[mlir][vector][memref] Add alignment attribute to memory access ops

mlir/docs/DefiningDialects/Operations.md

@@ -306,6 +306,8 @@ Right now, the following primitive constraints are supported:
 *   `IntPositive`: Specifying an integer attribute whose value is positive
 *   `IntNonNegative`: Specifying an integer attribute whose value is
     non-negative
+*   `IntPowerOf2`: Specifying an integer attribute whose value is a power of
+    two > 0
 *   `ArrayMinCount<N>`: Specifying an array attribute to have at least `N`
     elements
 *   `ArrayMaxCount<N>`: Specifying an array attribute to have at most `N`

mlir/include/mlir/Dialect/MemRef/IR/MemRefOps.td

@@ -1217,6 +1217,11 @@ def LoadOp : MemRef_Op<"load",
     be reused in the cache. For details, refer to the
     [https://llvm.org/docs/LangRef.html#load-instruction](LLVM load instruction).
 
+    An optional `alignment` attribute allows to specify the byte alignment of the
+    load operation. It must be a positive power of 2. The operation must access
+    memory at an address aligned to this boundary. Violations may lead to
+    architecture-specific faults or performance penalties.
+    A value of 0 indicates no specific alignment requirement.
     Example:
 
     ```mlir
@@ -1227,7 +1232,39 @@ def LoadOp : MemRef_Op<"load",
   let arguments = (ins Arg<AnyMemRef, "the reference to load from",
                            [MemRead]>:$memref,
                        Variadic<Index>:$indices,
-                       DefaultValuedOptionalAttr<BoolAttr, "false">:$nontemporal);
+                       DefaultValuedOptionalAttr<BoolAttr, "false">:$nontemporal,
+                       ConfinedAttr<OptionalAttr<I64Attr>,
+                                    [AllAttrOf<[IntPositive, IntPowerOf2]>]>:$alignment);
+
+  let builders = [
+    OpBuilder<(ins "Value":$memref,
+                   "ValueRange":$indices,
+                   CArg<"bool", "false">:$nontemporal,
+                   CArg<"uint64_t", "0">:$alignment), [{
+      return build($_builder, $_state, memref, indices, nontemporal,
+                   alignment != 0 ? $_builder.getI64IntegerAttr(alignment) :
+                                    nullptr);
+    }]>,
+    OpBuilder<(ins "Type":$resultType,
+                   "Value":$memref,
+                   "ValueRange":$indices,
+                   CArg<"bool", "false">:$nontemporal,
+                   CArg<"uint64_t", "0">:$alignment), [{
+      return build($_builder, $_state, resultType, memref, indices, nontemporal,
+                   alignment != 0 ? $_builder.getI64IntegerAttr(alignment) :
+                                    nullptr);
+    }]>,
+    OpBuilder<(ins "TypeRange":$resultTypes,
+                   "Value":$memref,
+                   "ValueRange":$indices,
+                   CArg<"bool", "false">:$nontemporal,
+                   CArg<"uint64_t", "0">:$alignment), [{
+      return build($_builder, $_state, resultTypes, memref, indices, nontemporal,
+                   alignment != 0 ? $_builder.getI64IntegerAttr(alignment) :
+                                    nullptr);
+    }]>
+  ];
+
   let results = (outs AnyType:$result);
 
   let extraClassDeclaration = [{
@@ -1913,6 +1950,11 @@ def MemRef_StoreOp : MemRef_Op<"store",
     be reused in the cache. For details, refer to the
     [https://llvm.org/docs/LangRef.html#store-instruction](LLVM store instruction).
 
+    An optional `alignment` attribute allows to specify the byte alignment of the
+    store operation. It must be a positive power of 2. The operation must access
+    memory at an address aligned to this boundary. Violations may lead to
+    architecture-specific faults or performance penalties.
+    A value of 0 indicates no specific alignment requirement.
     Example:
 
