133 lines
4.6 KiB
LLVM
133 lines
4.6 KiB
LLVM
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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt -S -basic-aa -licm < %s | FileCheck %s
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; RUN: opt -aa-pipeline=basic-aa -passes='require<opt-remark-emit>,loop(licm)' -S %s | FileCheck %s
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; Make sure we don't hoist the unsafe division to some executable block.
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define void @test_impossible_exit_in_untaken_block(i32 %a, i32 %b, i32* %p) {
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; CHECK-LABEL: @test_impossible_exit_in_untaken_block(
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; CHECK-NEXT: entry:
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; CHECK-NEXT: br label [[LOOP:%.*]]
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; CHECK: loop:
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; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
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; CHECK-NEXT: br i1 false, label [[NEVER_TAKEN:%.*]], label [[BACKEDGE]]
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; CHECK: never_taken:
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; CHECK-NEXT: [[DIV:%.*]] = sdiv i32 [[A:%.*]], [[B:%.*]]
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; CHECK-NEXT: store i32 [[DIV]], i32* [[P:%.*]]
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; CHECK-NEXT: br i1 true, label [[BACKEDGE]], label [[EXIT:%.*]]
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; CHECK: backedge:
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; CHECK-NEXT: [[IV_NEXT]] = add i32 [[IV]], 1
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; CHECK-NEXT: br label [[LOOP]]
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; CHECK: exit:
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; CHECK-NEXT: ret void
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;
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entry:
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br label %loop
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loop:
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%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
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br i1 false, label %never_taken, label %backedge
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never_taken:
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%div = sdiv i32 %a, %b
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store i32 %div, i32* %p
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br i1 true, label %backedge, label %exit
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backedge:
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%iv.next = add i32 %iv, 1
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br label %loop
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exit:
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ret void
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}
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; The test above is UB in C++, because there is a requirement that any
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; thead should eventually terminate, execute volatile access operation, call IO
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; or synchronize. In spite of that, the behavior in the test above *might* be
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; correct. This one is equivalent to the test above, but it has a volatile
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; memory access in the loop's mustexec block, so the compiler no longer has a
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; right to assume that it must terminate. Show that the same problem persists,
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; and that it was a bug and not a cool optimization based on loop infinity.
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; By the moment when this test was added, it was accidentally correct due to
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; reasons not directly related to this piece of logic. Make sure that it keeps
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; correct in the future.
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define void @test_impossible_exit_in_untaken_block_no_ub(i32 %a, i32 %b, i32* noalias %p, i32* noalias %vp) {
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; CHECK-LABEL: @test_impossible_exit_in_untaken_block_no_ub(
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; CHECK-NEXT: entry:
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; CHECK-NEXT: br label [[LOOP:%.*]]
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; CHECK: loop:
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; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
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; CHECK-NEXT: [[TMP0:%.*]] = load volatile i32, i32* [[VP:%.*]]
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; CHECK-NEXT: br i1 false, label [[NEVER_TAKEN:%.*]], label [[BACKEDGE]]
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; CHECK: never_taken:
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; CHECK-NEXT: [[DIV:%.*]] = sdiv i32 [[A:%.*]], [[B:%.*]]
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; CHECK-NEXT: store i32 [[DIV]], i32* [[P:%.*]]
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; CHECK-NEXT: br i1 true, label [[BACKEDGE]], label [[EXIT:%.*]]
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; CHECK: backedge:
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; CHECK-NEXT: [[IV_NEXT]] = add i32 [[IV]], 1
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; CHECK-NEXT: br label [[LOOP]]
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; CHECK: exit:
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; CHECK-NEXT: ret void
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;
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entry:
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br label %loop
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loop:
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%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
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load volatile i32, i32* %vp
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br i1 false, label %never_taken, label %backedge
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never_taken:
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%div = sdiv i32 %a, %b
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store i32 %div, i32* %p
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br i1 true, label %backedge, label %exit
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backedge:
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%iv.next = add i32 %iv, 1
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br label %loop
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exit:
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ret void
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}
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; Same as above, but the volatile access is in mustexecute backedge block. The
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; loop is no longer "finite by specification", make sure we don't hoist sdiv
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; from it no matter how general the MustThrow analysis is.
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define void @test_impossible_exit_in_untaken_block_no_ub_2(i32 %a, i32 %b, i32* noalias %p, i32* noalias %vp) {
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; CHECK-LABEL: @test_impossible_exit_in_untaken_block_no_ub_2(
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; CHECK-NEXT: entry:
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; CHECK-NEXT: br label [[LOOP:%.*]]
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; CHECK: loop:
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; CHECK-NEXT: [[IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
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; CHECK-NEXT: br i1 false, label [[NEVER_TAKEN:%.*]], label [[BACKEDGE]]
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; CHECK: never_taken:
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; CHECK-NEXT: [[DIV:%.*]] = sdiv i32 [[A:%.*]], [[B:%.*]]
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; CHECK-NEXT: store i32 [[DIV]], i32* [[P:%.*]]
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; CHECK-NEXT: br i1 true, label [[BACKEDGE]], label [[EXIT:%.*]]
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; CHECK: backedge:
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; CHECK-NEXT: [[IV_NEXT]] = add i32 [[IV]], 1
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; CHECK-NEXT: [[TMP0:%.*]] = load volatile i32, i32* [[VP:%.*]]
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; CHECK-NEXT: br label [[LOOP]]
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; CHECK: exit:
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; CHECK-NEXT: ret void
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;
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entry:
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br label %loop
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loop:
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%iv = phi i32 [ 0, %entry ], [ %iv.next, %backedge ]
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br i1 false, label %never_taken, label %backedge
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never_taken:
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%div = sdiv i32 %a, %b
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store i32 %div, i32* %p
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br i1 true, label %backedge, label %exit
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backedge:
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%iv.next = add i32 %iv, 1
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load volatile i32, i32* %vp
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br label %loop
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exit:
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ret void
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}
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