[mlir][LLVM] Add nneg flag #115498

lfrenot · 2024-11-08T15:17:54Z

This implementation is based on the existing one for the exact flag.

If the nneg flag is set and the argument is negative, the result is a poison value.

@zero9178, @gysit and @Dinistro, could you take a look?

This implementation is based on the existing one for the exact flag. If the nneg flag is set, and the argument is negative, the result is a poison value.

llvmbot · 2024-11-08T15:18:30Z

@llvm/pr-subscribers-mlir

@llvm/pr-subscribers-mlir-llvm

Author: None (lfrenot)

Changes

This implementation is based on the existing one for the exact flag.

If the nneg flag is set and the argument is negative, the result is a poison value.

@zero9178, @gysit and @Dinistro, could you take a look?

Full diff: https://github.com/llvm/llvm-project/pull/115498.diff

8 Files Affected:

(modified) mlir/include/mlir/Dialect/LLVMIR/LLVMInterfaces.td (+27)
(modified) mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td (+19-2)
(modified) mlir/include/mlir/Target/LLVMIR/ModuleImport.h (+5)
(modified) mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp (+3)
(modified) mlir/lib/Target/LLVMIR/ModuleImport.cpp (+6)
(modified) mlir/test/Dialect/LLVMIR/roundtrip.mlir (+13)
(added) mlir/test/Target/LLVMIR/Import/nneg.ll (+10)
(added) mlir/test/Target/LLVMIR/nneg.mlir (+10)

diff --git a/mlir/include/mlir/Dialect/LLVMIR/LLVMInterfaces.td b/mlir/include/mlir/Dialect/LLVMIR/LLVMInterfaces.td
index 12c430df208925..352e2ec91bdbea 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/LLVMInterfaces.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/LLVMInterfaces.td
@@ -114,6 +114,33 @@ def ExactFlagInterface : OpInterface<"ExactFlagInterface"> {
   ];
 }
 
+def NonNegFlagInterface : OpInterface<"NonNegFlagInterface"> {
+  let description = [{
+    This interface defines an LLVM operation with an nneg flag and
+    provides a uniform API for accessing it.
+  }];
+
+  let cppNamespace = "::mlir::LLVM";
+
+  let methods = [
+    InterfaceMethod<[{
+      Get the nneg flag for the operation.
+    }], "bool", "getNonNeg", (ins), [{}], [{
+      return $_op.getProperties().nonNeg;
+    }]>,
+    InterfaceMethod<[{
+      Set the nneg flag for the operation.
+    }], "void", "setNonNeg", (ins "bool":$nonNeg), [{}], [{
+      $_op.getProperties().nonNeg = nonNeg;
+    }]>,
+    StaticInterfaceMethod<[{
+      Get the attribute name of the nonNeg property.
+    }], "StringRef", "getNonNegName", (ins), [{}], [{
+      return "nonNeg";
+    }]>,
+  ];
+}
+
 def BranchWeightOpInterface : OpInterface<"BranchWeightOpInterface"> {
   let description = [{
     An interface for operations that can carry branch weights metadata. It
diff --git a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
index 315af2594047a5..afdba9b9a16b5f 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
@@ -508,6 +508,23 @@ class LLVM_CastOp<string mnemonic, string instName, Type type,
       $_location, $_resultType, $arg);
   }];
 }
+class LLVM_CastOpWithNNegFlag<string mnemonic, string instName, Type type,
+                  Type resultType, list<Trait> traits = []> :
+    LLVM_Op<mnemonic, !listconcat([Pure], [DeclareOpInterfaceMethods<NonNegFlagInterface>], traits)>,
+    LLVM_Builder<"$res = builder.Create" # instName # "($arg, $_resultType, /*Name=*/\"\", op.getNonNeg());"> {
+  let arguments = (ins type:$arg,  UnitAttr:$nonNeg);
+  let results = (outs resultType:$res);
+  let builders = [LLVM_OneResultOpBuilder];
+  let assemblyFormat = "(`nneg` $nonNeg^)? $arg attr-dict `:` type($arg) `to` type($res)";
+  string llvmInstName = instName;
+  string mlirBuilder = [{
+    auto op = $_builder.create<$_qualCppClassName>(
+      $_location, $_resultType, $arg);
+    moduleImport.setNonNegFlag(inst, op);
+    $res = op;
+  }];
+}
+
 def LLVM_BitcastOp : LLVM_CastOp<"bitcast", "BitCast", LLVM_AnyNonAggregate,
     LLVM_AnyNonAggregate, [DeclareOpInterfaceMethods<PromotableOpInterface>]> {
   let hasFolder = 1;
@@ -531,7 +548,7 @@ def LLVM_SExtOp : LLVM_CastOp<"sext", "SExt",
                               LLVM_ScalarOrVectorOf<AnySignlessInteger>> {
   let hasVerifier = 1;
 }
-def LLVM_ZExtOp : LLVM_CastOp<"zext", "ZExt",
+def LLVM_ZExtOp : LLVM_CastOpWithNNegFlag<"zext", "ZExt",
                               LLVM_ScalarOrVectorOf<AnySignlessInteger>,
                               LLVM_ScalarOrVectorOf<AnySignlessInteger>> {
   let hasFolder = 1;
@@ -543,7 +560,7 @@ def LLVM_TruncOp : LLVM_CastOp<"trunc", "Trunc",
 def LLVM_SIToFPOp : LLVM_CastOp<"sitofp", "SIToFP",
                                 LLVM_ScalarOrVectorOf<AnySignlessInteger>,
                                 LLVM_ScalarOrVectorOf<LLVM_AnyFloat>>;
-def LLVM_UIToFPOp : LLVM_CastOp<"uitofp", "UIToFP",
+def LLVM_UIToFPOp : LLVM_CastOpWithNNegFlag<"uitofp", "UIToFP",
                                 LLVM_ScalarOrVectorOf<AnySignlessInteger>,
                                 LLVM_ScalarOrVectorOf<LLVM_AnyFloat>>;
 def LLVM_FPToSIOp : LLVM_CastOp<"fptosi", "FPToSI",
diff --git a/mlir/include/mlir/Target/LLVMIR/ModuleImport.h b/mlir/include/mlir/Target/LLVMIR/ModuleImport.h
index 6c3a500f20e3a9..30164843f63675 100644
--- a/mlir/include/mlir/Target/LLVMIR/ModuleImport.h
+++ b/mlir/include/mlir/Target/LLVMIR/ModuleImport.h
@@ -192,6 +192,11 @@ class ModuleImport {
   /// implement the exact flag interface.
   void setExactFlag(llvm::Instruction *inst, Operation *op) const;
 
