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-rw-r--r--llvm/unittests/Transforms/Utils/SSAUpdaterBulkTest.cpp220
1 files changed, 220 insertions, 0 deletions
diff --git a/llvm/unittests/Transforms/Utils/SSAUpdaterBulkTest.cpp b/llvm/unittests/Transforms/Utils/SSAUpdaterBulkTest.cpp
index 841f44c..716f5f2 100644
--- a/llvm/unittests/Transforms/Utils/SSAUpdaterBulkTest.cpp
+++ b/llvm/unittests/Transforms/Utils/SSAUpdaterBulkTest.cpp
@@ -308,3 +308,223 @@ TEST(SSAUpdaterBulk, TwoBBLoop) {
EXPECT_EQ(Phi->getIncomingValueForBlock(Entry), ConstantInt::get(I32Ty, 0));
EXPECT_EQ(Phi->getIncomingValueForBlock(Loop), I);
}
+
+TEST(SSAUpdaterBulk, SimplifyPHIs) {
+ const char *IR = R"(
+ define void @main(i32 %val, i1 %cond) {
+ entry:
+ br i1 %cond, label %left, label %right
+ left:
+ %add = add i32 %val, 1
+ br label %exit
+ right:
+ %sub = sub i32 %val, 1
+ br label %exit
+ exit:
+ %phi = phi i32 [ %sub, %right ], [ %add, %left ]
+ %cmp = icmp slt i32 0, 42
+ ret void
+ }
+ )";
+
+ llvm::LLVMContext Context;
+ llvm::SMDiagnostic Err;
+ std::unique_ptr<llvm::Module> M = llvm::parseAssemblyString(IR, Err, Context);
+ ASSERT_NE(M, nullptr) << "Failed to parse IR: " << Err.getMessage();
+
+ Function *F = M->getFunction("main");
+ auto *Entry = &F->getEntryBlock();
+ auto *Left = Entry->getTerminator()->getSuccessor(0);
+ auto *Right = Entry->getTerminator()->getSuccessor(1);
+ auto *Exit = Left->getSingleSuccessor();
+ auto *Val = &*F->arg_begin();
+ auto *Phi = &Exit->front();
+ auto *Cmp = &*std::next(Exit->begin());
+ auto *Add = &Left->front();
+ auto *Sub = &Right->front();
+
+ SSAUpdaterBulk Updater;
+ Type *I32Ty = Type::getInt32Ty(Context);
+
+ // Use %val directly instead of creating a phi.
+ unsigned ValVar = Updater.AddVariable("Val", I32Ty);
+ Updater.AddAvailableValue(ValVar, Left, Val);
+ Updater.AddAvailableValue(ValVar, Right, Val);
+ Updater.AddUse(ValVar, &Cmp->getOperandUse(0));
+
+ // Use existing %phi for %add and %sub values.
+ unsigned AddSubVar = Updater.AddVariable("AddSub", I32Ty);
+ Updater.AddAvailableValue(AddSubVar, Left, Add);
+ Updater.AddAvailableValue(AddSubVar, Right, Sub);
+ Updater.AddUse(AddSubVar, &Cmp->getOperandUse(1));
+
+ auto ExitSizeBefore = Exit->size();
+ DominatorTree DT(*F);
+ Updater.RewriteAndOptimizeAllUses(DT);
+
+ // Output for Exit->dump():
+ // exit: ; preds = %right, %left
+ // %phi = phi i32 [ %sub, %right ], [ %add, %left ]
+ // %cmp = icmp slt i32 %val, %phi
+ // ret void
+
+ ASSERT_EQ(Exit->size(), ExitSizeBefore);
+ ASSERT_EQ(&Exit->front(), Phi);
+ EXPECT_EQ(Val, Cmp->getOperand(0));
+ EXPECT_EQ(Phi, Cmp->getOperand(1));
+}
+
+bool EliminateNewDuplicatePHINodes(BasicBlock *BB,
+ BasicBlock::phi_iterator FirstExistingPN);
+
+// Helper to run both versions on the same input.
+static void RunEliminateNewDuplicatePHINode(
+ const char *AsmText,
+ std::function<void(BasicBlock &,
+ bool(BasicBlock *BB, BasicBlock::phi_iterator))>
+ Check) {
+ LLVMContext C;
+
+ SMDiagnostic Err;
+ std::unique_ptr<Module> M = parseAssemblyString(AsmText, Err, C);
+ if (!M) {
+ Err.print("UtilsTests", errs());
+ return;
+ }
+
+ Function *F = M->getFunction("main");
+ auto BBIt = std::find_if(F->begin(), F->end(), [](const BasicBlock &Block) {
+ return Block.getName() == "testbb";
+ });
+ ASSERT_NE(BBIt, F->end());
+ Check(*BBIt, EliminateNewDuplicatePHINodes);
+}
+
+static BasicBlock::phi_iterator getPhiIt(BasicBlock &BB, unsigned Idx) {
+ return std::next(BB.phis().begin(), Idx);
+}
+
+static PHINode *getPhi(BasicBlock &BB, unsigned Idx) {
+ return &*getPhiIt(BB, Idx);
+}
+
+static int getNumPHIs(BasicBlock &BB) {
+ return std::distance(BB.phis().begin(), BB.phis().end());
+}
+
+TEST(SSAUpdaterBulk, EliminateNewDuplicatePHINodes_OrderExisting) {
+ RunEliminateNewDuplicatePHINode(R"(
+ define void @main() {
+ entry:
+ br label %testbb
+ testbb:
+ %np0 = phi i32 [ 1, %entry ]
+ %np1 = phi i32 [ 1, %entry ]
+ %ep0 = phi i32 [ 1, %entry ]
+ %ep1 = phi i32 [ 1, %entry ]
+ %u = add i32 %np0, %np1
+ ret void
+ }
+ )", [](BasicBlock &BB, auto *ENDPN) {
+ AssertingVH<PHINode> EP0 = getPhi(BB, 2);
+ AssertingVH<PHINode> EP1 = getPhi(BB, 3);
+ EXPECT_TRUE(ENDPN(&BB, getPhiIt(BB, 2)));
+ // Expected:
+ // %ep0 = phi i32 [ 1, %entry ]
+ // %ep1 = phi i32 [ 1, %entry ]
+ // %u = add i32 %ep0, %ep0
+ EXPECT_EQ(getNumPHIs(BB), 2);
+ Instruction &Add = *BB.getFirstNonPHIIt();
+ EXPECT_EQ(Add.getOperand(0), EP0);
+ EXPECT_EQ(Add.getOperand(1), EP0);
+ (void)EP1; // Avoid "unused" warning.
