--- /dev/null
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+; OSS-Fuzz: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=38057
+define void @PR51824() {
+; CHECK-LABEL: @PR51824(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: br label [[BB:%.*]]
+; CHECK: BB:
+; CHECK-NEXT: br i1 undef, label [[BB]], label [[BB1:%.*]]
+; CHECK: BB1:
+; CHECK-NEXT: ret void
+;
+entry:
+ %C7 = icmp sgt i1 false, true
+ %B2 = lshr i16 -32768, 0
+ %C1 = icmp uge i16 %B2, %B2
+ %E9 = extractelement <4 x i16> zeroinitializer, i16 %B2
+ %I2 = insertelement <4 x i16> undef, i16 %E9, i16 0
+ %i = sext <4 x i16> %I2 to <4 x i32>
+ %i1 = getelementptr inbounds i64, i64* null, <4 x i32> %i
+ %i2 = ptrtoint <4 x i64*> %i1 to <4 x i32>
+ %E2 = extractelement <4 x i32> %i2, i16 0
+ br label %BB
+
+BB: ; preds = %BB, %entry
+ %A15 = alloca <4 x i32>, align 16
+ %L2 = load <4 x i32>, <4 x i32>* %A15, align 16
+ %G1 = getelementptr i64, i64* null, i32 %E2
+ %i3 = getelementptr inbounds i64, i64* %G1, <4 x i16> undef
+ %i4 = ptrtoint <4 x i64*> %i3 to <4 x i32>
+ %E22 = extractelement <4 x i32> %L2, i1 false
+ %E8 = extractelement <4 x i32> %i4, i1 false
+ %I10 = insertelement <4 x i32> undef, i32 undef, i32 %E8
+ %I19 = insertelement <4 x i32> %I10, i32 %E22, i16 0
+ %S7 = shufflevector <4 x i32> %I19, <4 x i32> %L2, <4 x i32> undef
+ %I8 = insertelement <4 x i32> %I19, i32 0, i1 %C1
+ %E10 = extractelement <4 x i32> %I8, i1 undef
+ store i32 %E10, i32* undef, align 4
+ br i1 undef, label %BB, label %BB1
+
+BB1: ; preds = %BB
+ %S8 = shufflevector <4 x i32> %I10, <4 x i32> %S7, <4 x i32> undef
+ store <4 x i32> %S8, <4 x i32>* undef, align 16
+ ret void
+}