[llvm-branch-commits] [llvm] 0d255a3 - Revert "[llvm] Improve llvm.objectsize computation by computing GEP, alloca a…"
via llvm-branch-commits
llvm-branch-commits at lists.llvm.org
Wed Nov 20 10:01:24 PST 2024
Author: Florian Mayer
Date: 2024-11-20T10:01:21-08:00
New Revision: 0d255a3378917ea62c723454b2a1fc3927cdaa15
URL: https://github.com/llvm/llvm-project/commit/0d255a3378917ea62c723454b2a1fc3927cdaa15
DIFF: https://github.com/llvm/llvm-project/commit/0d255a3378917ea62c723454b2a1fc3927cdaa15.diff
LOG: Revert "[llvm] Improve llvm.objectsize computation by computing GEP, alloca a…"
This reverts commit 02b8ee281947f6cb39c7eb3c4bbba59322e9015b.
Added:
Modified:
llvm/include/llvm/IR/Value.h
llvm/lib/Analysis/MemoryBuiltins.cpp
Removed:
llvm/test/Transforms/LowerConstantIntrinsics/builtin-object-size-range.ll
################################################################################
diff --git a/llvm/include/llvm/IR/Value.h b/llvm/include/llvm/IR/Value.h
index d444a768a65436..945081b77e9536 100644
--- a/llvm/include/llvm/IR/Value.h
+++ b/llvm/include/llvm/IR/Value.h
@@ -723,16 +723,12 @@ class Value {
bool AllowInvariantGroup = false,
function_ref<bool(Value &Value, APInt &Offset)> ExternalAnalysis =
nullptr) const;
-
- Value *stripAndAccumulateConstantOffsets(
- const DataLayout &DL, APInt &Offset, bool AllowNonInbounds,
- bool AllowInvariantGroup = false,
- function_ref<bool(Value &Value, APInt &Offset)> ExternalAnalysis =
- nullptr) {
+ Value *stripAndAccumulateConstantOffsets(const DataLayout &DL, APInt &Offset,
+ bool AllowNonInbounds,
+ bool AllowInvariantGroup = false) {
return const_cast<Value *>(
static_cast<const Value *>(this)->stripAndAccumulateConstantOffsets(
- DL, Offset, AllowNonInbounds, AllowInvariantGroup,
- ExternalAnalysis));
+ DL, Offset, AllowNonInbounds, AllowInvariantGroup));
}
/// This is a wrapper around stripAndAccumulateConstantOffsets with the
diff --git a/llvm/lib/Analysis/MemoryBuiltins.cpp b/llvm/lib/Analysis/MemoryBuiltins.cpp
index 6c0940c4c81ebe..cd8594d670502d 100644
--- a/llvm/lib/Analysis/MemoryBuiltins.cpp
+++ b/llvm/lib/Analysis/MemoryBuiltins.cpp
@@ -673,69 +673,6 @@ STATISTIC(ObjectVisitorArgument,
STATISTIC(ObjectVisitorLoad,
"Number of load instructions with unsolved size and offset");
-static std::optional<APInt>
-combinePossibleConstantValues(std::optional<APInt> LHS,
- std::optional<APInt> RHS,
- ObjectSizeOpts::Mode EvalMode) {
- if (!LHS || !RHS)
- return std::nullopt;
- if (EvalMode == ObjectSizeOpts::Mode::Max)
- return LHS->sge(*RHS) ? *LHS : *RHS;
- else
- return LHS->sle(*RHS) ? *LHS : *RHS;
-}
-
-static std::optional<APInt> aggregatePossibleConstantValuesImpl(
- const Value *V, ObjectSizeOpts::Mode EvalMode, unsigned recursionDepth) {
- constexpr unsigned maxRecursionDepth = 4;
- if (recursionDepth == maxRecursionDepth)
- return std::nullopt;
-
- if (const auto *CI = dyn_cast<ConstantInt>(V)) {
- return CI->getValue();
- }
-
- else if (const auto *SI = dyn_cast<SelectInst>(V)) {
- return combinePossibleConstantValues(
- aggregatePossibleConstantValuesImpl(SI->getTrueValue(), EvalMode,
- recursionDepth + 1),
- aggregatePossibleConstantValuesImpl(SI->getFalseValue(), EvalMode,
- recursionDepth + 1),
- EvalMode);
- }
-
- else if (const auto *PN = dyn_cast<PHINode>(V)) {
- unsigned Count = PN->getNumIncomingValues();
- if (Count == 0)
- return std::nullopt;
- auto Acc = aggregatePossibleConstantValuesImpl(
- PN->getIncomingValue(0), EvalMode, recursionDepth + 1);
- for (unsigned I = 1; Acc && I < Count; ++I) {
- auto Tmp = aggregatePossibleConstantValuesImpl(
- PN->getIncomingValue(1), EvalMode, recursionDepth + 1);
- Acc = combinePossibleConstantValues(Acc, Tmp, EvalMode);
- }
- return Acc;
- }
-
- return std::nullopt;
-}
-
-static std::optional<APInt>
-aggregatePossibleConstantValues(const Value *V, ObjectSizeOpts::Mode EvalMode) {
- if (auto *CI = dyn_cast<ConstantInt>(V))
- return CI->getValue();
-
- if (EvalMode != ObjectSizeOpts::Mode::Min &&
- EvalMode != ObjectSizeOpts::Mode::Max)
- return std::nullopt;
-
- // Not using computeConstantRange here because we cannot guarantee it's not
- // doing optimization based on UB which we want to avoid when expanding
- // __builtin_object_size.
