[CodeMoverUtils] Add more tests to check code motion safety using data dependence information.

[RithikSharma]

Summary

This patch adds more test to verify code motion safety through dependence info which is generated by Dependence Info analysis and Alias analysis.

[Whitney]

Some quick first round review comments.

llvm/unittests/Transforms/Utils/CodeMoverUtilsTest.cpp

1006

remove dso_local

1014

bb0 -> header

1035

indent

1041

bb4 -> latch

1070

Please put a comment on the intension for each pair of tests.

[RithikSharma]

llvm/unittests/Transforms/Utils/CodeMoverUtilsTest.cpp

1035

Just to include a function call which would fail some existing sink and hoist test cases.

[Whitney]

llvm/unittests/Transforms/Utils/CodeMoverUtilsTest.cpp

1006

did you forget to update your patch? cause dso_local is still there.

1035

right, can you indent it? two spaces before the line.

1070

for test pairs with the same comment, please expend the comment with the difference, like the first four are all sink instruction from entry to header.

[RithikSharma]

llvm/unittests/Transforms/Utils/CodeMoverUtilsTest.cpp

1006

Updated, thanks.

llvm/unittests/Transforms/Utils/CodeMoverUtilsTest.cpp

function_ref<void(Function &F, DominatorTree &DT, PostDominatorTree &PDT,
         Test) {
   auto *F = M.getFunction(FuncName);
   DominatorTree DT(*F);
   PostDominatorTree PDT(*F);
   TargetLibraryInfoImpl TLII;
   TargetLibraryInfo TLI(TLII);
   AssumptionCache AC(*F);
   AAResults AA(TLI);
-  DataLayout DL("e-i64:64-f80:128-n8:16:32:64-S128");
+  DataLayout DL("");
   BasicAAResult BAA(DL, *F, TLI, AC, &DT);
   AA.addAAResult(BAA);
   LoopInfo LI(DT);
   ScalarEvolution SE(*F, TLI, AC, DT, LI);
   DependenceInfo DI(F, &AA, &SE, &LI);
   Test(*F, DT, PDT, DI, AA);
 }
 
