[flang-commits] [flang] [flang][FIR] add FirAliasAnalysisOpInterface (PR #68317)

Tom Eccles via flang-commits flang-commits at lists.llvm.org
Thu Oct 5 07:58:36 PDT 2023


https://github.com/tblah created https://github.com/llvm/llvm-project/pull/68317

This interface allows (HL)FIR passes to add TBAA information to fir.load and fir.store. If present, these TBAA tags take precedence over those added during CodeGen.

We can't reuse mlir::LLVMIR::AliasAnalysisOpInterface because that uses the mlir::LLVMIR namespace so it tries to define methods for fir operations in the wrong namespace. But I did re-use the tbaa tag type to minimise boilerplate code.

The new builders are to preserve the old interface without the tbaa tag.

>From c13a5dc6d0509e329c8735c26361cd3abfdde5a1 Mon Sep 17 00:00:00 2001
From: Tom Eccles <tom.eccles at arm.com>
Date: Tue, 12 Sep 2023 15:40:30 +0000
Subject: [PATCH] [flang][FIR] add FirAliasAnalysisOpInterface

This interface allows (HL)FIR passes to add TBAA information to fir.load
and fir.store. If present, these TBAA tags take precedence over those
added during CodeGen.

We can't reuse mlir::LLVMIR::AliasAnalysisOpInterface because that uses
the mlir::LLVMIR namespace so it tries to define methods for fir
operations in the wrong namespace. But I did re-use the tbaa tag type to
minimise boilerplate code.

The new builders are to preserve the old interface without the tbaa tag.
---
 .../flang/Optimizer/Dialect/CMakeLists.txt    |  4 ++
 .../include/flang/Optimizer/Dialect/FIROps.h  |  1 +
 .../include/flang/Optimizer/Dialect/FIROps.td | 17 ++++--
 .../Dialect/FirAliasAnalysisOpInterface.h     | 27 +++++++++
 .../Dialect/FirAliasAnalysisOpInterface.td    | 59 +++++++++++++++++++
 flang/lib/Optimizer/CodeGen/CodeGen.cpp       | 15 ++++-
 flang/lib/Optimizer/Dialect/CMakeLists.txt    |  1 +
 flang/lib/Optimizer/Dialect/FIROps.cpp        | 17 +++++-
 .../Dialect/FirAliasAnalysisOpInterface.cpp   | 31 ++++++++++
 flang/test/Fir/tbaa-codegen.fir               | 47 +++++++++++++++
 10 files changed, 210 insertions(+), 9 deletions(-)
 create mode 100644 flang/include/flang/Optimizer/Dialect/FirAliasAnalysisOpInterface.h
 create mode 100644 flang/include/flang/Optimizer/Dialect/FirAliasAnalysisOpInterface.td
 create mode 100644 flang/lib/Optimizer/Dialect/FirAliasAnalysisOpInterface.cpp
 create mode 100644 flang/test/Fir/tbaa-codegen.fir

diff --git a/flang/include/flang/Optimizer/Dialect/CMakeLists.txt b/flang/include/flang/Optimizer/Dialect/CMakeLists.txt
index d657e3f16690377..15c835aad9bc7d2 100644
--- a/flang/include/flang/Optimizer/Dialect/CMakeLists.txt
+++ b/flang/include/flang/Optimizer/Dialect/CMakeLists.txt
@@ -18,6 +18,10 @@ set(LLVM_TARGET_DEFINITIONS FortranVariableInterface.td)
 mlir_tablegen(FortranVariableInterface.h.inc -gen-op-interface-decls)
 mlir_tablegen(FortranVariableInterface.cpp.inc -gen-op-interface-defs)
 
