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Revert "[sil-code-motion] Read none builtins can not cause reads or writes. Don't let them disrupt load/store forwarding."

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This reverts commit r13291. Had a thinko here.

Swift SVN r13303
This commit is contained in:
Michael Gottesman
2014-02-01 19:20:41 +00:00
parent 0d6d693d91
commit 934e0756db
3 changed files with 0 additions and 39 deletions
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21
lib/SILPasses/SILCodeMotion.cpp
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@@ -23,7 +23,6 @@
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/RecyclingAllocator.h"
STATISTIC(NumSunk, "Number of instructions sunk");
@@ -34,15 +33,9 @@ using namespace swift;
static const int SinkSearchWindow = 6;
static unsigned NumNoRead = 0;
static llvm::cl::opt<unsigned>
MaxNoRead("max-no-read", llvm::cl::init(-1));
/// \brief Promote stored values to loads, remove dead stores and merge
/// duplicated loads.
void promoteMemoryOperationsInBlock(SILBasicBlock *BB) {
if (NumNoRead >= MaxNoRead)
return;
StoreInst *PrevStore = 0;
llvm::SmallVector<LoadInst *, 8> Loads;
@@ -58,9 +51,6 @@ void promoteMemoryOperationsInBlock(SILBasicBlock *BB) {
// If we are storing to the previously stored address then delete the old
// store.
if (PrevStore && PrevStore->getDest() == SI->getDest()) {
if (NumNoRead >= MaxNoRead)
return;
++NumNoRead;
recursivelyDeleteTriviallyDeadInstructions(PrevStore, true);
PrevStore = SI;
NumDeadStores++;
@@ -73,9 +63,6 @@ void promoteMemoryOperationsInBlock(SILBasicBlock *BB) {
if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) {
// If we are loading a value that we just saved then use the saved value.
if (PrevStore && PrevStore->getDest() == LI->getOperand()) {
if (NumNoRead >= MaxNoRead)
return;
++NumNoRead;
SILValue(LI, 0).replaceAllUsesWith(PrevStore->getSrc());
recursivelyDeleteTriviallyDeadInstructions(LI, true);
NumDupLoads++;
@@ -86,9 +73,6 @@ void promoteMemoryOperationsInBlock(SILBasicBlock *BB) {
// previous loads.
for (auto PrevLd : Loads) {
if (PrevLd->getOperand() == LI->getOperand()) {
if (NumNoRead >= MaxNoRead)
return;
++NumNoRead;
SILValue(LI, 0).replaceAllUsesWith(PrevLd);
recursivelyDeleteTriviallyDeadInstructions(LI, true);
LI = 0;
@@ -106,11 +90,6 @@ void promoteMemoryOperationsInBlock(SILBasicBlock *BB) {
if (isa<StrongRetainInst>(Inst))
continue;
if (auto *AI = dyn_cast<ApplyInst>(Inst))
if (auto *BI = dyn_cast<BuiltinFunctionRefInst>(&*AI->getCallee()))
if (isReadNone(BI))
continue;
// All other instructions that read from memory invalidate the store.
if (Inst->mayReadFromMemory())
PrevStore = 0;