmp => swap R1 R2 | move Src Tmp
-
-swap_temp R1 R2 Tmp | line Loc | apply Live | is_killed_apply(Tmp, Live) => \
-  swap R1 R2 | line Loc | apply Live
-swap_temp R1 R2 Tmp | line Loc | apply_last Live D | is_killed_apply(Tmp, Live) => \
-  swap R1 R2 | line Loc | apply_last Live D
-
-swap_temp R1 R2 Tmp | line Loc | call_fun Live | is_killed_by_call_fun(Tmp, Live) => \
-  swap R1 R2 | line Loc | call_fun Live
-swap_temp R1 R2 Tmp | make_fun2 OldIndex=u | is_killed_by_make_fun(Tmp, OldIndex) => \
-  swap R1 R2 | make_fun2 OldIndex
-
-swap_temp R1 R2 Tmp | line Loc | call Live Addr | is_killed(Tmp, Live) => \
-  swap R1 R2 | line Loc | call Live Addr
-swap_temp R1 R2 Tmp | call_only Live Addr | \
-  is_killed(Tmp, Live) => swap R1 R2 | call_only Live Addr
-swap_temp R1 R2 Tmp | call_last Live Addr D | \
-  is_killed(Tmp, Live) => swap R1 R2 | call_last Live Addr D
-
-swap_temp R1 R2 Tmp | line Loc | call_ext Live Addr | is_killed(Tmp, Live) => \
-  swap R1 R2 | line Loc | call_ext Live Addr
-swap_temp R1 R2 Tmp | line Loc | call_ext_only Live Addr | \
-  is_killed(Tmp, Live) => swap R1 R2 | line Loc | call_ext_only Live Addr
-swap_temp R1 R2 Tmp | line Loc | call_ext_last Live Addr D | \
-  is_killed(Tmp, Live) => swap R1 R2 | line Loc | call_ext_last Live Addr D
-
-swap_temp R1 R2 Tmp | call_ext Live Addr | is_killed(Tmp, Live) => \
-  swap R1 R2 | call_ext Live Addr
-swap_temp R1 R2 Tmp | call_ext_only Live Addr | is_killed(Tmp, Live) => \
-  swap R1 R2 | call_ext_only Live Addr
-swap_temp R1 R2 Tmp | call_ext_last Live Addr D | is_killed(Tmp, Live) => \
-  swap R1 R2 | call_ext_last Live Addr D
-
-swap_temp R1 R2 Tmp | move Src Any | line Loc | call Live Addr | \
-  is_killed(Tmp, Live) | distinct(Tmp, Src) => \
-     swap R1 R2 | move Src Any | line Loc | call Live Addr
-swap_temp R1 R2 Tmp | move Src Any | line Loc | call_ext Live Addr | \
-  is_killed(Tmp, Live) | distinct(Tmp, Src) => \
-     swap R1 R2 | move Src Any | line Loc | call_ext Live Addr
-swap_temp R1 R2 Tmp | move Src Any | call_only Live Addr | \
-  is_killed(Tmp, Live) | distinct(Tmp, Src) => \
-    swap R1 R2 | move Src Any | call_only Live Addr
-swap_temp R1 R2 Tmp | move Src Any | line Loc | call_ext_only Live Addr | \
-  is_killed(Tmp, Live) | distinct(Tmp, Src) => \
-    swap R1 R2 | move Src Any | line Loc | call_ext_only Live Addr
-swap_temp R1 R2 Tmp | move Src Any | line Loc | call_fun Live | \
-  is_killed(Tmp, Live) | distinct(Tmp, Src) => \
-    swap R1 R2 | move Src Any | line Loc | call_fun Live
-
-swap_temp R1 R2 Tmp | line Loc | send | is_killed_by_send(Tmp) => \
-  swap R1 R2 | line Loc | send
-
-# swap_temp/3 with Y register operands are rare.
-swap_temp R1 R2=y Tmp => swap R1 R2 | move R2 Tmp
-swap_temp R1=y R2 Tmp => swap R1 R2 | move R2 Tmp
-
 swap R1=x R2=y => swap R2 R1
 
-swap_temp x x x
-
 swap xy x
 swap y y
 
+swap R1=x R2=x | swap R3=x R1 => swap2 R1 R2 R3
+
+swap2 x x x
+
 # move_shift
 
 move SD=x    D=x | move Src=cxy SD=x  | distinct(D, Src) => move_shift Src SD D