[mlir][ods] Do not print default-valued attributes when the value is …

…equal to the default

This diff causes the `tblgen`-erated print() function to skip printing a
`DefaultValuedAttr` attribute when the value is equal to the default.

This feature will reduce the amount of custom printing code that needs to be
written by users a relatively common scenario. As a motivating example, for the
fastmath flags in the LLVMIR dialect, we would prefer to print this:

```
%0 = llvm.fadd %arg0, %arg1 : f32
```

instead of this:

```
%0 = llvm.fadd %arg0, %arg1 {fastmathFlags = #llvm.fastmath<none>} : f32
```

This diff makes the handling of print functionality for default-valued attributes
standard.

This is an updated version of https://reviews.llvm.org/D135398, without the per-attribute bit to control printing.

Reviewed By: Mogball

Differential Revision: https://reviews.llvm.org/D135993

mlir/docs/OpDefinitions.md

@@ -273,6 +273,9 @@ C++ default value. For example, a float default value should be specified as
 like `"0.5f"`, and an integer array default value should be specified as like
 `"{1, 2, 3}"`.
 
+The generated operation printing function will not print default-valued
+attributes when the attribute value is equal to the default.
+
 #### Confining attributes
 
 `ConfinedAttr` is provided as a general mechanism to help modelling further

mlir/test/Dialect/AMDGPU/ops.mlir

@@ -6,56 +6,56 @@
 
 // CHECK-LABEL: func @raw_buffer_load_f32_from_rank_1
 func.func @raw_buffer_load_f32_from_rank_1(%src : memref<128xf32>, %offset : i32, %idx0 : i32) -> f32 {
-  // CHECK: amdgpu.raw_buffer_load {boundsCheck = true, indexOffset = 1 : i32} %{{.*}}[{{.*}}] sgprOffset %{{.*}} : memref<128xf32>, i32 -> f32
+  // CHECK: amdgpu.raw_buffer_load {indexOffset = 1 : i32} %{{.*}}[{{.*}}] sgprOffset %{{.*}} : memref<128xf32>, i32 -> f32
   %0 = amdgpu.raw_buffer_load {boundsCheck = true, indexOffset = 1 : i32} %src[%idx0] sgprOffset %offset : memref<128xf32>, i32 -> f32
   func.return %0 : f32
 }
 
 // CHECK-LABEL: func @raw_buffer_load_f32_from_rank_4
 func.func @raw_buffer_load_f32_from_rank_4(%src : memref<128x64x32x16xf32>, %offset : i32, %idx0 : i32, %idx1 : i32, %idx2 : i32, %idx3 : i32) -> f32 {
-  // CHECK: amdgpu.raw_buffer_load {boundsCheck = true, indexOffset = 1 : i32} %{{.*}}[%{{.*}}, %{{.*}}, %{{.*}}] sgprOffset %{{.*}} : memref<128x64x32x16xf32>, i32, i32, i32, i32 -> f32
+  // CHECK: amdgpu.raw_buffer_load {indexOffset = 1 : i32} %{{.*}}[%{{.*}}, %{{.*}}, %{{.*}}] sgprOffset %{{.*}} : memref<128x64x32x16xf32>, i32, i32, i32, i32 -> f32
   %0 = amdgpu.raw_buffer_load {boundsCheck = true, indexOffset = 1 : i32} %src[%idx0, %idx1, %idx2, %idx3] sgprOffset %offset : memref<128x64x32x16xf32>, i32, i32, i32, i32 -> f32
   func.return %0 : f32
 }
 
 // CHECK-LABEL: func @raw_buffer_load_4xf32_from_rank_4
 func.func @raw_buffer_load_4xf32_from_rank_4(%src : memref<128x64x32x16xf32>, %offset : i32, %idx0 : i32, %idx1 : i32, %idx2 : i32, %idx3 : i32) -> vector<4xf32> {
-  // CHECK: amdgpu.raw_buffer_load {boundsCheck = true, indexOffset = 1 : i32} %{{.*}}[%{{.*}}, %{{.*}}, %{{.*}}] sgprOffset %{{.*}} : memref<128x64x32x16xf32>, i32, i32, i32, i32 -> vector<4xf32>
+  // CHECK: amdgpu.raw_buffer_load {indexOffset = 1 : i32} %{{.*}}[%{{.*}}, %{{.*}}, %{{.*}}] sgprOffset %{{.*}} : memref<128x64x32x16xf32>, i32, i32, i32, i32 -> vector<4xf32>
   %0 = amdgpu.raw_buffer_load {boundsCheck = true, indexOffset = 1 : i32} %src[%idx0, %idx1, %idx2, %idx3] sgprOffset %offset : memref<128x64x32x16xf32>, i32, i32, i32, i32 -> vector<4xf32>
   func.return %0 : vector<4xf32>
 }
 
