; NOTE: Assertions have been autogenerated by utils/update_test_checks.py ; RUN: opt -passes=dse -S < %s | FileCheck %s target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64" target triple = "x86_64-apple-macosx10.7.0" ; Basic correctness tests for atomic stores. ; Note that it turns out essentially every transformation DSE does is legal on ; atomic ops, just some transformations are not allowed across release-acquire pairs. @x = common global i32 0, align 4 @y = common global i32 0, align 4 declare void @randomop(ptr) ; DSE across unordered store (allowed) define void @test1() { ; CHECK-LABEL: @test1( ; CHECK-NEXT: store atomic i32 0, ptr @y unordered, align 4 ; CHECK-NEXT: store i32 1, ptr @x, align 4 ; CHECK-NEXT: ret void ; store i32 0, ptr @x store atomic i32 0, ptr @y unordered, align 4 store i32 1, ptr @x ret void } ; DSE remove unordered store (allowed) define void @test4() { ; CHECK-LABEL: @test4( ; CHECK-NEXT: store i32 1, ptr @x, align 4 ; CHECK-NEXT: ret void ; store atomic i32 0, ptr @x unordered, align 4 store i32 1, ptr @x ret void } ; DSE unordered store overwriting non-atomic store (allowed) define void @test5() { ; CHECK-LABEL: @test5( ; CHECK-NEXT: store atomic i32 1, ptr @x unordered, align 4 ; CHECK-NEXT: ret void ; store i32 0, ptr @x store atomic i32 1, ptr @x unordered, align 4 ret void } ; DSE no-op unordered atomic store (allowed) define void @test6() { ; CHECK-LABEL: @test6( ; CHECK-NEXT: ret void ; %x = load atomic i32, ptr @x unordered, align 4 store atomic i32 %x, ptr @x unordered, align 4 ret void } ; DSE seq_cst store (be conservative; DSE doesn't have infrastructure ; to reason about atomic operations). define void @test7() { ; CHECK-LABEL: @test7( ; CHECK-NEXT: [[A:%.*]] = alloca i32, align 4 ; CHECK-NEXT: store atomic i32 0, ptr [[A]] seq_cst, align 4 ; CHECK-NEXT: ret void ; %a = alloca i32 store atomic i32 0, ptr %a seq_cst, align 4 ret void } ; DSE and seq_cst load (be conservative; DSE doesn't have infrastructure ; to reason about atomic operations). define i32 @test8() { ; CHECK-LABEL: @test8( ; CHECK-NEXT: [[A:%.*]] = alloca i32, align 4 ; CHECK-NEXT: call void @randomop(ptr [[A]]) ; CHECK-NEXT: store i32 0, ptr [[A]], align 4 ; CHECK-NEXT: [[X:%.*]] = load atomic i32, ptr @x seq_cst, align 4 ; CHECK-NEXT: ret i32 [[X]] ; %a = alloca i32 call void @randomop(ptr %a) store i32 0, ptr %a, align 4 %x = load atomic i32, ptr @x seq_cst, align 4 ret i32 %x } ; DSE across monotonic store (allowed as long as the eliminated store isUnordered) define void @test10() { ; CHECK-LABEL: test10 ; CHECK-NOT: store i32 0 ; CHECK: store i32 1 store i32 0, ptr @x store atomic i32 42, ptr @y monotonic, align 4 store i32 1, ptr @x ret void } ; DSE across monotonic load (forbidden since the eliminated store is atomic) define i32 @test11() { ; CHECK-LABEL: @test11( ; CHECK-NEXT: store atomic i32 0, ptr @x monotonic, align 4 ; CHECK-NEXT: [[X:%.