Add test for r257279.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257280 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/JumpThreading/pr26096.ll

@@ -0,0 +1,68 @@
+; RUN: opt -prune-eh -inline -jump-threading -S < %s | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@d = external global i32*, align 8
+
+define void @fn3(i1 %B) {
+entry:
+  br i1 %B, label %if.end, label %if.then
+
+if.then:                                          ; preds = %entry
+  call void @fn2()
+  ret void
+
+if.end:                                           ; preds = %entry
+  call void @fn2()
+  ret void
+}
+
+define internal void @fn2() unnamed_addr {
+entry:
+  call void @fn1()
+  call void @fn1()
+  call void @fn1()
+  unreachable
+}
+
+; CHECK-LABEL: define internal void @fn2(
+; CHECK:   %[[LOAD:.*]] = load i32*, i32** @d, align 8
+; CHECK:   %tobool1.i = icmp eq i32* %[[LOAD]], null
+
+define internal void @fn1() unnamed_addr {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %entry
+  %0 = load i32*, i32** @d, align 8
+  %tobool1 = icmp eq i32* %0, null
+  br i1 %tobool1, label %cond.false, label %cond.end
+
+cond.false:                                       ; preds = %for.body
+  call void @__assert_fail(i8* null)
+  unreachable
+
+cond.end:                                         ; preds = %for.body
+  %1 = load i32*, i32** @d, align 8
+  %cmp = icmp eq i32* %1, null
+  br i1 %cmp, label %cond.end4, label %cond.false3
+
+cond.false3:                                      ; preds = %cond.end
+  call void @__assert_fail(i8* null)
+  unreachable
+
+cond.end4:                                        ; preds = %cond.end
+  call void @__assert_fail(i8* null)
+  unreachable
+
+for.end:                                          ; No predecessors!
+  ret void
+}
+
+declare void @__assert_fail(i8*)
+
+; Function Attrs: noreturn nounwind
+declare void @llvm.trap() #0
+
+attributes #0 = { noreturn nounwind }