Cranelift: Add egraph rule to rewrite x * C ==> x << log2(C) when C is a power of two (#5647)

2023-01-31 10:04:17 -08:00
parent 61270cdaed
commit c9d1c068bc
6 changed files with 64 additions and 4 deletions
--- a/cranelift/filetests/filetests/egraph/algebraic.clif
+++ b/cranelift/filetests/filetests/egraph/algebraic.clif
@@ -7,8 +7,8 @@ function %f0(i32) -> i32 {
 block0(v0: i32):
    v1 = iconst.i32 2
    v2 = imul v0, v1
-    ; check: v3 = iadd v0, v0
-    ; check: return v3
+    ; check: v5 = ishl v0, v4  ; v4 = 1
+    ; check: return v5
    return v2
 }