third_party/subzero/tests_lit/llvm2ice_tests/nacl-atomic-fence-all.ll

; Test that loads/stores don't move across a nacl.atomic.fence.all.
; This should apply to both atomic and non-atomic loads/stores
; (unlike the non-"all" variety of nacl.atomic.fence, which only
; applies to atomic load/stores).
;
; RUN: %p2i -i %s --filetype=obj --disassemble --args -O2 | FileCheck %s

declare void @llvm.nacl.atomic.fence.all()
declare i32 @llvm.nacl.atomic.load.i32(i32*, i32)
declare void @llvm.nacl.atomic.store.i32(i32, i32*, i32)

@g32_a = internal global [4 x i8] zeroinitializer, align 4
@g32_b = internal global [4 x i8] zeroinitializer, align 4
@g32_c = internal global [4 x i8] zeroinitializer, align 4
@g32_d = internal global [4 x i8] zeroinitializer, align 4

define internal i32 @test_fused_load_sub_a() {
entry:
  %p_alloca = alloca i8, i32 4, align 4
  %p_alloca_bc = bitcast i8* %p_alloca to i32*
  store i32 999, i32* %p_alloca_bc, align 1

  %p_a = bitcast [4 x i8]* @g32_a to i32*
  %l_a = call i32 @llvm.nacl.atomic.load.i32(i32* %p_a, i32 6)
  %l_a2 = sub i32 1, %l_a
  call void @llvm.nacl.atomic.store.i32(i32 %l_a2, i32* %p_a, i32 6)

  %p_b = bitcast [4 x i8]* @g32_b to i32*
  %l_b = load i32, i32* %p_b, align 1
  %l_b2 = sub i32 1, %l_b
  store i32 %l_b2, i32* %p_b, align 1

  %p_c = bitcast [4 x i8]* @g32_c to i32*
  %l_c = load i32, i32* %p_c, align 1
  %l_c2 = sub i32 1, %l_c
  call void @llvm.nacl.atomic.fence.all()
  store i32 %l_c2, i32* %p_c, align 1

  ret i32 %l_c2
}
; CHECK-LABEL: test_fused_load_sub_a
;    alloca store
; CHECK: mov DWORD PTR {{.*}},0x3e7
;    atomic store (w/ its own mfence)
; The load + sub are optimized into one everywhere.
; CHECK: sub {{.*}},DWORD PTR {{.*}}{{(g32_a)|(.bss)}}
; CHECK: mov {{(DWORD PTR)?}}
; CHECK: mfence
; CHECK: sub {{.*}},DWORD PTR {{.*}}{{(g32_b)|(.bss)}}
; CHECK: mov {{(DWORD PTR)?}}
; CHECK: sub {{.*}},DWORD PTR {{.*}}{{(g32_c)|(.bss)}}
; CHECK: mfence
; CHECK: mov {{(DWORD PTR)?}}

; Test with the fence moved up a bit.
define internal i32 @test_fused_load_sub_b() {
entry:
  %p_alloca = alloca i8, i32 4, align 4
  %p_alloca_bc = bitcast i8* %p_alloca to i32*
  store i32 999, i32* %p_alloca_bc, align 1

  %p_a = bitcast [4 x i8]* @g32_a to i32*
  %l_a = call i32 @llvm.nacl.atomic.load.i32(i32* %p_a, i32 6)
  %l_a2 = sub i32 1, %l_a
  call void @llvm.nacl.atomic.store.i32(i32 %l_a2, i32* %p_a, i32 6)

  %p_b = bitcast [4 x i8]* @g32_b to i32*
  %l_b = load i32, i32* %p_b, align 1
  %l_b2 = sub i32 1, %l_b
  store i32 %l_b2, i32* %p_b, align 1

  %p_c = bitcast [4 x i8]* @g32_c to i32*
  call void @llvm.nacl.atomic.fence.all()
  %l_c = load i32, i32* %p_c, align 1
  %l_c2 = sub i32 1, %l_c
  store i32 %l_c2, i32* %p_c, align 1

  ret i32 %l_c2
}
; CHECK-LABEL: test_fused_load_sub_b
;    alloca store
; CHECK: mov DWORD PTR {{.*}},0x3e7
;    atomic store (w/ its own mfence)
; CHECK: sub {{.*}},DWORD PTR {{.*}}{{(g32_a)|(.bss)}}
; CHECK: mov {{(DWORD PTR)?}}
; CHECK: mfence
; CHECK: sub {{.*}},DWORD PTR {{.*}}{{(g32_b)|(.bss)}}
; CHECK: mov {{(DWORD PTR)?}}
; CHECK: mfence
; Load + sub can still be optimized into one instruction
; because it is not separated by a fence.
; CHECK: sub {{.*}},DWORD PTR {{.*}}{{(g32_c)|(.bss)}}
; CHECK: mov {{(DWORD PTR)?}}

