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[Attributor] Ignore BlockAddress users in call site traversal 

BlockAddress users will not "call" the function so they do not qualify
as call sites in the first place. When we delete a function with
BlockAddress users we need to first remove the body so they are properly
discarded.
This commit is contained in:
Johannes Doerfert 2019-11-01 22:35:18 -05:00
parent 4c56086f8b
commit 2d77b0cad0
2 changed files with 29 additions and 0 deletions
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4
llvm/lib/Transforms/IPO/Attributor.cpp
View File

@ -4658,6 +4658,9 @@ bool Attributor::checkForAllCallSites(
<< Fn.getName()
<< " has non call site use " << *U.get() << " in "
<< *U.getUser() << "\n");
// BlockAddress users are allowed.
if (isa<BlockAddress>(U.getUser()))
continue;
return false;
}
@ -5072,6 +5075,7 @@ ChangeStatus Attributor::run(Module &M) {
STATS_TRACK(AAIsDead, Function);
ToBeDeletedFunctions.insert(F);
F->deleteBody();
F->replaceAllUsesWith(UndefValue::get(F->getType()));
F->eraseFromParent();
InternalFns[u] = nullptr;

25
llvm/test/Transforms/FunctionAttrs/liveness.ll
View File

@ -2,6 +2,9 @@
; RUN: opt -attributor --attributor-disable=false -attributor-max-iterations-verify -attributor-annotate-decl-cs -attributor-max-iterations=6 -S < %s | FileCheck %s
; UTC_ARGS: --turn off
; CHECK: @dead_with_blockaddress_users.l = constant [2 x i8*] [i8* inttoptr (i32 1 to i8*), i8* inttoptr (i32 1 to i8*)]
@dead_with_blockaddress_users.l = constant [2 x i8*] [i8* blockaddress(@dead_with_blockaddress_users, %lab0), i8* blockaddress(@dead_with_blockaddress_users, %end)]
declare void @no_return_call() nofree noreturn nounwind readnone
declare void @normal_call() readnone
@ -830,3 +833,25 @@ define i32 @switch_default_caller() {
ret i32 %call2
}
; UTC_ARGS: --turn off
; Allow blockaddress users
; CHECK-NOT @dead_with_blockaddress_users
define internal void @dead_with_blockaddress_users(i32* nocapture %pc) nounwind readonly {
entry:
br label %indirectgoto
lab0: ; preds = %indirectgoto
%indvar.next = add i32 %indvar, 1 ; <i32> [#uses=1]
br label %indirectgoto
end: ; preds = %indirectgoto
ret void
indirectgoto: ; preds = %lab0, %entry
%indvar = phi i32 [ %indvar.next, %lab0 ], [ 0, %entry ] ; <i32> [#uses=2]
%pc.addr.0 = getelementptr i32, i32* %pc, i32 %indvar ; <i32*> [#uses=1]
%tmp1.pn = load i32, i32* %pc.addr.0 ; <i32> [#uses=1]
%indirect.goto.dest.in = getelementptr inbounds [2 x i8*], [2 x i8*]* @dead_with_blockaddress_users.l, i32 0, i32 %tmp1.pn ; <i8**> [#uses=1]
%indirect.goto.dest = load i8*, i8** %indirect.goto.dest.in ; <i8*> [#uses=1]
indirectbr i8* %indirect.goto.dest, [label %lab0, label %end]
}