diff options
Diffstat (limited to 'llvm/test/Transforms/EarlyCSE/invariant.start.ll')
| -rw-r--r-- | llvm/test/Transforms/EarlyCSE/invariant.start.ll | 231 |
1 files changed, 219 insertions, 12 deletions
diff --git a/llvm/test/Transforms/EarlyCSE/invariant.start.ll b/llvm/test/Transforms/EarlyCSE/invariant.start.ll index 8b468a5b308..5fabd0cee0d 100644 --- a/llvm/test/Transforms/EarlyCSE/invariant.start.ll +++ b/llvm/test/Transforms/EarlyCSE/invariant.start.ll @@ -6,13 +6,12 @@ declare void @llvm.invariant.end.p0i8({}*, i64, i8* nocapture) nounwind ; Check that we do load-load forwarding over invariant.start, since it does not ; clobber memory -define i8 @test1(i8 *%P) { - ; CHECK-LABEL: @test1( +define i8 @test_bypass1(i8 *%P) { + ; CHECK-LABEL: @test_bypass1( ; CHECK-NEXT: %V1 = load i8, i8* %P ; CHECK-NEXT: %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P) ; CHECK-NEXT: ret i8 0 - %V1 = load i8, i8* %P %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P) %V2 = load i8, i8* %P @@ -22,13 +21,12 @@ define i8 @test1(i8 *%P) { ; Trivial Store->load forwarding over invariant.start -define i8 @test2(i8 *%P) { - ; CHECK-LABEL: @test2( +define i8 @test_bypass2(i8 *%P) { + ; CHECK-LABEL: @test_bypass2( ; CHECK-NEXT: store i8 42, i8* %P ; CHECK-NEXT: %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P) ; CHECK-NEXT: ret i8 42 - store i8 42, i8* %P %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P) %V1 = load i8, i8* %P @@ -38,13 +36,11 @@ define i8 @test2(i8 *%P) { ; We can DSE over invariant.start calls, since the first store to ; %P is valid, and the second store is actually unreachable based on semantics ; of invariant.start. -define void @test3(i8* %P) { - -; CHECK-LABEL: @test3( +define void @test_bypass3(i8* %P) { +; CHECK-LABEL: @test_bypass3( ; CHECK-NEXT: %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P) ; CHECK-NEXT: store i8 60, i8* %P - store i8 50, i8* %P %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P) store i8 60, i8* %P @@ -54,9 +50,9 @@ define void @test3(i8* %P) { ; FIXME: Now the first store can actually be eliminated, since there is no read within ; the invariant region, between start and end. -define void @test4(i8* %P) { +define void @test_bypass4(i8* %P) { -; CHECK-LABEL: @test4( +; CHECK-LABEL: @test_bypass4( ; CHECK-NEXT: store i8 50, i8* %P ; CHECK-NEXT: %i = call {}* @llvm.invariant.start.p0i8(i64 1, i8* %P) ; CHECK-NEXT: call void @llvm.invariant.end.p0i8({}* %i, i64 1, i8* %P) @@ -69,3 +65,214 @@ define void @test4(i8* %P) { store i8 60, i8* %P ret void } + + +declare void @clobber() +declare {}* @llvm.invariant.start.p0i32(i64 %size, i32* nocapture %ptr) +declare void @llvm.invariant.end.p0i32({}*, i64, i32* nocapture) nounwind + +define i32 @test_before_load(i32* %p) { +; CHECK-LABEL: @test_before_load +; CHECK: ret i32 0 + call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p) + %v1 = load i32, i32* %p + call void @clobber() + %v2 = load i32, i32* %p + %sub = sub i32 %v1, %v2 + ret i32 %sub +} + +define i32 @test_before_clobber(i32* %p) { +; CHECK-LABEL: @test_before_clobber +; CHECK: ret i32 0 + %v1 = load i32, i32* %p + call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p) + call void @clobber() + %v2 = load i32, i32* %p + %sub = sub i32 %v1, %v2 + ret i32 %sub +} + +define i32 @test_unanalzyable_load(i32* %p) { +; CHECK-LABEL: @test_unanalzyable_load +; CHECK: ret i32 0 + call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p) + call void @clobber() + %v1 = load i32, i32* %p + call void @clobber() + %v2 = load i32, i32* %p + %sub = sub i32 %v1, %v2 + ret i32 %sub +} + +define i32 @test_negative_after_clobber(i32* %p) { +; CHECK-LABEL: @test_negative_after_clobber +; CHECK: ret i32 %sub + %v1 = load i32, i32* %p + call void @clobber() + call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p) + %v2 = load i32, i32* %p + %sub = sub i32 %v1, %v2 + ret i32 %sub +} + +define i32 @test_merge(i32* %p, i1 %cnd) { +; CHECK-LABEL: @test_merge +; CHECK: ret i32 0 + %v1 = load i32, i32* %p + call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p) + br i1 %cnd, label %merge, label %taken + +taken: + call void @clobber() + br label %merge +merge: + %v2 = load i32, i32* %p + %sub = sub i32 %v1, %v2 + ret i32 %sub +} + +define i32 @test_negative_after_mergeclobber(i32* %p, i1 %cnd) { +; CHECK-LABEL: @test_negative_after_mergeclobber +; CHECK: ret i32 %sub + %v1 = load i32, i32* %p + br i1 %cnd, label %merge, label %taken + +taken: + call void @clobber() + br label %merge +merge: + call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p) + %v2 = load i32, i32* %p + %sub = sub i32 %v1, %v2 + ret i32 %sub +} + +; In theory, this version could work, but earlycse is incapable of +; merging facts along distinct paths. +define i32 @test_false_negative_merge(i32* %p, i1 %cnd) { +; CHECK-LABEL: @test_false_negative_merge +; CHECK: ret i32 %sub + %v1 = load i32, i32* %p + br i1 %cnd, label %merge, label %taken + +taken: + call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p) + call void @clobber() + br label %merge +merge: + %v2 = load i32, i32* %p + %sub = sub i32 %v1, %v2 + ret i32 %sub +} + +define i32 @test_merge_unanalyzable_load(i32* %p, i1 %cnd) { +; CHECK-LABEL: @test_merge_unanalyzable_load +; CHECK: ret i32 0 + call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p) + call void @clobber() + %v1 = load i32, i32* %p + br i1 %cnd, label %merge, label %taken + +taken: + call void @clobber() + br label %merge +merge: + %v2 = load i32, i32* %p + %sub = sub i32 %v1, %v2 + ret i32 %sub +} + +define void @test_dse_before_load(i32* %p, i1 %cnd) { +; CHECK-LABEL: @test_dse_before_load +; CHECK-NOT: store + call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p) + %v1 = load i32, i32* %p + call void @clobber() + store i32 %v1, i32* %p + ret void +} + +define void @test_dse_after_load(i32* %p, i1 %cnd) { +; CHECK-LABEL: @test_dse_after_load +; CHECK-NOT: store + %v1 = load i32, i32* %p + call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p) + call void @clobber() + store i32 %v1, i32* %p + ret void +} + + +; In this case, we have a false negative since MemoryLocation is implicitly +; typed due to the user of a Value to represent the address. Note that other +; passes will canonicalize away the bitcasts in this example. +define i32 @test_false_negative_types(i32* %p) { +; CHECK-LABEL: @test_false_negative_types +; CHECK: ret i32 %sub + call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p) + %v1 = load i32, i32* %p + call void @clobber() + %pf = bitcast i32* %p to float* + %v2f = load float, float* %pf + %v2 = bitcast float %v2f to i32 + %sub = sub i32 %v1, %v2 + ret i32 %sub +} + +define i32 @test_negative_size1(i32* %p) { +; CHECK-LABEL: @test_negative_size1 +; CHECK: ret i32 %sub + call {}* @llvm.invariant.start.p0i32(i64 3, i32* %p) + %v1 = load i32, i32* %p + call void @clobber() + %v2 = load i32, i32* %p + %sub = sub i32 %v1, %v2 + ret i32 %sub +} + +define i32 @test_negative_size2(i32* %p) { +; CHECK-LABEL: @test_negative_size2 +; CHECK: ret i32 %sub + call {}* @llvm.invariant.start.p0i32(i64 0, i32* %p) + %v1 = load i32, i32* %p + call void @clobber() + %v2 = load i32, i32* %p + %sub = sub i32 %v1, %v2 + ret i32 %sub +} + +define i32 @test_negative_scope(i32* %p) { +; CHECK-LABEL: @test_negative_scope +; CHECK: ret i32 %sub + %scope = call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p) + call void @llvm.invariant.end.p0i32({}* %scope, i64 4, i32* %p) + %v1 = load i32, i32* %p + call void @clobber() + %v2 = load i32, i32* %p + %sub = sub i32 %v1, %v2 + ret i32 %sub +} + +define i32 @test_false_negative_scope(i32* %p) { +; CHECK-LABEL: @test_false_negative_scope +; CHECK: ret i32 %sub + %scope = call {}* @llvm.invariant.start.p0i32(i64 4, i32* %p) + %v1 = load i32, i32* %p + call void @clobber() + %v2 = load i32, i32* %p + call void @llvm.invariant.end.p0i32({}* %scope, i64 4, i32* %p) + %sub = sub i32 %v1, %v2 + ret i32 %sub +} + +; Invariant load defact starts an invariant.start scope of the appropriate size +define i32 @test_invariant_load_scope(i32* %p) { +; CHECK-LABEL: @test_invariant_load_scope +; CHECK: ret i32 0 + %v1 = load i32, i32* %p, !invariant.load !{} + call void @clobber() + %v2 = load i32, i32* %p + %sub = sub i32 %v1, %v2 + ret i32 %sub +} |
