From 699ad918545ac7e716b77ea05a6a943434616020 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn-Egil=20Dahlberg?= <egil@erlang.org>
Date: Thu, 23 Apr 2015 19:06:03 +0200
Subject: erts: Specialize band instruction for common case

* i_band specialization on x registers and constants
---
 erts/emulator/beam/beam_emu.c | 33 +++++++++++++++++++++++++++++++++
 erts/emulator/beam/ops.tab    |  2 ++
 2 files changed, 35 insertions(+)

(limited to 'erts/emulator')

diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index beec8967fc..aca340db6b 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -2885,6 +2885,23 @@ do {								\
      goto do_big_arith2;
  }
 
+#define DO_BIG_ARITH(Func,Arg1,Arg2)     \
+    do {                                 \
+        Uint live = Arg(1);              \
+        SWAPOUT;                         \
+        reg[0] = r(0);                   \
+        reg[live] = (Arg1);              \
+        reg[live+1] = (Arg2);            \
+        result = (Func)(c_p, reg, live); \
+        r(0) = reg[0];                   \
+        SWAPIN;                          \
+        ERTS_HOLE_CHECK(c_p);            \
+        if (is_value(result)) {          \
+            StoreBifResult(4,result);    \
+        }                                \
+        goto lb_Cl_error;                \
+    } while(0)
+
  OpCase(i_rem_jId):
  {
      Eterm result;
@@ -2900,6 +2917,22 @@ do {								\
      }
  }
 
+ OpCase(i_band_jIxcd):
+ {
+     Eterm result;
+
+     if (is_both_small(xb(Arg(2)), Arg(3))) {
+         /*
+          * No need to untag -- TAG & TAG == TAG.
+          */
+         result = xb(Arg(2)) & Arg(3);
+         StoreBifResult(4, result);
+     }
+     DO_BIG_ARITH(ARITH_FUNC(band),xb(Arg(2)),Arg(3));
+ }
+
+#undef DO_BIG_ARITH
+
  OpCase(i_band_jId):
  {
      Eterm result;
diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab
index 3f7e69e07e..3436b664d9 100644
--- a/erts/emulator/beam/ops.tab
+++ b/erts/emulator/beam/ops.tab
@@ -1663,6 +1663,7 @@ gc_bif2 Fail I u$bif:erlang:rem/2 S1 S2 Dst=d => i_fetch S1 S2 | i_rem Fail I Ds
 gc_bif2 Fail I u$bif:erlang:bsl/2 S1 S2 Dst=d => i_fetch S1 S2 | i_bsl Fail I Dst
 gc_bif2 Fail I u$bif:erlang:bsr/2 S1 S2 Dst=d => i_fetch S1 S2 | i_bsr Fail I Dst
 
+gc_bif2 Fail I u$bif:erlang:band/2 S1=x S2=c Dst=d => i_band Fail I S1 S2 Dst
 gc_bif2 Fail I u$bif:erlang:band/2 S1 S2 Dst=d => i_fetch S1 S2 | i_band Fail I Dst
 gc_bif2 Fail I u$bif:erlang:bor/2 S1 S2 Dst=d => i_fetch S1 S2 | i_bor Fail I Dst
 gc_bif2 Fail I u$bif:erlang:bxor/2 S1 S2 Dst=d => i_fetch S1 S2 | i_bxor Fail I Dst
@@ -1686,6 +1687,7 @@ i_rem j I d
 i_bsl j I d
 i_bsr j I d
 
+i_band j I x c d
 i_band j I d
 i_bor j I d
 i_bxor j I d
-- 
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