mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-09-30 04:56:49 +00:00
3666e7f4c1
This adds an immutable pass, AssumptionTracker, which keeps a cache of @llvm.assume call instructions within a module. It uses callback value handles to keep stale functions and intrinsics out of the map, and it relies on any code that creates new @llvm.assume calls to notify it of the new instructions. The benefit is that code needing to find @llvm.assume intrinsics can do so directly, without scanning the function, thus allowing the cost of @llvm.assume handling to be negligible when none are present. The current design is intended to be lightweight. We don't keep track of anything until we need a list of assumptions in some function. The first time this happens, we scan the function. After that, we add/remove @llvm.assume calls from the cache in response to registration calls and ValueHandle callbacks. There are no new direct test cases for this pass, but because it calls it validation function upon module finalization, we'll pick up detectable inconsistencies from the other tests that touch @llvm.assume calls. This pass will be used by follow-up commits that make use of @llvm.assume. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@217334 91177308-0d34-0410-b5e6-96231b3b80d8
118 lines
4.0 KiB
C++
118 lines
4.0 KiB
C++
//===- InlineAlways.cpp - Code to inline always_inline functions ----------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements a custom inliner that handles only functions that
|
|
// are marked as "always inline".
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/Transforms/IPO.h"
|
|
#include "llvm/ADT/SmallPtrSet.h"
|
|
#include "llvm/Analysis/AliasAnalysis.h"
|
|
#include "llvm/Analysis/AssumptionTracker.h"
|
|
#include "llvm/Analysis/CallGraph.h"
|
|
#include "llvm/Analysis/InlineCost.h"
|
|
#include "llvm/IR/CallSite.h"
|
|
#include "llvm/IR/CallingConv.h"
|
|
#include "llvm/IR/DataLayout.h"
|
|
#include "llvm/IR/Instructions.h"
|
|
#include "llvm/IR/IntrinsicInst.h"
|
|
#include "llvm/IR/Module.h"
|
|
#include "llvm/IR/Type.h"
|
|
#include "llvm/Transforms/IPO/InlinerPass.h"
|
|
|
|
using namespace llvm;
|
|
|
|
#define DEBUG_TYPE "inline"
|
|
|
|
namespace {
|
|
|
|
/// \brief Inliner pass which only handles "always inline" functions.
|
|
class AlwaysInliner : public Inliner {
|
|
InlineCostAnalysis *ICA;
|
|
|
|
public:
|
|
// Use extremely low threshold.
|
|
AlwaysInliner() : Inliner(ID, -2000000000, /*InsertLifetime*/ true),
|
|
ICA(nullptr) {
|
|
initializeAlwaysInlinerPass(*PassRegistry::getPassRegistry());
|
|
}
|
|
|
|
AlwaysInliner(bool InsertLifetime)
|
|
: Inliner(ID, -2000000000, InsertLifetime), ICA(nullptr) {
|
|
initializeAlwaysInlinerPass(*PassRegistry::getPassRegistry());
|
|
}
|
|
|
|
static char ID; // Pass identification, replacement for typeid
|
|
|
|
InlineCost getInlineCost(CallSite CS) override;
|
|
|
|
void getAnalysisUsage(AnalysisUsage &AU) const override;
|
|
bool runOnSCC(CallGraphSCC &SCC) override;
|
|
|
|
using llvm::Pass::doFinalization;
|
|
bool doFinalization(CallGraph &CG) override {
|
|
return removeDeadFunctions(CG, /*AlwaysInlineOnly=*/ true);
|
|
}
|
|
};
|
|
|
|
}
|
|
|
|
char AlwaysInliner::ID = 0;
|
|
INITIALIZE_PASS_BEGIN(AlwaysInliner, "always-inline",
|
|
"Inliner for always_inline functions", false, false)
|
|
INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
|
|
INITIALIZE_PASS_DEPENDENCY(AssumptionTracker)
|
|
INITIALIZE_PASS_DEPENDENCY(CallGraphWrapperPass)
|
|
INITIALIZE_PASS_DEPENDENCY(InlineCostAnalysis)
|
|
INITIALIZE_PASS_END(AlwaysInliner, "always-inline",
|
|
"Inliner for always_inline functions", false, false)
|
|
|
|
Pass *llvm::createAlwaysInlinerPass() { return new AlwaysInliner(); }
|
|
|
|
Pass *llvm::createAlwaysInlinerPass(bool InsertLifetime) {
|
|
return new AlwaysInliner(InsertLifetime);
|
|
}
|
|
|
|
/// \brief Get the inline cost for the always-inliner.
|
|
///
|
|
/// The always inliner *only* handles functions which are marked with the
|
|
/// attribute to force inlining. As such, it is dramatically simpler and avoids
|
|
/// using the powerful (but expensive) inline cost analysis. Instead it uses
|
|
/// a very simple and boring direct walk of the instructions looking for
|
|
/// impossible-to-inline constructs.
|
|
///
|
|
/// Note, it would be possible to go to some lengths to cache the information
|
|
/// computed here, but as we only expect to do this for relatively few and
|
|
/// small functions which have the explicit attribute to force inlining, it is
|
|
/// likely not worth it in practice.
|
|
InlineCost AlwaysInliner::getInlineCost(CallSite CS) {
|
|
Function *Callee = CS.getCalledFunction();
|
|
|
|
// Only inline direct calls to functions with always-inline attributes
|
|
// that are viable for inlining. FIXME: We shouldn't even get here for
|
|
// declarations.
|
|
if (Callee && !Callee->isDeclaration() &&
|
|
CS.hasFnAttr(Attribute::AlwaysInline) &&
|
|
ICA->isInlineViable(*Callee))
|
|
return InlineCost::getAlways();
|
|
|
|
return InlineCost::getNever();
|
|
}
|
|
|
|
bool AlwaysInliner::runOnSCC(CallGraphSCC &SCC) {
|
|
ICA = &getAnalysis<InlineCostAnalysis>();
|
|
return Inliner::runOnSCC(SCC);
|
|
}
|
|
|
|
void AlwaysInliner::getAnalysisUsage(AnalysisUsage &AU) const {
|
|
AU.addRequired<InlineCostAnalysis>();
|
|
Inliner::getAnalysisUsage(AU);
|
|
}
|