- return aggregatePossibleConstantValuesImpl(V, EvalMode, 0u);
-}
-
/// Align \p Size according to \p Alignment. If \p Size is greater than
/// getSignedMaxValue(), set it as unknown as we can only represent signed value
/// in OffsetSpan.
@@ -783,36 +720,11 @@ OffsetSpan ObjectSizeOffsetVisitor::computeImpl(Value *V) {
V = V->stripAndAccumulateConstantOffsets(
DL, Offset, /* AllowNonInbounds */ true, /* AllowInvariantGroup */ true);
- // Give it another try with approximated analysis. We don't start with this
- // one because stripAndAccumulateConstantOffsets behaves
diff erently wrt.
- // overflows if we provide an external Analysis.
- if ((Options.EvalMode == ObjectSizeOpts::Mode::Min ||
- Options.EvalMode == ObjectSizeOpts::Mode::Max) &&
- isa<GEPOperator>(V)) {
- // External Analysis used to compute the Min/Max value of individual Offsets
- // within a GEP.
- ObjectSizeOpts::Mode EvalMode =
- Options.EvalMode == ObjectSizeOpts::Mode::Min
- ? ObjectSizeOpts::Mode::Max
- : ObjectSizeOpts::Mode::Min;
- auto OffsetRangeAnalysis = [EvalMode](Value &VOffset, APInt &Offset) {
- if (auto PossibleOffset =
- aggregatePossibleConstantValues(&VOffset, EvalMode)) {
- Offset = *PossibleOffset;
- return true;
- }
- return false;
- };
-
- V = V->stripAndAccumulateConstantOffsets(
- DL, Offset, /* AllowNonInbounds */ true, /* AllowInvariantGroup */ true,
- /*ExternalAnalysis=*/OffsetRangeAnalysis);
- }
-
// Later we use the index type size and zero but it will match the type of the
// value that is passed to computeImpl.
IntTyBits = DL.getIndexTypeSizeInBits(V->getType());
Zero = APInt::getZero(IntTyBits);
+
OffsetSpan ORT = computeValue(V);
bool IndexTypeSizeChanged = InitialIntTyBits != IntTyBits;
@@ -900,9 +812,8 @@ OffsetSpan ObjectSizeOffsetVisitor::visitAllocaInst(AllocaInst &I) {
return OffsetSpan(Zero, align(Size, I.getAlign()));
Value *ArraySize = I.getArraySize();
- if (auto PossibleSize =
- aggregatePossibleConstantValues(ArraySize, Options.EvalMode)) {
- APInt NumElems = *PossibleSize;
+ if (const ConstantInt *C = dyn_cast<ConstantInt>(ArraySize)) {
+ APInt NumElems = C->getValue();
if (!CheckedZextOrTrunc(NumElems))
return ObjectSizeOffsetVisitor::unknown();
@@ -928,18 +839,7 @@ OffsetSpan ObjectSizeOffsetVisitor::visitArgument(Argument &A) {
}
OffsetSpan ObjectSizeOffsetVisitor::visitCallBase(CallBase &CB) {
- auto Mapper = [this](const Value *V) -> const Value * {
- if (!V->getType()->isIntegerTy())
- return V;
-
- if (auto PossibleBound =
- aggregatePossibleConstantValues(V, Options.EvalMode))
- return ConstantInt::get(V->getType(), *PossibleBound);
-
- return V;
- };
-
- if (std::optional<APInt> Size = getAllocSize(&CB, TLI, Mapper)) {
+ if (std::optional<APInt> Size = getAllocSize(&CB, TLI)) {
// Very large unsigned value cannot be represented as OffsetSpan.
