[llvm] r249796 - Revert "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 18:13:18 PDT 2015
Author: rnk
Date: Thu Oct 8 20:13:17 2015
New Revision: 249796
URL: http://llvm.org/viewvc/llvm-project?rev=249796&view=rev
Log:
Revert "Revert "Revert r248959, "[WinEH] Emit int3 after noreturn calls on Win64"""
This reverts commit r249794.
Apparently my checkouts are full of unexpected surprises today.
Removed:
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=249796&r1=249795&r2=249796&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Target/TargetOptions.h (original)
+++ llvm/trunk/include/llvm/Target/TargetOptions.h Thu Oct 8 20:13:17 2015
@@ -71,7 +71,7 @@ namespace llvm {
EnableFastISel(false), PositionIndependentExecutable(false),
UseInitArray(false), DisableIntegratedAS(false),
CompressDebugSections(false), FunctionSections(false),
- DataSections(false), UniqueSectionNames(true),
+ DataSections(false), UniqueSectionNames(true), TrapUnreachable(false),
EmulatedTLS(false), FloatABIType(FloatABI::Default),
AllowFPOpFusion(FPOpFusion::Standard), Reciprocals(TargetRecip()),
JTType(JumpTable::Single),
@@ -169,6 +169,9 @@ 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;
@@ -231,6 +234,7 @@ 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=249796&r1=249795&r2=249796&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/FastISel.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/FastISel.cpp Thu Oct 8 20:13:17 2015
@@ -1569,8 +1569,10 @@ bool FastISel::selectOperator(const User
}
case Instruction::Unreachable:
- // Nothing to emit.
- return true;
+ if (TM.Options.TrapUnreachable)
+ return fastEmit_(MVT::Other, MVT::Other, ISD::TRAP) != 0;
+ else
+ 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=249796&r1=249795&r2=249796&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp Thu Oct 8 20:13:17 2015
@@ -2260,7 +2260,11 @@ void SelectionDAGBuilder::visitIndirectB
getValue(I.getAddress())));
}
-void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) {}
+void SelectionDAGBuilder::visitUnreachable(const UnreachableInst &I) {
+ if (DAG.getTarget().Options.TrapUnreachable)
+ DAG.setRoot(
+ DAG.getNode(ISD::TRAP, getCurSDLoc(), MVT::Other, DAG.getRoot()));
+}
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=249796&r1=249795&r2=249796&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Thu Oct 8 20:13:17 2015
@@ -2951,20 +2951,6 @@ 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 {
@@ -3470,15 +3456,6 @@ 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=249796&r1=249795&r2=249796&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86TargetMachine.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86TargetMachine.cpp Thu Oct 8 20:13:17 2015
@@ -110,6 +110,13 @@ 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=249796&r1=249795&r2=249796&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/br-fold.ll (original)
+++ llvm/trunk/test/CodeGen/X86/br-fold.ll Thu Oct 8 20:13:17 2015
@@ -10,10 +10,10 @@
; X64_LINUX-NEXT: %bb8.i329
; X64_WINDOWS: orq %rax, %rcx
-; X64_WINDOWS-NEXT: %bb8.i329
+; X64_WINDOWS-NEXT: ud2
; X64_WINDOWS_GNU: orq %rax, %rcx
-; X64_WINDOWS_GNU-NEXT: %bb8.i329
+; X64_WINDOWS_GNU-NEXT: ud2
@_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]
Removed: 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=249795&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/win-catchpad-rethrow.ll (original)
+++ llvm/trunk/test/CodeGen/X86/win-catchpad-rethrow.ll (removed)
@@ -1,103 +0,0 @@
-; 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=249796&r1=249795&r2=249796&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/win64_call_epi.ll (original)
+++ llvm/trunk/test/CodeGen/X86/win64_call_epi.ll Thu Oct 8 20:13:17 2015
@@ -24,9 +24,9 @@ catch:
; WIN64: nop
; WIN64: addq ${{[0-9]+}}, %rsp
; WIN64: retq
-; Check for 'int3' after noreturn call
+; Check for 'ud2' after noreturn call
; WIN64: callq _Unwind_Resume
-; WIN64-NEXT: int3
+; WIN64-NEXT: ud2
; WIN64: .seh_endproc
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