*]] = load atomic i32, ptr @y monotonic, align 4 ; CHECK-NEXT: store atomic i32 1, ptr @x monotonic, align 4 ; CHECK-NEXT: ret i32 [[X]] ; store atomic i32 0, ptr @x monotonic, align 4 %x = load atomic i32, ptr @y monotonic, align 4 store atomic i32 1, ptr @x monotonic, align 4 ret i32 %x } ; DSE across monotonic store (forbidden since the eliminated store is atomic) define void @test12() { ; CHECK-LABEL: @test12( ; CHECK-NEXT: store atomic i32 0, ptr @x monotonic, align 4 ; CHECK-NEXT: store atomic i32 42, ptr @y monotonic, align 4 ; CHECK-NEXT: store atomic i32 1, ptr @x monotonic, align 4 ; CHECK-NEXT: ret void ; store atomic i32 0, ptr @x monotonic, align 4 store atomic i32 42, ptr @y monotonic, align 4 store atomic i32 1, ptr @x monotonic, align 4 ret void } ; But DSE is not allowed across a release-acquire pair. define i32 @test15() { ; CHECK-LABEL: @test15( ; CHECK-NEXT: store i32 0, ptr @x, align 4 ; CHECK-NEXT: store atomic i32 0, ptr @y release, align 4 ; CHECK-NEXT: [[X:%.*]] = load atomic i32, ptr @y acquire, align 4 ; CHECK-NEXT: store i32 1, ptr @x, align 4 ; CHECK-NEXT: ret i32 [[X]] ; store i32 0, ptr @x store atomic i32 0, ptr @y release, align 4 %x = load atomic i32, ptr @y acquire, align 4 store i32 1, ptr @x ret i32 %x } @z = common global i64 0, align 4 @a = common global i64 0, align 4 ; Be conservative, do not kill regular store. define i64 @test_atomicrmw_0() { ; CHECK-LABEL: @test_atomicrmw_0( ; CHECK-NEXT: store i64 1, ptr @z, align 8 ; CHECK-NEXT: [[RES:%.*]] = atomicrmw add ptr @z, i64 -1 monotonic ; CHECK-NEXT: ret i64 [[RES]] ; store i64 1, ptr @z %res = atomicrmw add ptr @z, i64 -1 monotonic ret i64 %res } ; Be conservative, do not kill regular store. define i64 @test_atomicrmw_1() { ; CHECK-LABEL: @test_atomicrmw_1( ; CHECK-NEXT: store i64 1, ptr @z, align 8 ; CHECK-NEXT: [[RES:%.*]] = atomicrmw add ptr @z, i64 -1 acq_rel ; CHECK-NEXT: ret i64 [[RES]] ; store i64 1, ptr @z %res = atomicrmw add ptr @z, i64 -1 acq_rel ret i64 %res } ; Monotonic atomicrmw should not block eliminating no-aliasing stores. define i64 @test_atomicrmw_2() { ; CHECK-LABEL: @test_atomicrmw_2( ; CHECK-NEXT: [[RES:%.*]] = atomicrmw add ptr @a, i64 -1 monotonic ; CHECK-NEXT: store i64 2, ptr @z, align 8 ; CHECK-NEXT: ret i64 [[RES]] ; store i64 1, ptr @z %res = atomicrmw add ptr @a, i64 -1 monotonic store i64 2, ptr @z ret i64 %res } ; Be conservative, do not eliminate stores across atomic operations > monotonic. define i64 @test_atomicrmw_3() { ; CHECK-LABEL: @test_atomicrmw_3( ; CHECK-NEXT: store i64 1, ptr @z, align 8 ; CHECK-NEXT: [[RES:%.*]] = atomicrmw add ptr @a, i64 -1 release ; CHECK-NEXT: store i64 2, ptr @z, align 8 ; CHECK-NEXT: ret i64 [[RES]] ; store i64 1, ptr @z %res = atomicrmw add ptr @a, i64 -1 release store i64 2, ptr @z ret i64 %res } ; Be conservative, do not eliminate may-alias stores. define i64 @test_atomicrmw_4(ptr %ptr) { ; CHECK-LABEL: @test_atomicrmw_4( ; CHECK-NEXT: store i64 1, ptr @z, align 8 ; CHECK-NEXT: [[RES:%.*]] = atomicrmw add ptr [[PTR:%.*]], i64 -1 monotonic ; CHECK-NEXT: store i64 2, ptr @z, align 8 ; CHECK-NEXT: ret i64 [[RES]] ; store i64 1, ptr @z %res = atomicrmw add ptr %ptr, i64 -1 monotonic store i64 2, ptr @z ret i64 %res } ; Be conservative, do not eliminate aliasing stores. define i64 @test_atomicrmw_5() { ; CHECK-LABEL: @test_atomicrmw_5( ; CHECK-NEXT: store i64 1, ptr @z, align 8 ; CHECK-NEXT: [[RES:%.*]] = atomicrmw add ptr @z, i64 -1 monotonic ; CHECK-NEXT: store i64 2, ptr @z, align 8 ; CHECK-NEXT: ret i64 [[RES]] ; store i64 1, ptr @z %res = atomicrmw add ptr @z, i64 -1 monotonic store i64 2, ptr @z ret i64 %res } ; Be conservative, do not eliminate non-monotonic cmpxchg. define { i32, i1} @test_cmpxchg_1() { ; CHECK-LABEL: @test_cmpxchg_1( ; CHECK-NEXT: store i32 1, ptr @x, align 4 ; CHECK-NEXT: [[RET:%.