if (Size->isNegative())
return ObjectSizeOffsetVisitor::unknown();
diff --git a/llvm/test/Transforms/LowerConstantIntrinsics/builtin-object-size-range.ll b/llvm/test/Transforms/LowerConstantIntrinsics/builtin-object-size-range.ll
deleted file mode 100644
index f84ebee1442893..00000000000000
--- a/llvm/test/Transforms/LowerConstantIntrinsics/builtin-object-size-range.ll
+++ /dev/null
@@ -1,109 +0,0 @@
-; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt -passes=lower-constant-intrinsics -S < %s | FileCheck %s
-
-target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
-target triple = "x86_64-unknown-linux-gnu"
-
-declare i64 @llvm.objectsize.i64.p0(ptr, i1 immarg, i1 immarg, i1 immarg)
-declare noalias ptr @malloc(i64 noundef) #0
-
-define i64 @select_alloc_size(i1 %cond) {
-; CHECK-LABEL: @select_alloc_size(
-; CHECK-NEXT: [[SIZE:%.*]] = select i1 [[COND:%.*]], i64 3, i64 4
-; CHECK-NEXT: [[PTR:%.*]] = alloca i8, i64 [[SIZE]], align 1
-; CHECK-NEXT: [[RES:%.*]] = select i1 [[COND]], i64 4, i64 3
-; CHECK-NEXT: ret i64 [[RES]]
-;
- %size = select i1 %cond, i64 3, i64 4
- %ptr = alloca i8, i64 %size
- %objsize_max = call i64 @llvm.objectsize.i64.p0(ptr %ptr, i1 false, i1 true, i1 false)
- %objsize_min = call i64 @llvm.objectsize.i64.p0(ptr %ptr, i1 true, i1 true, i1 false)
- %res = select i1 %cond, i64 %objsize_max, i64 %objsize_min
- ret i64 %res
-}
-
-define i64 @select_malloc_size(i1 %cond) {
-; CHECK-LABEL: @select_malloc_size(
-; CHECK-NEXT: [[SIZE:%.*]] = select i1 [[COND:%.*]], i64 3, i64 4
-; CHECK-NEXT: [[PTR:%.*]] = call noalias ptr @malloc(i64 noundef [[SIZE]])
-; CHECK-NEXT: [[RES:%.*]] = select i1 [[COND]], i64 4, i64 3
-; CHECK-NEXT: ret i64 [[RES]]
-;
- %size = select i1 %cond, i64 3, i64 4
- %ptr = call noalias ptr @malloc(i64 noundef %size)
- %objsize_max = call i64 @llvm.objectsize.i64.p0(ptr %ptr, i1 false, i1 true, i1 false)
- %objsize_min = call i64 @llvm.objectsize.i64.p0(ptr %ptr, i1 true, i1 true, i1 false)
- %res = select i1 %cond, i64 %objsize_max, i64 %objsize_min
- ret i64 %res
-}
-
-define i64 @select_gep_offset(i1 %cond) {
-; CHECK-LABEL: @select_gep_offset(
-; CHECK-NEXT: [[PTR:%.*]] = alloca i8, i64 10, align 1
-; CHECK-NEXT: [[OFFSET:%.*]] = select i1 [[COND:%.*]], i64 3, i64 4
-; CHECK-NEXT: [[PTR_SLIDE:%.*]] = getelementptr inbounds i8, ptr [[PTR]], i64 [[OFFSET]]
-; CHECK-NEXT: [[RES:%.*]] = select i1 [[COND]], i64 7, i64 6
-; CHECK-NEXT: ret i64 [[RES]]
-;
- %ptr = alloca i8, i64 10
- %offset = select i1 %cond, i64 3, i64 4
- %ptr.slide = getelementptr inbounds i8, ptr %ptr, i64 %offset
- %objsize_max = call i64 @llvm.objectsize.i64.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
- %objsize_min = call i64 @llvm.objectsize.i64.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
