``@llvm.experimental.guard`` cannot be invoked.
+'``llvm.load.relative``' Intrinsic
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Syntax:
+"""""""
+
+::
+
+ declare i8* @llvm.load.relative.iN(i8* %ptr, iN %offset) argmemonly nounwind readonly
+
+Overview:
+"""""""""
+
+This intrinsic loads a 32-bit value from the address ``%ptr + %offset``,
+adds ``%ptr`` to that value and returns it. The constant folder specifically
+recognizes the form of this intrinsic and the constant initializers it may
+load from; if a loaded constant initializer is known to have the form
+``i32 trunc(x - %ptr)``, the intrinsic call is folded to ``x``.
+
+LLVM provides that the calculation of such a constant initializer will
+not overflow at link time under the medium code model if ``x`` is an
+``unnamed_addr`` function. However, it does not provide this guarantee for
+a constant initializer folded into a function body. This intrinsic can be
+used to avoid the possibility of overflows when loading from such a constant.
+
Stack Map Intrinsics
--------------------
///
ModulePass *createLowerEmuTLSPass(const TargetMachine *TM);
+ /// This pass lowers the @llvm.load.relative intrinsic to instructions.
+ /// This is unsafe to do earlier because a pass may combine the constant
+ /// initializer into the load, which may result in an overflowing evaluation.
+ ModulePass *createPreISelIntrinsicLoweringPass();
+
/// GlobalMerge - This pass merges internal (by default) globals into structs
/// to enable reuse of a base pointer by indexed addressing modes.
/// It can also be configured to focus on size optimizations only.
def int_bitset_test : Intrinsic<[llvm_i1_ty], [llvm_ptr_ty, llvm_metadata_ty],
[IntrNoMem]>;
+def int_load_relative: Intrinsic<[llvm_ptr_ty], [llvm_ptr_ty, llvm_anyint_ty],
+ [IntrReadMem, IntrArgMemOnly]>;
+
//===----------------------------------------------------------------------===//
// Target-specific intrinsics
//===----------------------------------------------------------------------===//
void initializePostRAHazardRecognizerPass(PassRegistry&);
void initializePostRASchedulerPass(PassRegistry&);
void initializePostMachineSchedulerPass(PassRegistry&);
+void initializePreISelIntrinsicLoweringPass(PassRegistry&);
void initializePrintFunctionPassWrapperPass(PassRegistry&);
void initializePrintModulePassWrapperPass(PassRegistry&);
void initializePrintBasicBlockPassPass(PassRegistry&);
default:
return Base::visitCallSite(CS);
+ case Intrinsic::load_relative:
+ // This is normally lowered to 4 LLVM instructions.
+ Cost += 3 * InlineConstants::InstrCost;
+ return false;
+
case Intrinsic::memset:
case Intrinsic::memcpy:
case Intrinsic::memmove:
}
}
+static Value *SimplifyRelativeLoad(Constant *Ptr, Constant *Offset,
+ const DataLayout &DL) {
+ GlobalValue *PtrSym;
+ APInt PtrOffset;
+ if (!IsConstantOffsetFromGlobal(Ptr, PtrSym, PtrOffset, DL))
+ return nullptr;
+
+ Type *Int8PtrTy = Type::getInt8PtrTy(Ptr->getContext());
+ Type *Int32Ty = Type::getInt32Ty(Ptr->getContext());
+ Type *Int32PtrTy = Int32Ty->getPointerTo();
+ Type *Int64Ty = Type::getInt64Ty(Ptr->getContext());
+
+ auto *OffsetConstInt = dyn_cast<ConstantInt>(Offset);
+ if (!OffsetConstInt || OffsetConstInt->getType()->getBitWidth() > 64)
+ return nullptr;
+
+ uint64_t OffsetInt = OffsetConstInt->getSExtValue();
+ if (OffsetInt % 4 != 0)
+ return nullptr;
+
+ Constant *C = ConstantExpr::getGetElementPtr(
+ Int32Ty, ConstantExpr::getBitCast(Ptr, Int32PtrTy),
+ ConstantInt::get(Int64Ty, OffsetInt / 4));