; Test with the fence splitting a load/sub.
define internal i32 @test_fused_load_sub_c() {
entry:
  %p_alloca = alloca i8, i32 4, align 4
  %p_alloca_bc = bitcast i8* %p_alloca to i32*
  store i32 999, i32* %p_alloca_bc, align 1

  %p_a = bitcast [4 x i8]* @g32_a to i32*
  %l_a = call i32 @llvm.nacl.atomic.load.i32(i32* %p_a, i32 6)
  %l_a2 = sub i32 1, %l_a
  call void @llvm.nacl.atomic.store.i32(i32 %l_a2, i32* %p_a, i32 6)

  %p_b = bitcast [4 x i8]* @g32_b to i32*
  %l_b = load i32, i32* %p_b, align 1
  call void @llvm.nacl.atomic.fence.all()
  %l_b2 = sub i32 1, %l_b
  store i32 %l_b2, i32* %p_b, align 1

  %p_c = bitcast [4 x i8]* @g32_c to i32*
  %l_c = load i32, i32* %p_c, align 1
  %l_c2 = sub i32 1, %l_c
  store i32 %l_c2, i32* %p_c, align 1

  ret i32 %l_c2
}
; CHECK-LABEL: test_fused_load_sub_c
;    alloca store
; CHECK: mov DWORD PTR {{.*}},0x3e7
;    atomic store (w/ its own mfence)
; CHECK: sub {{.*}},DWORD PTR {{.*}}{{(g32_a)|(.bss)}}
; CHECK: mov {{(DWORD PTR)?}}
; CHECK: mfence
; This load + sub are no longer optimized into one,
; though perhaps it should be legal as long as
; the load stays on the same side of the fence.
; CHECK: mov {{.*}},{{(DWORD PTR )?}}{{.*}}{{(g32_b)|(.bss)}}
; CHECK: mfence
; CHECK: mov {{.*}},0x1
; CHECK: sub
; CHECK: mov {{(DWORD PTR)?}}
; CHECK: sub {{.*}},DWORD PTR {{.*}}{{(g32_c)|(.bss)}}
; CHECK: mov {{(DWORD PTR)?}}


; Test where a bunch of i8 loads could have been fused into one
; i32 load, but a fence blocks that.
define internal i32 @could_have_fused_loads() {
entry:
  %ptr1 = bitcast [4 x i8]* @g32_d to i8*
  %b1 = load i8, i8* %ptr1, align 1

  %int_ptr2 = ptrtoint [4 x i8]* @g32_d to i32
  %int_ptr_bump2 = add i32 %int_ptr2, 1
  %ptr2 = inttoptr i32 %int_ptr_bump2 to i8*
  %b2 = load i8, i8* %ptr2, align 1

  %int_ptr_bump3 = add i32 %int_ptr2, 2
  %ptr3 = inttoptr i32 %int_ptr_bump3 to i8*
  %b3 = load i8, i8* %ptr3, align 1

  call void @llvm.nacl.atomic.fence.all()

  %int_ptr_bump4 = add i32 %int_ptr2, 3
  %ptr4 = inttoptr i32 %int_ptr_bump4 to i8*
  %b4 = load i8, i8* %ptr4, align 1

  %b1.ext = zext i8 %b1 to i32
  %b2.ext = zext i8 %b2 to i32
  %b2.shift = shl i32 %b2.ext, 8
  %b12 = or i32 %b1.ext, %b2.shift
  %b3.ext = zext i8 %b3 to i32
  %b3.shift = shl i32 %b3.ext, 16
  %b123 = or i32 %b12, %b3.shift
  %b4.ext = zext i8 %b4 to i32
  %b4.shift = shl i32 %b4.ext, 24
  %b1234 = or i32 %b123, %b4.shift
  ret i32 %b1234
}
; CHECK-LABEL: could_have_fused_loads
; CHECK: mov {{.*}},{{(BYTE PTR)?}}
; CHECK: mov {{.*}},BYTE PTR
; CHECK: mov {{.*}},BYTE PTR
; CHECK: mfence
; CHECK: mov {{.*}},BYTE PTR


; Test where an identical load from two branches could have been hoisted
; up, and then the code merged, but a fence prevents it.
define internal i32 @could_have_hoisted_loads(i32 %x) {
entry:
  %ptr = bitcast [4 x i8]* @g32_d to i32*
  %cmp = icmp eq i32 %x, 1
  br i1 %cmp, label %branch1, label %branch2
branch1:
  %y = load i32, i32* %ptr, align 1
  ret i32 %y
branch2:
  call void @llvm.nacl.atomic.fence.all()
  %z = load i32, i32* %ptr, align 1
  ret i32 %z
}
; CHECK-LABEL: could_have_hoisted_loads
; CHECK: jne {{.*}}
; CHECK: mov {{.*}},{{(DWORD PTR )?}}{{.*}}{{(g32_d)|(.bss)}}
; CHECK: ret
; CHECK: mfence
; CHECK: mov {{.*}},{{(DWORD PTR )?}}{{.*}}{{(g32_d)|(.bss)}}
; CHECK: ret