run(*M, "dependence",
             isSafeToMoveBefore(StoreB0, *LoadA0, DT, &PDT, nullptr, &AA));
         // No anti forward dependency
         EXPECT_TRUE(
             isSafeToMoveBefore(*LoadA0, *LoadA1, DT, &PDT, &DI, nullptr));
         EXPECT_TRUE(
             isSafeToMoveBefore(*LoadA0, *LoadA1, DT, &PDT, nullptr, &AA));
       });
 }
+
+TEST(CodeMoverUtils, IsSafeToMoveTest7) {
+  LLVMContext C;
+
+  std::unique_ptr<Module> M =
+      parseIR(C, R"(define i32 @dependence(i32* noalias %A, i32* noalias %B) {
+entry:
+  store i32 0, i32* %A, align 4 ; storeA0
+  store i32 4, i32* %A, align 4 ; storeA1
+  store i32 8, i32* %B, align 4 ; storeB0
+  %tmp0 = load i32, i32* %A, align 4 ; LoadA0
+  br label %header
+
+header:
+  %b = phi i32 [ 0, %entry ], [ %c, %latch ]
+  %c = add i32 %b, 1
+  %z = icmp eq i32 %c, 0
+  store i32 2, i32* %A, align 4 ;  StoreA2
+  %tmp1 = load i32, i32* %B, align 4 ; LoadB0
+  %tmp2 = icmp slt i32 %tmp1, %tmp1
+  br i1 %tmp2, label %bb1, label %bb5
+
+bb1:
+  store i32 7, i32* %B, align 4 ; StoreB1
+  %tmp3 = load i32, i32* %B, align 4 ; LoadB1
+  %tmp4 = load i32, i32* %A, align 4 ; LoadA1
+  %tmp5 = icmp sgt i32 %tmp3, 10
+  br i1 %tmp5, label %bb2, label %bb3
+
+bb2:
+  store i32 9, i32* %B, align 4 ; StoreB2
+  br label %bb3
+
+bb3:
+  call void @function(i32 %tmp1)
+  %tmp6 = load i32, i32* %B, align 4 ; LoadB2
+  store i32 5, i32* %A, align 4 ; StoreA3
+  %tmp7 = load i32, i32* %A, align 4 ; LoadA2
+  br label %latch
+
+latch:
+  store i32 8, i32* %B, align 4 ; StoreB3
+  %tmp8 = load i32, i32* %B, align 4 ; LoadB3
+  store i32 2, i32* %A, align 4 ; StoreA4
+  %tmp9 = add nsw i32 %tmp8, 1
+  br label %header
+
+bb5:
+  %tmp10 = load i32, i32* %B, align 4 ; LoadB4
+  store i32 1, i32* %B, align 4 ; StoreB4
+  store i32 2, i32* %A, align 4 ; StoreA5
+  ret i32 0
+}
+declare void @function(i32) willreturn nosync nounwind
+)");
+  run(*M, "dependence",
+      [&](Function &F, DominatorTree &DT, PostDominatorTree &PDT,
+          DependenceInfo &DI, AAResults &AA) {
+        Instruction *LoadA0 = getInstructionByName(F, "tmp0");
+        Instruction *LoadB0 = getInstructionByName(F, "tmp1");
+        Instruction *LoadB2 = getInstructionByName(F, "tmp6");
+        Instruction *LoadA2 = getInstructionByName(F, "tmp7");
+        Instruction *LoadB3 = getInstructionByName(F, "tmp8");
+        Instruction *StoreB0 = LoadA0->getPrevNode();
+        Instruction *StoreA2 = LoadB0->getPrevNode();
+        Instruction *StoreA3 = LoadA2->getPrevNode();
+        Instruction *StoreB3 = LoadB3->getPrevNode();
+        Instruction *StoreA4 = LoadB3->getNextNode();
+
+        // sink instruction from entry to header
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*StoreB0, *StoreA2, DT, &PDT, &DI, nullptr));
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*StoreB0, *StoreA2, DT, &PDT, nullptr, &AA));
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*StoreB0, *LoadB0, DT, &PDT, &DI, nullptr));
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*StoreB0, *LoadB0, DT, &PDT, nullptr, &AA));
+        EXPECT_FALSE(
+            isSafeToMoveBefore(*LoadA0, *LoadB0, DT, &PDT, &DI, nullptr));
+        EXPECT_FALSE(
+            isSafeToMoveBefore(*LoadA0, *LoadB0, DT, &PDT, nullptr, &AA));
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*LoadA0, *StoreA2, DT, &PDT, &DI, nullptr));
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*LoadA0, *StoreA2, DT, &PDT, nullptr, &AA));
+
+        // hoist instrcution from header to entry
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*LoadB0, *LoadA0, DT, &PDT, &DI, nullptr));
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*LoadB0, *LoadA0, DT, &PDT, nullptr, &AA));
+        EXPECT_FALSE(
+            isSafeToMoveBefore(*LoadB0, *StoreB0, DT, &PDT, &DI, nullptr));
+        EXPECT_FALSE(
+            isSafeToMoveBefore(*LoadB0, *StoreB0, DT, &PDT, nullptr, &AA));
+
+        // sink instrcutions from bb3 to latch
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*LoadA2, *StoreB3, DT, &PDT, &DI, nullptr));
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*LoadA2, *StoreB3, DT, &PDT, nullptr, &AA));
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*LoadA2, *LoadB3, DT, &PDT, &DI, nullptr));
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*LoadA2, *LoadB3, DT, &PDT, nullptr, &AA));
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*StoreB3, *LoadA2, DT, &PDT, &DI, nullptr));
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*StoreB3, *LoadA2, DT, &PDT, nullptr, &AA));
+
+        // hoist instructions from latch to bb3
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*StoreB3, *StoreA3, DT, &PDT, &DI, nullptr));
+        EXPECT_TRUE(
+            isSafeToMoveBefore(*StoreB3, *StoreA3, DT, &PDT, nullptr, &AA));
+        EXPECT_FALSE(
+            isSafeToMoveBefore(*StoreA4, *LoadA2, DT, &PDT, &DI, nullptr));
+        EXPECT_FALSE(
+            isSafeToMoveBefore(*StoreA4, *LoadA2, DT, &PDT, nullptr, &AA));
+        EXPECT_FALSE(
+            isSafeToMoveBefore(*StoreB3, *LoadB2, DT, &PDT, &DI, nullptr));
+        EXPECT_FALSE(
+            isSafeToMoveBefore(*StoreB3, *LoadB2, DT, &PDT, nullptr, &AA));
+      });
+}