summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--llvm/include/llvm/Transforms/Scalar/SimplifyCFG.h46
-rw-r--r--llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp109
-rw-r--r--llvm/test/Transforms/SimplifyCFG/basictest.ll1
-rw-r--r--llvm/tools/opt/PassRegistry.def1
-rw-r--r--llvm/tools/opt/Passes.cpp1
5 files changed, 114 insertions, 44 deletions
diff --git a/llvm/include/llvm/Transforms/Scalar/SimplifyCFG.h b/llvm/include/llvm/Transforms/Scalar/SimplifyCFG.h
new file mode 100644
index 00000000000..ef28e0f78a4
--- /dev/null
+++ b/llvm/include/llvm/Transforms/Scalar/SimplifyCFG.h
@@ -0,0 +1,46 @@
+//===- SimplifyCFG.h - Simplify and canonicalize the CFG --------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+/// \file
+/// This file provides the interface for the pass responsible for both
+/// simplifying and canonicalizing the CFG.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TRANSFORMS_SCALAR_SIMPLIFYCFG_H
+#define LLVM_TRANSFORMS_SCALAR_SIMPLIFYCFG_H
+
+#include "llvm/IR/Function.h"
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+/// \brief A pass to simplify and canonicalize the CFG of a function.
+///
+/// This pass iteratively simplifies the entire CFG of a function, removing
+/// unnecessary control flows and bringing it into the canonical form expected
+/// by the rest of the mid-level optimizer.
+class SimplifyCFGPass {
+ int BonusInstThreshold;
+
+public:
+ static StringRef name() { return "SimplifyCFGPass"; }
+
+ /// \brief Construct a pass with the default thresholds.
+ SimplifyCFGPass();
+
+ /// \brief Construct a pass with a specific bonus threshold.
+ SimplifyCFGPass(int BonusInstThreshold);
+
+ /// \brief Run the pass over the function.
+ PreservedAnalyses run(Function &F, AnalysisManager<Function> *AM);
+};
+
+}
+
+#endif
diff --git a/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp b/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
index 0a4bc871afe..bc2ae2423e1 100644
--- a/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
+++ b/llvm/lib/Transforms/Scalar/SimplifyCFGPass.cpp
@@ -21,7 +21,7 @@
//
//===----------------------------------------------------------------------===//
-#include "llvm/Transforms/Scalar.h"
+#include "llvm/Transforms/Scalar/SimplifyCFG.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
@@ -37,6 +37,7 @@
#include "llvm/Pass.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Transforms/Scalar.h"
using namespace llvm;
#define DEBUG_TYPE "simplifycfg"
@@ -47,36 +48,6 @@ UserBonusInstThreshold("bonus-inst-threshold", cl::Hidden, cl::init(1),
STATISTIC(NumSimpl, "Number of blocks simplified");
-namespace {
-struct CFGSimplifyPass : public FunctionPass {
- static char ID; // Pass identification, replacement for typeid
- unsigned BonusInstThreshold;
- CFGSimplifyPass(int T = -1) : FunctionPass(ID) {
- BonusInstThreshold = (T == -1) ? UserBonusInstThreshold : unsigned(T);
- initializeCFGSimplifyPassPass(*PassRegistry::getPassRegistry());
- }
- bool runOnFunction(Function &F) override;
-
- void getAnalysisUsage(AnalysisUsage &AU) const override {
- AU.addRequired<AssumptionCacheTracker>();
- AU.addRequired<TargetTransformInfoWrapperPass>();
- }
-};
-}
-
-char CFGSimplifyPass::ID = 0;
-INITIALIZE_PASS_BEGIN(CFGSimplifyPass, "simplifycfg", "Simplify the CFG", false,
- false)
-INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
-INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
-INITIALIZE_PASS_END(CFGSimplifyPass, "simplifycfg", "Simplify the CFG", false,
- false)
-
-// Public interface to the CFGSimplification pass
-FunctionPass *llvm::createCFGSimplificationPass(int Threshold) {
- return new CFGSimplifyPass(Threshold);
-}
-
/// mergeEmptyReturnBlocks - If we have more than one empty (other than phi
/// node) return blocks, merge them together to promote recursive block merging.
static bool mergeEmptyReturnBlocks(Function &F) {
@@ -176,19 +147,9 @@ static bool iterativelySimplifyCFG(Function &F, const TargetTransformInfo &TTI,
return Changed;
}
-// It is possible that we may require multiple passes over the code to fully
-// simplify the CFG.
