Optimize and clean-up the exact equality/non-equality instructions

The is_eq_exact/3 and is_ne_exact/3 instructions are commonly used
with one immediate or literal operand.

Introduce three new specialized instructions:

i_is_eq_exact_literal/3
i_is_ne_exact_immed/3
i_is_ne_exact_literal/3

The i_is_ne_exact_literal/3 instruction is not very frequently
used, but its existence is justified because we removed in a
a previous commit the special instruction for matching bignums
and we now use i_is_ne_exact_literal/3 instead.

For consistency, rename the existing is_eq_immed/3 instruction to
is_eq_exact_immed/3.

While at it, remove the optimization of an is_eq/3 instruction
with an immediate operand because that optimization is already
done by the compiler.

2 files changed, 80 insertions, 13 deletions

diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index 741ba8fb93..b90613079a 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -738,6 +738,7 @@ extern int count_instructions;
   } while (0)
 
 #define EqualImmed(X, Y, Action) if (X != Y) { Action; }
+#define NotEqualImmed(X, Y, Action) if (X == Y) { Action; }
 
 #define IsFloat(Src, Fail) if (is_not_float(Src)) { Fail; }
 
@@ -1385,6 +1386,52 @@ void process_main(void)
     }
     Next(1);
 
+    {
+	Eterm is_eq_exact_lit_val;
+
+    OpCase(i_is_eq_exact_literal_xfc):
+	is_eq_exact_lit_val = xb(Arg(0));
+	I++;
+	goto do_is_eq_exact_literal;
+
+    OpCase(i_is_eq_exact_literal_yfc):
+	is_eq_exact_lit_val = yb(Arg(0));
+	I++;
+	goto do_is_eq_exact_literal;
+
+    OpCase(i_is_eq_exact_literal_rfc):
+	is_eq_exact_lit_val = r(0);
+
+    do_is_eq_exact_literal:
+	if (!eq(Arg(1), is_eq_exact_lit_val)) {
+	    ClauseFail();
+	}
+	Next(2);
+    }
+
+    {
+	Eterm is_ne_exact_lit_val;
+
+    OpCase(i_is_ne_exact_literal_xfc):
+	is_ne_exact_lit_val = xb(Arg(0));
+	I++;
+	goto do_is_ne_exact_literal;
+
+    OpCase(i_is_ne_exact_literal_yfc):
+	is_ne_exact_lit_val = yb(Arg(0));
+	I++;
+	goto do_is_ne_exact_literal;
+
+    OpCase(i_is_ne_exact_literal_rfc):
+	is_ne_exact_lit_val = r(0);
+
+    do_is_ne_exact_literal:
+	if (eq(Arg(1), is_ne_exact_lit_val)) {
+	    ClauseFail();
+	}
+	Next(2);
+    }
+
  OpCase(i_move_call_only_fcr): {
      r(0) = Arg(1);
  }
diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab
index 029d7b512c..9b3d1da018 100644
--- a/erts/emulator/beam/ops.tab
+++ b/erts/emulator/beam/ops.tab
@@ -339,31 +339,51 @@ i_wait_error_locked
 send
 
 #
-# Comparisions.
+# Optimized comparisons with one immediate/literal operand.
 #
 
-is_eq_exact Lbl=f R=rxy C=ian => i_is_eq_immed Lbl R C
-is_eq Lbl=f R=rxy C=an => i_is_eq_immed Lbl R C
+is_eq_exact Lbl R=rxy C=ian => i_is_eq_exact_immed Lbl R C
+is_eq_exact Lbl R=rxy C=q => i_is_eq_exact_literal R Lbl C
+
+is_ne_exact Lbl R=rxy C=ian => i_is_ne_exact_immed Lbl R C
+is_ne_exact Lbl R=rxy C=q => i_is_ne_exact_literal R Lbl C
+
+%macro: i_is_eq_exact_immed EqualImmed -fail_action
+i_is_eq_exact_immed f r c
+i_is_eq_exact_immed f x c
+i_is_eq_exact_immed f y c
+
+i_is_eq_exact_literal r f c
+i_is_eq_exact_literal x f c
+i_is_eq_exact_literal y f c
+
+%macro: i_is_ne_exact_immed NotEqualImmed -fail_action
+i_is_ne_exact_immed f r c
+i_is_ne_exact_immed f x c
+i_is_ne_exact_immed f y c
+
+i_is_ne_exact_literal r f c
+i_is_ne_exact_literal x f c
+i_is_ne_exact_literal y f c
+
+#
+# All other comparisons.
+#
+
+is_eq_exact Lbl S1 S2 => i_fetch S1 S2 | i_is_eq_exact Lbl
+is_ne_exact Lbl S1 S2 => i_fetch S1 S2 | i_is_ne_exact Lbl
 
 is_ge Lbl S1 S2 => i_fetch S1 S2 | i_is_ge Lbl
 is_lt Lbl S1 S2 => i_fetch S1 S2 | i_is_lt Lbl
 is_eq Lbl S1 S2 => i_fetch S1 S2 | i_is_eq Lbl
 is_ne Lbl S1 S2 => i_fetch S1 S2 | i_is_ne Lbl
 
-is_eq_exact Lbl=f S1 S2 => i_fetch S1 S2 | i_is_eq_exact Lbl
-is_ne_exact Lbl S1 S2 => i_fetch S1 S2 | i_is_ne_exact Lbl
-
+i_is_eq_exact f
+i_is_ne_exact f
 i_is_lt f
 i_is_ge f
 i_is_eq f
 i_is_ne f
-i_is_eq_exact f
-i_is_ne_exact f
-
-%macro: i_is_eq_immed EqualImmed -fail_action
-i_is_eq_immed f r c
-i_is_eq_immed f x c
-i_is_eq_immed f y c
 
 #
 # Putting things.