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      1 ; Test that the strncat libcall simplifier works correctly.
      2 ;
      3 ; RUN: opt < %s -instcombine -S | FileCheck %s
      4 
      5 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
      6 
      7 @hello = constant [6 x i8] c"hello\00"
      8 @null = constant [1 x i8] zeroinitializer
      9 @null_hello = constant [7 x i8] c"\00hello\00"
     10 
     11 declare i8* @strncat(i8*, i8*, i32)
     12 declare i32 @puts(i8*)
     13 
     14 define i32 @main() {
     15 ; CHECK-LABEL: @main(
     16 ; CHECK-NOT: call i8* @strncat
     17 ; CHECK: call i32 @puts
     18 
     19   %target = alloca [1024 x i8]
     20   %arg1 = getelementptr [1024 x i8], [1024 x i8]* %target, i32 0, i32 0
     21   store i8 0, i8* %arg1
     22 
     23   ; rslt1 = strncat(target, "hello\00")
     24   %arg2 = getelementptr [6 x i8], [6 x i8]* @hello, i32 0, i32 0
     25   %rslt1 = call i8* @strncat(i8* %arg1, i8* %arg2, i32 6)
     26 
     27   ; rslt2 = strncat(rslt1, "\00")
     28   %arg3 = getelementptr [1 x i8], [1 x i8]* @null, i32 0, i32 0
     29   %rslt2 = call i8* @strncat(i8* %rslt1, i8* %arg3, i32 42)
     30 
     31   ; rslt3 = strncat(rslt2, "\00hello\00")
     32   %arg4 = getelementptr [7 x i8], [7 x i8]* @null_hello, i32 0, i32 0
     33   %rslt3 = call i8* @strncat(i8* %rslt2, i8* %arg4, i32 42)
     34 
     35   call i32 @puts(i8* %rslt3)
     36   ret i32 0
     37 }
     38