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; RUN: opt < %s -basicaa -gvn -instcombine -S | FileCheck %s
declare i32* @test(i32* nocapture)
define i32 @test2() {
; CHECK: ret i32 0
%P = alloca i32
%Q = call i32* @test(i32* %P)
%a = load i32, i32* %P
store i32 4, i32* %Q ;; cannot clobber P since it is nocapture.
%b = load i32, i32* %P
%c = sub i32 %a, %b
ret i32 %c
}
declare void @test3(i32** %p, i32* %q) nounwind
define i32 @test4(i32* noalias nocapture %p) nounwind {
; CHECK: call void @test3
; CHECK: store i32 0, i32* %p
; CHECK: store i32 1, i32* %x
; CHECK: %y = load i32, i32* %p
; CHECK: ret i32 %y
entry:
%q = alloca i32*
; Here test3 might store %p to %q. This doesn't violate %p's nocapture
; attribute since the copy doesn't outlive the function.
call void @test3(i32** %q, i32* %p) nounwind
store i32 0, i32* %p
%x = load i32*, i32** %q
; This store might write to %p and so we can't eliminate the subsequent
; load
store i32 1, i32* %x
%y = load i32, i32* %p
ret i32 %y
}
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