Move getOrEnforceKnownAlignment out of instcombine into Transforms/Utils.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122554 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/InstCombine/InstCombineCalls.cpp b/lib/Transforms/InstCombine/InstCombineCalls.cpp
index f872a9b..35f9791 100644
--- a/lib/Transforms/InstCombine/InstCombineCalls.cpp
+++ b/lib/Transforms/InstCombine/InstCombineCalls.cpp
@@ -17,6 +17,7 @@
#include "llvm/Target/TargetData.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/Transforms/Utils/BuildLibCalls.h"
+#include "llvm/Transforms/Utils/Local.h"
using namespace llvm;
/// getPromotedType - Return the specified type promoted as it would be to pass
@@ -29,100 +30,10 @@
return Ty;
}
-/// EnforceKnownAlignment - If the specified pointer points to an object that
-/// we control, modify the object's alignment to PrefAlign. This isn't
-/// often possible though. If alignment is important, a more reliable approach
-/// is to simply align all global variables and allocation instructions to
-/// their preferred alignment from the beginning.
-///
-static unsigned EnforceKnownAlignment(Value *V,
- unsigned Align, unsigned PrefAlign) {
-
- User *U = dyn_cast<User>(V);
- if (!U) return Align;
-
- switch (Operator::getOpcode(U)) {
- default: break;
- case Instruction::BitCast:
- return EnforceKnownAlignment(U->getOperand(0), Align, PrefAlign);
- case Instruction::GetElementPtr: {
- // If all indexes are zero, it is just the alignment of the base pointer.
- bool AllZeroOperands = true;
- for (User::op_iterator i = U->op_begin() + 1, e = U->op_end(); i != e; ++i)
- if (!isa<Constant>(*i) ||
- !cast<Constant>(*i)->isNullValue()) {
- AllZeroOperands = false;
- break;
- }
-
- if (AllZeroOperands) {
- // Treat this like a bitcast.
- return EnforceKnownAlignment(U->getOperand(0), Align, PrefAlign);
- }
- return Align;
- }
- case Instruction::Alloca: {
- AllocaInst *AI = cast<AllocaInst>(V);
- // If there is a requested alignment and if this is an alloca, round up.
- if (AI->getAlignment() >= PrefAlign)
- return AI->getAlignment();
- AI->setAlignment(PrefAlign);
- return PrefAlign;
- }
- }
-
- if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
- // If there is a large requested alignment and we can, bump up the alignment
- // of the global.
- if (GV->isDeclaration()) return Align;
-
- if (GV->getAlignment() >= PrefAlign)
- return GV->getAlignment();
- // We can only increase the alignment of the global if it has no alignment
- // specified or if it is not assigned a section. If it is assigned a
- // section, the global could be densely packed with other objects in the
- // section, increasing the alignment could cause padding issues.
- if (!GV->hasSection() || GV->getAlignment() == 0)
- GV->setAlignment(PrefAlign);
- return GV->getAlignment();
- }
-
- return Align;
-}
-
-/// GetOrEnforceKnownAlignment - If the specified pointer has an alignment that
-/// we can determine, return it, otherwise return 0. If PrefAlign is specified,
-/// and it is more than the alignment of the ultimate object, see if we can
-/// increase the alignment of the ultimate object, making this check succeed.
-unsigned InstCombiner::GetOrEnforceKnownAlignment(Value *V,
- unsigned PrefAlign) {
- assert(V->getType()->isPointerTy() &&
- "GetOrEnforceKnownAlignment expects a pointer!");
- unsigned BitWidth = TD ? TD->getPointerSizeInBits() : 64;
- APInt Mask = APInt::getAllOnesValue(BitWidth);
- APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
- ComputeMaskedBits(V, Mask, KnownZero, KnownOne);
- unsigned TrailZ = KnownZero.countTrailingOnes();
-
- // Avoid trouble with rediculously large TrailZ values, such as
- // those computed from a null pointer.
