[llvm] r249794 - Revert "Revert r248959, "[WinEH] Emit int3 after noreturn calls on Win64""
Reid Kleckner via llvm-commits
llvm-commits at lists.llvm.org
Thu Oct 8 18:11:38 PDT 2015
Author: rnk
Date: Thu Oct 8 20:11:37 2015
New Revision: 249794
URL: http://llvm.org/viewvc/llvm-project?rev=249794&view=rev
Log:
Revert "Revert r248959, "[WinEH] Emit int3 after noreturn calls on Win64""
This reverts commit r249032.
TODO write commit msg
Added:
llvm/trunk/test/CodeGen/X86/win-catchpad-rethrow.ll
Modified:
llvm/trunk/include/llvm/Target/TargetOptions.h
llvm/trunk/lib/CodeGen/SelectionDAG/FastISel.cpp
llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
llvm/trunk/lib/Target/X86/X86TargetMachine.cpp
llvm/trunk/test/CodeGen/X86/br-fold.ll
llvm/trunk/test/CodeGen/X86/win64_call_epi.ll
Modified: llvm/trunk/include/llvm/Target/TargetOptions.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Target/TargetOptions.h?rev=249794&r1=249793&r2=249794&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Target/TargetOptions.h (original)
+++ llvm/trunk/include/llvm/Target/TargetOptions.h Thu Oct 8 20:11:37 2015
@@ -71,7 +71,7 @@ namespace llvm {
EnableFastISel(false), PositionIndependentExecutable(false),
UseInitArray(false), DisableIntegratedAS(false),
CompressDebugSections(false), FunctionSections(false),
- DataSections(false), UniqueSectionNames(true), TrapUnreachable(false),
+ DataSections(false), UniqueSectionNames(true),
EmulatedTLS(false), FloatABIType(FloatABI::Default),
AllowFPOpFusion(FPOpFusion::Standard), Reciprocals(TargetRecip()),
JTType(JumpTable::Single),
@@ -169,9 +169,6 @@ namespace llvm {
unsigned UniqueSectionNames : 1;
- /// Emit target-specific trap instruction for 'unreachable' IR instructions.
- unsigned TrapUnreachable : 1;
-
/// EmulatedTLS - This flag enables emulated TLS model, using emutls
/// function in the runtime library..
unsigned EmulatedTLS : 1;
@@ -234,7 +231,6 @@ inline bool operator==(const TargetOptio
ARE_EQUAL(EnableFastISel) &&
ARE_EQUAL(PositionIndependentExecutable) &&
ARE_EQUAL(UseInitArray) &&
- ARE_EQUAL(TrapUnreachable) &&
ARE_EQUAL(EmulatedTLS) &&
ARE_EQUAL(FloatABIType) &&
ARE_EQUAL(AllowFPOpFusion) &&
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/FastISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/FastISel.cpp?rev=249794&r1=249793&r2=249794&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/FastISel.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/FastISel.cpp Thu Oct 8 20:11:37 2015
@@ -1569,10 +1569,8 @@ bool FastISel::selectOperator(const User
}
case Instruction::Unreachable:
- if (TM.Options.TrapUnreachable)
- return fastEmit_(MVT::Other, MVT::Other, ISD::TRAP) != 0;
- else
- return true;
+ // Nothing to emit.
+ return true;
case Instruction::Alloca:
// FunctionLowering has the static-sized case covered.
Modified: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp?rev=249794&r1=249793&r2=249794&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Thu Oct 8 20:11:37 2015
@@ -2260,11 +2260,7 @@ void SelectionDAGBuilder::visitIndirectB
getValue(I.getAddress())));
}
-void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) {
- if (DAG.getTarget().Options.TrapUnreachable)
- DAG.setRoot(
- DAG.getNode(ISD::TRAP, getCurSDLoc(), MVT::Other, DAG.getRoot()));
-}
+void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) {}
void SelectionDAGBuilder::visitFSub(const User &I) {
// -0.0 - X --> fneg
Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=249794&r1=249793&r2=249794&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Thu Oct 8 20:11:37 2015
@@ -2951,6 +2951,20 @@ static SDValue getMOVL(SelectionDAG &DAG
return DAG.getVectorShuffle(VT, dl, V1, V2, &Mask[0]);
}
+/// Check if the fall through instruction after a call site is unreachable.
+/// FIXME: This will fail if there are interesting non-code generating IR
+/// instructions between the call and the unreachable (lifetime.end). In
+/// practice, this should be rare because optimizations like to delete non-call
+/// code before unreachable.
