From bdd56eca49fc56677b06029747835deafa3bca03 Mon Sep 17 00:00:00 2001
From: Lei Zhang <antiagainst@google.com>
Date: Wed, 10 Apr 2019 08:00:34 -0700
Subject: [PATCH]     Remove checks guaranteed to be true by the type

    This addresses the compiler wraning of "comparison of unsigned expression
    >= 0 is always true [-Wtype-limits]".

--

PiperOrigin-RevId: 242868703
---
 mlir/lib/Analysis/AffineStructures.cpp      |  2 +-
 mlir/lib/Transforms/MaterializeVectors.cpp  |  3 +--
 mlir/test/mlir-tblgen/op-operand.td         | 19 ++++++++++++++-----
 mlir/test/mlir-tblgen/op-result.td          | 11 +++++++++++
 mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp | 18 ++++++++++--------
 5 files changed, 37 insertions(+), 16 deletions(-)

diff --git a/mlir/lib/Analysis/AffineStructures.cpp b/mlir/lib/Analysis/AffineStructures.cpp
index c38881a1..5ffc749 100644
--- a/mlir/lib/Analysis/AffineStructures.cpp
+++ b/mlir/lib/Analysis/AffineStructures.cpp
@@ -928,7 +928,7 @@ static void eliminateFromConstraint(FlatAffineConstraints *constraints,
 static void shiftColumnsToLeft(FlatAffineConstraints *constraints,
                                unsigned colStart, unsigned colLimit,
                                bool isEq) {
-  assert(colStart >= 0 && colLimit <= constraints->getNumIds());
+  assert(colLimit <= constraints->getNumIds());
   if (colLimit <= colStart)
     return;
 
diff --git a/mlir/lib/Transforms/MaterializeVectors.cpp b/mlir/lib/Transforms/MaterializeVectors.cpp
index df29c8e..76dbdaf 100644
--- a/mlir/lib/Transforms/MaterializeVectors.cpp
+++ b/mlir/lib/Transforms/MaterializeVectors.cpp
@@ -229,8 +229,7 @@ static SmallVector<unsigned, 8> delinearize(unsigned linearIndex,
     assert(strides[idx] > 0);
     auto val = linearIndex / strides[idx];
     res.push_back(val);
-    assert((val >= 0 && val < shape[idx]) &&
-           "delinearization is out of bounds");
+    assert(val < shape[idx] && "delinearization is out of bounds");
     linearIndex %= strides[idx];
   }
   // Sanity check.
diff --git a/mlir/test/mlir-tblgen/op-operand.td b/mlir/test/mlir-tblgen/op-operand.td
index 3dd2754..132d382 100644
--- a/mlir/test/mlir-tblgen/op-operand.td
+++ b/mlir/test/mlir-tblgen/op-operand.td
@@ -2,21 +2,30 @@
 
 include "mlir/IR/OpBase.td"
 
-def OneOperandOp : Op<"one_operand_op", []> {
+def OpA : Op<"one_operand_op", []> {
   let arguments = (ins I32:$input);
 }
 
-// CHECK-LABEL: OneOperandOp definitions
+// CHECK-LABEL: OpA definitions
 
-// CHECK:      void OneOperandOp::build
+// CHECK:      void OpA::build
 // CHECK-SAME:   Value *input
 // CHECK:        tblgen_state->addOperands({input});
 
-// CHECK:      void OneOperandOp::build
+// CHECK:      void OpA::build
 // CHECK-SAME:   ArrayRef<Value *> operands
 // CHECK:        assert(operands.size() == 1u && "mismatched number of parameters");
 // CHECK:        tblgen_state->addOperands(operands);
 
-// CHECK:      LogicalResult OneOperandOp::verify() {
+// CHECK:      LogicalResult OpA::verify() {
 // CHECK:        if (!((this->getOperation()->getOperand(0)->getType().isInteger(32))))
 // CHECK-NEXT:     return emitOpError("operand #0 must be 32-bit integer");
+
+def OpB : Op<"variadic_operand_op", []> {
+  let arguments = (ins Variadic<I32>:$input);
+}
+
+// CHECK-LABEL: OpB::build
+// CHECK-SAME:  ArrayRef<Value *> input
+// CHECK-NOT:   assert
+// CHECK:       tblgen_state->addOperands(input);
diff --git a/mlir/test/mlir-tblgen/op-result.td b/mlir/test/mlir-tblgen/op-result.td
index 11b6cc2..06bc3b4 100644
--- a/mlir/test/mlir-tblgen/op-result.td
+++ b/mlir/test/mlir-tblgen/op-result.td
@@ -56,6 +56,17 @@ def ValueAttrResultTypeOp : Op<"value_attr_as_result_type", [FirstAttrDerivedRes
 // CHECK: void ValueAttrResultTypeOp::build(Builder *, OperationState *tblgen_state, Value *x, FloatAttr attr)
 // CHECK: tblgen_state->addTypes({attr.getType()});
 
+def VariadicResultAloneOp : Op<"variadic_alone_op", []> {
+  let results = (outs Variadic<I32>:$x);
+}
+
+// CHECK-LABEL: VariadicResultAloneOp definitions
+
+// CHECK-LABEL: void VariadicResultAloneOp::build
+// CHECK-SAME:  ArrayRef<Type> x
+// CHECK-NOT:   assert
+// CHECK:       tblgen_state->addTypes(x);
+
 def VariadicResultOp : Op<"variadic_op", []> {
   let results = (outs I32:$x, Variadic<I32>:$y);
 }
diff --git a/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp b/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp
index 7c3a6cf..122e579 100644
--- a/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp
+++ b/mlir/tools/mlir-tblgen/OpDefinitionsGen.cpp
@@ -696,16 +696,18 @@ void OpEmitter::genBuilder() {
   auto &body = m.body();
 
   // Result types
-  body << "  assert(resultTypes.size()" << (hasVariadicResult ? " >= " : " == ")
-       << numNonVariadicResults
-       << "u && \"mismatched number of return types\");\n"
-       << "  " << builderOpState << "->addTypes(resultTypes);\n";
+  if (!(hasVariadicResult && numNonVariadicResults == 0))
+    body << "  assert(resultTypes.size()"
+         << (hasVariadicResult ? " >= " : " == ") << numNonVariadicResults
+         << "u && \"mismatched number of return types\");\n";
+  body << "  " << builderOpState << "->addTypes(resultTypes);\n";
 
   // Operands
-  body << "  assert(operands.size()" << (hasVariadicOperand ? " >= " : " == ")
-       << numNonVariadicOperands
-       << "u && \"mismatched number of parameters\");\n"
-       << "  " << builderOpState << "->addOperands(operands);\n\n";
+  if (!(hasVariadicOperand && numNonVariadicOperands == 0))
+    body << "  assert(operands.size()" << (hasVariadicOperand ? " >= " : " == ")
+         << numNonVariadicOperands
+         << "u && \"mismatched number of parameters\");\n";
+  body << "  " << builderOpState << "->addOperands(operands);\n\n";
 
   // Attributes
   body << "  for (const auto& pair : attributes)\n"
-- 
2.7.4