Add a quick and dirty "loop aligner pass". x86 uses it to align its loops to 16-byte boundaries.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47703 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/AsmPrinter.cpp b/lib/CodeGen/AsmPrinter.cpp
index 7a01a87..9cdae34 100644
--- a/lib/CodeGen/AsmPrinter.cpp
+++ b/lib/CodeGen/AsmPrinter.cpp
@@ -39,7 +39,8 @@
char AsmPrinter::ID = 0;
AsmPrinter::AsmPrinter(std::ostream &o, TargetMachine &tm,
const TargetAsmInfo *T)
- : MachineFunctionPass((intptr_t)&ID), FunctionNumber(0), O(o), TM(tm), TAI(T)
+ : MachineFunctionPass((intptr_t)&ID), FunctionNumber(0), O(o), TM(tm), TAI(T),
+ IsInTextSection(false)
{}
std::string AsmPrinter::getSectionForFunction(const Function &F) const {
@@ -69,6 +70,8 @@
if (!CurrentSection.empty())
O << CurrentSection << TAI->getTextSectionStartSuffix() << '\n';
+
+ IsInTextSection = true;
}
/// SwitchToDataSection - Switch to the specified data section of the executable
@@ -93,6 +96,8 @@
if (!CurrentSection.empty())
O << CurrentSection << TAI->getDataSectionStartSuffix() << '\n';
+
+ IsInTextSection = false;
}
@@ -344,7 +349,7 @@
O << TAI->getPrivateGlobalPrefix() << getFunctionNumber()
<< '_' << uid << "_set_" << MBB->getNumber();
} else {
- printBasicBlockLabel(MBB, false, false);
+ printBasicBlockLabel(MBB, false, false, false);
// If the arch uses custom Jump Table directives, don't calc relative to
// JT
if (!HadJTEntryDirective)
@@ -352,7 +357,7 @@
<< getFunctionNumber() << '_' << uid;
}
} else {
- printBasicBlockLabel(MBB, false, false);
+ printBasicBlockLabel(MBB, false, false, false);
}
}
@@ -679,8 +684,7 @@
// Align = std::max(Align, ForcedAlignBits);
//
void AsmPrinter::EmitAlignment(unsigned NumBits, const GlobalValue *GV,
- unsigned ForcedAlignBits, bool UseFillExpr,
- unsigned FillValue) const {
+ unsigned ForcedAlignBits) const {
if (GV && GV->getAlignment())
NumBits = Log2_32(GV->getAlignment());
NumBits = std::max(NumBits, ForcedAlignBits);
@@ -688,6 +692,9 @@
if (NumBits == 0) return; // No need to emit alignment.
if (TAI->getAlignmentIsInBytes()) NumBits = 1 << NumBits;
O << TAI->getAlignDirective() << NumBits;
+
+ unsigned FillValue = TAI->getTextAlignFillValue();
+ bool UseFillExpr = IsInTextSection && FillValue;
if (UseFillExpr) O << ",0x" << std::hex << FillValue << std::dec;
O << "\n";
}
@@ -1252,7 +1259,7 @@
if (Modifier[0]=='l') // labels are target independent
printBasicBlockLabel(MI->getOperand(OpNo).getMBB(),
- false, false);
+ false, false, false);
else {
AsmPrinter *AP = const_cast<AsmPrinter*>(this);
if ((OpFlags & 7) == 4 /*ADDR MODE*/) {
@@ -1318,8 +1325,15 @@
/// printBasicBlockLabel - This method prints the label for the specified
/// MachineBasicBlock
void AsmPrinter::printBasicBlockLabel(const MachineBasicBlock *MBB,
+ bool printAlign,
bool printColon,
bool printComment) const {
+ if (printAlign) {
+ unsigned Align = MBB->getAlignment();
+ if (Align)
+ EmitAlignment(Log2_32(Align));
+ }
+
O << TAI->getPrivateGlobalPrefix() << "BB" << getFunctionNumber() << "_"
<< MBB->getNumber();
if (printColon)
@@ -1338,7 +1352,7 @@
O << TAI->getSetDirective() << ' ' << TAI->getPrivateGlobalPrefix()
<< getFunctionNumber() << '_' << uid << "_set_" << MBB->getNumber() << ',';
- printBasicBlockLabel(MBB, false, false);
+ printBasicBlockLabel(MBB, false, false, false);
O << '-' << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
<< '_' << uid << '\n';
}
@@ -1351,7 +1365,7 @@
O << TAI->getSetDirective() << ' ' << TAI->getPrivateGlobalPrefix()
<< getFunctionNumber() << '_' << uid << '_' << uid2
<< "_set_" << MBB->getNumber() << ',';
- printBasicBlockLabel(MBB, false, false);
+ printBasicBlockLabel(MBB, false, false, false);
O << '-' << TAI->getPrivateGlobalPrefix() << "JTI" << getFunctionNumber()