 // CHECK-LABEL: func @raw_buffer_store_f32_to_rank_1
 func.func @raw_buffer_store_f32_to_rank_1(%value : f32, %dst : memref<128xf32>, %offset : i32, %idx0 : i32) {
-  // CHECK: amdgpu.raw_buffer_store {boundsCheck = true, indexOffset = 1 : i32} %{{.*}} -> %{{.*}}[{{.*}}] sgprOffset %{{.*}} : f32 -> memref<128xf32>, i32
+  // CHECK: amdgpu.raw_buffer_store {indexOffset = 1 : i32} %{{.*}} -> %{{.*}}[{{.*}}] sgprOffset %{{.*}} : f32 -> memref<128xf32>, i32
   amdgpu.raw_buffer_store {boundsCheck = true, indexOffset = 1 : i32} %value -> %dst[%idx0] sgprOffset %offset : f32 -> memref<128xf32>, i32
   func.return
 }
 
 // CHECK-LABEL: func @raw_buffer_store_f32_to_rank_4
 func.func @raw_buffer_store_f32_to_rank_4(%value : f32, %dst : memref<128x64x32x16xf32>, %offset : i32, %idx0 : i32, %idx1 : i32, %idx2 : i32, %idx3 : i32) {
-  // CHECK: amdgpu.raw_buffer_store {boundsCheck = true, indexOffset = 1 : i32} %{{.*}} -> %{{.*}}[%{{.*}}, %{{.*}}, %{{.*}}] sgprOffset %{{.*}} : f32 -> memref<128x64x32x16xf32>, i32, i32, i32, i32
+  // CHECK: amdgpu.raw_buffer_store {indexOffset = 1 : i32} %{{.*}} -> %{{.*}}[%{{.*}}, %{{.*}}, %{{.*}}] sgprOffset %{{.*}} : f32 -> memref<128x64x32x16xf32>, i32, i32, i32, i32
   amdgpu.raw_buffer_store {boundsCheck = true, indexOffset = 1 : i32} %value -> %dst[%idx0, %idx1, %idx2, %idx3] sgprOffset %offset : f32 -> memref<128x64x32x16xf32>, i32, i32, i32, i32
   func.return
 }
 
 // CHECK-LABEL: func @raw_buffer_store_4xf32_to_rank_4
 func.func @raw_buffer_store_4xf32_to_rank_4(%value : vector<4xf32>, %dst : memref<128x64x32x16xf32>, %offset : i32, %idx0 : i32, %idx1 : i32, %idx2 : i32, %idx3 : i32) {
-  // CHECK: amdgpu.raw_buffer_store {boundsCheck = true, indexOffset = 1 : i32} %{{.*}} -> %{{.*}}[%{{.*}}, %{{.*}}, %{{.*}}] sgprOffset %{{.*}} : vector<4xf32> -> memref<128x64x32x16xf32>, i32, i32, i32, i32
+  // CHECK: amdgpu.raw_buffer_store {indexOffset = 1 : i32} %{{.*}} -> %{{.*}}[%{{.*}}, %{{.*}}, %{{.*}}] sgprOffset %{{.*}} : vector<4xf32> -> memref<128x64x32x16xf32>, i32, i32, i32, i32
   amdgpu.raw_buffer_store {boundsCheck = true, indexOffset = 1 : i32} %value -> %dst[%idx0, %idx1, %idx2, %idx3] sgprOffset %offset : vector<4xf32> -> memref<128x64x32x16xf32>, i32, i32, i32, i32
   func.return
 }
 
