[llvm] r331548 - [ObjCARC] Account for catchswitch in bitcast insertion
Shoaib Meenai via llvm-commits
llvm-commits at lists.llvm.org
Fri May 4 12:03:11 PDT 2018
Author: smeenai
Date: Fri May 4 12:03:11 2018
New Revision: 331548
URL: http://llvm.org/viewvc/llvm-project?rev=331548&view=rev
Log:
[ObjCARC] Account for catchswitch in bitcast insertion
A catchswitch is both a pad and a terminator, meaning it must be the
only non-phi instruction in its basic block. When we're inserting a
bitcast in the incoming basic block for a phi, if that incoming block is
a catchswitch, we should go up the dominator tree to find a valid
insertion point rather than attempting to insert before the catchswitch
(which would result in invalid IR).
Differential Revision: https://reviews.llvm.org/D46412
Added:
llvm/trunk/test/Transforms/ObjCARC/contract-catchswitch.ll
Modified:
llvm/trunk/lib/Transforms/ObjCARC/ObjCARCContract.cpp
Modified: llvm/trunk/lib/Transforms/ObjCARC/ObjCARCContract.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/ObjCARC/ObjCARCContract.cpp?rev=331548&r1=331547&r2=331548&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/ObjCARC/ObjCARCContract.cpp (original)
+++ llvm/trunk/lib/Transforms/ObjCARC/ObjCARCContract.cpp Fri May 4 12:03:11 2018
@@ -606,14 +606,27 @@ bool ObjCARCContract::runOnFunction(Func
if (PHINode *PHI = dyn_cast<PHINode>(U.getUser())) {
// For PHI nodes, insert the bitcast in the predecessor block.
unsigned ValNo = PHINode::getIncomingValueNumForOperand(OperandNo);
- BasicBlock *BB = PHI->getIncomingBlock(ValNo);
- if (Replacement->getType() != UseTy)
- Replacement = new BitCastInst(Replacement, UseTy, "", &BB->back());
+ BasicBlock *IncomingBB = PHI->getIncomingBlock(ValNo);
+ if (Replacement->getType() != UseTy) {
+ // A catchswitch is both a pad and a terminator, meaning a basic
+ // block with a catchswitch has no insertion point. Keep going up
+ // the dominator tree until we find a non-catchswitch.
+ BasicBlock *InsertBB = IncomingBB;
+ while (isa<CatchSwitchInst>(InsertBB->getFirstNonPHI())) {
+ InsertBB = DT->getNode(InsertBB)->getIDom()->getBlock();
+ }
+
+ assert(DT->dominates(Inst, &InsertBB->back()) &&
+ "Invalid insertion point for bitcast");
+ Replacement =
+ new BitCastInst(Replacement, UseTy, "", &InsertBB->back());
+ }
+
// While we're here, rewrite all edges for this PHI, rather
// than just one use at a time, to minimize the number of
// bitcasts we emit.
for (unsigned i = 0, e = PHI->getNumIncomingValues(); i != e; ++i)
- if (PHI->getIncomingBlock(i) == BB) {
+ if (PHI->getIncomingBlock(i) == IncomingBB) {
// Keep the UI iterator valid.
if (UI != UE &&
&PHI->getOperandUse(
Added: llvm/trunk/test/Transforms/ObjCARC/contract-catchswitch.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ObjCARC/contract-catchswitch.ll?rev=331548&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/ObjCARC/contract-catchswitch.ll (added)
+++ llvm/trunk/test/Transforms/ObjCARC/contract-catchswitch.ll Fri May 4 12:03:11 2018
@@ -0,0 +1,81 @@
+; RUN: opt -S -objc-arc-contract < %s | FileCheck %s
+
+target datalayout = "e-m:x-p:32:32-i64:64-f80:32-n8:16:32-a:0:32-S32"
+target triple = "i686--windows-msvc19.11.0"
+
+%0 = type opaque
+
+declare i32 @__CxxFrameHandler3(...)
+declare dllimport void @objc_release(i8*) local_unnamed_addr
+declare dllimport i8* @objc_retain(i8* returned) local_unnamed_addr
+
+ at p = global i8* null, align 4
+
+declare void @f() local_unnamed_addr
+
+define void @g() local_unnamed_addr personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*) {
+entry:
+ %tmp = load i8*, i8** @p, align 4
+ %cast = bitcast i8* %tmp to %0*
+ %tmp1 = tail call i8* @objc_retain(i8* %tmp) #0
+ ; Split the basic block to ensure bitcast ends up in entry.split.
+ br label %entry.split
+
+entry.split:
+ invoke void @f()
+ to label %invoke.cont unwind label %catch.dispatch
+
+; Dummy nested catchswitch to test looping through the dominator tree.
+catch.dispatch:
+ %tmp2 = catchswitch within none [label %catch] unwind label %catch.dispatch1
+
+catch:
+ %tmp3 = catchpad within %tmp2 [i8* null, i32 64, i8* null]
+ catchret from %tmp3 to label %invoke.cont
+
+catch.dispatch1:
+ %tmp4 = catchswitch within none [label %catch1] unwind label %ehcleanup
+
+catch1:
+ %tmp5 = catchpad within %tmp4 [i8 *null, i32 64, i8* null]
+ catchret from %tmp5 to label %invoke.cont
+
+invoke.cont:
+ %tmp6 = load i8*, i8** @p, align 4
+ %cast1 = bitcast i8* %tmp6 to %0*
+ %tmp7 = tail call i8* @objc_retain(i8* %tmp6) #0
+ call void @objc_release(i8* %tmp) #0, !clang.imprecise_release !0
+ ; Split the basic block to ensure bitcast ends up in invoke.cont.split.
+ br label %invoke.cont.split
+
+invoke.cont.split:
+ invoke void @f()
+ to label %invoke.cont1 unwind label %ehcleanup
+
+invoke.cont1:
+ ret void
+
+ehcleanup:
+ %tmp8 = phi %0* [ %cast, %catch.dispatch1 ], [ %cast1, %invoke.cont.split ]
+ %tmp9 = cleanuppad within none []
+ %tmp10 = bitcast %0* %tmp8 to i8*
+ call void @objc_release(i8* %tmp10) #0 [ "funclet"(token %tmp9) ]
+ cleanupret from %tmp9 unwind to caller
+}
+
+; CHECK-LABEL: entry.split:
+; CHECK-NEXT: %0 = bitcast i8* %tmp1 to %0*
+; CHECK-NEXT: invoke void @f()
+; CHECK-NEXT: to label %invoke.cont unwind label %catch.dispatch
+
+; CHECK-LABEL: invoke.cont.split:
+; CHECK-NEXT: %1 = bitcast i8* %tmp7 to %0*
+; CHECK-NEXT: invoke void @f()
+; CHECK-NEXT: to label %invoke.cont1 unwind label %ehcleanup
+
+; CHECK-LABEL: ehcleanup:
+; CHECK-NEXT: %tmp8 = phi %0* [ %0, %catch.dispatch1 ], [ %1, %invoke.cont.split ]
+
+attributes #0 = { nounwind }
+
+!0 = !{}
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