[Mlir-commits] [mlir] [mlir][x86vector] AVX2 i8/i32 Dot Op (PR #147908)

llvmlistbot at llvm.org llvmlistbot at llvm.org
Thu Jul 10 00:50:15 PDT 2025


https://github.com/arun-thmn updated https://github.com/llvm/llvm-project/pull/147908

>From bf558772085f53fc3ef3a2722aefaf5fd4c4bcb1 Mon Sep 17 00:00:00 2001
From: Arun Thangamani <arun.thangamani at intel.com>
Date: Thu, 10 Jul 2025 00:40:53 -0700
Subject: [PATCH 1/2] MLIR support for VPDPBSSD instruction through llvm
 instrincs

---
 .../mlir/Dialect/X86Vector/X86Vector.td       | 53 +++++++++++++++++++
 .../Dialect/X86Vector/legalize-for-llvm.mlir  | 16 ++++++
 mlir/test/Dialect/X86Vector/roundtrip.mlir    | 16 ++++++
 mlir/test/Target/LLVMIR/x86vector.mlir        | 16 ++++++
 4 files changed, 101 insertions(+)

diff --git a/mlir/include/mlir/Dialect/X86Vector/X86Vector.td b/mlir/include/mlir/Dialect/X86Vector/X86Vector.td
index 3bf0be0a716aa..c3f7904fa1249 100644
--- a/mlir/include/mlir/Dialect/X86Vector/X86Vector.td
+++ b/mlir/include/mlir/Dialect/X86Vector/X86Vector.td
@@ -302,6 +302,8 @@ def DotBF16Op : AVX512_Op<"dot", [Pure,
   }];
 }
 
+
+
 //----------------------------------------------------------------------------//
 // Convert packed F32 to packed BF16
 //----------------------------------------------------------------------------//
@@ -420,6 +422,57 @@ def DotOp : AVX_LowOp<"dot", [Pure,
   }];
 }
 