-//
-bool CFGSimplifyPass::runOnFunction(Function &F) {
- if (skipOptnoneFunction(F))
- return false;
-
- AssumptionCache *AC =
- &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
- const TargetTransformInfo &TTI =
- getAnalysis<TargetTransformInfoWrapperPass>().getTTI();
- DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
- const DataLayout *DL = DLP ? &DLP->getDataLayout() : nullptr;
+static bool simplifyFunctionCFG(Function &F, const TargetTransformInfo &TTI,
+ const DataLayout *DL, AssumptionCache *AC,
+ int BonusInstThreshold) {
bool EverChanged = removeUnreachableBlocks(F);
EverChanged |= mergeEmptyReturnBlocks(F);
EverChanged |= iterativelySimplifyCFG(F, TTI, DL, AC, BonusInstThreshold);
@@ -211,3 +172,63 @@ bool CFGSimplifyPass::runOnFunction(Function &F) {
return true;
}
+
+SimplifyCFGPass::SimplifyCFGPass()
+ : BonusInstThreshold(UserBonusInstThreshold) {}
+
+SimplifyCFGPass::SimplifyCFGPass(int BonusInstThreshold)
+ : BonusInstThreshold(BonusInstThreshold) {}
+
+PreservedAnalyses SimplifyCFGPass::run(Function &F,
+ AnalysisManager<Function> *AM) {
+ auto *DL = F.getParent()->getDataLayout();
+ auto &TTI = AM->getResult<TargetIRAnalysis>(F);
+ auto &AC = AM->getResult<AssumptionAnalysis>(F);
+
+ if (!simplifyFunctionCFG(F, TTI, DL, &AC, BonusInstThreshold))
+ return PreservedAnalyses::none();
+
+ return PreservedAnalyses::all();
+}
+
+namespace {
+struct CFGSimplifyPass : public FunctionPass {
+ static char ID; // Pass identification, replacement for typeid
+ unsigned BonusInstThreshold;
+ CFGSimplifyPass(int T = -1) : FunctionPass(ID) {
+ BonusInstThreshold = (T == -1) ? UserBonusInstThreshold : unsigned(T);
+ initializeCFGSimplifyPassPass(*PassRegistry::getPassRegistry());
+ }
+ bool runOnFunction(Function &F) override {
+ if (skipOptnoneFunction(F))
+ return false;
+
+ AssumptionCache *AC =
+ &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F);
+ const TargetTransformInfo &TTI =
+ getAnalysis<TargetTransformInfoWrapperPass>().getTTI();
+ DataLayoutPass *DLP = getAnalysisIfAvailable<DataLayoutPass>();
+ const DataLayout *DL = DLP ? &DLP->getDataLayout() : nullptr;
+ return simplifyFunctionCFG(F, TTI, DL, AC, BonusInstThreshold);
+ }
+
+ void getAnalysisUsage(AnalysisUsage &AU) const override {
+ AU.addRequired<AssumptionCacheTracker>();
+ AU.addRequired<TargetTransformInfoWrapperPass>();
+ }
+};
+}
+
+char CFGSimplifyPass::ID = 0;
+INITIALIZE_PASS_BEGIN(CFGSimplifyPass, "simplifycfg", "Simplify the CFG", false,
+ false)
+INITIALIZE_PASS_DEPENDENCY(TargetTransformInfoWrapperPass)
+INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)
+INITIALIZE_PASS_END(CFGSimplifyPass, "simplifycfg", "Simplify the CFG", false,
+ false)
+
+// Public interface to the CFGSimplification pass
+FunctionPass *llvm::createCFGSimplificationPass(int Threshold) {
+ return new CFGSimplifyPass(Threshold);
+}
+
diff --git a/llvm/test/Transforms/SimplifyCFG/basictest.ll b/llvm/test/Transforms/SimplifyCFG/basictest.ll
index 5de7cc5e31d..5d9dad4cf7e 100644
--- a/llvm/test/Transforms/SimplifyCFG/basictest.ll
+++ b/llvm/test/Transforms/SimplifyCFG/basictest.ll
@@ -1,6 +1,7 @@
; Test CFG simplify removal of branch instructions.
;
; RUN: opt < %s -simplifycfg -S | FileCheck %s
+; RUN: opt < %s -passes=simplify-cfg -S | FileCheck %s
define void @test1() {
br label %1
diff --git a/llvm/tools/opt/PassRegistry.def b/llvm/tools/opt/PassRegistry.def
index db1c25f4856..d768a3ad1d2 100644
--- a/llvm/tools/opt/PassRegistry.def
+++ b/llvm/tools/opt/PassRegistry.def
@@ -71,6 +71,7 @@ FUNCTION_PASS("print", PrintFunctionPass(dbgs()))
FUNCTION_PASS("print<assumptions>", AssumptionPrinterPass(dbgs()))
FUNCTION_PASS("print<domtree>", DominatorTreePrinterPass(dbgs()))
FUNCTION_PASS("print<loops>", LoopPrinterPass(dbgs()))
+FUNCTION_PASS("simplify-cfg", SimplifyCFGPass())
FUNCTION_PASS("verify", VerifierPass())
FUNCTION_PASS("verify<domtree>", DominatorTreeVerifierPass())
#undef FUNCTION_PASS
diff --git a/llvm/tools/opt/Passes.cpp b/llvm/tools/opt/Passes.cpp
index 357cf41d076..e5ad5c06644 100644
--- a/llvm/tools/opt/Passes.cpp
+++ b/llvm/tools/opt/Passes.cpp
@@ -30,6 +30,7 @@
#include "llvm/Transforms/InstCombine/InstCombine.h"
#include "llvm/Transforms/Scalar/EarlyCSE.h"
#include "llvm/Transforms/Scalar/LowerExpectIntrinsic.h"
+#include "llvm/Transforms/Scalar/SimplifyCFG.h"
using namespace llvm;
OpenPOWER on IntegriCloud