+ Constant *Loaded = ConstantFoldLoadFromConstPtr(C, Int32Ty, DL);
+ if (!Loaded)
+ return nullptr;
+
+ auto *LoadedCE = dyn_cast<ConstantExpr>(Loaded);
+ if (!LoadedCE)
+ return nullptr;
+
+ if (LoadedCE->getOpcode() == Instruction::Trunc) {
+ LoadedCE = dyn_cast<ConstantExpr>(LoadedCE->getOperand(0));
+ if (!LoadedCE)
+ return nullptr;
+ }
+
+ if (LoadedCE->getOpcode() != Instruction::Sub)
+ return nullptr;
+
+ auto *LoadedLHS = dyn_cast<ConstantExpr>(LoadedCE->getOperand(0));
+ if (!LoadedLHS || LoadedLHS->getOpcode() != Instruction::PtrToInt)
+ return nullptr;
+ auto *LoadedLHSPtr = LoadedLHS->getOperand(0);
+
+ Constant *LoadedRHS = LoadedCE->getOperand(1);
+ GlobalValue *LoadedRHSSym;
+ APInt LoadedRHSOffset;
+ if (!IsConstantOffsetFromGlobal(LoadedRHS, LoadedRHSSym, LoadedRHSOffset,
+ DL) ||
+ PtrSym != LoadedRHSSym || PtrOffset != LoadedRHSOffset)
+ return nullptr;
+
+ return ConstantExpr::getBitCast(LoadedLHSPtr, Int8PtrTy);
+}
+
template <typename IterTy>
static Value *SimplifyIntrinsic(Function *F, IterTy ArgBegin, IterTy ArgEnd,
const Query &Q, unsigned MaxRecurse) {
if (match(RHS, m_Undef()))
return Constant::getNullValue(ReturnType);
}
+
+ if (IID == Intrinsic::load_relative && isa<Constant>(LHS) &&
+ isa<Constant>(RHS))
+ return SimplifyRelativeLoad(cast<Constant>(LHS), cast<Constant>(RHS),
+ Q.DL);
}
// Perform idempotent optimizations
PHIEliminationUtils.cpp
PostRAHazardRecognizer.cpp
PostRASchedulerList.cpp
+ PreISelIntrinsicLowering.cpp
ProcessImplicitDefs.cpp
PrologEpilogInserter.cpp
PseudoSourceValue.cpp
initializePostMachineSchedulerPass(Registry);
initializePostRAHazardRecognizerPass(Registry);
initializePostRASchedulerPass(Registry);
+ initializePreISelIntrinsicLoweringPass(Registry);
initializeProcessImplicitDefsPass(Registry);
initializeRegisterCoalescerPass(Registry);
initializeShrinkWrapPass(Registry);
if (TM->Options.EmulatedTLS)
PM.add(createLowerEmuTLSPass(TM));
+ PM.add(createPreISelIntrinsicLoweringPass());
+
// Add internal analysis passes from the target machine.
PM.add(createTargetTransformInfoWrapperPass(TM->getTargetIRAnalysis()));
--- /dev/null
+//===-- PreISelIntrinsicLowering.cpp - Pre-ISel intrinsic lowering pass ---===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass implements IR lowering for the llvm.load.relative intrinsic.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/IR/Function.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/Instructions.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/Module.h"
+#include "llvm/Pass.h"
+
+using namespace llvm;
+
+namespace {
+
+bool lowerLoadRelative(Function &F) {
+ if (F.use_empty())
+ return false;
+
+ bool Changed = false;
+ Type *Int32Ty = Type::getInt32Ty(F.getContext());
+ Type *Int32PtrTy = Int32Ty->getPointerTo();
+ Type *Int8Ty = Type::getInt8Ty(F.getContext());
+
+ for (auto I = F.use_begin(), E = F.use_end(); I != E;) {
+ auto CI = dyn_cast<CallInst>(I->getUser());
+ ++I;
+ if (!CI || CI->getCalledValue() != &F)
+ continue;
+
+ IRBuilder<> B(CI);
+ Value *OffsetPtr =
+ B.CreateGEP(Int8Ty, CI->getArgOperand(0), CI->getArgOperand(1));
+ Value *OffsetPtrI32 = B.CreateBitCast(OffsetPtr, Int32PtrTy);
+ Value *OffsetI32 = B.CreateAlignedLoad(OffsetPtrI32, 4);
+
+ Value *ResultPtr = B.CreateGEP(Int8Ty, CI->getArgOperand(0), OffsetI32);
+
+ CI->replaceAllUsesWith(ResultPtr);
+ CI->eraseFromParent();
+ Changed = true;
+ }
+
+ return Changed;
+}
+
+bool lowerIntrinsics(Module &M) {
+ bool Changed = false;
+ for (Function &F : M) {
+ if (F.getName().startswith("llvm.load.relative."))