+//----------------------------------------------------------------------------//
+// AVX Int8 Dot
+//----------------------------------------------------------------------------//
+
+def DotInt8Op : AVX_Op<"dot.i32", [Pure,
+    X86IntrinsicOpInterface,
+    AllTypesMatch<["a", "b"]>,
+    AllTypesMatch<["src", "dst"]>,
+    TypesMatchWith<"`a` has same elements as `src`",
+                   "src", "a",
+                   "VectorType::get({::llvm::cast<VectorType>($_self).getShape()[0]}, "
+                   "IntegerType::get($_self.getContext(), 32))">
+  ]> {
+  let summary = "Dot Int8 op";
+  let description = [{
+    The `dot` op is an AVX2-I32/I8 specific op that can lower to the proper
+    LLVMAVX2-INT8/32 operation `llvm.vpdpbssd` depending on the width of MLIR
+    vectors it is applied to.
+
+    #### From the Intel Intrinsics Guide:
+
+    Multiply groups of 4 adjacent pairs of signed 8-bit integers in `a` with 
+    corresponding signed 8-bit integers in `b`, producing 4 intermediate signed 16-bit 
+    results. Sum these 4 results with the corresponding 32-bit integer in `src`, and 
+    store the packed 32-bit results in `dst`.
+
+    Example:
+    ```mlir
+    %dst = x86vector.avx.dot %src, %a, %b : vector<8xi32> -> vector<8xi32>
+    ```
+  }];
+  let arguments = (ins VectorOfLengthAndType<[4, 8], [I32]>:$src,
+                   VectorOfLengthAndType<[4, 8], [I32]>:$a,
+                   VectorOfLengthAndType<[4, 8], [I32]>:$b
+                   );
+  let results = (outs VectorOfLengthAndType<[4, 8], [I32]>:$dst);
+  let assemblyFormat =
+    "$src `,` $a `,` $b attr-dict `:` type($a) `->` type($src)";
+
+  let extraClassDeclaration = [{
+    std::string getIntrinsicName() {
+      std::string intr = "llvm.x86.avx2.vpdpbssd";
+      VectorType vecType = getSrc().getType();
+      unsigned elemBitWidth = vecType.getElementTypeBitWidth();
+      unsigned opBitWidth = vecType.getShape()[0] * elemBitWidth;
+      intr += "." + std::to_string(opBitWidth);
+      return intr;
+    }
+  }];
+}
+
 //----------------------------------------------------------------------------//
 // AVX: Convert BF16/F16 to F32 and broadcast into packed F32
 //----------------------------------------------------------------------------//
diff --git a/mlir/test/Dialect/X86Vector/legalize-for-llvm.mlir b/mlir/test/Dialect/X86Vector/legalize-for-llvm.mlir
index 63f06624ef897..a70410497acbd 100644
--- a/mlir/test/Dialect/X86Vector/legalize-for-llvm.mlir
+++ b/mlir/test/Dialect/X86Vector/legalize-for-llvm.mlir
@@ -219,3 +219,19 @@ func.func @avx_dot(%a: vector<8xf32>, %b: vector<8xf32>) -> (vector<8xf32>)
   %0 = x86vector.avx.intr.dot %a, %b : vector<8xf32>
   return %0 : vector<8xf32>
 }
+
+// CHECK-LABEL: func @avx_dot_i32_128
+func.func @avx_dot_i32_128(%src: vector<4xi32>, %a: vector<4xi32>,
+    %b: vector<4xi32>) -> vector<4xi32> {
+  // CHECK: llvm.call_intrinsic "llvm.x86.avx2.vpdpbssd.128"
+  %0 = x86vector.avx.dot.i32 %src, %a, %b : vector<4xi32> -> vector<4xi32>
+  return %0 : vector<4xi32>
+}
+
+// CHECK-LABEL: func @avx_dot_i32_256
+func.func @avx_dot_i32_256(%src: vector<8xi32>, %a: vector<8xi32>,
+    %b: vector<8xi32>) -> vector<8xi32> {
+  // CHECK: llvm.call_intrinsic "llvm.x86.avx2.vpdpbssd.256"
+  %0 = x86vector.avx.dot.i32 %src, %a, %b : vector<8xi32> -> vector<8xi32>
+  return %0 : vector<8xi32>
+}
diff --git a/mlir/test/Dialect/X86Vector/roundtrip.mlir b/mlir/test/Dialect/X86Vector/roundtrip.mlir
index 7dcab3eb4dcb8..bd3509eb07b2b 100644
--- a/mlir/test/Dialect/X86Vector/roundtrip.mlir
+++ b/mlir/test/Dialect/X86Vector/roundtrip.mlir
@@ -229,3 +229,19 @@ func.func @avx_dot(%a: vector<8xf32>, %b: vector<8xf32>) -> (vector<8xf32>)
   %0 = x86vector.avx.intr.dot %a, %b : vector<8xf32>
   return %0 : vector<8xf32>
 }
+
+// CHECK-LABEL: func @avx_dot_i32_128
+func.func @avx_dot_i32_128(%src: vector<4xi32>, %a: vector<4xi32>,
+    %b: vector<4xi32>) -> vector<4xi32> {
+  // CHECK: x86vector.avx.dot.i32 {{.*}} : vector<4xi32> -> vector<4xi32>
+  %0 = x86vector.avx.dot.i32 %src, %a, %b : vector<4xi32> -> vector<4xi32>
+  return %0 : vector<4xi32>
+}
+
+// CHECK-LABEL: func @avx_dot_i32_256
+func.func @avx_dot_i32_256(%src: vector<8xi32>, %a: vector<8xi32>,
+    %b: vector<8xi32>) -> vector<8xi32> {
+  // CHECK: x86vector.avx.dot.i32 {{.*}} : vector<8xi32> -> vector<8xi32>
+  %0 = x86vector.avx.dot.i32 %src, %a, %b : vector<8xi32> -> vector<8xi32>
+  return %0 : vector<8xi32>
+}
diff --git a/mlir/test/Target/LLVMIR/x86vector.mlir b/mlir/test/Target/LLVMIR/x86vector.mlir
index d11dc89bdc7c9..ac2f3e1277df3 100644
--- a/mlir/test/Target/LLVMIR/x86vector.mlir
+++ b/mlir/test/Target/LLVMIR/x86vector.mlir
@@ -234,3 +234,19 @@ func.func @LLVM_x86_avx_dp_ps_256(
   %0 = x86vector.avx.intr.dot %a, %b : vector<8xf32>
   return %0 : vector<8xf32>
 }
+
+// CHECK-LABEL: define <4 x i32> @LLVM_x86_avx2_vpdpbssd_128
+func.func @LLVM_x86_avx2_vpdpbssd_128(%src: vector<4xi32>, %a: vector<4xi32>,
+    %b: vector<4xi32>) -> vector<4xi32> {
+    // CHECK: call <4 x i32> @llvm.x86.avx2.vpdpbssd.128(
+  %0 = x86vector.avx.dot.i32 %src, %a, %b : vector<4xi32> -> vector<4xi32>
+  return %0 : vector<4xi32>
+}
+
+// CHECK-LABEL: define <8 x i32> @LLVM_x86_avx2_vpdpbssd_256
+func.func @LLVM_x86_avx2_vpdpbssd_256(%src: vector<8xi32>, %a: vector<8xi32>,
+    %b: vector<8xi32>) -> vector<8xi32> {
+    // CHECK: call <8 x i32> @llvm.x86.avx2.vpdpbssd.256(
+  %0 = x86vector.avx.dot.i32 %src, %a, %b : vector<8xi32> -> vector<8xi32>
+  return %0 : vector<8xi32>
+}

>From df153cfc5d8e9c60a5fb38b058a3bfffcce37516 Mon Sep 17 00:00:00 2001
From: Arun Thangamani <arun.thangamani at intel.com>
Date: Thu, 10 Jul 2025 00:49:48 -0700
Subject: [PATCH 2/2] removing extra space

---
 mlir/include/mlir/Dialect/X86Vector/X86Vector.td | 2 --
 1 file changed, 2 deletions(-)

diff --git a/mlir/include/mlir/Dialect/X86Vector/X86Vector.td b/mlir/include/mlir/Dialect/X86Vector/X86Vector.td
index c3f7904fa1249..688f26211e48d 100644
--- a/mlir/include/mlir/Dialect/X86Vector/X86Vector.td
+++ b/mlir/include/mlir/Dialect/X86Vector/X86Vector.td
@@ -302,8 +302,6 @@ def DotBF16Op : AVX512_Op<"dot", [Pure,
   }];
 }
 
-
-
 //----------------------------------------------------------------------------//
 // Convert packed F32 to packed BF16
 //----------------------------------------------------------------------------//



More information about the Mlir-commits mailing list