[llvm] 7547508 - Revert "[StackSafety] Skip ambiguous lifetime analysis"
Vitaly Buka via llvm-commits
llvm-commits at lists.llvm.org
Fri Aug 7 14:03:20 PDT 2020
Author: Vitaly Buka
Date: 2020-08-07T14:02:50-07:00
New Revision: 7547508b7ae0985bde2b2cbba953f87e5c30e242
URL: https://github.com/llvm/llvm-project/commit/7547508b7ae0985bde2b2cbba953f87e5c30e242
DIFF: https://github.com/llvm/llvm-project/commit/7547508b7ae0985bde2b2cbba953f87e5c30e242.diff
LOG: Revert "[StackSafety] Skip ambiguous lifetime analysis"
This reverts commit 0b2616a8045cb776ea1514c3401d0a8577de1060.
Crashes with safe-stack.
Added:
Modified:
llvm/include/llvm/Analysis/StackLifetime.h
llvm/lib/Analysis/StackLifetime.cpp
llvm/test/Analysis/StackSafetyAnalysis/lifetime.ll
llvm/test/CodeGen/AArch64/stack-tagging.ll
Removed:
################################################################################
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 @@ class StackLifetime {
DenseMap<const BasicBlock *, SmallVector<std::pair<unsigned, Marker>, 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<IntrinsicInst>(I);
+ *IsStart = II->getIntrinsicID() == Intrinsic::lifetime_start;
+ return true;
+}
+
void StackLifetime::collectMarkers() {
InterestingAllocas.resize(NumAllocas);
DenseMap<const BasicBlock *, SmallDenseMap<const IntrinsicInst *, Marker>>
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<IntrinsicInst>(&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<const Instruction *, 8> 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<BitCastInst>(U)) {
+ WorkList.push_back(BI);
+ continue;
+ }
+ auto *UI = dyn_cast<IntrinsicInst>(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: <x y>
; MUST-NEXT: Alive: <y>
- ret void
+ret void
}
define void @unreachable() {
@@ -778,62 +778,7 @@ end:
; CHECK: end:
; CHECK-NEXT: Alive: <x y>
- ret void
-}
-
-define void @non_alloca(i8* %p) {
-; CHECK-LABEL: define void @non_alloca
-entry:
-; CHECK: entry:
-; MAY-NEXT: Alive: <x y>
-; 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: <x y>
-; 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: <x y>
-; 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: <x y>
-; MUST-NEXT: Alive: <>
-
- ret void
-}
-
-define void @select_alloca(i1 %v) {
-; CHECK-LABEL: define void @select_alloca
-entry:
-; CHECK: entry:
-; MAY-NEXT: Alive: <x y>
-; 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: <x y>
-; 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: <x y>
-; 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: <x y>
-; 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
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