[mlir][IR][NFC] Cleanup insertion point API usage (#115415)

Use `setInsertionPointToStart` / `setInsertionPointToEnd` when possible.

Author: matthias-springer

mlir/include/mlir/IR/Builders.h

@@ -225,7 +225,7 @@ class OpBuilder : public Builder {
   explicit OpBuilder(Region *region, Listener *listener = nullptr)
       : OpBuilder(region->getContext(), listener) {
     if (!region->empty())
-      setInsertionPoint(&region->front(), region->front().begin());
+      setInsertionPointToStart(&region->front());
   }
   explicit OpBuilder(Region &region, Listener *listener = nullptr)
       : OpBuilder(&region, listener) {}

mlir/lib/Conversion/GPUToSPIRV/GPUToSPIRVPass.cpp

@@ -76,8 +76,7 @@ void GPUToSPIRVPass::runOnOperation() {
     // module inside the original GPU module, as that's the expectaion of the
     // normal GPU compilation pipeline.
     if (targetEnvSupportsKernelCapability(moduleOp)) {
-      builder.setInsertionPoint(moduleOp.getBody(),
-                                moduleOp.getBody()->begin());
+      builder.setInsertionPointToStart(moduleOp.getBody());
     } else {
       builder.setInsertionPoint(moduleOp.getOperation());
     }

mlir/lib/Conversion/SPIRVToLLVM/SPIRVToLLVM.cpp

@@ -706,7 +706,7 @@ class ExecutionModePattern
     Block *block = rewriter.createBlock(&region);
 
     // Initialize the struct and set the execution mode value.
-    rewriter.setInsertionPoint(block, block->begin());
+    rewriter.setInsertionPointToStart(block);
     Value structValue = rewriter.create<LLVM::UndefOp>(loc, structType);
     Value executionMode = rewriter.create<LLVM::ConstantOp>(
         loc, llvmI32Type,

mlir/lib/Dialect/LLVMIR/Transforms/InlinerInterfaceImpl.cpp

@@ -115,7 +115,7 @@ handleInlinedAllocas(Operation *call,
     stackPtr = builder.create<LLVM::StackSaveOp>(
         call->getLoc(), LLVM::LLVMPointerType::get(call->getContext()));
   }
-  builder.setInsertionPoint(callerEntryBlock, callerEntryBlock->begin());
+  builder.setInsertionPointToStart(callerEntryBlock);
   for (auto &[allocaOp, arraySize, shouldInsertLifetime] : allocasToMove) {
     auto newConstant = builder.create<LLVM::ConstantOp>(
         allocaOp->getLoc(), allocaOp.getArraySize().getType(), arraySize);

mlir/lib/Dialect/Linalg/Transforms/Promotion.cpp

@@ -451,7 +451,7 @@ static std::optional<Value> allocateSubviewGPUMemoryInAddressSpace(
     shape.push_back(value.getSExtValue());
   }
 
-  builder.setInsertionPoint(&funcOp.front(), funcOp.front().begin());
+  builder.setInsertionPointToStart(&funcOp.front());
   auto type = MemRefType::get(
       shape, subview.getType().getElementType(), MemRefLayoutAttrInterface{},
       gpu::AddressSpaceAttr::get(builder.getContext(), addressSpace));

mlir/lib/Dialect/SCF/IR/SCF.cpp

@@ -805,7 +805,7 @@ mlir::scf::replaceAndCastForOpIterArg(RewriterBase &rewriter, scf::ForOp forOp,
   // 3. Inject an incoming cast op at the beginning of the block for the bbArg
   // corresponding to the `replacement` value.
   OpBuilder::InsertionGuard g(rewriter);
-  rewriter.setInsertionPoint(&newBlock, newBlock.begin());
+  rewriter.setInsertionPointToStart(&newBlock);
   BlockArgument newRegionIterArg = newForOp.getTiedLoopRegionIterArg(
       &newForOp->getOpOperand(operand.getOperandNumber()));
   Value castIn = castFn(rewriter, newForOp.getLoc(), oldType, newRegionIterArg);

mlir/lib/Dialect/SCF/Utils/Utils.cpp

@@ -456,8 +456,7 @@ FailureOr<UnrolledLoopInfo> mlir::loopUnrollByFactor(
   // Create epilogue clean up loop starting at 'upperBoundUnrolled'.
   if (generateEpilogueLoop) {
     OpBuilder epilogueBuilder(forOp->getContext());
-    epilogueBuilder.setInsertionPoint(forOp->getBlock(),
-                                      std::next(Block::iterator(forOp)));
+    epilogueBuilder.setInsertionPointAfter(forOp);
     auto epilogueForOp = cast<scf::ForOp>(epilogueBuilder.clone(*forOp));
     epilogueForOp.setLowerBound(upperBoundUnrolled);
 

mlir/lib/Dialect/Shape/Transforms/OutlineShapeComputation.cpp

@@ -71,7 +71,7 @@ createFuncFromCluster(OpBuilder &b, const SmallVector<Operation *, 8> &cluster,
           : b.getFunctionType(ValueRange(inputs).getTypes(), shape.getType());
   shape::FuncOp fnOp = b.create<shape::FuncOp>(loc, fnName, fnType);
   Block *block = fnOp.addEntryBlock();
-  b.setInsertionPoint(block, block->end());
+  b.setInsertionPointToEnd(block);
   IRMapping bvm;
   if (cluster.empty()) {
     bvm.map(shape, fnOp.getArgument(0));

mlir/lib/Dialect/Vector/Transforms/VectorDistribute.cpp

@@ -1720,7 +1720,7 @@ struct WarpOpScfForOp : public OpRewritePattern<WarpExecuteOnLane0Op> {
     auto newForOp = rewriter.create<scf::ForOp>(
         forOp.getLoc(), forOp.getLowerBound(), forOp.getUpperBound(),
         forOp.getStep(), newOperands);
-    rewriter.setInsertionPoint(newForOp.getBody(), newForOp.getBody()->begin());
+    rewriter.setInsertionPointToStart(newForOp.getBody());
 
     SmallVector<Value> warpInput(newForOp.getRegionIterArgs().begin(),
                                  newForOp.getRegionIterArgs().end());
@@ -1747,7 +1747,7 @@ struct WarpOpScfForOp : public OpRewritePattern<WarpExecuteOnLane0Op> {
       yieldOperands.push_back(operand);
     rewriter.eraseOp(forOp.getBody()->getTerminator());
     rewriter.mergeBlocks(forOp.getBody(), innerWarp.getBody(), argMapping);
-    rewriter.setInsertionPoint(innerWarp.getBody(), innerWarp.getBody()->end());
+    rewriter.setInsertionPointToEnd(innerWarp.getBody());
     rewriter.create<vector::YieldOp>(innerWarp.getLoc(), yieldOperands);
     rewriter.setInsertionPointAfter(innerWarp);
     if (!innerWarp.getResults().empty())

mlir/lib/Target/LLVMIR/ModuleImport.cpp

@@ -2041,7 +2041,7 @@ LogicalResult ModuleImport::processFunction(llvm::Function *func) {
 
   // Insert the function at the end of the module.
   OpBuilder::InsertionGuard guard(builder);
-  builder.setInsertionPoint(mlirModule.getBody(), mlirModule.getBody()->end());
+  builder.setInsertionPointToEnd(mlirModule.getBody());
 
   Location loc = debugImporter->translateFuncLocation(func);
   LLVMFuncOp funcOp = builder.create<LLVMFuncOp>(