llvm/test/Transforms/InstCombine/strncat-1.ll
Meador Inge 73d8a5864f instcombine: Migrate strcat and strncat optimizations
This patch migrates the strcat and strncat optimizations from the
simplify-libcalls pass into the instcombine library call simplifier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165874 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-13 16:45:32 +00:00

38 lines
1.1 KiB
LLVM

; Test that the strncat libcall simplifier works correctly.
;
; RUN: opt < %s -instcombine -S | FileCheck %s
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"
@hello = constant [6 x i8] c"hello\00"
@null = constant [1 x i8] zeroinitializer
@null_hello = constant [7 x i8] c"\00hello\00"
declare i8* @strncat(i8*, i8*, i32)
declare i32 @puts(i8*)
define i32 @main() {
; CHECK: @main
; CHECK-NOT: call i8* @strncat
; CHECK: call i32 @puts
%target = alloca [1024 x i8]
%arg1 = getelementptr [1024 x i8]* %target, i32 0, i32 0
store i8 0, i8* %arg1
; rslt1 = strncat(target, "hello\00")
%arg2 = getelementptr [6 x i8]* @hello, i32 0, i32 0
%rslt1 = call i8* @strncat(i8* %arg1, i8* %arg2, i32 6)
; rslt2 = strncat(rslt1, "\00")
%arg3 = getelementptr [1 x i8]* @null, i32 0, i32 0
%rslt2 = call i8* @strncat(i8* %rslt1, i8* %arg3, i32 42)
; rslt3 = strncat(rslt2, "\00hello\00")
%arg4 = getelementptr [7 x i8]* @null_hello, i32 0, i32 0
%rslt3 = call i8* @strncat(i8* %rslt2, i8* %arg4, i32 42)
call i32 @puts(i8* %rslt3)
ret i32 0
}