     ```mlir
@@ -1924,13 +1966,25 @@ def MemRef_StoreOp : MemRef_Op<"store",
                        Arg<AnyMemRef, "the reference to store to",
                            [MemWrite]>:$memref,
                        Variadic<Index>:$indices,
-                       DefaultValuedOptionalAttr<BoolAttr, "false">:$nontemporal);
+                       DefaultValuedOptionalAttr<BoolAttr, "false">:$nontemporal,
+                       ConfinedAttr<OptionalAttr<I64Attr>,
+                                    [AllAttrOf<[IntPositive, IntPowerOf2]>]>:$alignment);
 
   let builders = [
+    OpBuilder<(ins "Value":$valueToStore,
+                   "Value":$memref,
+                   "ValueRange":$indices,
+                   CArg<"bool", "false">:$nontemporal,
+                   CArg<"uint64_t", "0">:$alignment), [{
+      return build($_builder, $_state, valueToStore, memref, indices, nontemporal,
+                   alignment != 0 ? $_builder.getI64IntegerAttr(alignment) :
+                                    nullptr);
+    }]>,
     OpBuilder<(ins "Value":$valueToStore, "Value":$memref), [{
       $_state.addOperands(valueToStore);
       $_state.addOperands(memref);
-    }]>];
+    }]>
+  ];
 
   let extraClassDeclaration = [{
       Value getValueToStore() { return getOperand(0); }

mlir/include/mlir/Dialect/Vector/IR/VectorOps.td

@@ -1734,12 +1734,42 @@ def Vector_LoadOp : Vector_Op<"load"> {
     ```mlir
     %result = vector.load %memref[%c0] : memref<7xf32>, vector<8xf32>
     ```
+
+    An optional `alignment` attribute allows to specify the byte alignment of the
+    load operation. It must be a positive power of 2. The operation must access
+    memory at an address aligned to this boundary. Violations may lead to
+    architecture-specific faults or performance penalties.
+    A value of 0 indicates no specific alignment requirement.
   }];
 
   let arguments = (ins Arg<AnyMemRef, "the reference to load from",
       [MemRead]>:$base,
       Variadic<Index>:$indices,
-      DefaultValuedOptionalAttr<BoolAttr, "false">:$nontemporal);
+      DefaultValuedOptionalAttr<BoolAttr, "false">:$nontemporal,
+      ConfinedAttr<OptionalAttr<I64Attr>,
+                   [AllAttrOf<[IntPositive, IntPowerOf2]>]>:$alignment);
+
+  let builders = [
+    OpBuilder<(ins "VectorType":$resultType,
+                   "Value":$base,
+                   "ValueRange":$indices,
+                   CArg<"bool", "false">:$nontemporal,
+                   CArg<"uint64_t", "0">:$alignment), [{
+      return build($_builder, $_state, resultType, base, indices, nontemporal,
+                   alignment != 0 ? $_builder.getI64IntegerAttr(alignment) :
+                                    nullptr);
+    }]>,
+    OpBuilder<(ins "TypeRange":$resultTypes,
+                   "Value":$base,
+                   "ValueRange":$indices,
+                   CArg<"bool", "false">:$nontemporal,
+                   CArg<"uint64_t", "0">:$alignment), [{
+      return build($_builder, $_state, resultTypes, base, indices, nontemporal,
+                   alignment != 0 ? $_builder.getI64IntegerAttr(alignment) :
+                                    nullptr);
+    }]>
+  ];
+
   let results = (outs AnyVectorOfAnyRank:$result);
 
   let extraClassDeclaration = [{
@@ -1818,15 +1848,34 @@ def Vector_StoreOp : Vector_Op<"store"> {
     ```mlir
     vector.store %valueToStore, %memref[%c0] : memref<7xf32>, vector<8xf32>
     ```
+
+    An optional `alignment` attribute allows to specify the byte alignment of the
+    store operation. It must be a positive power of 2. The operation must access
+    memory at an address aligned to this boundary. Violations may lead to
+    architecture-specific faults or performance penalties.
+    A value of 0 indicates no specific alignment requirement.
   }];
 
   let arguments = (ins
       AnyVectorOfAnyRank:$valueToStore,
       Arg<AnyMemRef, "the reference to store to",
       [MemWrite]>:$base,
       Variadic<Index>:$indices,
-      DefaultValuedOptionalAttr<BoolAttr, "false">:$nontemporal
-  );
+      DefaultValuedOptionalAttr<BoolAttr, "false">:$nontemporal,
+      ConfinedAttr<OptionalAttr<I64Attr>,
+                   [AllAttrOf<[IntPositive, IntPowerOf2]>]>:$alignment);
+
+  let builders = [
+    OpBuilder<(ins "Value":$valueToStore,
+                   "Value":$base,
+                   "ValueRange":$indices,
+                   CArg<"bool", "false">:$nontemporal,
+                   CArg<"uint64_t", "0">:$alignment), [{
+      return build($_builder, $_state, valueToStore, base, indices, nontemporal,
+                   alignment != 0 ? $_builder.getI64IntegerAttr(alignment) :
+                                    nullptr);
+    }]>
+  ];
 
   let extraClassDeclaration = [{
     MemRefType getMemRefType() {

mlir/include/mlir/IR/CommonAttrConstraints.td

@@ -796,6 +796,10 @@ def IntPositive : AttrConstraint<
     CPred<"::llvm::cast<::mlir::IntegerAttr>($_self).getValue().isStrictlyPositive()">,
     "whose value is positive">;
 
