[llvm] ec4749e - Revert "[LoopUtils] Updated deleteDeadLoop() to handle loop nest."

[Whitney Tsang via llvm-commits]

Author: Whitney Tsang
Date: 2019-12-17T03:51:41Z
New Revision: ec4749e3b8d0366b11eb01d513608a823871f58e

URL: https://github.com/llvm/llvm-project/commit/ec4749e3b8d0366b11eb01d513608a823871f58e
DIFF: https://github.com/llvm/llvm-project/commit/ec4749e3b8d0366b11eb01d513608a823871f58e.diff

LOG: Revert "[LoopUtils] Updated deleteDeadLoop() to handle loop nest."

This reverts commit cd09fee3d63296dd2df0bbb1fae363ca9f311d44.
This reverts commit c066ff11d84a7797503ad5a44c4129136926dc85.

Added: 
    

Modified: 
    llvm/lib/Transforms/Utils/LoopUtils.cpp
    llvm/unittests/Transforms/Utils/CMakeLists.txt

Removed: 
    llvm/unittests/Transforms/Utils/LoopUtilsTest.cpp


################################################################################
diff  --git a/llvm/lib/Transforms/Utils/LoopUtils.cpp b/llvm/lib/Transforms/Utils/LoopUtils.cpp
index 2340e8c72e10..68ef0fe40714 100644
--- a/llvm/lib/Transforms/Utils/LoopUtils.cpp
+++ b/llvm/lib/Transforms/Utils/LoopUtils.cpp
@@ -673,18 +673,7 @@ void llvm::deleteDeadLoop(Loop *L, DominatorTree *DT = nullptr,
       LI->removeBlock(BB);
 
     // The last step is to update LoopInfo now that we've eliminated this loop.
-    // Note: LoopInfo::erase remove the given loop and relink its subloops with
-    // its parent. While removeLoop/removeChildLoop remove the given loop but
-    // not relink its subloops, which is what we want.
-    if (Loop *ParentLoop = L->getParentLoop()) {
-      Loop::iterator I = find(ParentLoop->begin(), ParentLoop->end(), L);
-      assert(I != ParentLoop->end() && "Couldn't find loop");
-      ParentLoop->removeChildLoop(I);
-    } else {
-      Loop::iterator I = find(LI->begin(), LI->end(), L);
-      assert(I != LI->end() && "Couldn't find loop");
-      LI->removeLoop(I);
-    }
+    LI->erase(L);
   }
 }
 

diff  --git a/llvm/unittests/Transforms/Utils/CMakeLists.txt b/llvm/unittests/Transforms/Utils/CMakeLists.txt
index 424f09025ea2..5a8204cb86ac 100644
--- a/llvm/unittests/Transforms/Utils/CMakeLists.txt
+++ b/llvm/unittests/Transforms/Utils/CMakeLists.txt
@@ -15,7 +15,6 @@ add_llvm_unittest(UtilsTests
   FunctionComparatorTest.cpp
   IntegerDivisionTest.cpp
   LocalTest.cpp
-  LoopUtilsTest.cpp
   SizeOptsTest.cpp
   SSAUpdaterBulkTest.cpp
   UnrollLoopTest.cpp

diff  --git a/llvm/unittests/Transforms/Utils/LoopUtilsTest.cpp b/llvm/unittests/Transforms/Utils/LoopUtilsTest.cpp
deleted file mode 100644
index 35fd97a50d09..000000000000
--- a/llvm/unittests/Transforms/Utils/LoopUtilsTest.cpp
+++ /dev/null
@@ -1,90 +0,0 @@
-//===- LoopUtilsTest.cpp - Unit tests for LoopUtils -----------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-
-#include "llvm/Transforms/Utils/LoopUtils.h"
-#include "llvm/AsmParser/Parser.h"
-#include "llvm/Support/SourceMgr.h"
-#include "gtest/gtest.h"
-
-using namespace llvm;
-
-static std::unique_ptr<Module> parseIR(LLVMContext &C, const char *IR) {
-  SMDiagnostic Err;
-  std::unique_ptr<Module> Mod = parseAssemblyString(IR, Err, C);
-  if (!Mod)
-    Err.print("LoopUtilsTests", errs());
-  return Mod;
-}
-
-static void run(Module &M, StringRef FuncName,
-                function_ref<void(Function &F, DominatorTree &DT,
-                                  ScalarEvolution &SE, LoopInfo &LI)>
-                    Test) {
-  Function *F = M.getFunction(FuncName);
-  DominatorTree DT(*F);
-  TargetLibraryInfoImpl TLII;
-  TargetLibraryInfo TLI(TLII);
-  AssumptionCache AC(*F);
-  LoopInfo LI(DT);
-  ScalarEvolution SE(*F, TLI, AC, DT, LI);
-  Test(*F, DT, SE, LI);
-}
-
-TEST(LoopUtils, DeleteDeadLoopNest) {
-  LLVMContext C;
-  std::unique_ptr<Module> M =
-      parseIR(C, "define void @foo() {\n"
-                 "entry:\n"
-                 "  br label %for.i\n"
-                 "for.i:\n"
-                 "  %i = phi i64 [ 0, %entry ], [ %inc.i, %for.i.latch ]\n"
-                 "  br label %for.j\n"
-                 "for.j:\n"
-                 "  %j = phi i64 [ 0, %for.i ], [ %inc.j, %for.j ]\n"
-                 "  %inc.j = add nsw i64 %j, 1\n"
-                 "  %cmp.j = icmp slt i64 %inc.j, 100\n"
-                 "  br i1 %cmp.j, label %for.j, label %for.k.preheader\n"
-                 "for.k.preheader:\n"
-                 "  br label %for.k\n"
-                 "for.k:\n"
-                 "  %k = phi i64 [ %inc.k, %for.k ], [ 0, %for.k.preheader ]\n"
-                 "  %inc.k = add nsw i64 %k, 1\n"
-                 "  %cmp.k = icmp slt i64 %inc.k, 100\n"
-                 "  br i1 %cmp.k, label %for.k, label %for.i.latch\n"
-                 "for.i.latch:\n"
-                 "  %inc.i = add nsw i64 %i, 1\n"
-                 "  %cmp.i = icmp slt i64 %inc.i, 100\n"
-                 "  br i1 %cmp.i, label %for.i, label %for.end\n"
-                 "for.end:\n"
-                 "  ret void\n"
-                 "}\n");
-
-  run(*M, "foo",
-      [&](Function &F, DominatorTree &DT, ScalarEvolution &SE, LoopInfo &LI) {
-        assert(LI.begin() != LI.end() && "Expecting loops in function F");
-        Loop *L = *LI.begin();
-        assert(L && L->getName() == "for.i" && "Expecting loop for.i");
-
-        deleteDeadLoop(L, &DT, &SE, &LI);
-
-        assert(DT.verify(DominatorTree::VerificationLevel::Fast) &&
-               "Expecting valid dominator tree");
-        LI.verify(DT);
-        assert(LI.begin() == LI.end() &&
-               "Expecting no loops left in function F");
-        SE.verify();
-
-        Function::iterator FI = F.begin();
-        BasicBlock *Entry = &*(FI++);
-        assert(Entry->getName() == "entry" && "Expecting BasicBlock entry");
-        const BranchInst *BI = dyn_cast<BranchInst>(Entry->getTerminator());
-        assert(BI && "Expecting valid branch instruction");
-        EXPECT_EQ(BI->getNumSuccessors(), (unsigned)1);
-        EXPECT_EQ(BI->getSuccessor(0)->getName(), "for.end");
-      });
-}