[llvm] r274959 - [PM] Port LoopSimplify to the new pass manager.
Davide Italiano via llvm-commits
llvm-commits at lists.llvm.org
Fri Jul 8 20:03:01 PDT 2016
Author: davide
Date: Fri Jul 8 22:03:01 2016
New Revision: 274959
URL: http://llvm.org/viewvc/llvm-project?rev=274959&view=rev
Log:
[PM] Port LoopSimplify to the new pass manager.
While here move simplifyLoop() function to the new header, as
suggested by Chandler in the review.
Differential Revision: http://reviews.llvm.org/D21404
Added:
llvm/trunk/include/llvm/Transforms/Utils/LoopSimplify.h
Modified:
llvm/trunk/include/llvm/Transforms/Utils/LoopUtils.h
llvm/trunk/lib/Passes/PassBuilder.cpp
llvm/trunk/lib/Passes/PassRegistry.def
llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp
llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp
llvm/trunk/test/Transforms/LoopSimplify/basictest.ll
Added: llvm/trunk/include/llvm/Transforms/Utils/LoopSimplify.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/LoopSimplify.h?rev=274959&view=auto
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/LoopSimplify.h (added)
+++ llvm/trunk/include/llvm/Transforms/Utils/LoopSimplify.h Fri Jul 8 22:03:01 2016
@@ -0,0 +1,65 @@
+//===- LoopSimplify.h - Loop Canonicalization Pass --------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass performs several transformations to transform natural loops into a
+// simpler form, which makes subsequent analyses and transformations simpler and
+// more effective.
+//
+// Loop pre-header insertion guarantees that there is a single, non-critical
+// entry edge from outside of the loop to the loop header. This simplifies a
+// number of analyses and transformations, such as LICM.
+//
+// Loop exit-block insertion guarantees that all exit blocks from the loop
+// (blocks which are outside of the loop that have predecessors inside of the
+// loop) only have predecessors from inside of the loop (and are thus dominated
+// by the loop header). This simplifies transformations such as store-sinking
+// that are built into LICM.
+//
+// This pass also guarantees that loops will have exactly one backedge.
+//
+// Indirectbr instructions introduce several complications. If the loop
+// contains or is entered by an indirectbr instruction, it may not be possible
+// to transform the loop and make these guarantees. Client code should check
+// that these conditions are true before relying on them.
+//
+// Note that the simplifycfg pass will clean up blocks which are split out but
+// end up being unnecessary, so usage of this pass should not pessimize
+// generated code.
+//
+// This pass obviously modifies the CFG, but updates loop information and
+// dominator information.
+//
+//===----------------------------------------------------------------------===//
+#ifndef LLVM_TRANSFORMS_UTILS_LOOPSIMPLIFY_H
+#define LLVM_TRANSFORMS_UTILS_LOOPSIMPLIFY_H
+
+#include "llvm/Analysis/AssumptionCache.h"
+#include "llvm/Analysis/ScalarEvolution.h"
+#include "llvm/IR/Dominators.h"
+#include "llvm/IR/PassManager.h"
+
+namespace llvm {
+
+/// This pass is responsible for loop canonicalization.
+class LoopSimplifyPass : public PassInfoMixin<LoopSimplifyPass> {
+public:
+ PreservedAnalyses run(Function &F, AnalysisManager<Function> &AM);
+};
+
+/// \brief Simplify each loop in a loop nest recursively.
+///
+/// This takes a potentially un-simplified loop L (and its children) and turns
+/// it into a simplified loop nest with preheaders and single backedges. It will
+/// update \c AliasAnalysis and \c ScalarEvolution analyses if they're non-null.
+bool simplifyLoop(Loop *L, DominatorTree *DT, LoopInfo *LI, ScalarEvolution *SE,
+ AssumptionCache *AC, bool PreserveLCSSA);
+
+} // end namespace llvm
+
+#endif // LLVM_TRANSFORMS_UTILS_LOOPSIMPLIFY_H
Modified: llvm/trunk/include/llvm/Transforms/Utils/LoopUtils.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/LoopUtils.h?rev=274959&r1=274958&r2=274959&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/LoopUtils.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/LoopUtils.h Fri Jul 8 22:03:01 2016
@@ -323,14 +323,6 @@ private:
BasicBlock *InsertPreheaderForLoop(Loop *L, DominatorTree *DT, LoopInfo *LI,
bool PreserveLCSSA);
-/// \brief Simplify each loop in a loop nest recursively.
-///
-/// This takes a potentially un-simplified loop L (and its children) and turns
-/// it into a simplified loop nest with preheaders and single backedges. It will
-/// update \c AliasAnalysis and \c ScalarEvolution analyses if they're non-null.
-bool simplifyLoop(Loop *L, DominatorTree *DT, LoopInfo *LI, ScalarEvolution *SE,
- AssumptionCache *AC, bool PreserveLCSSA);
-
/// \brief Put loop into LCSSA form.