- TrailZ = std::min(TrailZ, unsigned(sizeof(unsigned) * CHAR_BIT - 1));
-
- unsigned Align = 1u << std::min(BitWidth - 1, TrailZ);
-
- // LLVM doesn't support alignments larger than this currently.
- Align = std::min(Align, +Value::MaximumAlignment);
-
- if (PrefAlign > Align)
- Align = EnforceKnownAlignment(V, Align, PrefAlign);
-
- // We don't need to make any adjustment.
- return Align;
-}
Instruction *InstCombiner::SimplifyMemTransfer(MemIntrinsic *MI) {
- unsigned DstAlign = GetOrEnforceKnownAlignment(MI->getArgOperand(0));
- unsigned SrcAlign = GetOrEnforceKnownAlignment(MI->getArgOperand(1));
+ unsigned DstAlign = getKnownAlignment(MI->getArgOperand(0), TD);
+ unsigned SrcAlign = getKnownAlignment(MI->getArgOperand(1), TD);
unsigned MinAlign = std::min(DstAlign, SrcAlign);
unsigned CopyAlign = MI->getAlignment();
@@ -211,7 +122,7 @@
}
Instruction *InstCombiner::SimplifyMemSet(MemSetInst *MI) {
- unsigned Alignment = GetOrEnforceKnownAlignment(MI->getDest());
+ unsigned Alignment = getKnownAlignment(MI->getDest());
if (MI->getAlignment() < Alignment) {
MI->setAlignment(ConstantInt::get(MI->getAlignmentType(),
Alignment, false));
@@ -611,7 +522,7 @@
case Intrinsic::x86_sse2_loadu_dq:
// Turn PPC lvx -> load if the pointer is known aligned.
// Turn X86 loadups -> load if the pointer is known aligned.
- if (GetOrEnforceKnownAlignment(II->getArgOperand(0), 16) >= 16) {
+ if (getOrEnforceKnownAlignment(II->getArgOperand(0), 16, TD) >= 16) {
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0),
PointerType::getUnqual(II->getType()));
return new LoadInst(Ptr);
@@ -620,7 +531,7 @@
case Intrinsic::ppc_altivec_stvx:
case Intrinsic::ppc_altivec_stvxl:
// Turn stvx -> store if the pointer is known aligned.
- if (GetOrEnforceKnownAlignment(II->getArgOperand(1), 16) >= 16) {
+ if (getOrEnforceKnownAlignment(II->getArgOperand(1), 16, TD) >= 16) {
const Type *OpPtrTy =
PointerType::getUnqual(II->getArgOperand(0)->getType());
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(1), OpPtrTy);
@@ -631,7 +542,7 @@
case Intrinsic::x86_sse2_storeu_pd:
case Intrinsic::x86_sse2_storeu_dq:
// Turn X86 storeu -> store if the pointer is known aligned.
- if (GetOrEnforceKnownAlignment(II->getArgOperand(0), 16) >= 16) {
+ if (getOrEnforceKnownAlignment(II->getArgOperand(0), 16, TD) >= 16) {
const Type *OpPtrTy =
PointerType::getUnqual(II->getArgOperand(1)->getType());
Value *Ptr = Builder->CreateBitCast(II->getArgOperand(0), OpPtrTy);
@@ -718,7 +629,7 @@
case Intrinsic::arm_neon_vst2lane:
case Intrinsic::arm_neon_vst3lane:
case Intrinsic::arm_neon_vst4lane: {
- unsigned MemAlign = GetOrEnforceKnownAlignment(II->getArgOperand(0));
+ unsigned MemAlign = getKnownAlignment(II->getArgOperand(0));
unsigned AlignArg = II->getNumArgOperands() - 1;
ConstantInt *IntrAlign = dyn_cast<ConstantInt>(II->getArgOperand(AlignArg));
if (IntrAlign && IntrAlign->getZExtValue() < MemAlign) {