+static bool isCallFollowedByUnreachable(ImmutableCallSite CS) {
+ const Instruction *NextInst;
+ if (auto *II = dyn_cast<InvokeInst>(CS.getInstruction()))
+ NextInst = II->getNormalDest()->getFirstNonPHIOrDbg();
+ else
+ NextInst = CS.getInstruction()->getNextNode();
+ return isa<UnreachableInst>(NextInst);
+}
+
SDValue
X86TargetLowering::LowerCall(TargetLowering::CallLoweringInfo &CLI,
SmallVectorImpl<SDValue> &InVals) const {
@@ -3456,6 +3470,15 @@ X86TargetLowering::LowerCall(TargetLower
InFlag = Chain.getValue(1);
}
+ if (Subtarget->isTargetWin64() && CLI.CS) {
+ // Look for a call followed by unreachable. On Win64, we need to ensure that
+ // the call does not accidentally fall through to something that looks like
+ // an epilogue. We do this by inserting a DEBUGTRAP, which lowers to int3,
+ // which is what MSVC emits after noreturn calls.
+ if (isCallFollowedByUnreachable(*CLI.CS))
+ Chain = DAG.getNode(ISD::DEBUGTRAP, dl, MVT::Other, Chain);
+ }
+
// Handle result values, copying them out of physregs into vregs that we
// return.
return LowerCallResult(Chain, InFlag, CallConv, isVarArg,
Modified: llvm/trunk/lib/Target/X86/X86TargetMachine.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86TargetMachine.cpp?rev=249794&r1=249793&r2=249794&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86TargetMachine.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86TargetMachine.cpp Thu Oct 8 20:11:37 2015
@@ -110,13 +110,6 @@ X86TargetMachine::X86TargetMachine(const
OL),
TLOF(createTLOF(getTargetTriple())),
Subtarget(TT, CPU, FS, *this, Options.StackAlignmentOverride) {
- // Windows stack unwinder gets confused when execution flow "falls through"
- // after a call to 'noreturn' function.
- // To prevent that, we emit a trap for 'unreachable' IR instructions.
- // (which on X86, happens to be the 'ud2' instruction)
- if (Subtarget.isTargetWin64())
- this->Options.TrapUnreachable = true;
-
// By default (and when -ffast-math is on), enable estimate codegen for
// everything except scalar division. By default, use 1 refinement step for
// all operations. Defaults may be overridden by using command-line options.
Modified: llvm/trunk/test/CodeGen/X86/br-fold.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/br-fold.ll?rev=249794&r1=249793&r2=249794&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/br-fold.ll (original)
+++ llvm/trunk/test/CodeGen/X86/br-fold.ll Thu Oct 8 20:11:37 2015
@@ -10,10 +10,10 @@
; X64_LINUX-NEXT: %bb8.i329
; X64_WINDOWS: orq %rax, %rcx
-; X64_WINDOWS-NEXT: ud2
+; X64_WINDOWS-NEXT: %bb8.i329
; X64_WINDOWS_GNU: orq %rax, %rcx
-; X64_WINDOWS_GNU-NEXT: ud2
+; X64_WINDOWS_GNU-NEXT: %bb8.i329
@_ZN11xercesc_2_513SchemaSymbols21fgURI_SCHEMAFORSCHEMAE = external constant [33 x i16], align 32 ; <[33 x i16]*> [#uses=1]
@_ZN11xercesc_2_56XMLUni16fgNotationStringE = external constant [9 x i16], align 16 ; <[9 x i16]*> [#uses=1]
Added: llvm/trunk/test/CodeGen/X86/win-catchpad-rethrow.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/win-catchpad-rethrow.ll?rev=249794&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/win-catchpad-rethrow.ll (added)
+++ llvm/trunk/test/CodeGen/X86/win-catchpad-rethrow.ll Thu Oct 8 20:11:37 2015
@@ -0,0 +1,103 @@
+; RUN: llc -mtriple=x86_64-pc-windows-msvc < %s | FileCheck %s
+
+; C++ EH rethrows are interesting, because they are calls to noreturn
+; functions. There *must* be some code after the call instruction that doesn't
+; look like an epilogue. We use int3 to be consistent with MSVC.