+ Changed |= lowerLoadRelative(F);
+ }
+ return Changed;
+}
+
+class PreISelIntrinsicLowering : public ModulePass {
+public:
+ static char ID;
+ PreISelIntrinsicLowering() : ModulePass(ID) {}
+
+ bool runOnModule(Module &M) {
+ return lowerIntrinsics(M);
+ }
+};
+
+char PreISelIntrinsicLowering::ID;
+
+}
+
+INITIALIZE_PASS(PreISelIntrinsicLowering, "pre-isel-intrinsic-lowering",
+ "Pre-ISel Intrinsic Lowering", false, false)
+
+ModulePass *llvm::createPreISelIntrinsicLoweringPass() {
+ return new PreISelIntrinsicLowering;
+}
; STOP-NEXT: Machine Function Analysis
; STOP-NEXT: MIR Printing Pass
-; START: -machine-branch-prob -gc-lowering
+; START: -machine-branch-prob -pre-isel-intrinsic-lowering
; START: FunctionPass Manager
; START-NEXT: Lower Garbage Collection Instructions
--- /dev/null
+; RUN: opt < %s -instsimplify -S | FileCheck %s
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32-n8:16:32"
+target triple = "i386-unknown-linux-gnu"
+
+@a = external global i8
+
+@c1 = constant [3 x i32] [i32 0, i32 0,
+i32 sub (i32 ptrtoint (i8* @a to i32), i32 ptrtoint (i32* getelementptr ([3 x i32], [3 x i32]* @c1, i32 0, i32 2) to i32))
+]
+
+; CHECK: @f1
+define i8* @f1() {
+ ; CHECK: ret i8* @a
+ %l = call i8* @llvm.load.relative.i32(i8* bitcast (i32* getelementptr ([3 x i32], [3 x i32]* @c1, i32 0, i32 2) to i8*), i32 0)
+ ret i8* %l
+}
+
+declare i8* @llvm.load.relative.i32(i8*, i32)
--- /dev/null
+; RUN: opt < %s -instsimplify -S | FileCheck %s
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-linux-gnu"
+
+@a = external global i8
+@b = external global i8
+
+@c1 = constant i32 trunc (i64 sub (i64 ptrtoint (i8* @a to i64), i64 ptrtoint (i32* @c1 to i64)) to i32)
+@c2 = constant [7 x i32] [i32 0, i32 0,
+i32 trunc (i64 sub (i64 ptrtoint (i8* @a to i64), i64 ptrtoint (i32* getelementptr ([7 x i32], [7 x i32]* @c2, i32 0, i32 2) to i64)) to i32),
+i32 trunc (i64 sub (i64 ptrtoint (i8* @b to i64), i64 ptrtoint (i32* getelementptr ([7 x i32], [7 x i32]* @c2, i32 0, i32 2) to i64)) to i32),
+i32 trunc (i64 add (i64 ptrtoint (i8* @b to i64), i64 ptrtoint (i32* getelementptr ([7 x i32], [7 x i32]* @c2, i32 0, i32 2) to i64)) to i32),
+i32 trunc (i64 sub (i64 ptrtoint (i8* @b to i64), i64 1) to i32),
+i32 trunc (i64 sub (i64 0, i64 ptrtoint (i32* getelementptr ([7 x i32], [7 x i32]* @c2, i32 0, i32 2) to i64)) to i32)
+]
+
+; CHECK: @f1
+define i8* @f1() {
+ ; CHECK: ret i8* @a
+ %l = call i8* @llvm.load.relative.i32(i8* bitcast (i32* @c1 to i8*), i32 0)
+ ret i8* %l
+}
+
+; CHECK: @f2
+define i8* @f2() {
+ ; CHECK: ret i8* @a