///
/// Looks at all instructions in the loop which have uses outside of the
Modified: llvm/trunk/lib/Passes/PassBuilder.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Passes/PassBuilder.cpp?rev=274959&r1=274958&r2=274959&view=diff
==============================================================================
--- llvm/trunk/lib/Passes/PassBuilder.cpp (original)
+++ llvm/trunk/lib/Passes/PassBuilder.cpp Fri Jul 8 22:03:01 2016
@@ -102,6 +102,7 @@
#include "llvm/Transforms/Scalar/TailRecursionElimination.h"
#include "llvm/Transforms/Utils/AddDiscriminators.h"
#include "llvm/Transforms/Utils/LCSSA.h"
+#include "llvm/Transforms/Utils/LoopSimplify.h"
#include "llvm/Transforms/Utils/Mem2Reg.h"
#include "llvm/Transforms/Utils/MemorySSA.h"
#include "llvm/Transforms/Utils/SimplifyInstructions.h"
Modified: llvm/trunk/lib/Passes/PassRegistry.def
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Passes/PassRegistry.def?rev=274959&r1=274958&r2=274959&view=diff
==============================================================================
--- llvm/trunk/lib/Passes/PassRegistry.def (original)
+++ llvm/trunk/lib/Passes/PassRegistry.def Fri Jul 8 22:03:01 2016
@@ -140,6 +140,7 @@ FUNCTION_PASS("loweratomic", LowerAtomic
FUNCTION_PASS("lower-expect", LowerExpectIntrinsicPass())
FUNCTION_PASS("guard-widening", GuardWideningPass())
FUNCTION_PASS("gvn", GVN())
+FUNCTION_PASS("loop-simplify", LoopSimplifyPass())
FUNCTION_PASS("mem2reg", PromotePass())
FUNCTION_PASS("memcpyopt", MemCpyOptPass())
FUNCTION_PASS("mldst-motion", MergedLoadStoreMotionPass())
Modified: llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp?rev=274959&r1=274958&r2=274959&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/LoopSimplify.cpp Fri Jul 8 22:03:01 2016
@@ -37,6 +37,7 @@
//
//===----------------------------------------------------------------------===//
+#include "llvm/Transforms/Utils/LoopSimplify.h"
#include "llvm/Transforms/Scalar.h"
#include "llvm/ADT/DepthFirstIterator.h"
#include "llvm/ADT/SetOperations.h"
@@ -802,6 +803,36 @@ bool LoopSimplify::runOnFunction(Functio
return Changed;
}
+PreservedAnalyses LoopSimplifyPass::run(Function &F,
+ AnalysisManager<Function> &AM) {
+ bool Changed = false;
+ LoopInfo *LI = &AM.getResult<LoopAnalysis>(F);
+ DominatorTree *DT = &AM.getResult<DominatorTreeAnalysis>(F);
+ ScalarEvolution *SE = AM.getCachedResult<ScalarEvolutionAnalysis>(F);
+ AssumptionCache *AC = &AM.getResult<AssumptionAnalysis>(F);
+
+ // FIXME: This pass should verify that the loops on which it's operating
+ // are in canonical SSA form, and that the pass itself preserves this form.
+ for (LoopInfo::iterator I = LI->begin(), E = LI->end(); I != E; ++I)
+ Changed |= simplifyLoop(*I, DT, LI, SE, AC, true /* PreserveLCSSA */);
+
+ if (!Changed)
+ return PreservedAnalyses::all();
+ PreservedAnalyses PA;
+
+ // The old PM also preserved LCSSAID and BreakCriticalEdgesID.
+ // This makes no sense in the new PM so we omit those from the set
+ // of preserved passes.
+ PA.preserve<DominatorTreeAnalysis>();
+ PA.preserve<LoopAnalysis>();
+ PA.preserve<BasicAA>();
+ PA.preserve<GlobalsAA>();
+ PA.preserve<SCEVAA>();
+ PA.preserve<ScalarEvolutionAnalysis>();
+ PA.preserve<DependenceAnalysis>();
+ return PA;
+}
+
// FIXME: Restore this code when we re-enable verification in verifyAnalysis
// below.
#if 0
Modified: llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp?rev=274959&r1=274958&r2=274959&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/LoopUnroll.cpp Fri Jul 8 22:03:01 2016
@@ -34,6 +34,7 @@
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Cloning.h"
#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Transforms/Utils/LoopSimplify.h"
#include "llvm/Transforms/Utils/LoopUtils.h"
#include "llvm/Transforms/Utils/SimplifyIndVar.h"
using namespace llvm;
Modified: llvm/trunk/test/Transforms/LoopSimplify/basictest.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopSimplify/basictest.ll?rev=274959&r1=274958&r2=274959&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LoopSimplify/basictest.ll (original)
+++ llvm/trunk/test/Transforms/LoopSimplify/basictest.ll Fri Jul 8 22:03:01 2016
@@ -1,4 +1,5 @@
; RUN: opt < %s -loop-simplify
+; RUN: opt < %s -passes=loop-simplify
; This function should get a preheader inserted before BB3, that is jumped
; to by BB1 & BB2
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