From 7547508b7ae0985bde2b2cbba953f87e5c30e242 Mon Sep 17 00:00:00 2001 From: Vitaly Buka Date: Fri, 7 Aug 2020 13:59:22 -0700 Subject: [PATCH] Revert "[StackSafety] Skip ambiguous lifetime analysis" This reverts commit 0b2616a8045cb776ea1514c3401d0a8577de1060. Crashes with safe-stack. --- llvm/include/llvm/Analysis/StackLifetime.h | 2 - llvm/lib/Analysis/StackLifetime.cpp | 58 +++++++++--------- .../Analysis/StackSafetyAnalysis/lifetime.ll | 59 +------------------ llvm/test/CodeGen/AArch64/stack-tagging.ll | 11 ++-- 4 files changed, 37 insertions(+), 93 deletions(-) diff --git a/llvm/include/llvm/Analysis/StackLifetime.h b/llvm/include/llvm/Analysis/StackLifetime.h index 1c0e10368daf..8abc6cc1ce00 100644 --- a/llvm/include/llvm/Analysis/StackLifetime.h +++ b/llvm/include/llvm/Analysis/StackLifetime.h @@ -121,8 +121,6 @@ private: DenseMap, 4>> BBMarkers; - bool HasUnknownLifetimeStartOrEnd = false; - void dumpAllocas() const; void dumpBlockLiveness() const; void dumpLiveRanges() const; diff --git a/llvm/lib/Analysis/StackLifetime.cpp b/llvm/lib/Analysis/StackLifetime.cpp index d953a8762608..9727b7a33d1f 100644 --- a/llvm/lib/Analysis/StackLifetime.cpp +++ b/llvm/lib/Analysis/StackLifetime.cpp @@ -11,7 +11,6 @@ #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/SmallVector.h" #include "llvm/ADT/StringExtras.h" -#include "llvm/Analysis/ValueTracking.h" #include "llvm/Config/llvm-config.h" #include "llvm/IR/AssemblyAnnotationWriter.h" #include "llvm/IR/BasicBlock.h" @@ -64,27 +63,42 @@ bool StackLifetime::isAliveAfter(const AllocaInst *AI, return getLiveRange(AI).test(InstNum); } +static bool readMarker(const Instruction *I, bool *IsStart) { + if (!I->isLifetimeStartOrEnd()) + return false; + + auto *II = cast(I); + *IsStart = II->getIntrinsicID() == Intrinsic::lifetime_start; + return true; +} + void StackLifetime::collectMarkers() { InterestingAllocas.resize(NumAllocas); DenseMap> BBMarkerSet; // Compute the set of start/end markers per basic block. - for (const BasicBlock *BB : depth_first(&F)) { - for (const Instruction &I : *BB) { - const IntrinsicInst *II = dyn_cast(&I); - if (!II || !II->isLifetimeStartOrEnd()) - continue; - const AllocaInst *AI = llvm::findAllocaForValue(II->getArgOperand(1)); - if (!AI) { - HasUnknownLifetimeStartOrEnd = true; - continue; + for (unsigned AllocaNo = 0; AllocaNo < NumAllocas; ++AllocaNo) { + const AllocaInst *AI = Allocas[AllocaNo]; + SmallVector WorkList; + WorkList.push_back(AI); + while (!WorkList.empty()) { + const Instruction *I = WorkList.pop_back_val(); + for (const User *U : I->users()) { + if (auto *BI = dyn_cast(U)) { + WorkList.push_back(BI); + continue; + } + auto *UI = dyn_cast(U); + if (!UI) + continue; + bool IsStart; + if (!readMarker(UI, &IsStart)) + continue; + if (IsStart) + InterestingAllocas.set(AllocaNo); + BBMarkerSet[UI->getParent()][UI] = {AllocaNo, IsStart}; } - bool IsStart = II->getIntrinsicID() == Intrinsic::lifetime_start; - unsigned AllocaNo = AllocaNumbering[AI]; - if (IsStart) - InterestingAllocas.set(AllocaNo); - BBMarkerSet[BB][II] = {AllocaNo, IsStart}; } } @@ -290,20 +304,6 @@ StackLifetime::StackLifetime(const Function &F, } void StackLifetime::run() { - if (HasUnknownLifetimeStartOrEnd) { - // There is marker which we can't assign to a specific alloca, so we - // fallback to the most conservative results for the type. - switch (Type) { - case