[llvm] r245238 - [WinEHPrepare] Replace unreasonable funclet terminators with unreachable
David Majnemer via llvm-commits
llvm-commits at lists.llvm.org
Mon Aug 17 13:56:40 PDT 2015
Author: majnemer
Date: Mon Aug 17 15:56:39 2015
New Revision: 245238
URL: http://llvm.org/viewvc/llvm-project?rev=245238&view=rev
Log:
[WinEHPrepare] Replace unreasonable funclet terminators with unreachable
It is possible to be in a situation where more than one funclet token is
a valid SSA value. If we see a terminator which exits a funclet which
doesn't use the funclet's token, replace it with unreachable.
Differential Revision: http://reviews.llvm.org/D12074
Modified:
llvm/trunk/lib/CodeGen/WinEHPrepare.cpp
llvm/trunk/test/CodeGen/WinEH/wineh-demotion.ll
Modified: llvm/trunk/lib/CodeGen/WinEHPrepare.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/WinEHPrepare.cpp?rev=245238&r1=245237&r2=245238&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/WinEHPrepare.cpp (original)
+++ llvm/trunk/lib/CodeGen/WinEHPrepare.cpp Mon Aug 17 15:56:39 2015
@@ -3085,6 +3085,33 @@ bool WinEHPrepare::prepareExplicitEH(Fun
RemapInstruction(&I, VMap, RF_IgnoreMissingEntries);
}
+ // Remove implausible terminators and replace them with UnreachableInst.
+ for (auto &Funclet : FuncletBlocks) {
+ BasicBlock *FuncletPadBB = Funclet.first;
+ std::set<BasicBlock *> &BlocksInFunclet = Funclet.second;
+ Instruction *FirstNonPHI = FuncletPadBB->getFirstNonPHI();
+ auto *CatchPad = dyn_cast<CatchPadInst>(FirstNonPHI);
+ auto *CleanupPad = dyn_cast<CleanupPadInst>(FirstNonPHI);
+
+ for (BasicBlock *BB : BlocksInFunclet) {
+ TerminatorInst *TI = BB->getTerminator();
+ // CatchPadInst and CleanupPadInst can't transfer control to a ReturnInst.
+ bool IsUnreachableRet = isa<ReturnInst>(TI) && (CatchPad || CleanupPad);
+ // The token consumed by a CatchReturnInst must match the funclet token.
+ bool IsUnreachableCatchret = false;
+ if (auto *CRI = dyn_cast<CatchReturnInst>(TI))
+ IsUnreachableCatchret = CRI->getReturnValue() != CatchPad;
+ // The token consumed by a CleanupPadInst must match the funclet token.
+ bool IsUnreachableCleanupret = false;
+ if (auto *CRI = dyn_cast<CleanupReturnInst>(TI))
+ IsUnreachableCleanupret = CRI->getReturnValue() != CleanupPad;
+ if (IsUnreachableRet || IsUnreachableCatchret || IsUnreachableCleanupret) {
+ new UnreachableInst(BB->getContext(), TI);
+ TI->eraseFromParent();
+ }
+ }
+ }
+
// Clean-up some of the mess we made by removing useles PHI nodes, trivial
// branches, etc.
for (Function::iterator FI = F.begin(), FE = F.end(); FI != FE;) {
@@ -3094,9 +3121,6 @@ bool WinEHPrepare::prepareExplicitEH(Fun
MergeBlockIntoPredecessor(BB);
}
- // TODO: Do something about cleanupblocks which branch to implausible
- // cleanuprets.
-
// We might have some unreachable blocks after cleaning up some impossible
// control flow.
removeUnreachableBlocks(F);
@@ -3215,6 +3239,12 @@ void WinEHPrepare::insertPHIStore(
void WinEHPrepare::demoteNonlocalUses(Value *V,
std::set<BasicBlock *> &ColorsForBB,
Function &F) {
+ // Tokens can only be used non-locally due to control flow involving
+ // unreachable edges. Don't try to demote the token usage, we'll simply
+ // delete the cloned user later.