+ });
+}
+
+TEST(SSAUpdaterBulk, EliminateNewDuplicatePHINodes_OrderNew) {
+ RunEliminateNewDuplicatePHINode(R"(
+ define void @main() {
+ entry:
+ br label %testbb
+ testbb:
+ %np0 = phi i32 [ 1, %entry ]
+ %np1 = phi i32 [ 1, %entry ]
+ %ep0 = phi i32 [ 2, %entry ]
+ %ep1 = phi i32 [ 2, %entry ]
+ %u = add i32 %np0, %np1
+ ret void
+ }
+ )", [](BasicBlock &BB, auto *ENDPN) {
+ AssertingVH<PHINode> NP0 = getPhi(BB, 0);
+ AssertingVH<PHINode> EP0 = getPhi(BB, 2);
+ AssertingVH<PHINode> EP1 = getPhi(BB, 3);
+ EXPECT_TRUE(ENDPN(&BB, getPhiIt(BB, 2)));
+ // Expected:
+ // %np0 = phi i32 [ 1, %entry ]
+ // %ep0 = phi i32 [ 2, %entry ]
+ // %ep1 = phi i32 [ 2, %entry ]
+ // %u = add i32 %np0, %np0
+ EXPECT_EQ(getNumPHIs(BB), 3);
+ Instruction &Add = *BB.getFirstNonPHIIt();
+ EXPECT_EQ(Add.getOperand(0), NP0);
+ EXPECT_EQ(Add.getOperand(1), NP0);
+ (void)EP0;
+ (void)EP1; // Avoid "unused" warning.
+ });
+}
+
+TEST(SSAUpdaterBulk, EliminateNewDuplicatePHINodes_NewRefExisting) {
+ RunEliminateNewDuplicatePHINode(R"(
+ define void @main() {
+ entry:
+ br label %testbb
+ testbb:
+ %np0 = phi i32 [ 1, %entry ], [ %ep0, %testbb ]
+ %np1 = phi i32 [ 1, %entry ], [ %ep1, %testbb ]
+ %ep0 = phi i32 [ 1, %entry ], [ %ep0, %testbb ]
+ %ep1 = phi i32 [ 1, %entry ], [ %ep1, %testbb ]
+ %u = add i32 %np0, %np1
+ br label %testbb
+ }
+ )", [](BasicBlock &BB, auto *ENDPN) {
+ AssertingVH<PHINode> EP0 = getPhi(BB, 2);
+ AssertingVH<PHINode> EP1 = getPhi(BB, 3);
+ EXPECT_TRUE(ENDPN(&BB, getPhiIt(BB, 2)));
+ // Expected:
+ // %ep0 = phi i32 [ 1, %entry ], [ %ep0, %testbb ]
+ // %ep1 = phi i32 [ 1, %entry ], [ %ep1, %testbb ]
+ // %u = add i32 %ep0, %ep1
+ EXPECT_EQ(getNumPHIs(BB), 2);
+ Instruction &Add = *BB.getFirstNonPHIIt();
+ EXPECT_EQ(Add.getOperand(0), EP0);
+ EXPECT_EQ(Add.getOperand(1), EP1);
+ });
+}
+
+TEST(SSAUpdaterBulk, EliminateNewDuplicatePHINodes_ExistingRefNew) {
+ RunEliminateNewDuplicatePHINode(R"(
+ define void @main() {
+ entry:
+ br label %testbb
+ testbb:
+ %np0 = phi i32 [ 1, %entry ], [ %np0, %testbb ]
+ %np1 = phi i32 [ 1, %entry ], [ %np1, %testbb ]
+ %ep0 = phi i32 [ 1, %entry ], [ %np0, %testbb ]
+ %ep1 = phi i32 [ 1, %entry ], [ %np1, %testbb ]
+ %u = add i32 %np0, %np1
+ br label %testbb
+ }
+ )", [](BasicBlock &BB, auto *ENDPN) {
+ AssertingVH<PHINode> EP0 = getPhi(BB, 2);
+ AssertingVH<PHINode> EP1 = getPhi(BB, 3);
+ EXPECT_TRUE(ENDPN(&BB, getPhiIt(BB, 2)));
+ // Expected:
+ // %ep0 = phi i32 [ 1, %entry ], [ %ep0, %testbb ]
+ // %ep1 = phi i32 [ 1, %entry ], [ %ep1, %testbb ]
+ // %u = add i32 %ep0, %ep1
+ EXPECT_EQ(getNumPHIs(BB), 2);
+ Instruction &Add = *BB.getFirstNonPHIIt();
+ EXPECT_EQ(Add.getOperand(0), EP0);
+ EXPECT_EQ(Add.getOperand(1), EP1);
+ });
+}
generated by cgit v1.1 at 2025-10-13 21:58:17 +0000