LivenessType::May: - LiveRanges.resize(NumAllocas, getFullLiveRange()); - break; - case LivenessType::Must: - LiveRanges.resize(NumAllocas, LiveRange(Instructions.size())); - break; - } - return; - } - LiveRanges.resize(NumAllocas, LiveRange(Instructions.size())); for (unsigned I = 0; I < NumAllocas; ++I) if (!InterestingAllocas.test(I)) diff --git a/llvm/test/Analysis/StackSafetyAnalysis/lifetime.ll b/llvm/test/Analysis/StackSafetyAnalysis/lifetime.ll index 470450a3a977..1c7eeb5ac69c 100644 --- a/llvm/test/Analysis/StackSafetyAnalysis/lifetime.ll +++ b/llvm/test/Analysis/StackSafetyAnalysis/lifetime.ll @@ -742,7 +742,7 @@ if.end: ; MAY-NEXT: Alive: ; MUST-NEXT: Alive: - ret void +ret void } define void @unreachable() { @@ -778,62 +778,7 @@ end: ; CHECK: end: ; CHECK-NEXT: Alive: - ret void -} - -define void @non_alloca(i8* %p) { -; CHECK-LABEL: define void @non_alloca -entry: -; CHECK: entry: -; MAY-NEXT: Alive: -; MUST-NEXT: Alive: <> - %x = alloca i8, align 4 - %y = alloca i8, align 4 - - call void @llvm.lifetime.start.p0i8(i64 4, i8* %p) -; CHECK: call void @llvm.lifetime.start.p0i8(i64 4, i8* %p) -; MAY-NEXT: Alive: -; MUST-NEXT: Alive: <> - - call void @llvm.lifetime.start.p0i8(i64 4, i8* %x) -; CHECK: call void @llvm.lifetime.start.p0i8(i64 4, i8* %x) -; MAY-NEXT: Alive: -; MUST-NEXT: Alive: <> - - call void @llvm.lifetime.end.p0i8(i64 4, i8* %p) -; CHECK: call void @llvm.lifetime.end.p0i8(i64 4, i8* %p) -; MAY-NEXT: Alive: -; MUST-NEXT: Alive: <> - - ret void -} - -define void @select_alloca(i1 %v) { -; CHECK-LABEL: define void @select_alloca -entry: -; CHECK: entry: -; MAY-NEXT: Alive: -; MUST-NEXT: Alive: <> - %x = alloca i8, align 4 - %y = alloca i8, align 4 - %cxcy = select i1 %v, i8* %x, i8* %y - - call void @llvm.lifetime.start.p0i8(i64 1, i8* %cxcy) -; CHECK: call void @llvm.lifetime.start.p0i8(i64 1, i8* %cxcy) -; MAY-NEXT: Alive: -; MUST-NEXT: Alive: <> - - call void @llvm.lifetime.start.p0i8(i64 1, i8* %x) -; CHECK: call void @llvm.lifetime.start.p0i8(i64 1, i8* %x) -; MAY-NEXT: Alive: -; MUST-NEXT: Alive: <> - - call void @llvm.lifetime.end.p0i8(i64 1, i8* %x) -; CHECK: call void @llvm.lifetime.end.p0i8(i64 1, i8* %x) -; MAY-NEXT: Alive: -; MUST-NEXT: Alive: <> - - ret void +ret void } declare void @llvm.lifetime.start.p0i8(i64, i8* nocapture) diff --git a/llvm/test/CodeGen/AArch64/stack-tagging.ll b/llvm/test/CodeGen/AArch64/stack-tagging.ll index 83fe4025ea0c..275b8a7dbad7 100644 --- a/llvm/test/CodeGen/AArch64/stack-tagging.ll +++ b/llvm/test/CodeGen/AArch64/stack-tagging.ll @@ -192,9 +192,10 @@ another_bb: ; CHECK: alloca { i32, [12 x i8] }, align 16 ; CHECK: call { i32, [12 x i8] }* @llvm.aarch64.tagp ; CHECK: call void @llvm.aarch64.settag( -; CHECK: alloca { i32, [12 x i8] }, align 16 -; CHECK: call { i32, [12 x i8] }* @llvm.aarch64.tagp -; CHECK: call void @llvm.aarch64.settag( +; SSI: alloca i32, align 4 +; NOSSI: alloca { i32, [12 x i8] }, align 16 +; NOSSI: call { i32, [12 x i8] }* @llvm.aarch64.tagp +; NOSSI: call void @llvm.aarch64.settag( ; CHECK: store i32 ; CHECK: call void @noUse32(i32* ; CHECK: store i32 @@ -202,7 +203,7 @@ another_bb: ; CHECK: call void @noUse32(i32* ; CHECK: call void @llvm.aarch64.settag( ; CHECK: call void @llvm.aarch64.settag( -; CHECK: call void @llvm.aarch64.settag( +; NOSSI: call void @llvm.aarch64.settag( ; CHECK: ret void -!0 = !{} +!0 = !{} \ No newline at end of file