From: David Majnemer Date: Tue, 27 Oct 2015 07:36:42 +0000 (+0000) Subject: [ScalarEvolutionExpander] Properly insert no-op casts + EH Pads X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=commitdiff_plain;h=1089dfcf5c7b5ac67b17b4586f88a01644192d60 [ScalarEvolutionExpander] Properly insert no-op casts + EH Pads We want to insert no-op casts as close as possible to the def. This is tricky when the cast is of a PHI node and the BasicBlocks between the def and the use cannot hold any instructions. Iteratively walk EH pads until we hit a non-EH pad. This fixes PR25326. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251393 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/Analysis/ScalarEvolutionExpander.cpp b/lib/Analysis/ScalarEvolutionExpander.cpp index 86c2f50ac29..428d989285c 100644 --- a/lib/Analysis/ScalarEvolutionExpander.cpp +++ b/lib/Analysis/ScalarEvolutionExpander.cpp @@ -86,6 +86,41 @@ Value *SCEVExpander::ReuseOrCreateCast(Value *V, Type *Ty, return Ret; } +static BasicBlock::iterator findInsertPointAfter(Instruction *I, + DominatorTree &DT, + BasicBlock *MustDominate) { + BasicBlock::iterator IP = ++I->getIterator(); + if (auto *II = dyn_cast(I)) + IP = II->getNormalDest()->begin(); + if (auto *CPI = dyn_cast(I)) + IP = CPI->getNormalDest()->begin(); + + while (isa(IP)) + ++IP; + + while (IP->isEHPad()) { + if (isa(IP) || isa(IP)) { + ++IP; + } else if (auto *TPI = dyn_cast(IP)) { + IP = TPI->getUnwindDest()->getFirstNonPHI(); + } else if (auto *CEPI = dyn_cast(IP)) { + IP = CEPI->getUnwindDest()->getFirstNonPHI(); + } else if (auto *CEPI = dyn_cast(IP)) { + IP = CEPI->getUnwindDest()->getFirstNonPHI(); + } else if (auto *CPI = dyn_cast(IP)) { + BasicBlock *NormalDest = CPI->getNormalDest(); + if (NormalDest == MustDominate || DT.dominates(NormalDest, MustDominate)) + IP = NormalDest->getFirstNonPHI(); + else + IP = CPI->getUnwindDest()->getFirstNonPHI(); + } else { + llvm_unreachable("unexpected eh pad!"); + } + } + + return IP; +} + /// InsertNoopCastOfTo - Insert a cast of V to the specified type, /// which must be possible with a noop cast, doing what we can to share /// the casts. @@ -135,21 +170,15 @@ Value *SCEVExpander::InsertNoopCastOfTo(Value *V, Type *Ty) { while ((isa(IP) && isa(cast(IP)->getOperand(0)) && cast(IP)->getOperand(0) != A) || - isa(IP) || - isa(IP)) + isa(IP)) ++IP; return ReuseOrCreateCast(A, Ty, Op, IP); } // Cast the instruction immediately after the instruction. Instruction *I = cast(V); - BasicBlock::iterator IP = ++I->getIterator(); - if (InvokeInst *II = dyn_cast(I)) - IP = II->getNormalDest()->begin(); - if (CatchPadInst *CPI = dyn_cast(I)) - IP = CPI->getNormalDest()->begin(); - while (isa(IP) || isa(IP)) - ++IP; + BasicBlock::iterator IP = + findInsertPointAfter(I, SE.DT, Builder.GetInsertBlock()); return ReuseOrCreateCast(I, Ty, Op, IP); } @@ -1394,12 +1423,8 @@ Value *SCEVExpander::visitAddRecExpr(const SCEVAddRecExpr *S) { NewOps[i] = SE.getAnyExtendExpr(S->op_begin()[i], CanonicalIV->getType()); Value *V = expand(SE.getAddRecExpr(NewOps, S->getLoop(), S->getNoWrapFlags(SCEV::FlagNW))); - BasicBlock::iterator NewInsertPt = - std::next(BasicBlock::iterator(cast(V))); - BuilderType::InsertPointGuard Guard(Builder); - while (isa(NewInsertPt) || isa(NewInsertPt) || - isa(NewInsertPt)) - ++NewInsertPt; + BasicBlock::iterator NewInsertPt = findInsertPointAfter( + cast(V), SE.DT, Builder.GetInsertBlock()); V = expandCodeFor(SE.getTruncateExpr(SE.getUnknown(V), Ty), nullptr, &*NewInsertPt); return V; diff --git a/test/Transforms/LoopStrengthReduce/funclet.ll b/test/Transforms/LoopStrengthReduce/funclet.ll new file mode 100644 index 00000000000..60bec76e7e6 --- /dev/null +++ b/test/Transforms/LoopStrengthReduce/funclet.ll @@ -0,0 +1,148 @@ +; RUN: opt < %s -loop-reduce -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-pc-windows-msvc" + +declare i32 @_except_handler3(...) + +declare void @reserve() + +define void @f() personality i32 (...)