+set(LLVM_TARGET_DEFINITIONS FirAliasAnalysisOpInterface.td)
+mlir_tablegen(FirAliasAnalaysOpInterface.h.inc -gen-op-interface-decls)
+mlir_tablegen(FirAliasAnalysisOpInterface.cpp.inc -gen-op-interface-defs)
+
 set(LLVM_TARGET_DEFINITIONS CanonicalizationPatterns.td)
 mlir_tablegen(CanonicalizationPatterns.inc -gen-rewriters)
 add_public_tablegen_target(CanonicalizationPatternsIncGen)
diff --git a/flang/include/flang/Optimizer/Dialect/FIROps.h b/flang/include/flang/Optimizer/Dialect/FIROps.h
index 8f03dc5cf795225..bab35bac5c81f4b 100644
--- a/flang/include/flang/Optimizer/Dialect/FIROps.h
+++ b/flang/include/flang/Optimizer/Dialect/FIROps.h
@@ -11,6 +11,7 @@
 
 #include "flang/Optimizer/Dialect/FIRAttr.h"
 #include "flang/Optimizer/Dialect/FIRType.h"
+#include "flang/Optimizer/Dialect/FirAliasAnalysisOpInterface.h"
 #include "flang/Optimizer/Dialect/FortranVariableInterface.h"
 #include "mlir/Dialect/Arith/IR/Arith.h"
 #include "mlir/Dialect/Func/IR/FuncOps.h"
diff --git a/flang/include/flang/Optimizer/Dialect/FIROps.td b/flang/include/flang/Optimizer/Dialect/FIROps.td
index a57add9f731979d..fae9b92662f3559 100644
--- a/flang/include/flang/Optimizer/Dialect/FIROps.td
+++ b/flang/include/flang/Optimizer/Dialect/FIROps.td
@@ -16,10 +16,12 @@
 
 include "mlir/Dialect/Arith/IR/ArithBase.td"
 include "mlir/Dialect/Arith/IR/ArithOpsInterfaces.td"
+include "mlir/Dialect/LLVMIR/LLVMAttrDefs.td"
 include "flang/Optimizer/Dialect/FIRDialect.td"
 include "flang/Optimizer/Dialect/FIRTypes.td"
 include "flang/Optimizer/Dialect/FIRAttr.td"
 include "flang/Optimizer/Dialect/FortranVariableInterface.td"
+include "flang/Optimizer/Dialect/FirAliasAnalysisOpInterface.td"
 include "mlir/IR/BuiltinAttributes.td"
 
 // Base class for FIR operations.
@@ -258,7 +260,7 @@ def fir_FreeMemOp : fir_Op<"freemem", [MemoryEffects<[MemFree]>]> {
   let assemblyFormat = "$heapref attr-dict `:` qualified(type($heapref))";
 }
 
-def fir_LoadOp : fir_OneResultOp<"load", []> {
+def fir_LoadOp : fir_OneResultOp<"load", [FirAliasAnalysisOpInterface]> {
   let summary = "load a value from a memory reference";
   let description = [{
     Load a value from a memory reference into an ssa-value (virtual register).
@@ -274,9 +276,11 @@ def fir_LoadOp : fir_OneResultOp<"load", []> {
     or null.
   }];
 
-  let arguments = (ins Arg<AnyReferenceLike, "", [MemRead]>:$memref);
+  let arguments = (ins Arg<AnyReferenceLike, "", [MemRead]>:$memref,
+                  OptionalAttr<LLVM_TBAATagArrayAttr>:$tbaa);
 
-  let builders = [OpBuilder<(ins "mlir::Value":$refVal)>];
+  let builders = [OpBuilder<(ins "mlir::Value":$refVal)>,
+                  OpBuilder<(ins "mlir::Type":$resTy, "mlir::Value":$refVal)>];
 
   let hasCustomAssemblyFormat = 1;
 
