llvm-6502/test/Transforms/DeadStoreElimination/const-pointers.ll
Nick Lewycky 20162ac566 Teach BasicAA that a constant expression can't alias memory provably not
allocated until runtime (such as an alloca). Patch by Hans Wennborg!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88760 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-14 06:15:14 +00:00

40 lines
763 B
LLVM

; RUN: opt %s -dse -S | FileCheck %s
%t = type { i32 }
@g = global i32 42;
define void @test1(%t* noalias %pp) {
%p = getelementptr inbounds %t* %pp, i32 0, i32 0
store i32 1, i32* %p; <-- This is dead
%x = load i32* inttoptr (i32 12345 to i32*)
store i32 %x, i32* %p
ret void
; CHECK define void @test1
; CHECK: store
; CHECK-NOT: store
; CHECK: ret void
}
define void @test3() {
store i32 1, i32* @g; <-- This is dead.
store i32 42, i32* @g
ret void
;CHECK define void @test3
;CHECK: store
;CHECK-NOT: store
;CHECK: ret void
}
define void @test4(i32* %p) {
store i32 1, i32* %p
%x = load i32* @g; <-- %p and @g could alias
store i32 %x, i32* %p
ret void
; CHECK define void @test4
; CHECK: store
; CHECK: store
; CHECK: ret void
}