 // CHECK-LABEL: func @raw_buffer_atomic_fadd_f32_to_rank_1
 func.func @raw_buffer_atomic_fadd_f32_to_rank_1(%value : f32, %dst : memref<128xf32>, %offset : i32, %idx0 : i32) {
-  // CHECK: amdgpu.raw_buffer_atomic_fadd {boundsCheck = true, indexOffset = 1 : i32} %{{.*}} -> %{{.*}}[{{.*}}] sgprOffset %{{.*}} : f32 -> memref<128xf32>, i32
+  // CHECK: amdgpu.raw_buffer_atomic_fadd {indexOffset = 1 : i32} %{{.*}} -> %{{.*}}[{{.*}}] sgprOffset %{{.*}} : f32 -> memref<128xf32>, i32
   amdgpu.raw_buffer_atomic_fadd {boundsCheck = true, indexOffset = 1 : i32} %value -> %dst[%idx0] sgprOffset %offset : f32 -> memref<128xf32>, i32
   func.return
 }
 
 // CHECK-LABEL: func @raw_buffer_atomic_fadd_f32_to_rank_4
 func.func @raw_buffer_atomic_fadd_f32_to_rank_4(%value : f32, %dst : memref<128x64x32x16xf32>, %offset : i32, %idx0 : i32, %idx1 : i32, %idx2 : i32, %idx3 : i32) {
-  // CHECK: amdgpu.raw_buffer_atomic_fadd {boundsCheck = true, indexOffset = 1 : i32} %{{.*}} -> %{{.*}}[%{{.*}}, %{{.*}}, %{{.*}}] sgprOffset %{{.*}} : f32 -> memref<128x64x32x16xf32>, i32, i32, i32, i32
+  // CHECK: amdgpu.raw_buffer_atomic_fadd {indexOffset = 1 : i32} %{{.*}} -> %{{.*}}[%{{.*}}, %{{.*}}, %{{.*}}] sgprOffset %{{.*}} : f32 -> memref<128x64x32x16xf32>, i32, i32, i32, i32
   amdgpu.raw_buffer_atomic_fadd {boundsCheck = true, indexOffset = 1 : i32} %value -> %dst[%idx0, %idx1, %idx2, %idx3] sgprOffset %offset : f32 -> memref<128x64x32x16xf32>, i32, i32, i32, i32
   func.return
 }

mlir/test/IR/attribute.mlir

@@ -786,3 +786,20 @@ func.func @wrong_shape_fail() {
   } : () -> ()
   return
 }
+
+// -----
+
+//===----------------------------------------------------------------------===//
+// Test DefaultValuedAttr Printing
+//===----------------------------------------------------------------------===//
+
+// CHECK-LABEL: @default_value_printing
+func.func @default_value_printing(%arg0 : i32) {
+  // The attribute SHOULD NOT be printed because it is equal to the default
+  // CHECK: test.default_value_print %arg0
+  "test.default_value_print"(%arg0) {"value_with_default" = 0 : i32} : (i32) -> ()
+  // The attribute SHOULD be printed because it is not equal to the default
+  // CHECK: test.default_value_print {value_with_default = 1 : i32} %arg0
+  "test.default_value_print"(%arg0) {"value_with_default" = 1 : i32} : (i32) -> ()
+  return
+}

mlir/test/lib/Dialect/Test/TestOps.td

@@ -2919,6 +2919,16 @@ def TestDefaultStrAttrHasValueOp : TEST_Op<"has_str_value"> {
 def : Pat<(TestDefaultStrAttrNoValueOp $value),
           (TestDefaultStrAttrHasValueOp ConstantStrAttr<StrAttr, "foo">)>;
 
+//===----------------------------------------------------------------------===//
+// Test Ops with Default-Valued Attributes and Differing Print Settings
+//===----------------------------------------------------------------------===//
+
+def TestDefaultAttrPrintOp : TEST_Op<"default_value_print"> {
+  let arguments = (ins DefaultValuedAttr<I32Attr, "0">:$value_with_default,
+                   I32:$operand);
+  let assemblyFormat = "attr-dict $operand";
+}
+
 //===----------------------------------------------------------------------===//
 // Test Ops with effects
 //===----------------------------------------------------------------------===//

mlir/test/python/dialects/transform_loop_ext.py

@@ -61,7 +61,7 @@ def loopPipeline():
   # CHECK-LABEL: TEST: loopPipeline
   # CHECK: = transform.loop.pipeline %
   # CHECK-DAG: iteration_interval = 3
-  # CHECK-DAG: read_latency = 10
+  # (read_latency has default value and is not printed)
 
