c71a0ea9a5
This PR introduces coalescing of RC operations to the RC optimizer. Whenever we perform multiple `inc`s for a single value within one basic block it is legal to instead perform all of these `inc`s at once at the first `inc` side. This is the case because the value will stay alive until at least the last `inc` and was thus never observable with `RC=1`. Hence, this change of `inc` location never destroys reuse opportunities.
41 lines
833 B
Text
41 lines
833 B
Text
module
|
|
|
|
/-! This test demonstrates basic coalescing capabilities of the RC optimizer -/
|
|
|
|
public section
|
|
|
|
@[extern "foo"]
|
|
opaque foo (x : String) (n : Nat) : Nat
|
|
|
|
|
|
/--
|
|
trace: [Compiler.coalesceRc] size: 18
|
|
def test x : tobj :=
|
|
let _x.1 := 0;
|
|
inc[3][ref] x;
|
|
let a := foo x _x.1;
|
|
let _x.2 := 1;
|
|
let _x.3 := foo x _x.2;
|
|
let a := Nat.add a _x.3;
|
|
dec _x.3;
|
|
dec a;
|
|
let _x.4 := 2;
|
|
let _x.5 := foo x _x.4;
|
|
let a := Nat.add a _x.5;
|
|
dec _x.5;
|
|
dec a;
|
|
let _x.6 := 3;
|
|
let _x.7 := foo x _x.6;
|
|
let a := Nat.add a _x.7;
|
|
dec _x.7;
|
|
dec a;
|
|
return a
|
|
-/
|
|
#guard_msgs in
|
|
set_option trace.Compiler.coalesceRc true in
|
|
def test (x : String) : Nat :=
|
|
let a := foo x 0
|
|
let a := a + foo x 1
|
|
let a := a + foo x 2
|
|
let a := a + foo x 3
|
|
a
|