- %res = select i1 %cond, i64 %objsize_max, i64 %objsize_min
- ret i64 %res
-}
-
-define i64 @select_gep_neg_offset(i1 %c0, i1 %c1) {
-; CHECK-LABEL: @select_gep_neg_offset(
-; CHECK-NEXT: [[PTR:%.*]] = alloca i8, i64 10, align 1
-; CHECK-NEXT: [[PTR_SLIDE_1:%.*]] = getelementptr inbounds i8, ptr [[PTR]], i64 5
-; CHECK-NEXT: [[OFFSET:%.*]] = select i1 [[COND:%.*]], i64 -3, i64 -4
-; CHECK-NEXT: [[PTR_SLIDE_2:%.*]] = getelementptr inbounds i8, ptr [[PTR_SLIDE_1]], i64 [[OFFSET]]
-; CHECK-NEXT: [[RES:%.*]] = select i1 [[C1:%.*]], i64 9, i64 8
-; CHECK-NEXT: ret i64 [[RES]]
-;
- %ptr = alloca i8, i64 10
- %ptr.slide.1 = getelementptr inbounds i8, ptr %ptr, i64 5
- %offset = select i1 %c0, i64 -3, i64 -4
- %ptr.slide.2 = getelementptr inbounds i8, ptr %ptr.slide.1, i64 %offset
- %objsize_max = call i64 @llvm.objectsize.i64.p0(ptr %ptr.slide.2, i1 false, i1 true, i1 false)
- %objsize_min = call i64 @llvm.objectsize.i64.p0(ptr %ptr.slide.2, i1 true, i1 true, i1 false)
- %res = select i1 %c1, i64 %objsize_max, i64 %objsize_min
- ret i64 %res
-}
-
-define i64 @select_neg_oob_offset(i1 %c0, i1 %c1) {
-; CHECK-LABEL: @select_neg_oob_offset(
-; CHECK-NEXT: [[PTR:%.*]] = alloca i8, i64 10, align 1
-; CHECK-NEXT: [[OFFSET:%.*]] = select i1 [[C0:%.*]], i64 -3, i64 -4
-; CHECK-NEXT: [[PTR_SLIDE:%.*]] = getelementptr inbounds i8, ptr [[PTR]], i64 [[OFFSET]]
-; CHECK-NEXT: ret i64 0
-;
- %ptr = alloca i8, i64 10
- %offset = select i1 %c0, i64 -3, i64 -4
- %ptr.slide = getelementptr inbounds i8, ptr %ptr, i64 %offset
- %objsize_max = call i64 @llvm.objectsize.i64.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
- %objsize_min = call i64 @llvm.objectsize.i64.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
- %res = select i1 %c1, i64 %objsize_max, i64 %objsize_min
- ret i64 %res
-}
-
-define i64 @select_gep_offsets(i1 %cond) {
-; CHECK-LABEL: @select_gep_offsets(
-; CHECK-NEXT: [[PTR:%.*]] = alloca [10 x i8], i64 2, align 1
-; CHECK-NEXT: [[OFFSET:%.*]] = select i1 [[COND:%.*]], i32 0, i32 1
-; CHECK-NEXT: [[PTR_SLIDE:%.*]] = getelementptr inbounds [10 x i8], ptr [[PTR]], i32 [[OFFSET]], i32 5
-; CHECK-NEXT: [[RES:%.*]] = select i1 [[COND]], i64 15, i64 5
-; CHECK-NEXT: ret i64 [[RES]]
-;
- %ptr = alloca [10 x i8], i64 2
- %offset = select i1 %cond, i32 0, i32 1
- %ptr.slide = getelementptr inbounds [10 x i8], ptr %ptr, i32 %offset, i32 5
- %objsize_max = call i64 @llvm.objectsize.i64.p0(ptr %ptr.slide, i1 false, i1 true, i1 false)
- %objsize_min = call i64 @llvm.objectsize.i64.p0(ptr %ptr.slide, i1 true, i1 true, i1 false)
- %res = select i1 %cond, i64 %objsize_max, i64 %objsize_min
- ret i64 %res
-}
-
-attributes #0 = { nounwind allocsize(0) }
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