[GVN] Basic optimization remark support
[recommitting after the fix in r288307]
Follow-on patches will add more interesting cases.
The goal of this patch-set is to get the GVN messages printed in
opt-viewer from Dhrystone as was presented in my Dev Meeting talk. This
is the optimization view for the function (the last remark in the
function has a bug which is fixed in this series):
http://lab.llvm.org:8080/artifacts/opt-view_test-suite/build/SingleSource/Benchmarks/Dhrystone/CMakeFiles/dry.dir/html/_org_test-suite_SingleSource_Benchmarks_Dhrystone_dry.c.html#L430
Differential Revision: https://reviews.llvm.org/D26488
llvm-svn: 288370
diff --git a/llvm/lib/Transforms/Scalar/GVN.cpp b/llvm/lib/Transforms/Scalar/GVN.cpp
index 79afff2..050cc2e 100644
--- a/llvm/lib/Transforms/Scalar/GVN.cpp
+++ b/llvm/lib/Transforms/Scalar/GVN.cpp
@@ -33,6 +33,7 @@
#include "llvm/Analysis/Loads.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/Analysis/MemoryDependenceAnalysis.h"
+#include "llvm/Analysis/OptimizationDiagnosticInfo.h"
#include "llvm/Analysis/PHITransAddr.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/Analysis/ValueTracking.h"
@@ -587,7 +588,8 @@
auto &AA = AM.getResult<AAManager>(F);
auto &MemDep = AM.getResult<MemoryDependenceAnalysis>(F);
auto *LI = AM.getCachedResult<LoopAnalysis>(F);
- bool Changed = runImpl(F, AC, DT, TLI, AA, &MemDep, LI);
+ auto &ORE = AM.getResult<OptimizationRemarkEmitterAnalysis>(F);
+ bool Changed = runImpl(F, AC, DT, TLI, AA, &MemDep, LI, &ORE);
if (!Changed)
return PreservedAnalyses::all();
PreservedAnalyses PA;
@@ -1583,10 +1585,18 @@
if (V->getType()->getScalarType()->isPointerTy())
MD->invalidateCachedPointerInfo(V);
markInstructionForDeletion(LI);
+ ORE->emit(OptimizationRemark(DEBUG_TYPE, "LoadPRE", LI)
+ << "load eliminated by PRE");
++NumPRELoad;
return true;
}
+static void reportLoadElim(LoadInst *LI, OptimizationRemarkEmitter *ORE) {
+ ORE->emit(OptimizationRemark(DEBUG_TYPE, "LoadElim", LI)
+ << "load of type " << ore::NV("Type", LI->getType())
+ << " eliminated");
+}
+
/// Attempt to eliminate a load whose dependencies are
/// non-local by performing PHI construction.
bool GVN::processNonLocalLoad(LoadInst *LI) {
@@ -1657,6 +1667,7 @@
MD->invalidateCachedPointerInfo(V);
markInstructionForDeletion(LI);
++NumGVNLoad;
+ reportLoadElim(LI, ORE);
return true;
}
@@ -1803,6 +1814,7 @@
patchAndReplaceAllUsesWith(L, AvailableValue);
markInstructionForDeletion(L);
++NumGVNLoad;
+ reportLoadElim(L, ORE);
// Tell MDA to rexamine the reused pointer since we might have more
// information after forwarding it.
if (MD && AvailableValue->getType()->getScalarType()->isPointerTy())
@@ -2180,7 +2192,8 @@
/// runOnFunction - This is the main transformation entry point for a function.
bool GVN::runImpl(Function &F, AssumptionCache &RunAC, DominatorTree &RunDT,
const TargetLibraryInfo &RunTLI, AAResults &RunAA,
- MemoryDependenceResults *RunMD, LoopInfo *LI) {
+ MemoryDependenceResults *RunMD, LoopInfo *LI,
+ OptimizationRemarkEmitter *RunORE) {
AC = &RunAC;
DT = &RunDT;
VN.setDomTree(DT);
@@ -2188,6 +2201,7 @@
VN.setAliasAnalysis(&RunAA);
MD = RunMD;
VN.setMemDep(MD);
+ ORE = RunORE;
bool Changed = false;
bool ShouldContinue = true;
@@ -2703,7 +2717,8 @@
getAnalysis<AAResultsWrapperPass>().getAAResults(),
NoLoads ? nullptr
: &getAnalysis<MemoryDependenceWrapperPass>().getMemDep(),
- LIWP ? &LIWP->getLoopInfo() : nullptr);
+ LIWP ? &LIWP->getLoopInfo() : nullptr,
+ &getAnalysis<OptimizationRemarkEmitterWrapperPass>().getORE());
}
void getAnalysisUsage(AnalysisUsage &AU) const override {
@@ -2716,6 +2731,7 @@
AU.addPreserved<DominatorTreeWrapperPass>();
AU.addPreserved<GlobalsAAWrapperPass>();
+ AU.addRequired<OptimizationRemarkEmitterWrapperPass>();
}
private:
@@ -2737,4 +2753,5 @@
INITIALIZE_PASS_DEPENDENCY(TargetLibraryInfoWrapperPass)
INITIALIZE_PASS_DEPENDENCY(AAResultsWrapperPass)
INITIALIZE_PASS_DEPENDENCY(GlobalsAAWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(OptimizationRemarkEmitterWrapperPass)
INITIALIZE_PASS_END(GVNLegacyPass, "gvn", "Global Value Numbering", false, false)