* @_except_handler3 { +entry: + br label %throw + +throw: ; preds = %throw, %entry + %tmp96 = getelementptr inbounds i8, i8* undef, i32 1 + invoke void @reserve() + to label %throw unwind label %pad + +pad: ; preds = %throw + %phi2 = phi i8* [ %tmp96, %throw ] + terminatepad [] unwind label %blah + +blah: + catchpad [] to label %unreachable unwind label %blah3 + +unreachable: + unreachable + +blah3: + catchendpad unwind label %blah2 + +blah2: + %cleanuppadi4.i.i.i = cleanuppad [] + br label %loop_body + +loop_body: ; preds = %iter, %pad + %tmp99 = phi i8* [ %tmp101, %iter ], [ %phi2, %blah2 ] + %tmp100 = icmp eq i8* %tmp99, undef + br i1 %tmp100, label %unwind_out, label %iter + +iter: ; preds = %loop_body + %tmp101 = getelementptr inbounds i8, i8* %tmp99, i32 1 + br i1 undef, label %unwind_out, label %loop_body + +unwind_out: ; preds = %iter, %loop_body + cleanupret %cleanuppadi4.i.i.i unwind to caller +} + +; CHECK-LABEL: define void @f( +; CHECK: cleanuppad [] +; CHECK-NEXT: ptrtoint i8* %phi2 to i32 + +define void @g() personality i32 (...)* @_except_handler3 { +entry: + br label %throw + +throw: ; preds = %throw, %entry + %tmp96 = getelementptr inbounds i8, i8* undef, i32 1 + invoke void @reserve() + to label %throw unwind label %pad + +pad: + %phi2 = phi i8* [ %tmp96, %throw ] + catchpad [] to label %unreachable unwind label %blah + +unreachable: + unreachable + +blah: + %catchpad = catchpad [] to label %loop_body unwind label %blah3 + + +blah3: + catchendpad unwind to caller ;label %blah2 + +unwind_out: + catchret %catchpad to label %leave + +leave: + ret void + +loop_body: ; preds = %iter, %pad + %tmp99 = phi i8* [ %tmp101, %iter ], [ %phi2, %blah ] + %tmp100 = icmp eq i8* %tmp99, undef + br i1 %tmp100, label %unwind_out, label %iter + +iter: ; preds = %loop_body + %tmp101 = getelementptr inbounds i8, i8* %tmp99, i32 1 + br i1 undef, label %unwind_out, label %loop_body +} + +; CHECK-LABEL: define void @g( +; CHECK: blah: +; CHECK-NEXT: catchpad [] +; CHECK-NEXT: to label %loop_body.preheader + +; CHECK: loop_body.preheader: +; CHECK-NEXT: ptrtoint i8* %phi2 to i32 + + +define void @h() personality i32 (...)* @_except_handler3 { +entry: + br label %throw + +throw: ; preds = %throw, %entry + %tmp96 = getelementptr inbounds i8, i8* undef, i32 1 + invoke void @reserve() + to label %throw unwind label %pad + +pad: + catchpad [] to label %unreachable unwind label %blug + +unreachable: + unreachable + +blug: + %phi2 = phi i8* [ %tmp96, %pad ] + %catchpad = catchpad [] to label %blah2 unwind label %blah3 + +blah2: + br label %loop_body + +blah3: + catchendpad unwind to caller ;label %blah2 + +unwind_out: + catchret %catchpad to label %leave + +leave: + ret void + +loop_body: ; preds = %iter, %pad + %tmp99 = phi i8* [ %tmp101, %iter ], [ %phi2, %blah2 ] + %tmp100 = icmp eq i8* %tmp99, undef + br i1 %tmp100, label %unwind_out, label %iter + +iter: ; preds = %loop_body + %tmp101 = getelementptr inbounds i8, i8* %tmp99, i32 1 + br i1 undef, label %unwind_out, label %loop_body +} + +; CHECK-LABEL: define void @h( +; CHECK: blug: +; CHECK: catchpad [] +; CHECK-NEXT: to label %blah2 + +; CHECK: blah2: +; CHECK-NEXT: ptrtoint i8* %phi2 to i32