From bdbbd8381fdbdd76f53449a43c843a69e5660da6 Mon Sep 17 00:00:00 2001
From: John Brawn <john.brawn@arm.com>
Date: Thu, 28 Jun 2018 14:13:06 +0000
Subject: Add a PhiValuesAnalysis pass to calculate the underlying values of
 phis

This pass is being added in order to make the information available to BasicAA,
which can't do caching of this information itself, but possibly this information
may be useful for other passes.

Incorporates code based on Daniel Berlin's implementation of Tarjan's algorithm.

Differential Revision: https://reviews.llvm.org/D47893

llvm-svn: 335857
---
 llvm/test/Analysis/PhiValues/big_phi.ll | 78 +++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 llvm/test/Analysis/PhiValues/big_phi.ll

(limited to 'llvm/test/Analysis/PhiValues/big_phi.ll')

diff --git a/llvm/test/Analysis/PhiValues/big_phi.ll b/llvm/test/Analysis/PhiValues/big_phi.ll
new file mode 100644
index 00000000000..6f13098db60
--- /dev/null
+++ b/llvm/test/Analysis/PhiValues/big_phi.ll
@@ -0,0 +1,78 @@
+; RUN: opt < %s -passes='print<phi-values>' -disable-output 2>&1 | FileCheck %s
+
+; This test has a phi with a large number of incoming values that are all the
+; same phi, and that phi depends on this phi. This is to check that phi values
+; analysis doesn't repeatedly add a phis values to itself until it segfaults.
+
+; CHECK-LABEL: PHI Values for function: fn
+define void @fn(i8* %arg) {
+entry:
+  br label %for.body
+
+for.body:
+; CHECK: PHI %phi1 has values:
+; CHECK-DAG: i8* %arg
+; CHECK-DAG: i8* undef
+  %phi1 = phi i8* [ %arg, %entry ], [ %phi2, %end ]
+  switch i32 undef, label %end [
+    i32 1, label %bb1
+    i32 2, label %bb2
+    i32 3, label %bb3
+    i32 4, label %bb4
+    i32 5, label %bb5
+    i32 6, label %bb6
+    i32 7, label %bb7
+    i32 8, label %bb8
+    i32 9, label %bb9
+    i32 10, label %bb10
+    i32 11, label %bb11
+    i32 12, label %bb12
+    i32 13, label %bb13
+  ]
+
+bb1:
+  br label %end
+
+bb2:
+  br label %end
+
+bb3:
+  br label %end
+
+bb4:
+  br label %end
+
+bb5:
+  br label %end
+
+bb6:
+  br label %end
+
+bb7:
+  br label %end
+
+bb8:
+  br label %end
+
+bb9:
+  br label %end
+
+bb10:
+  br label %end
+
+bb11:
+  br label %end
+
+bb12:
+  br label %end
+
+bb13:
+  br label %end
+
+end:
+; CHECK: PHI %phi2 has values:
+; CHECK-DAG: i8* %arg
+; CHECK-DAG: i8* undef
+  %phi2 = phi i8* [ %phi1, %for.body ], [ %phi1, %bb1 ], [ %phi1, %bb2 ], [ %phi1, %bb3 ], [ %phi1, %bb4 ], [ %phi1, %bb5 ], [ %phi1, %bb6 ], [ %phi1, %bb7 ], [ undef, %bb8 ], [ %phi1, %bb9 ], [ %phi1, %bb10 ], [ %phi1, %bb11 ], [ %phi1, %bb12 ], [ %phi1, %bb13 ]
+  br label %for.body
+}
-- 
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