From bf1638daa81cca23073649ec57b21f94c8a57533 Mon Sep 17 00:00:00 2001 From: Arnold Schwaighofer Date: Wed, 14 Mar 2018 15:44:07 +0000 Subject: [PATCH] SjLjEHPrepare: Don't reg-to-mem swifterror values swifterror llvm values model the swifterror register as memory at the LLVM IR level. ISel will perform adhoc mem-to-reg on them. swifterror values are constraint in how they can be used. Spilling them to memory is not allowed. SjLjEHPrepare tried to lower swifterror values to memory which is unecessary since the back-end will spill and reload the register as neccessary (as long as clobbering calls are marked as such which is the case here) and further leads to invalid IR because swifterror values can't be stored to memory. rdar://38164004 llvm-svn: 327521 --- llvm/lib/CodeGen/SjLjEHPrepare.cpp | 29 +++++-------------- llvm/test/CodeGen/ARM/sjljeh-swifterror.ll | 33 ++++++++++++++++++++-- 2 files changed, 38 insertions(+), 24 deletions(-) diff --git a/llvm/lib/CodeGen/SjLjEHPrepare.cpp b/llvm/lib/CodeGen/SjLjEHPrepare.cpp index 17a3a84ecda5..539bbb6ba88d 100644 --- a/llvm/lib/CodeGen/SjLjEHPrepare.cpp +++ b/llvm/lib/CodeGen/SjLjEHPrepare.cpp @@ -64,7 +64,6 @@ public: private: bool setupEntryBlockAndCallSites(Function &F); - bool undoSwiftErrorSelect(Function &F); void substituteLPadValues(LandingPadInst *LPI, Value *ExnVal, Value *SelVal); Value *setupFunctionContext(Function &F, ArrayRef LPads); void lowerIncomingArguments(Function &F); @@ -233,6 +232,13 @@ void SjLjEHPrepare::lowerIncomingArguments(Function &F) { assert(AfterAllocaInsPt != F.front().end()); for (auto &AI : F.args()) { + // Swift error really is a register that we model as memory -- instruction + // selection will perform mem-to-reg for us and spill/reload appropriately + // around calls that clobber it. There is no need to spill this + // value to the stack and doing so would not be allowed. + if (AI.isSwiftError()) + continue; + Type *Ty = AI.getType(); // Use 'select i8 true, %arg, undef' to simulate a 'no-op' instruction. @@ -462,25 +468,6 @@ bool SjLjEHPrepare::setupEntryBlockAndCallSites(Function &F) { return true; } -bool SjLjEHPrepare::undoSwiftErrorSelect(Function &F) { - // We have inserted dummy copies 'select true, arg, undef' in the entry block - // for arguments to simplify this pass. - // swifterror arguments cannot be used in this way. Undo the select for the - // swifterror argument. - for (auto &AI : F.args()) { - if (AI.isSwiftError()) { - assert(AI.hasOneUse() && "Must have converted the argument to a select"); - auto *Select = dyn_cast(AI.use_begin()->getUser()); - assert(Select && "There must be single select user"); - auto *OrigSwiftError = cast(Select->getTrueValue()); - Select->replaceAllUsesWith(OrigSwiftError); - Select->eraseFromParent(); - return true; - } - } - return false; -} - bool SjLjEHPrepare::runOnFunction(Function &F) { Module &M = *F.getParent(); RegisterFn = M.getOrInsertFunction( @@ -499,7 +486,5 @@ bool SjLjEHPrepare::runOnFunction(Function &F) { FuncCtxFn = Intrinsic::getDeclaration(&M, Intrinsic::eh_sjlj_functioncontext); bool Res = setupEntryBlockAndCallSites(F); - if (Res) - Res |= undoSwiftErrorSelect(F); return Res; } diff --git a/llvm/test/CodeGen/ARM/sjljeh-swifterror.ll b/llvm/test/CodeGen/ARM/sjljeh-swifterror.ll index aae0e75c98af..2018e08a44f3 100644 --- a/llvm/test/CodeGen/ARM/sjljeh-swifterror.ll +++ b/llvm/test/CodeGen/ARM/sjljeh-swifterror.ll @@ -1,4 +1,4 @@ -; RUN: opt -sjljehprepare -verify < %s | FileCheck %s +; RUN: opt -sjljehprepare -verify < %s -S | FileCheck %s target datalayout = "e-m:o-p:32:32-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32" target triple = "armv7s-apple-ios7.0" @@ -9,7 +9,7 @@ declare void @objc_msgSend() local_unnamed_addr declare i32 @__objc_personality_v0(...) ; Make sure we don't leave a select on a swifterror argument. -; CHECK-LABEL; @test +; CHECK-LABEL: @test ; CHECK-NOT: select true, %0 define swiftcc void @test(%swift.error** swifterror) local_unnamed_addr personality i32 (...)* @__objc_personality_v0 { entry: @@ -25,3 +25,32 @@ lpad.i: resume { i8*, i32 } undef } +%struct._objc_typeinfo = type { i8**, i8*, i64* } +@"OBJC_EHTYPE_$_NSException" = external global %struct._objc_typeinfo + +; Make sure this does not crash. +; CHECK-LABEL: @swift_error_bug +; CHECK: store %swift.error* null, %swift.error** %0 + +define hidden swiftcc void @swift_error_bug(%swift.error** swifterror, void (i8*)** %fun, i1 %b) local_unnamed_addr #0 personality i32 (...)* @__objc_personality_v0 { + %2 = load void (i8*)*, void (i8*)** %fun, align 4 + invoke void %2(i8* null) #1 + to label %tryBlock.exit unwind label %3, !clang.arc.no_objc_arc_exceptions !1 + +;