@@ -285,7 +289,7 @@ def fir_LoadOp : fir_OneResultOp<"load", []> {
   }];
 }
 
-def fir_StoreOp : fir_Op<"store", []> {
+def fir_StoreOp : fir_Op<"store", [FirAliasAnalysisOpInterface]> {
   let summary = "store an SSA-value to a memory location";
 
   let description = [{
@@ -305,7 +309,10 @@ def fir_StoreOp : fir_Op<"store", []> {
   }];
 
   let arguments = (ins AnyType:$value,
-                   Arg<AnyReferenceLike, "", [MemWrite]>:$memref);
+                   Arg<AnyReferenceLike, "", [MemWrite]>:$memref,
+                   OptionalAttr<LLVM_TBAATagArrayAttr>:$tbaa);
+
+  let builders = [OpBuilder<(ins "mlir::Value":$value, "mlir::Value":$memref)>];
 
   let hasCustomAssemblyFormat = 1;
   let hasVerifier = 1;
diff --git a/flang/include/flang/Optimizer/Dialect/FirAliasAnalysisOpInterface.h b/flang/include/flang/Optimizer/Dialect/FirAliasAnalysisOpInterface.h
new file mode 100644
index 000000000000000..c07bf648eab454a
--- /dev/null
+++ b/flang/include/flang/Optimizer/Dialect/FirAliasAnalysisOpInterface.h
@@ -0,0 +1,27 @@
+//===- FirAliasAnalysisInterface.h ------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains an interface for adding alias analysis information to
+// loads and stores
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef FORTRAN_OPTIMIZER_DIALECT_FIR_ALIAS_ANALYSIS_INTERFACE_H
+#define FORTRAN_OPTIMIZER_DIALECT_FIR_ALIAS_ANALYSIS_INTERFACE_H
+
+#include "mlir/IR/OpDefinition.h"
+#include "mlir/IR/Operation.h"
+#include "mlir/Support/LogicalResult.h"
+
+namespace fir::detail {
+mlir::LogicalResult verifyFirAliasAnalysisOpInterface(mlir::Operation *op);
+} // namespace fir::detail
+
+#include "flang/Optimizer/Dialect/FirAliasAnalaysOpInterface.h.inc"
+
+#endif // FORTRAN_OPTIMIZER_DIALECT_FIR_ALIAS_ANALYSIS_INTERFACE_H
diff --git a/flang/include/flang/Optimizer/Dialect/FirAliasAnalysisOpInterface.td b/flang/include/flang/Optimizer/Dialect/FirAliasAnalysisOpInterface.td
new file mode 100644
index 000000000000000..1d3e49d383f63a4
--- /dev/null
+++ b/flang/include/flang/Optimizer/Dialect/FirAliasAnalysisOpInterface.td
@@ -0,0 +1,59 @@
+//===-- FirAliasAnalysisOpInterface.td ---------------------*- tablegen -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+include "mlir/IR/Interfaces.td"
+
+def FirAliasAnalysisOpInterface : OpInterface<"FirAliasAnalysisOpInterface"> {
+  let description = [{
+    An interface for memory operations that can carry alias analysis metadata.
+    It provides setters and getters for the operation's alias analysis
+    attributes. The default implementations of the interface methods expect
+    the operation to have an attribute of type ArrayAttr named tbaa.
+    Unlike the mlir::LLVM::AliasAnalysisOpInterface, this only supports tbaa.
+  }];
+
+  let cppNamespace = "::fir";
+  let verify = [{ return detail::verifyFirAliasAnalysisOpInterface($_op); }];
+
+  let methods = [
+    InterfaceMethod<
+      /*desc=*/        "Returns the tbaa attribute or nullptr",
+      /*returnType=*/  "mlir::ArrayAttr",
+      /*methodName=*/  "getTBAATagsOrNull",
+      /*args=*/        (ins),
+      /*methodBody=*/  [{}],
+      /*defaultImpl=*/ [{
+        auto op = mlir::cast<ConcreteOp>(this->getOperation());
+        return op.getTbaaAttr();
+      }]
+      >,
+    InterfaceMethod<