+
+; Based on this C++ source:
+; int main() {
+; try {
+; throw 42;
+; } catch (int) {
+; try {
+; throw;
+; } catch (int) {
+; }
+; }
+; return 0;
+; }
+
+; ModuleID = 't.cpp'
+target datalayout = "e-m:w-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc"
+
+%rtti.TypeDescriptor2 = type { i8**, i8*, [3 x i8] }
+%eh.CatchableType = type { i32, i32, i32, i32, i32, i32, i32 }
+%eh.CatchableTypeArray.1 = type { i32, [1 x i32] }
+%eh.ThrowInfo = type { i32, i32, i32, i32 }
+
+$"\01??_R0H at 8" = comdat any
+
+$"_CT??_R0H at 84" = comdat any
+
+$_CTA1H = comdat any
+
+$_TI1H = comdat any
+
+@"\01??_7type_info@@6B@" = external constant i8*
+@"\01??_R0H at 8" = linkonce_odr global %rtti.TypeDescriptor2 { i8** @"\01??_7type_info@@6B@", i8* null, [3 x i8] c".H\00" }, comdat
+ at __ImageBase = external constant i8
+@"_CT??_R0H at 84" = linkonce_odr unnamed_addr constant %eh.CatchableType { i32 1, i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%rtti.TypeDescriptor2* @"\01??_R0H at 8" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32), i32 0, i32 -1, i32 0, i32 4, i32 0 }, section ".xdata", comdat
+ at _CTA1H = linkonce_odr unnamed_addr constant %eh.CatchableTypeArray.1 { i32 1, [1 x i32] [i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%eh.CatchableType* @"_CT??_R0H at 84" to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32)] }, section ".xdata", comdat
+ at _TI1H = linkonce_odr unnamed_addr constant %eh.ThrowInfo { i32 0, i32 0, i32 0, i32 trunc (i64 sub nuw nsw (i64 ptrtoint (%eh.CatchableTypeArray.1* @_CTA1H to i64), i64 ptrtoint (i8* @__ImageBase to i64)) to i32) }, section ".xdata", comdat
+
+define i32 @main() #0 personality i8* bitcast (i32 (...)* @__CxxFrameHandler3 to i8*) {
+entry:
+ %tmp = alloca i32, align 4
+ store i32 42, i32* %tmp, align 4
+ %0 = bitcast i32* %tmp to i8*
+ invoke void @_CxxThrowException(i8* %0, %eh.ThrowInfo* nonnull @_TI1H) #1
+ to label %unreachable unwind label %catch.dispatch
+
+catch.dispatch: ; preds = %entry
+ %1 = catchpad [%rtti.TypeDescriptor2* @"\01??_R0H at 8", i32 0, i8* null]
+ to label %catch unwind label %catchendblock
+
+catch: ; preds = %catch.dispatch
+ invoke void @_CxxThrowException(i8* null, %eh.ThrowInfo* null) #1
+ to label %unreachable unwind label %catch.dispatch.1
+
+catch.dispatch.1: ; preds = %catch
+ %2 = catchpad [%rtti.TypeDescriptor2* @"\01??_R0H at 8", i32 0, i8* null]
+ to label %catch.3 unwind label %catchendblock.2
+
+catch.3: ; preds = %catch.dispatch.1
+ catchret %2 to label %try.cont
+
+try.cont: ; preds = %catch.3
+ catchret %1 to label %try.cont.5
+
+try.cont.5: ; preds = %try.cont
+ ret i32 0
+
+catchendblock.2: ; preds = %catch.dispatch.1
+ catchendpad unwind label %catchendblock
+
+catchendblock: ; preds = %catchendblock.2, %catch.dispatch
+ catchendpad unwind to caller
+
+unreachable: ; preds = %catch, %entry
+ unreachable
+}
+
+declare void @_CxxThrowException(i8*, %eh.ThrowInfo*)
+
+declare i32 @__CxxFrameHandler3(...)
+
+attributes #0 = { "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="false" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "target-features"="+sse,+sse2" "unsafe-fp-math"="false" "use-soft-float"="false" }
+attributes #1 = { noreturn }
+
+; CHECK: main:
+; CHECK: .seh_proc main
+; CHECK: movl $42,
+; CHECK-DAG: leaq {{.*}}, %rcx
+; CHECK-DAG: leaq _TI1H(%rip), %rdx
+; CHECK: callq _CxxThrowException
+; CHECK-NEXT: int3
+
+; CHECK: "?catch$1@?0?main at 4HA":
+; CHECK: .seh_proc "?catch$1@?0?main at 4HA"
+; CHECK-DAG: xorl %ecx, %ecx
+; CHECK-DAG: xorl %edx, %edx
+; CHECK: callq _CxxThrowException
+; CHECK-NEXT: int3
Modified: llvm/trunk/test/CodeGen/X86/win64_call_epi.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/win64_call_epi.ll?rev=249794&r1=249793&r2=249794&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/win64_call_epi.ll (original)
+++ llvm/trunk/test/CodeGen/X86/win64_call_epi.ll Thu Oct 8 20:11:37 2015
@@ -24,9 +24,9 @@ catch:
; WIN64: nop
; WIN64: addq ${{[0-9]+}}, %rsp
; WIN64: retq
-; Check for 'ud2' after noreturn call
+; Check for 'int3' after noreturn call
; WIN64: callq _Unwind_Resume
-; WIN64-NEXT: ud2
+; WIN64-NEXT: int3
; WIN64: .seh_endproc
More information about the llvm-commits
mailing list