From fcc56edb5fc34158454dd063013823ed000f1d82 Mon Sep 17 00:00:00 2001 From: Xin Tong Date: Sun, 15 Jan 2017 21:17:52 +0000 Subject: [PATCH] Use getLoopLatch in place of isLoopSimplifyForm Summary: Use getLoopLatch in place of isLoopSimplifyForm. we do not need to know whether the loop has a preheader nor dedicated exits. Reviewers: hfinkel, sanjoy, atrick, mkuper Subscribers: mzolotukhin, llvm-commits Differential Revision: https://reviews.llvm.org/D28724 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@292078 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/LoopInfo.cpp | 11 +++-- unittests/Analysis/CMakeLists.txt | 1 + unittests/Analysis/LoopInfoTest.cpp | 77 +++++++++++++++++++++++++++++ 3 files changed, 85 insertions(+), 4 deletions(-) create mode 100644 unittests/Analysis/LoopInfoTest.cpp diff --git a/lib/Analysis/LoopInfo.cpp b/lib/Analysis/LoopInfo.cpp index 714e0d5173f..e7e7612a66d 100644 --- a/lib/Analysis/LoopInfo.cpp +++ b/lib/Analysis/LoopInfo.cpp @@ -211,9 +211,11 @@ bool Loop::isSafeToClone() const { MDNode *Loop::getLoopID() const { MDNode *LoopID = nullptr; - if (isLoopSimplifyForm()) { - LoopID = getLoopLatch()->getTerminator()->getMetadata(LLVMContext::MD_loop); + if (BasicBlock *Latch = getLoopLatch()) { + LoopID = Latch->getTerminator()->getMetadata(LLVMContext::MD_loop); } else { + assert(!getLoopLatch() && + "The loop should have no single latch at this point"); // Go through each predecessor of the loop header and check the // terminator for the metadata. BasicBlock *H = getHeader(); @@ -248,11 +250,12 @@ void Loop::setLoopID(MDNode *LoopID) const { assert(LoopID->getNumOperands() > 0 && "Loop ID needs at least one operand"); assert(LoopID->getOperand(0) == LoopID && "Loop ID should refer to itself"); - if (isLoopSimplifyForm()) { - getLoopLatch()->getTerminator()->setMetadata(LLVMContext::MD_loop, LoopID); + if (BasicBlock *Latch = getLoopLatch()) { + Latch->getTerminator()->setMetadata(LLVMContext::MD_loop, LoopID); return; } + assert(!getLoopLatch() && "The loop should have no single latch at this point"); BasicBlock *H = getHeader(); for (BasicBlock *BB : this->blocks()) { TerminatorInst *TI = BB->getTerminator(); diff --git a/unittests/Analysis/CMakeLists.txt b/unittests/Analysis/CMakeLists.txt index 45f479a6fc1..5ecf3e0ef20 100644 --- a/unittests/Analysis/CMakeLists.txt +++ b/unittests/Analysis/CMakeLists.txt @@ -13,6 +13,7 @@ add_llvm_unittest(AnalysisTests CFGTest.cpp CGSCCPassManagerTest.cpp LazyCallGraphTest.cpp + LoopInfoTest.cpp MemoryBuiltinsTest.cpp ProfileSummaryInfoTest.cpp ScalarEvolutionTest.cpp diff --git a/unittests/Analysis/LoopInfoTest.cpp b/unittests/Analysis/LoopInfoTest.cpp new file mode 100644 index 00000000000..3832d887377 --- /dev/null +++ b/unittests/Analysis/LoopInfoTest.cpp @@ -0,0 +1,77 @@ +//===- LoopInfoTest.cpp - LoopInfo unit tests -----------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Analysis/LoopInfo.h" +#include "llvm/AsmParser/Parser.h" +#include "llvm/IR/Dominators.h" +#include "llvm/Support/SourceMgr.h" +#include "gtest/gtest.h" + +using namespace llvm; + +static std::unique_ptr makeLLVMModule(LLVMContext &Context, + const char *ModuleStr) { + SMDiagnostic Err; + return parseAssemblyString(ModuleStr, Err, Context); +} + +// This tests that for a loop with a single latch, we get the loop id from +// its only latch, even in case the loop may not be in a simplified form. +TEST(LoopInfoTest, LoopWithSingleLatch) { + const char *ModuleStr = + "target datalayout = \"e-m:o-i64:64-f80:128-n8:16:32:64-S128\"\n" + "define void @foo(i32 %n) {\n" + "entry:\n" + " br i1 undef, label %for.cond, label %for.end\n" + "for.cond:\n" + " %i.0 = phi i32 [ 0, %entry ], [ %inc, %for.inc ]\n" + " %cmp = icmp slt i32 %i.0, %n\n" + " br i1 %cmp, label %for.inc, label %for.end\n" + "for.inc:\n" + " %inc = add nsw i32 %i.0, 1\n" + " br label %for.cond, !llvm.loop !0\n" + "for.end:\n" + " ret void\n" + "}\n" + "!0 = distinct !{!0, !1}\n" + "!1 = !{!\"llvm.loop.distribute.enable\", i1 true}\n"; + + // Parse the module. + LLVMContext Context; + std::unique_ptr M = makeLLVMModule(Context, ModuleStr); + + // Build the dominator tree and loop info. + DominatorTree DT; + DT.recalculate(*M->begin()); + LoopInfo LI; + LI.analyze(DT); + + + Function &F = *M->begin(); + Function::iterator FI = F.begin(); + FI++; // First basic block is entry - skip it. + BasicBlock *Header = &*FI++; + assert(Header->getName() == "for.cond"); + Loop *L = LI.getLoopFor(Header); + + // This loop is not in simplified form. + EXPECT_FALSE(L->isLoopSimplifyForm()); + + // Analyze the loop metadata id. + bool loopIDFoundAndSet = false; + // Try to get and set the metadata id for the loop. + if (MDNode *D = L->getLoopID()) { + L->setLoopID(D); + loopIDFoundAndSet = true; + } + + // We must have successfully found and set the loop id in the + // only latch the loop has. + EXPECT_TRUE(loopIDFoundAndSet); +} -- 2.40.0