1 files changed, 34 insertions, 0 deletions
diff --git a/llvm/test/Transforms/LoopIdiom/ctpop-multiple-users-crash.ll b/llvm/test/Transforms/LoopIdiom/ctpop-multiple-users-crash.ll
new file mode 100644
index 00000000000..ddb7bdbe7d1
--- /dev/null
+++ b/llvm/test/Transforms/LoopIdiom/ctpop-multiple-users-crash.ll
@@ -0,0 +1,34 @@
+; RUN: opt -loop-idiom -S < %s | FileCheck %s
+
+target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
+target triple = "arm64-apple-ios8.0.0"
+
+; When we replace the precondition with a ctpop, we need to ensure
+; that only the first branch reads the ctpop.  The store prior
+; to that should continue to read from the original compare.
+
+; CHECK: %tobool.5 = icmp ne i32 %num, 0
+; CHECK: store i1 %tobool.5, i1* %ptr
+
+define internal fastcc i32 @num_bits_set(i32 %num, i1* %ptr) #1 {
+entry:
+  %tobool.5 = icmp ne i32 %num, 0
+  store i1 %tobool.5, i1* %ptr
+  br i1 %tobool.5, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph:                                   ; preds = %entry
+  br label %for.body
+
+for.body:                                         ; preds = %for.body.lr.ph, %for.body
+  %count.07 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.body ]
+  %num.addr.06 = phi i32 [ %num, %for.body.lr.ph ], [ %and, %for.body ]
+  %sub = add i32 %num.addr.06, -1
+  %and = and i32 %sub, %num.addr.06
+  %inc = add nsw i32 %count.07, 1
+  %tobool = icmp ne i32 %and, 0
+  br i1 %tobool, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.cond.for.end_crit_edge, %entry
+  %count.0.lcssa = phi i32 [ %inc, %for.body ], [ 0, %entry ]
+  ret i32 %count.0.lcssa
+}
+\ No newline at end of file