+      /*desc=*/        "Sets the tbaa attribute",
+      /*returnType=*/  "void",
+      /*methodName=*/  "setTBAATags",
+      /*args=*/        (ins "const mlir::ArrayAttr":$attr),
+      /*methodBody=*/  [{}],
+      /*defaultImpl=*/ [{
+        auto op = mlir::cast<ConcreteOp>(this->getOperation());
+        op.setTbaaAttr(attr);
+      }]
+      >,
+    InterfaceMethod<
+      /*desc=*/        "Returns a list of all pointer operands accessed by the "
+                       "operation",
+      /*returnType=*/  "::llvm::SmallVector<::mlir::Value>",
+      /*methodName=*/  "getAccessedOperands",
+      /*args=*/        (ins),
+      /*methodBody=*/  [{}],
+      /*defaultImpl=*/ [{
+        auto op = mlir::cast<ConcreteOp>(this->getOperation());
+        return {op.getMemref()};
+      }]
+      >
+  ];
+}
diff --git a/flang/lib/Optimizer/CodeGen/CodeGen.cpp b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
index d1b7f3de93b4647..f2ce123124895e0 100644
--- a/flang/lib/Optimizer/CodeGen/CodeGen.cpp
+++ b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
@@ -3085,7 +3085,10 @@ struct LoadOpConversion : public FIROpConversion<fir::LoadOp> {
       auto boxValue = rewriter.create<mlir::LLVM::LoadOp>(
           loc, boxPtrTy.cast<mlir::LLVM::LLVMPointerType>().getElementType(),
           inputBoxStorage);
-      attachTBAATag(boxValue, boxTy, boxTy, nullptr);
+      if (std::optional<mlir::ArrayAttr> optionalTag = load.getTbaa())
+        boxValue.setTBAATags(*optionalTag);
+      else
+        attachTBAATag(boxValue, boxTy, boxTy, nullptr);
       auto newBoxStorage =
           genAllocaWithType(loc, boxPtrTy, defaultAlign, rewriter);
       auto storeOp =
@@ -3096,7 +3099,10 @@ struct LoadOpConversion : public FIROpConversion<fir::LoadOp> {
       mlir::Type loadTy = convertType(load.getType());
       auto loadOp = rewriter.create<mlir::LLVM::LoadOp>(
           load.getLoc(), loadTy, adaptor.getOperands(), load->getAttrs());
-      attachTBAATag(loadOp, load.getType(), load.getType(), nullptr);
+      if (std::optional<mlir::ArrayAttr> optionalTag = load.getTbaa())
+        loadOp.setTBAATags(*optionalTag);
+      else
+        attachTBAATag(loadOp, load.getType(), load.getType(), nullptr);
       rewriter.replaceOp(load, loadOp.getResult());
     }
     return mlir::success();
@@ -3340,7 +3346,10 @@ struct StoreOpConversion : public FIROpConversion<fir::StoreOp> {
       newStoreOp = rewriter.create<mlir::LLVM::StoreOp>(
           loc, adaptor.getOperands()[0], adaptor.getOperands()[1]);
     }
-    attachTBAATag(newStoreOp, storeTy, storeTy, nullptr);
+    if (std::optional<mlir::ArrayAttr> optionalTag = store.getTbaa())
+      newStoreOp.setTBAATags(*optionalTag);
+    else
+      attachTBAATag(newStoreOp, storeTy, storeTy, nullptr);
     rewriter.eraseOp(store);
     return mlir::success();
   }
diff --git a/flang/lib/Optimizer/Dialect/CMakeLists.txt b/flang/lib/Optimizer/Dialect/CMakeLists.txt
index fe5edb54a78e9e5..6beabcdb4e25d76 100644
--- a/flang/lib/Optimizer/Dialect/CMakeLists.txt
+++ b/flang/lib/Optimizer/Dialect/CMakeLists.txt
@@ -6,6 +6,7 @@ add_flang_library(FIRDialect
   FIROps.cpp
   FIRType.cpp
   FortranVariableInterface.cpp
+  FirAliasAnalysisOpInterface.cpp
   Inliner.cpp
 