+ if (isa<CatchPadInst>(V) || isa<CleanupPadInst>(V))
+ return;
+
DenseMap<BasicBlock *, Value *> Loads;
AllocaInst *SpillSlot = nullptr;
for (Value::use_iterator UI = V->use_begin(), UE = V->use_end(); UI != UE;) {
Modified: llvm/trunk/test/CodeGen/WinEH/wineh-demotion.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/WinEH/wineh-demotion.ll?rev=245238&r1=245237&r2=245238&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/WinEH/wineh-demotion.ll (original)
+++ llvm/trunk/test/CodeGen/WinEH/wineh-demotion.ll Mon Aug 17 15:56:39 2015
@@ -36,14 +36,14 @@ merge:
; CHECK: merge:
; CHECK-NOT: = phi
%phi = phi i32 [ %x, %left ], [ %y, %right ]
- catchpad void [] to label %catch unwind label %catchend
+ %cp = catchpad token [] to label %catch unwind label %catchend
catch:
; CHECK: catch:
; CHECK: [[Reload:%[^ ]+]] = load i32, i32* [[Slot]]
; CHECK-NEXT: call void @h(i32 [[Reload]])
call void @h(i32 %phi)
- catchret void to label %exit
+ catchret token %cp to label %exit
catchend:
catchendpad unwind to caller
@@ -75,9 +75,9 @@ right:
merge.inner:
; CHECK: merge.inner:
; CHECK-NOT: = phi
- ; CHECK: catchpad void
+ ; CHECK: catchpad token
%x = phi i32 [ 1, %left ], [ 2, %right ]
- catchpad void [] to label %catch.inner unwind label %catchend.inner
+ %cpinner = catchpad token [] to label %catch.inner unwind label %catchend.inner
catch.inner:
; Need just one store here because only %y is affected
@@ -89,16 +89,16 @@ catch.inner:
to label %catchret.inner unwind label %merge.outer
catchret.inner:
- catchret void to label %exit
+ catchret token %cpinner to label %exit
catchend.inner:
catchendpad unwind label %merge.outer
merge.outer:
; CHECK: merge.outer:
; CHECK-NOT: = phi
- ; CHECK: catchpad void
+ ; CHECK: [[CatchPad:%[^ ]+]] = catchpad token
%y = phi i32 [ %x, %catchend.inner ], [ %z, %catch.inner ]
- catchpad void [] to label %catch.outer unwind label %catchend.outer
+ %cpouter = catchpad token [] to label %catch.outer unwind label %catchend.outer
catchend.outer:
catchendpad unwind to caller
@@ -109,10 +109,10 @@ catch.outer:
; CHECK: catch.outer:
; CHECK-DAG: load i32, i32* [[Slot1]]
; CHECK-DAG: load i32, i32* [[Slot2]]
- ; CHECK: catchret void to label
+ ; CHECK: catchret token [[CatchPad]] to label
call void @h(i32 %x)
call void @h(i32 %y)
- catchret void to label %exit
+ catchret token %cpouter to label %exit
exit:
ret void
@@ -131,7 +131,7 @@ entry:
to label %exit unwind label %catchpad
catchpad:
- catchpad void [] to label %catch unwind label %catchend
+ %cp = catchpad token [] to label %catch unwind label %catchend
catch:
; Need to reload %B here
@@ -152,7 +152,7 @@ merge:
; CHECK: %phi = phi i32 [ [[ReloadX]], %left ]
%phi = phi i32 [ %x, %left ], [ 42, %right ]
call void @h(i32 %phi)
- catchret void to label %exit
+ catchret token %cp to label %exit
catchend:
catchendpad unwind to caller
@@ -188,11 +188,11 @@ right:
to label %join unwind label %catchpad.inner
catchpad.inner:
; CHECK: catchpad.inner:
- ; CHECK-NEXT: catchpad void
+ ; CHECK-NEXT: catchpad token
%phi.inner = phi i32 [ %l, %left ], [ %r, %right ]
- catchpad void [] to label %catch.inner unwind label %catchend.inner
+ %cp1 = catchpad token [] to label %catch.inner unwind label %catchend.inner
catch.inner:
- catchret void to label %join
+ catchret token %cp1 to label %join
catchend.inner:
catchendpad unwind label %catchpad.outer
join:
@@ -205,15 +205,15 @@ join:
to label %exit unwind label %catchpad.outer
catchpad.outer:
; CHECK: catchpad.outer:
- ; CHECK-NEXT: catchpad void
+ ; CHECK-NEXT: catchpad token
%phi.outer = phi i32 [ %phi.inner, %catchend.inner ], [ %j, %join ]
- catchpad void [] to label %catch.outer unwind label %catchend.outer
+ %cp2 = catchpad token [] to label %catch.outer unwind label %catchend.outer
catch.outer:
; CHECK: catch.outer:
; CHECK: [[Reload:%[^ ]+]] = load i32, i32* [[Slot]]
; CHECK: call void @h(i32 [[Reload]])
call void @h(i32 %phi.outer)
- catchret void to label %exit
+ catchret token %cp2 to label %exit
catchend.outer:
catchendpad unwind to caller
