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llvm-project/llvm/test/Analysis/ValueTracking/invariant.group.ll

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Propagate nonnull and dereferenceable throught launder Summary: invariant.group.launder should not stop propagation of nonnull and dereferenceable, because e.g. we would not be able to hoist loads speculatively. Reviewers: rsmith, amharc, kuhar, xbolva00, hfinkel Subscribers: hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D46972 llvm-svn: 332788
2018-05-19 07:54:33 +08:00
; RUN: opt -S -instsimplify -instcombine < %s | FileCheck %s
Implement strip.invariant.group Summary: This patch introduce new intrinsic - strip.invariant.group that was described in the RFC: Devirtualization v2 Reviewers: rsmith, hfinkel, nlopes, sanjoy, amharc, kuhar Subscribers: arsenm, nhaehnle, JDevlieghere, hiraditya, xbolva00, llvm-commits Differential Revision: https://reviews.llvm.org/D47103 Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com> llvm-svn: 336073
2018-07-02 12:49:30 +08:00
; CHECK-LABEL: define void @checkNonnullLaunder()
define void @checkNonnullLaunder() {
Simplify recursive launder.invariant.group and strip Summary: This patch is crucial for proving equality laundered/stripped pointers. eg: bool foo(A *a) { return a == std::launder(a); } Clang with -fstrict-vtable-pointers will emit something like: define dso_local zeroext i1 @_Z3fooP1A(%struct.A* %a) { entry: %c = bitcast %struct.A* %a to i8* %call = tail call i8* @llvm.launder.invariant.group.p0i8(i8* %c) %0 = bitcast %struct.A* %a to i8* %1 = tail call i8* @llvm.strip.invariant.group.p0i8(i8* %0) %2 = tail call i8* @llvm.strip.invariant.group.p0i8(i8* %call) %cmp = icmp eq i8* %1, %2 ret i1 %cmp } and because %2 can be replaced with @llvm.strip.invariant.group(%0) and that %2 and %1 will produce the same value (because strip is readnone) we can replace compare with true. Reviewers: rsmith, hfinkel, majnemer, amharc, kuhar Subscribers: llvm-commits, hiraditya Differential Revision: https://reviews.llvm.org/D47423 llvm-svn: 336963
2018-07-13 07:55:20 +08:00
; CHECK: %[[p:.*]] = call i8* @llvm.launder.invariant.group.p0i8(i8* nonnull %0)
; CHECK: call void @use(i8* nonnull %[[p]])
Propagate nonnull and dereferenceable throught launder Summary: invariant.group.launder should not stop propagation of nonnull and dereferenceable, because e.g. we would not be able to hoist loads speculatively. Reviewers: rsmith, amharc, kuhar, xbolva00, hfinkel Subscribers: hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D46972 llvm-svn: 332788
2018-05-19 07:54:33 +08:00
entry:
%0 = alloca i8, align 8
%p = call i8* @llvm.launder.invariant.group.p0i8(i8* %0)
%p2 = call i8* @llvm.launder.invariant.group.p0i8(i8* %p)
call void @use(i8* %p2)
ret void
}
Implement strip.invariant.group Summary: This patch introduce new intrinsic - strip.invariant.group that was described in the RFC: Devirtualization v2 Reviewers: rsmith, hfinkel, nlopes, sanjoy, amharc, kuhar Subscribers: arsenm, nhaehnle, JDevlieghere, hiraditya, xbolva00, llvm-commits Differential Revision: https://reviews.llvm.org/D47103 Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com> llvm-svn: 336073
2018-07-02 12:49:30 +08:00
; CHECK-LABEL: define void @checkNonnullStrip()
define void @checkNonnullStrip() {
Simplify recursive launder.invariant.group and strip Summary: This patch is crucial for proving equality laundered/stripped pointers. eg: bool foo(A *a) { return a == std::launder(a); } Clang with -fstrict-vtable-pointers will emit something like: define dso_local zeroext i1 @_Z3fooP1A(%struct.A* %a) { entry: %c = bitcast %struct.A* %a to i8* %call = tail call i8* @llvm.launder.invariant.group.p0i8(i8* %c) %0 = bitcast %struct.A* %a to i8* %1 = tail call i8* @llvm.strip.invariant.group.p0i8(i8* %0) %2 = tail call i8* @llvm.strip.invariant.group.p0i8(i8* %call) %cmp = icmp eq i8* %1, %2 ret i1 %cmp } and because %2 can be replaced with @llvm.strip.invariant.group(%0) and that %2 and %1 will produce the same value (because strip is readnone) we can replace compare with true. Reviewers: rsmith, hfinkel, majnemer, amharc, kuhar Subscribers: llvm-commits, hiraditya Differential Revision: https://reviews.llvm.org/D47423 llvm-svn: 336963
2018-07-13 07:55:20 +08:00
; CHECK: %[[p:.*]] = call i8* @llvm.strip.invariant.group.p0i8(i8* nonnull %0)
; CHECK: call void @use(i8* nonnull %[[p]])
Implement strip.invariant.group Summary: This patch introduce new intrinsic - strip.invariant.group that was described in the RFC: Devirtualization v2 Reviewers: rsmith, hfinkel, nlopes, sanjoy, amharc, kuhar Subscribers: arsenm, nhaehnle, JDevlieghere, hiraditya, xbolva00, llvm-commits Differential Revision: https://reviews.llvm.org/D47103 Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com> llvm-svn: 336073
2018-07-02 12:49:30 +08:00
entry:
%0 = alloca i8, align 8
%p = call i8* @llvm.strip.invariant.group.p0i8(i8* %0)
%p2 = call i8* @llvm.strip.invariant.group.p0i8(i8* %p)
call void @use(i8* %p2)
ret void
}
Propagate nonnull and dereferenceable throught launder Summary: invariant.group.launder should not stop propagation of nonnull and dereferenceable, because e.g. we would not be able to hoist loads speculatively. Reviewers: rsmith, amharc, kuhar, xbolva00, hfinkel Subscribers: hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D46972 llvm-svn: 332788
2018-05-19 07:54:33 +08:00
declare i8* @llvm.launder.invariant.group.p0i8(i8*)
Implement strip.invariant.group Summary: This patch introduce new intrinsic - strip.invariant.group that was described in the RFC: Devirtualization v2 Reviewers: rsmith, hfinkel, nlopes, sanjoy, amharc, kuhar Subscribers: arsenm, nhaehnle, JDevlieghere, hiraditya, xbolva00, llvm-commits Differential Revision: https://reviews.llvm.org/D47103 Co-authored-by: Krzysztof Pszeniczny <krzysztof.pszeniczny@gmail.com> llvm-svn: 336073
2018-07-02 12:49:30 +08:00
declare i8* @llvm.strip.invariant.group.p0i8(i8*)
Propagate nonnull and dereferenceable throught launder Summary: invariant.group.launder should not stop propagation of nonnull and dereferenceable, because e.g. we would not be able to hoist loads speculatively. Reviewers: rsmith, amharc, kuhar, xbolva00, hfinkel Subscribers: hiraditya, llvm-commits Differential Revision: https://reviews.llvm.org/D46972 llvm-svn: 332788
2018-05-19 07:54:33 +08:00
declare void @use(i8*)