llvm-project/llvm/test/Transforms/DeadStoreElimination/simple.ll

; RUN: opt < %s -basicaa -dse -S | FileCheck %s
target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"

define void @test1(i32* %Q, i32* %P) {
        %DEAD = load i32* %Q
        store i32 %DEAD, i32* %P
        store i32 0, i32* %P
        ret void
; CHECK: @test1
; CHECK-NEXT: store i32 0, i32* %P
; CHECK-NEXT: ret void
}

; PR8576 - Should delete store of 10 even though p/q are may aliases.
define void @test2(i32 *%p, i32 *%q) {
  store i32 10, i32* %p, align 4
  store i32 20, i32* %q, align 4
  store i32 30, i32* %p, align 4
  ret void
; CHECK: @test2
; CHECK-NEXT: store i32 20
}


; PR8677
@g = global i32 1

define i32 @test3(i32* %g_addr) nounwind {
; CHECK: @test3
; CHECK: load i32* %g_addr
  %g_value = load i32* %g_addr, align 4
  store i32 -1, i32* @g, align 4
  store i32 %g_value, i32* %g_addr, align 4
  %tmp3 = load i32* @g, align 4
  ret i32 %tmp3
}


define void @test4(i32* %Q) {
        %a = load i32* %Q
        volatile store i32 %a, i32* %Q
        ret void
; CHECK: @test4
; CHECK-NEXT: load i32
; CHECK-NEXT: volatile store
; CHECK-NEXT: ret void
}

define void @test5(i32* %Q) {
        %a = volatile load i32* %Q
        store i32 %a, i32* %Q
        ret void
; CHECK: @test5
; CHECK-NEXT: volatile load
; CHECK-NEXT: ret void
}