exit:
@@ -241,10 +241,10 @@ invoke.cont:
cleanup:
; cleanup phi can be loaded at cleanup entry
; CHECK: cleanup:
- ; CHECK-NEXT: cleanuppad void
+ ; CHECK-NEXT: cleanuppad token
; CHECK: [[CleanupReload:%[^ ]+]] = load i32, i32* [[CleanupSlot]]
%phi.cleanup = phi i32 [ 1, %entry ], [ 2, %invoke.cont ]
- cleanuppad void []
+ %cp = cleanuppad token []
%b = call i1 @i()
br i1 %b, label %left, label %right
@@ -264,8 +264,8 @@ merge:
; need store for %phi.catch
; CHECK: merge:
; CHECK-NEXT: store i32 [[CleanupReload]], i32* [[CatchSlot:%[^ ]+]]
- ; CHECK-NEXT: cleanupret void
- cleanupret void unwind label %catchpad
+ ; CHECK-NEXT: cleanupret token
+ cleanupret token %cp unwind label %catchpad
invoke.cont2:
; need store for %phi.catch
@@ -277,16 +277,16 @@ invoke.cont2:
catchpad:
; CHECK: catchpad:
- ; CHECK-NEXT: catchpad void
+ ; CHECK-NEXT: catchpad token
%phi.catch = phi i32 [ %phi.cleanup, %merge ], [ 3, %invoke.cont2 ]
- catchpad void [] to label %catch unwind label %catchend
+ %cp2 = catchpad token [] to label %catch unwind label %catchend
catch:
; CHECK: catch:
; CHECK: [[CatchReload:%[^ ]+]] = load i32, i32* [[CatchSlot]]
; CHECK: call void @h(i32 [[CatchReload]]
call void @h(i32 %phi.catch)
- catchret void to label %exit
+ catchret token %cp2 to label %exit
catchend:
catchendpad unwind to caller
@@ -310,8 +310,8 @@ entry:
; CHECK: store i32 %x, i32* [[SpillSlot:%[^ ]+]]
; CHECK: br label %loop
to_caller:
- cleanuppad void []
- cleanupret void unwind to caller
+ %cp1 = cleanuppad token []
+ cleanupret token %cp1 unwind to caller
loop:
invoke void @f()
to label %loop unwind label %cleanup
@@ -319,9 +319,9 @@ cleanup:
; CHECK: cleanup:
; CHECK: [[Load:%[^ ]+]] = load i32, i32* [[SpillSlot]]
; CHECK: call void @h(i32 [[Load]])
- cleanuppad void []
+ %cp2 = cleanuppad token []
call void @h(i32 %x)
- cleanupret void unwind to caller
+ cleanupret token %cp2 unwind to caller
}
; CHECK-LABEL: @test7(
@@ -343,9 +343,9 @@ invoke.cont:
catchpad:
; %x phi should be eliminated
; CHECK: catchpad:
- ; CHECK-NEXT: catchpad void
+ ; CHECK-NEXT: %[[CatchPad:[^ ]+]] = catchpad token
%x = phi i32 [ 1, %entry ], [ 2, %invoke.cont ]
- catchpad void [] to label %catch unwind label %catchend
+ %cp = catchpad token [] to label %catch unwind label %catchend
catch:
%b = call i1 @i()
br i1 %b, label %left, label %right
@@ -353,8 +353,8 @@ left:
; Edge from %left to %join needs to be split so that
; the load of %x can be inserted *after* the catchret
; CHECK: left:
- ; CHECK-NEXT: catchret void to label %[[SplitLeft:[^ ]+]]
- catchret void to label %join
+ ; CHECK-NEXT: catchret token %[[CatchPad]] to label %[[SplitLeft:[^ ]+]]
+ catchret token %cp to label %join
; CHECK: [[SplitLeft]]:
; CHECK: [[LoadX:%[^ ]+]] = load i32, i32* [[SlotX]]
; CHECK: br label %join
@@ -363,9 +363,9 @@ right:
; the load of %y can be inserted *after* the catchret
; CHECK: right:
; CHECK: store i32 %y, i32* [[SlotY:%[^ ]+]]
- ; CHECK: catchret void to label %[[SplitRight:[^ ]+]]
+ ; CHECK: catchret token %[[CatchPad]] to label %[[SplitRight:[^ ]+]]
%y = call i32 @g()
- catchret void to label %join
+ catchret token %cp to label %join
; CHECK: [[SplitRight]]:
; CHECK: [[LoadY:%[^ ]+]] = load i32, i32* [[SlotY]]
; CHECK: br label %join
@@ -380,3 +380,32 @@ join:
exit:
ret void
}
+
+; CHECK-LABEL: @test8(
+define void @test8() personality i32 (...)* @__CxxFrameHandler3 { entry:
+ invoke void @f()
+ to label %done unwind label %cleanup1
+ invoke void @f()
+ to label %done unwind label %cleanup2
+
+done:
+ ret void
+
+cleanup1:
+ ; CHECK: [[CleanupPad1:%[^ ]+]] = cleanuppad token
+ ; CHECK-NEXT: call void @f()
+ ; CHECK-NEXT: cleanupret token [[CleanupPad1]]
+ %cp0 = cleanuppad token []
+ br label %cleanupexit
+
+cleanup2:
+ ; CHECK: cleanuppad token
+ ; CHECK-NEXT: call void @f()
+ ; CHECK-NEXT: unreachable
+ %cp1 = cleanuppad token []
+ br label %cleanupexit
+
+cleanupexit:
+ call void @f()
+ cleanupret token %cp0 unwind label %cleanup2
+}
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