Make GVN aware of instructions that write to CPU flags.

2017-10-19 12:57:55 -07:00
parent bce3c38042
commit cc0bb70c5d
4 changed files with 29 additions and 1 deletions
--- a/cranelift/filetests/simple_gvn/reject.cton
+++ b/cranelift/filetests/simple_gvn/reject.cton
@@ -23,3 +23,19 @@ ebb0:
    v5 = iadd v4, v3
    return v5
 }
+
+function %cpu_flags() -> b1 {
+ebb0:
+    v0 = iconst.i32 7
+    v1 = iconst.i32 8
+    v2 = ifcmp v0, v1
+    v3 = trueif eq v2
+    v4 = ifcmp v0, v1
+    v5 = trueif eq v4
+    v6 = bor v3, v5
+; check: v2 = ifcmp v0, v1
+; check: v3 = trueif eq v2
+; check: v4 = ifcmp v0, v1
+; check: v5 = trueif eq v4
+    return v6
+}