*]] = cmpxchg volatile ptr @x, i32 10, i32 20 seq_cst monotonic ; CHECK-NEXT: store i32 2, ptr @x, align 4 ; CHECK-NEXT: ret { i32, i1 } [[RET]] ; store i32 1, ptr @x %ret = cmpxchg volatile ptr @x, i32 10, i32 20 seq_cst monotonic store i32 2, ptr @x ret { i32, i1 } %ret } ; Monotonic cmpxchg should not block DSE for non-aliasing stores. define { i32, i1} @test_cmpxchg_2() { ; CHECK-LABEL: @test_cmpxchg_2( ; CHECK-NEXT: [[RET:%.*]] = cmpxchg volatile ptr @y, i32 10, i32 20 monotonic monotonic ; CHECK-NEXT: store i32 2, ptr @x, align 4 ; CHECK-NEXT: ret { i32, i1 } [[RET]] ; store i32 1, ptr @x %ret = cmpxchg volatile ptr @y, i32 10, i32 20 monotonic monotonic store i32 2, ptr @x ret { i32, i1 } %ret } ; Be conservative, do not eliminate non-monotonic cmpxchg. define { i32, i1} @test_cmpxchg_3() { ; CHECK-LABEL: @test_cmpxchg_3( ; CHECK-NEXT: store i32 1, ptr @x, align 4 ; CHECK-NEXT: [[RET:%.*]] = cmpxchg volatile ptr @y, i32 10, i32 20 seq_cst seq_cst ; CHECK-NEXT: store i32 2, ptr @x, align 4 ; CHECK-NEXT: ret { i32, i1 } [[RET]] ; store i32 1, ptr @x %ret = cmpxchg volatile ptr @y, i32 10, i32 20 seq_cst seq_cst store i32 2, ptr @x ret { i32, i1 } %ret } ; Be conservative, do not eliminate may-alias stores. define { i32, i1} @test_cmpxchg_4(ptr %ptr) { ; CHECK-LABEL: @test_cmpxchg_4( ; CHECK-NEXT: store i32 1, ptr @x, align 4 ; CHECK-NEXT: [[RET:%.*]] = cmpxchg volatile ptr [[PTR:%.*]], i32 10, i32 20 monotonic monotonic ; CHECK-NEXT: store i32 2, ptr @x, align 4 ; CHECK-NEXT: ret { i32, i1 } [[RET]] ; store i32 1, ptr @x %ret = cmpxchg volatile ptr %ptr, i32 10, i32 20 monotonic monotonic store i32 2, ptr @x ret { i32, i1 } %ret } ; Be conservative, do not eliminate alias stores. define { i32, i1} @test_cmpxchg_5(ptr %ptr) { ; CHECK-LABEL: @test_cmpxchg_5( ; CHECK-NEXT: store i32 1, ptr @x, align 4 ; CHECK-NEXT: [[RET:%.*]] = cmpxchg volatile ptr @x, i32 10, i32 20 monotonic monotonic ; CHECK-NEXT: store i32 2, ptr @x, align 4 ; CHECK-NEXT: ret { i32, i1 } [[RET]] ; store i32 1, ptr @x %ret = cmpxchg volatile ptr @x, i32 10, i32 20 monotonic monotonic store i32 2, ptr @x ret { i32, i1 } %ret } ; **** Noop load->store tests ************************************************** ; We can optimize unordered atomic loads or stores. define void @test_load_atomic(ptr %Q) { ; CHECK-LABEL: @test_load_atomic( ; CHECK-NEXT: ret void ; %a = load atomic i32, ptr %Q unordered, align 4 store atomic i32 %a, ptr %Q unordered, align 4 ret void } ; We can optimize unordered atomic loads or stores. define void @test_store_atomic(ptr %Q) { ; CHECK-LABEL: @test_store_atomic( ; CHECK-NEXT: ret void ; %a = load i32, ptr %Q store atomic i32 %a, ptr %Q unordered, align 4 ret void } ; We can NOT optimize release atomic loads or stores. define void @test_store_atomic_release(ptr %Q) { ; CHECK-LABEL: @test_store_atomic_release( ; CHECK-NEXT: [[A:%.*]] = load i32, ptr [[Q:%.*]], align 4 ; CHECK-NEXT: store atomic i32 [[A]], ptr [[Q]] release, align 4 ; CHECK-NEXT: ret void ; %a = load i32, ptr %Q store atomic i32 %a, ptr %Q release, align 4 ret void }