cranelift: simplify x-x to 0 (#6032)

* cranelift: simplify `x-x` to `0` * Guard `x-x => 0` rewrite with `fits_in_64`
2023-03-17 15:14:28 +00:00
parent 28371bfd40
commit b53d66e634
2 changed files with 11 additions and 0 deletions
--- a/cranelift/filetests/filetests/egraph/algebraic.clif
+++ b/cranelift/filetests/filetests/egraph/algebraic.clif
@@ -232,6 +232,14 @@ block0(v0: i32):
    ; check: return v0
 }

+function %isub_self(i32) -> i32 {
+block0(v0: i32):
+    v1 = isub v0, v0
+    return v1
+    ; check: v2 = iconst.i32 0
+    ; check: return v2
+}
+
 function %or_and_y_with_not_y_i8(i8, i8) -> i8 {
 block0(v0: i8, v1: i8):
    v2 = band v0, v1