   DEPENDS
diff --git a/flang/lib/Optimizer/Dialect/FIROps.cpp b/flang/lib/Optimizer/Dialect/FIROps.cpp
index 962b87acd5a8050..2f08cd1b8111531 100644
--- a/flang/lib/Optimizer/Dialect/FIROps.cpp
+++ b/flang/lib/Optimizer/Dialect/FIROps.cpp
@@ -2016,8 +2016,18 @@ void fir::LoadOp::build(mlir::OpBuilder &builder, mlir::OperationState &result,
     mlir::emitError(result.location, "not a memory reference type");
     return;
   }
+  build(builder, result, eleTy, refVal);
+}
+
+void fir::LoadOp::build(mlir::OpBuilder &builder, mlir::OperationState &result,
+                        mlir::Type resTy, mlir::Value refVal) {
+
+  if (!refVal) {
+    mlir::emitError(result.location, "LoadOp has null argument");
+    return;
+  }
   result.addOperands(refVal);
-  result.addTypes(eleTy);
+  result.addTypes(resTy);
 }
 
 mlir::ParseResult fir::LoadOp::getElementOf(mlir::Type &ele, mlir::Type ref) {
@@ -3288,6 +3298,11 @@ mlir::LogicalResult fir::StoreOp::verify() {
   return mlir::success();
 }
 
