38 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			38 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			LLVM
		
	
	
	
; RUN: opt < %s -S -basicaa -memcpyopt | FileCheck %s
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target datalayout = "E-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64"
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declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind
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declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind
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; The resulting memset is only 4-byte aligned, despite containing
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; a 16-byte aligned store in the middle.
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define void @foo(i32* %p) {
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; CHECK-LABEL: @foo(
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; CHECK: call void @llvm.memset.p0i8.i64(i8* {{.*}}, i8 0, i64 16, i32 4, i1 false)
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  %a0 = getelementptr i32, i32* %p, i64 0
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  store i32 0, i32* %a0, align 4
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  %a1 = getelementptr i32, i32* %p, i64 1
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  store i32 0, i32* %a1, align 16
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  %a2 = getelementptr i32, i32* %p, i64 2
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  store i32 0, i32* %a2, align 4
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  %a3 = getelementptr i32, i32* %p, i64 3
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  store i32 0, i32* %a3, align 4
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  ret void
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}
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; Replacing %a8 with %a4 in the memset requires boosting the alignment of %a4.
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define void @bar() {
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; CHECK-LABEL: @bar(
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; CHECK: %a4 = alloca i32, align 8
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; CHECK-NOT: memcpy
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  %a4 = alloca i32, align 4
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  %a8 = alloca i32, align 8
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  %a8.cast = bitcast i32* %a8 to i8*
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  %a4.cast = bitcast i32* %a4 to i8*
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  call void @llvm.memset.p0i8.i64(i8* %a8.cast, i8 0, i64 4, i32 8, i1 false)
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  call void @llvm.memcpy.p0i8.p0i8.i64(i8* %a4.cast, i8* %a8.cast, i64 4, i32 4, i1 false)
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  ret void
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}
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