make jump threading recursively simplify expressions instead of doing it
just one level deep. On the testcase we go from getting this:
F1: ; preds = %T2
%F = and i1 true, %cond ; <i1> [#uses=1]
br i1 %F, label %X, label %Y
to a fully threaded:
F1: ; preds = %T2
br label %Y
This changes gets us to the point where we're forming (too many) switch
instructions on doug's strswitch testcase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86646 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Transforms/JumpThreading/basic.ll b/test/Transforms/JumpThreading/basic.ll
index 7b444ad..1be086b 100644
--- a/test/Transforms/JumpThreading/basic.ll
+++ b/test/Transforms/JumpThreading/basic.ll
@@ -203,3 +203,35 @@
; CHECK-NEXT: phi i32
}
+
+declare i1 @test8a()
+
+define i32 @test8b(i1 %cond, i1 %cond2) {
+; CHECK: @test8b
+T0:
+ %A = call i1 @test8a()
+ br i1 %A, label %T1, label %F1
+T1:
+ %B = call i1 @test8a()
+ br i1 %B, label %T2, label %F1
+T2:
+ %C = call i1 @test8a()
+ br i1 %cond, label %T3, label %F1
+T3:
+ ret i32 0
+
+F1:
+; TODO: F1 uncond branch block should be removed, T2 should jump directly to Y.
+; CHECK: F1:
+; CHECK-NEXT br label %Y
+ %D = phi i32 [0, %T0], [0, %T1], [1, %T2]
+ %E = icmp eq i32 %D, 1
+ %F = and i1 %E, %cond
+ br i1 %F, label %X, label %Y
+X:
+ call i1 @test8a()
+ ret i32 1
+Y:
+ ret i32 2
+}
+