+void fir::StoreOp::build(mlir::OpBuilder &builder, mlir::OperationState &result,
+                         mlir::Value value, mlir::Value memref) {
+  build(builder, result, value, memref, {});
+}
+
 //===----------------------------------------------------------------------===//
 // StringLitOp
 //===----------------------------------------------------------------------===//
diff --git a/flang/lib/Optimizer/Dialect/FirAliasAnalysisOpInterface.cpp b/flang/lib/Optimizer/Dialect/FirAliasAnalysisOpInterface.cpp
new file mode 100644
index 000000000000000..63686b1d0e7ebb6
--- /dev/null
+++ b/flang/lib/Optimizer/Dialect/FirAliasAnalysisOpInterface.cpp
@@ -0,0 +1,31 @@
+//===-- FirAliasAnalysisOpInterface.cpp ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Coding style: https://mlir.llvm.org/getting_started/DeveloperGuide/
+//
+//===----------------------------------------------------------------------===//
+
+#include "flang/Optimizer/Dialect/FirAliasAnalysisOpInterface.h"
+#include "mlir/Dialect/LLVMIR/LLVMDialect.h"
+
+#include "flang/Optimizer/Dialect/FirAliasAnalysisOpInterface.cpp.inc"
+
+mlir::LogicalResult
+fir::detail::verifyFirAliasAnalysisOpInterface(mlir::Operation *op) {
+  auto iface = mlir::cast<FirAliasAnalysisOpInterface>(op);
+
+  mlir::ArrayAttr tags = iface.getTBAATagsOrNull();
+  if (!tags)
+    return mlir::success();
+
+  for (mlir::Attribute iter : tags)
+    if (!mlir::isa<mlir::LLVM::TBAATagAttr>(iter))
+      return op->emitOpError("expected op to return array of ")
+             << mlir::LLVM::TBAATagAttr::getMnemonic() << " attributes";
+  return mlir::success();
+}
diff --git a/flang/test/Fir/tbaa-codegen.fir b/flang/test/Fir/tbaa-codegen.fir
new file mode 100644
index 000000000000000..386fe42eaaba9a2
--- /dev/null
+++ b/flang/test/Fir/tbaa-codegen.fir
@@ -0,0 +1,47 @@
+// test that tbaa attributes can be added to fir.load and fir.store
+// and that these attributes are propagated to LLVMIR
+
+// RUN: tco %s | FileCheck %s
+
+// subroutine simple(a)
+//   integer, intent(inout) :: a(:)
+//   a(1) = a(2)
+// end subroutine
+#tbaa_root = #llvm.tbaa_root<id = "Flang function root _QPsimple">
+#tbaa_type_desc = #llvm.tbaa_type_desc<id = "any access", members = {<#tbaa_root, 0>}>
+#tbaa_type_desc1 = #llvm.tbaa_type_desc<id = "any data access", members = {<#tbaa_type_desc, 0>}>
+#tbaa_type_desc2 = #llvm.tbaa_type_desc<id = "dummy arg data", members = {<#tbaa_type_desc1, 0>}>
+#tbaa_type_desc3 = #llvm.tbaa_type_desc<id = "dummy arg data/a", members = {<#tbaa_type_desc2, 0>}>
+#tbaa_tag = #llvm.tbaa_tag<base_type = #tbaa_type_desc3, access_type = #tbaa_type_desc3, offset = 0>
+module attributes {fir.defaultkind = "a1c4d8i4l4r4", fir.kindmap = "", llvm.target_triple = "aarch64-unknown-linux-gnu"} {
+  func.func @_QPsimple(%arg0: !fir.box<!fir.array<?xi32>> {fir.bindc_name = "a"}) {
+    %c1 = arith.constant 1 : index
+    %c2 = arith.constant 2 : index
+    %0 = fir.declare %arg0 {fortran_attrs = #fir.var_attrs<intent_inout>, uniq_name = "_QFfuncEa"} : (!fir.box<!fir.array<?xi32>>) -> !fir.box<!fir.array<?xi32>>
+    %1 = fir.rebox %0 : (!fir.box<!fir.array<?xi32>>) -> !fir.box<!fir.array<?xi32>>
+    %2 = fir.array_coor %1 %c2 : (!fir.box<!fir.array<?xi32>>, index) -> !fir.ref<i32>
+    %3 = fir.load %2 {tbaa = [#tbaa_tag]} : !fir.ref<i32>
+    %4 = fir.array_coor %1 %c1 : (!fir.box<!fir.array<?xi32>>, index) -> !fir.ref<i32>
+    fir.store %3 to %4 {tbaa = [#tbaa_tag]} : !fir.ref<i32>
+    return
+  }
+}
+
+// CHECK-LABEL: define void @_QPsimple(
+// CHECK-SAME:      ptr %[[ARG0:.*]]) {
+// [...]
+// load  a(2):
+// CHECK:  %[[VAL20:.*]] = getelementptr i8, ptr %{{.*}}, i64 %{{.*}}
+// CHECK:  %[[A2:.*]] = load i32, ptr %[[VAL20]], align 4, !tbaa ![[A_ACCESS_TAG:.*]]
+// [...]
+// store a(2) to a(1):
+// CHECK:  %[[A1:.*]] = getelementptr i8, ptr %{{.*}}, i64 %{{.*}}
+// CHECK:  store i32 %[[A2]], ptr %[[A1]], align 4, !tbaa ![[A_ACCESS_TAG]]
+// CHECK:  ret void
+// CHECK: }
+// CHECK: ![[A_ACCESS_TAG]] = !{![[A_ACCESS_TYPE:.*]], ![[A_ACCESS_TYPE]], i64 0}
+// CHECK: ![[A_ACCESS_TYPE]] = !{!"dummy arg data/a", ![[DUMMY_ARG_TYPE:.*]], i64 0}
+// CHECK: ![[DUMMY_ARG_TYPE]] = !{!"dummy arg data", ![[DATA_ACCESS_TYPE:.*]], i64 0}
+// CHECK: ![[DATA_ACCESS_TYPE]] = !{!"any data access", ![[ANY_ACCESS_TYPE:.*]], i64 0}
+// CHECK: ![[ANY_ACCESS_TYPE]] = !{!"any access", ![[ROOT:.*]], i64 0}
+// CHECK: ![[ROOT]] = !{!"Flang function root _QPsimple"}
\ No newline at end of file



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