<< '_' << uid << '_' << uid2 << '\n';
}
diff --git a/lib/CodeGen/BranchFolding.cpp b/lib/CodeGen/BranchFolding.cpp
index 2d7836f..d9874b5 100644
--- a/lib/CodeGen/BranchFolding.cpp
+++ b/lib/CodeGen/BranchFolding.cpp
@@ -44,7 +44,7 @@
cl::desc("Max number of predecessors to consider tail merging"),
cl::init(100), cl::Hidden);
- struct BranchFolder : public MachineFunctionPass {
+ struct VISIBILITY_HIDDEN BranchFolder : public MachineFunctionPass {
static char ID;
explicit BranchFolder(bool defaultEnableTailMerge) :
MachineFunctionPass((intptr_t)&ID) {
diff --git a/lib/CodeGen/IfConversion.cpp b/lib/CodeGen/IfConversion.cpp
index 7d7f33e..a77ccb7 100644
--- a/lib/CodeGen/IfConversion.cpp
+++ b/lib/CodeGen/IfConversion.cpp
@@ -56,7 +56,7 @@
STATISTIC(NumDupBBs, "Number of duplicated blocks");
namespace {
- class IfConverter : public MachineFunctionPass {
+ class VISIBILITY_HIDDEN IfConverter : public MachineFunctionPass {
enum IfcvtKind {
ICNotClassfied, // BB data valid, but not classified.
ICSimpleFalse, // Same as ICSimple, but on the false path.
diff --git a/lib/CodeGen/LoopAligner.cpp b/lib/CodeGen/LoopAligner.cpp
new file mode 100644
index 0000000..a40bb50
--- /dev/null
+++ b/lib/CodeGen/LoopAligner.cpp
@@ -0,0 +1,65 @@
+//===-- LoopAligner.cpp - Loop aligner pass. ------------------------------===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the pass that align loop headers to target specific
+// alignment boundary.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "loopalign"
+#include "llvm/CodeGen/MachineLoopInfo.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/Target/TargetLowering.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Support/Compiler.h"
+#include "llvm/Support/Debug.h"
+using namespace llvm;
+
+namespace {
+ class LoopAligner : public MachineFunctionPass {
+ const TargetLowering *TLI;
+
+ public:
+ static char ID;
+ LoopAligner() : MachineFunctionPass((intptr_t)&ID) {}
+
+ virtual bool runOnMachineFunction(MachineFunction &MF);
+ virtual const char *getPassName() const { return "Loop aligner"; }
+
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addRequired<MachineLoopInfo>();
+ AU.addPreserved<MachineLoopInfo>();
+ MachineFunctionPass::getAnalysisUsage(AU);
+ }
+ };
+
+ char LoopAligner::ID = 0;
+} // end anonymous namespace
+
+FunctionPass *llvm::createLoopAlignerPass() { return new LoopAligner(); }
+
+bool LoopAligner::runOnMachineFunction(MachineFunction &MF) {
+ const MachineLoopInfo *MLI = &getAnalysis<MachineLoopInfo>();
+
+ if (MLI->begin() == MLI->end())
+ return false; // No loops.
+
+ unsigned Align = MF.getTarget().getTargetLowering()->getPrefLoopAlignment();
+ if (!Align)
+ return false; // Don't care about loop alignment.
+
+ for (MachineFunction::iterator I = MF.begin(), E = MF.end(); I != E; ++I) {
+ MachineBasicBlock *MBB = I;
+ if (MLI->isLoopHeader(MBB))
+ MBB->setAlignment(Align);
+ }
+
+ return true;
+}
diff --git a/lib/CodeGen/MachineBasicBlock.cpp b/lib/CodeGen/MachineBasicBlock.cpp
index dc6a618..af91a2f 100644
--- a/lib/CodeGen/MachineBasicBlock.cpp
+++ b/lib/CodeGen/MachineBasicBlock.cpp
@@ -166,6 +166,7 @@
if (LBB) OS << LBB->getName() << ": ";
OS << (const void*)this
<< ", LLVM BB @" << (const void*) LBB << ", ID#" << getNumber();
+ if (Alignment) OS << ", Alignment " << Alignment;
if (isLandingPad()) OS << ", EH LANDING PAD";
OS << ":\n";
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index ba5a34b..ff5289e 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -206,6 +206,8 @@
JumpBufSize = 0;
JumpBufAlignment = 0;
IfCvtBlockSizeLimit = 2;
+ IfCvtDupBlockSizeLimit = 0;
+ PrefLoopAlignment = 0;
InitLibcallNames(LibcallRoutineNames);
InitCmpLibcallCCs(CmpLibcallCCs);