96 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			96 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			LLVM
		
	
	
	
; Test that the strncpy library call simplifier works correctly.
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;
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; RUN: opt < %s -instcombine -S | FileCheck %s
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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"
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@hello = constant [6 x i8] c"hello\00"
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@null = constant [1 x i8] zeroinitializer
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@null_hello = constant [7 x i8] c"\00hello\00"
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@a = common global [32 x i8] zeroinitializer, align 1
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@b = common global [32 x i8] zeroinitializer, align 1
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declare i8* @strncpy(i8*, i8*, i32)
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declare i32 @puts(i8*)
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; Check a bunch of strncpy invocations together.
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define i32 @test_simplify1() {
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; CHECK-LABEL: @test_simplify1(
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; CHECK-NOT: call i8* @strncpy
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; CHECK: call i32 @puts
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  %target = alloca [1024 x i8]
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  %arg1 = getelementptr [1024 x i8]* %target, i32 0, i32 0
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  store i8 0, i8* %arg1
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  %arg2 = getelementptr [6 x i8]* @hello, i32 0, i32 0
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  %rslt1 = call i8* @strncpy(i8* %arg1, i8* %arg2, i32 6)
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  %arg3 = getelementptr [1 x i8]* @null, i32 0, i32 0
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  %rslt2 = call i8* @strncpy(i8* %rslt1, i8* %arg3, i32 42)
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  %arg4 = getelementptr [7 x i8]* @null_hello, i32 0, i32 0
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  %rslt3 = call i8* @strncpy(i8* %rslt2, i8* %arg4, i32 42)
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  call i32 @puts( i8* %rslt3 )
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  ret i32 0
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}
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; Check strncpy(x, "", y) -> memset(x, '\0', y, 1).
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define void @test_simplify2() {
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; CHECK-LABEL: @test_simplify2(
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  %dst = getelementptr [32 x i8]* @a, i32 0, i32 0
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  %src = getelementptr [1 x i8]* @null, i32 0, i32 0
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  call i8* @strncpy(i8* %dst, i8* %src, i32 32)
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; CHECK: call void @llvm.memset.p0i8.i32
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  ret void
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}
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; Check strncpy(x, y, 0) -> x.
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define i8* @test_simplify3() {
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; CHECK-LABEL: @test_simplify3(
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  %dst = getelementptr [32 x i8]* @a, i32 0, i32 0
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  %src = getelementptr [6 x i8]* @hello, i32 0, i32 0
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  %ret = call i8* @strncpy(i8* %dst, i8* %src, i32 0)
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  ret i8* %ret
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; CHECK: ret i8* getelementptr inbounds ([32 x i8]* @a, i32 0, i32 0)
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}
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; Check  strncpy(x, s, c) -> memcpy(x, s, c, 1) [s and c are constant].
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define void @test_simplify4() {
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; CHECK-LABEL: @test_simplify4(
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  %dst = getelementptr [32 x i8]* @a, i32 0, i32 0
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  %src = getelementptr [6 x i8]* @hello, i32 0, i32 0
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  call i8* @strncpy(i8* %dst, i8* %src, i32 6)
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; CHECK: call void @llvm.memcpy.p0i8.p0i8.i32
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  ret void
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}
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; Check cases that shouldn't be simplified.
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define void @test_no_simplify1() {
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; CHECK-LABEL: @test_no_simplify1(
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  %dst = getelementptr [32 x i8]* @a, i32 0, i32 0
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  %src = getelementptr [32 x i8]* @b, i32 0, i32 0
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  call i8* @strncpy(i8* %dst, i8* %src, i32 32)
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; CHECK: call i8* @strncpy
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  ret void
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}
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define void @test_no_simplify2() {
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; CHECK-LABEL: @test_no_simplify2(
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  %dst = getelementptr [32 x i8]* @a, i32 0, i32 0
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  %src = getelementptr [6 x i8]* @hello, i32 0, i32 0
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  call i8* @strncpy(i8* %dst, i8* %src, i32 8)
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; CHECK: call i8* @strncpy
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  ret void
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}
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