+def IntPowerOf2 : AttrConstraint<
+    CPred<"::llvm::cast<::mlir::IntegerAttr>($_self).getValue().isPowerOf2()">,
+    "whose value is a power of two > 0">;
+
 class ArrayMaxCount<int n> : AttrConstraint<
     CPred<"::llvm::cast<::mlir::ArrayAttr>($_self).size() <= " # n>,
     "with at most " # n # " elements">;

mlir/test/Dialect/MemRef/load-store-alignment.mlir

@@ -0,0 +1,27 @@
+// RUN: mlir-opt -split-input-file -verify-diagnostics %s | FileCheck %s
+
+// CHECK-LABEL: func @test_load_store_alignment
+// CHECK: memref.load {{.*}} {alignment = 16 : i64}
+// CHECK: memref.store {{.*}} {alignment = 16 : i64}
+func.func @test_load_store_alignment(%memref: memref<4xi32>) {
+  %c0 = arith.constant 0 : index
+  %val = memref.load %memref[%c0] { alignment = 16 } : memref<4xi32>
+  memref.store %val, %memref[%c0] { alignment = 16 } : memref<4xi32>
+  return
+}
+
+// -----
+
+func.func @test_invalid_negative_load_alignment(%memref: memref<4xi32>) {
+  // expected-error @+1 {{custom op 'memref.load' 'memref.load' op attribute 'alignment' failed to satisfy constraint: 64-bit signless integer attribute whose value is positive and whose value is a power of two > 0}}
+  %val = memref.load %memref[%c0] { alignment = -1 } : memref<4xi32>
+  return
+}
+
+// -----
+
+func.func @test_invalid_non_power_of_2_store_alignment(%memref: memref<4xi32>, %val: i32) {
+  // expected-error @+1 {{custom op 'memref.store' 'memref.store' op attribute 'alignment' failed to satisfy constraint: 64-bit signless integer attribute whose value is positive and whose value is a power of two > 0}}
+  memref.store %val, %memref[%c0] { alignment = 1 } : memref<4xi32>
+  return
+}

mlir/test/Dialect/Vector/load-store-alignment.mlir

@@ -0,0 +1,27 @@
+// RUN: mlir-opt -split-input-file -verify-diagnostics %s | FileCheck %s
+
+// CHECK-LABEL: func @test_load_store_alignment
+// CHECK: vector.load {{.*}} {alignment = 16 : i64}
+// CHECK: vector.store {{.*}} {alignment = 16 : i64}
+func.func @test_load_store_alignment(%memref: memref<4xi32>) {
+  %c0 = arith.constant 0 : index
+  %val = vector.load %memref[%c0] { alignment = 16 } : memref<4xi32>, vector<4xi32>
+  vector.store %val, %memref[%c0] { alignment = 16 } : memref<4xi32>, vector<4xi32>
+  return
+}
+
+// -----
+
+func.func @test_invalid_negative_load_alignment(%memref: memref<4xi32>) {
+  // expected-error @+1 {{custom op 'vector.load' 'vector.load' op attribute 'alignment' failed to satisfy constraint: 64-bit signless integer attribute whose value is positive and whose value is a power of two > 0}}
+  %val = vector.load %memref[%c0] { alignment = -1 } : memref<4xi32>, vector<4xi32>
+  return
+}
+
+// -----
+
+func.func @test_invalid_non_power_of_2_store_alignment(%memref: memref<4xi32>, %val: vector<4xi32>) {
+  // expected-error @+1 {{custom op 'vector.store' 'vector.store' op attribute 'alignment' failed to satisfy constraint: 64-bit signless integer attribute whose value is positive and whose value is a power of two > 0}}
+  vector.store %val, %memref[%c0] { alignment = 1 } : memref<4xi32>, vector<4xi32>
+  return
+}