 
 @run

mlir/test/python/dialects/transform_structured_ext.py

@@ -84,9 +84,7 @@ def testPad():
   # CHECK-DAG: padding_values = [4.200000e+01 : f32]
   # CHECK-DAG: padding_dimensions = [1]
   # CHECK-DAG: transpose_paddings = {{\[}}[1, 0]]
-  # CHECK-DAG: hoist_paddings = []
-  # CHECK-DAG: pack_paddings = []
-
+  # (hoist_paddings and pack_paddings have default values)
 
 @run
 def testScalarize():

mlir/tools/mlir-tblgen/OpFormatGen.cpp

@@ -1644,24 +1644,39 @@ const char *enumAttrBeginPrinterCode = R"(
 /// Generate the printer for the 'attr-dict' directive.
 static void genAttrDictPrinter(OperationFormat &fmt, Operator &op,
                                MethodBody &body, bool withKeyword) {
-  body << "  _odsPrinter.printOptionalAttrDict"
-       << (withKeyword ? "WithKeyword" : "")
-       << "((*this)->getAttrs(), /*elidedAttrs=*/{";
+  body << "  ::llvm::SmallVector<::llvm::StringRef, 2> elidedAttrs;\n";
   // Elide the variadic segment size attributes if necessary.
   if (!fmt.allOperands &&
       op.getTrait("::mlir::OpTrait::AttrSizedOperandSegments"))
-    body << "\"operand_segment_sizes\", ";
+    body << "  elidedAttrs.push_back(\"operand_segment_sizes\");\n";
   if (!fmt.allResultTypes &&
       op.getTrait("::mlir::OpTrait::AttrSizedResultSegments"))
-    body << "\"result_segment_sizes\", ";
-  if (!fmt.inferredAttributes.empty()) {
-    for (const auto &attr : fmt.inferredAttributes)
-      body << "\"" << attr.getKey() << "\", ";
-  }
-  llvm::interleaveComma(
-      fmt.usedAttributes, body,
-      [&](const NamedAttribute *attr) { body << "\"" << attr->name << "\""; });
-  body << "});\n";
+    body << "  elidedAttrs.push_back(\"result_segment_sizes\");\n";
+  for (const StringRef key : fmt.inferredAttributes.keys())
+    body << "  elidedAttrs.push_back(\"" << key << "\");\n";
+  for (const NamedAttribute *attr : fmt.usedAttributes)
+    body << "  elidedAttrs.push_back(\"" << attr->name << "\");\n";
+  // Add code to check attributes for equality with the default value
+  // for attributes with the elidePrintingDefaultValue bit set.
+  for (const NamedAttribute &namedAttr : op.getAttributes()) {
+    const Attribute &attr = namedAttr.attr;
+    if (!attr.isDerivedAttr() && attr.hasDefaultValue()) {
+      const StringRef &name = namedAttr.name;
+      FmtContext fctx;
+      fctx.withBuilder("odsBuilder");
+      std::string defaultValue = std::string(
+          tgfmt(attr.getConstBuilderTemplate(), &fctx, attr.getDefaultValue()));
+      body << "  {\n";
+      body << "     ::mlir::Builder odsBuilder(getContext());\n";
+      body << "     Attribute attr = " << op.getGetterName(name) << "Attr();\n";
+      body << "     if(attr && (attr == " << defaultValue << "))\n";
+      body << "       elidedAttrs.push_back(\"" << name << "\");\n";
+      body << "  }\n";
+    }
+  }
+  body << "  _odsPrinter.printOptionalAttrDict"
+       << (withKeyword ? "WithKeyword" : "")
+       << "((*this)->getAttrs(), elidedAttrs);\n";
 }
 
 /// Generate the printer for a literal value. `shouldEmitSpace` is true if a