1 files changed, 47 insertions, 0 deletions
diff --git a/llvm/test/Transforms/LoopStrengthReduce/X86/pr28719.ll b/llvm/test/Transforms/LoopStrengthReduce/X86/pr28719.ll
new file mode 100644
index 00000000000..0e74ff20073
--- /dev/null
+++ b/llvm/test/Transforms/LoopStrengthReduce/X86/pr28719.ll
@@ -0,0 +1,47 @@
+; RUN: opt < %s -loop-reduce -S | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@a = global i32 0, align 4
+@b = global i8 0, align 1
+@c = global [4 x i8] zeroinitializer, align 1
+
+; Just make sure we don't generate code with uses not dominated by defs.
+; CHECK-LABEL: @main(
+define i32 @main() {
+entry:
+  %a0 = load i32, i32* @a, align 4
+  %cmpa = icmp slt i32 %a0, 4
+  br i1 %cmpa, label %preheader, label %for.end
+
+preheader:
+  %b0 = load i8, i8* @b, align 1
+  %b0sext = sext i8 %b0 to i64
+  br label %for.body
+
+for.body:
+  %iv = phi i64 [ 0, %preheader ], [ %iv.next, %lor.false ]
+  %mul = mul nsw i64 %b0sext, %iv
+  %multrunc = trunc i64 %mul to i32
+  %cmp = icmp eq i32 %multrunc, 0
+  br i1 %cmp, label %lor.false, label %if.then
+
+lor.false:
+  %cgep = getelementptr inbounds [4 x i8], [4 x i8]* @c, i64 0, i64 %iv
+  %ci = load i8, i8* %cgep, align 1
+  %cisext = sext i8 %ci to i32
+  %ivtrunc = trunc i64 %iv to i32
+  %cmp2 = icmp eq i32 %cisext, %ivtrunc
+  %iv.next = add i64 %iv, 1
+  br i1 %cmp2, label %for.body, label %if.then
+
+if.then:
+  tail call void @abort()
+  unreachable
+
+for.end:
+  ret i32 0
+}
+
+declare void @abort()