llvm-project/llvm/test/Analysis/ValueTracking/knownzero-addrspacecast.ll

25 lines
688 B
LLVM

; RUN: opt -instcombine -S < %s | FileCheck %s
; When a pointer is addrspacecasted to a another addr space, we cannot assume
; anything about the new bits.
target datalayout = "p:32:32-p3:32:32-p4:64:64"
; CHECK-LABEL: @test_shift
; CHECK-NOT: ret i64 0
define i64 @test_shift(i8* %p) {
%g = addrspacecast i8* %p to i8 addrspace(4)*
%i = ptrtoint i8 addrspace(4)* %g to i64
%shift = lshr i64 %i, 32
ret i64 %shift
}
; CHECK-LABEL: @test_null
; A null pointer casted to another addr space may no longer have null value.
; CHECK-NOT: ret i32 0
define i32 @test_null() {
%g = addrspacecast i8* null to i8 addrspace(3)*
%i = ptrtoint i8 addrspace(3)* %g to i32
ret i32 %i
}