+ %l = call i8* @llvm.load.relative.i32(i8* bitcast (i32* getelementptr ([7 x i32], [7 x i32]* @c2, i64 0, i64 2) to i8*), i32 0)
+ ret i8* %l
+}
+
+; CHECK: @f3
+define i8* @f3() {
+ ; CHECK: ret i8* @b
+ %l = call i8* @llvm.load.relative.i64(i8* bitcast (i32* getelementptr ([7 x i32], [7 x i32]* @c2, i64 0, i64 2) to i8*), i64 4)
+ ret i8* %l
+}
+
+; CHECK: @f4
+define i8* @f4() {
+ ; CHECK: ret i8* %
+ %l = call i8* @llvm.load.relative.i32(i8* bitcast (i32* getelementptr ([7 x i32], [7 x i32]* @c2, i64 0, i64 2) to i8*), i32 1)
+ ret i8* %l
+}
+
+; CHECK: @f5
+define i8* @f5() {
+ ; CHECK: ret i8* %
+ %l = call i8* @llvm.load.relative.i32(i8* zeroinitializer, i32 0)
+ ret i8* %l
+}
+
+; CHECK: @f6
+define i8* @f6() {
+ ; CHECK: ret i8* %
+ %l = call i8* @llvm.load.relative.i32(i8* bitcast (i32* getelementptr ([7 x i32], [7 x i32]* @c2, i64 0, i64 2) to i8*), i32 8)
+ ret i8* %l
+}
+
+; CHECK: @f7
+define i8* @f7() {
+ ; CHECK: ret i8* %
+ %l = call i8* @llvm.load.relative.i32(i8* bitcast (i32* getelementptr ([7 x i32], [7 x i32]* @c2, i64 0, i64 2) to i8*), i32 12)
+ ret i8* %l
+}
+
+; CHECK: @f8
+define i8* @f8() {
+ ; CHECK: ret i8* %
+ %l = call i8* @llvm.load.relative.i32(i8* bitcast (i32* getelementptr ([7 x i32], [7 x i32]* @c2, i64 0, i64 2) to i8*), i32 16)
+ ret i8* %l
+}
+
+declare i8* @llvm.load.relative.i32(i8*, i32)
+declare i8* @llvm.load.relative.i64(i8*, i64)
--- /dev/null
+; RUN: opt -pre-isel-intrinsic-lowering -S -o - %s | FileCheck %s
+
+; CHECK: define i8* @foo32(i8* [[P:%.*]], i32 [[O:%.*]])
+define i8* @foo32(i8* %p, i32 %o) {
+ ; CHECK: [[OP:%.*]] = getelementptr i8, i8* [[P]], i32 [[O]]
+ ; CHECK: [[OPI32:%.*]] = bitcast i8* [[OP]] to i32*
+ ; CHECK: [[OI32:%.*]] = load i32, i32* [[OPI32]], align 4
+ ; CHECK: [[R:%.*]] = getelementptr i8, i8* [[P]], i32 [[OI32]]
+ ; CHECK: ret i8* [[R]]
+ %l = call i8* @llvm.load.relative.i32(i8* %p, i32 %o)
+ ret i8* %l
+}
+
+; CHECK: define i8* @foo64(i8* [[P:%.*]], i64 [[O:%.*]])
+define i8* @foo64(i8* %p, i64 %o) {
+ ; CHECK: [[OP:%.*]] = getelementptr i8, i8* [[P]], i64 [[O]]
+ ; CHECK: [[OPI32:%.*]] = bitcast i8* [[OP]] to i32*
+ ; CHECK: [[OI32:%.*]] = load i32, i32* [[OPI32]], align 4
+ ; CHECK: [[R:%.*]] = getelementptr i8, i8* [[P]], i32 [[OI32]]
+ ; CHECK: ret i8* [[R]]
+ %l = call i8* @llvm.load.relative.i64(i8* %p, i64 %o)
+ ret i8* %l
+}
+
+declare i8* @llvm.load.relative.i32(i8*, i32)
+declare i8* @llvm.load.relative.i64(i8*, i64)
initializeDwarfEHPreparePass(Registry);
initializeSafeStackPass(Registry);
initializeSjLjEHPreparePass(Registry);
+ initializePreISelIntrinsicLoweringPass(Registry);
#ifdef LINK_POLLY_INTO_TOOLS
polly::initializePollyPasses(Registry);