ISel: We need to notify FastIS of the IMPLICIT_DEF we created in createSwiftErrorEntriesInEntryBlock

Otherwise, it will insert instructions before it.

rdar://30536186

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@296395 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Arnold Schwaighofer 2017-02-27 22:12:06 +00:00
parent 2219387eaf
commit e4e218c802
2 changed files with 34 additions and 1 deletions

View File

@ -1306,6 +1306,7 @@ static void setupSwiftErrorVals(const Function &Fn, const TargetLowering *TLI,
}
static void createSwiftErrorEntriesInEntryBlock(FunctionLoweringInfo *FuncInfo,
FastISel *FastIS,
const TargetLowering *TLI,
const TargetInstrInfo *TII,
SelectionDAGBuilder *SDB) {
@ -1332,6 +1333,11 @@ static void createSwiftErrorEntriesInEntryBlock(FunctionLoweringInfo *FuncInfo,
BuildMI(*FuncInfo->MBB, FuncInfo->MBB->getFirstNonPHI(),
SDB->getCurDebugLoc(), TII->get(TargetOpcode::IMPLICIT_DEF),
VReg);
// Keep FastIS informed about the value we just inserted.
if (FastIS)
FastIS->setLastLocalValue(&*std::prev(FuncInfo->InsertPt));
FuncInfo->setCurrentSwiftErrorVReg(FuncInfo->MBB, SwiftErrorVal, VReg);
}
}
@ -1501,7 +1507,7 @@ void SelectionDAGISel::SelectAllBasicBlocks(const Function &Fn) {
else
FastIS->setLastLocalValue(nullptr);
}
createSwiftErrorEntriesInEntryBlock(FuncInfo, TLI, TII, SDB);
createSwiftErrorEntriesInEntryBlock(FuncInfo, FastIS, TLI, TII, SDB);
// Iterate over all basic blocks in the function.
for (const BasicBlock *LLVMBB : RPOT) {

View File

@ -685,3 +685,30 @@ entry:
tail call void @acallee(i8* null)
ret void
}
; Make sure we don't crash on this function during -O0.
; We used to crash because we would insert an IMPLICIT_DEF for the swifterror at
; beginning of the machine basic block but did not inform FastISel of the
; inserted instruction. When computing the InsertPoint in the entry block
; FastISel would choose an insertion point before the IMPLICIT_DEF causing a
; crash later on.
declare hidden swiftcc i8* @testFunA()
%TSb = type <{ i1 }>
define swiftcc void @dontCrash() {
entry:
%swifterror = alloca swifterror %swift_error*, align 8
store %swift_error* null, %swift_error** %swifterror, align 8
%a = call i8* @testFunA()
%b = bitcast i8* %a to %TSb*
%._value = getelementptr inbounds %TSb, %TSb* %b, i32 0, i32 0
%c = load i1, i1* %._value, align 1
br i1 %c, label %trueBB, label %falseBB
trueBB:
ret void
falseBB:
ret void
}