+  /// Sets the nneg flag attribute for the imported operation `op` given
+  /// the original instruction `inst`. Asserts if the operation does not
+  /// implement the nneg flag interface.
+  void setNonNegFlag(llvm::Instruction *inst, Operation *op) const;
+
   /// Sets the fastmath flags attribute for the imported operation `op` given
   /// the original instruction `inst`. Asserts if the operation does not
   /// implement the fastmath interface.
diff --git a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
index 6b2d8943bf4885..d39edb8020ccb6 100644
--- a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
@@ -146,6 +146,9 @@ static void printLLVMOpAttrs(OpAsmPrinter &printer, Operation *op,
   } else if (auto iface = dyn_cast<ExactFlagInterface>(op)) {
     printer.printOptionalAttrDict(filteredAttrs,
                                   /*elidedAttrs=*/{iface.getIsExactName()});
+  } else if (auto iface = dyn_cast<NonNegFlagInterface>(op)) {
+    printer.printOptionalAttrDict(filteredAttrs,
+                                  /*elidedAttrs=*/{iface.getNonNegName()});
   } else {
     printer.printOptionalAttrDict(filteredAttrs);
   }
diff --git a/mlir/lib/Target/LLVMIR/ModuleImport.cpp b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
index 12145f7a2217df..71d88d3a62f2b9 100644
--- a/mlir/lib/Target/LLVMIR/ModuleImport.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
@@ -689,6 +689,12 @@ void ModuleImport::setExactFlag(llvm::Instruction *inst, Operation *op) const {
   iface.setIsExact(inst->isExact());
 }
 
+void ModuleImport::setNonNegFlag(llvm::Instruction *inst, Operation *op) const {
+  auto iface = cast<NonNegFlagInterface>(op);
+
+  iface.setNonNeg(inst->hasNonNeg());
+}
+
 void ModuleImport::setFastmathFlagsAttr(llvm::Instruction *inst,
                                         Operation *op) const {
   auto iface = cast<FastmathFlagsInterface>(op);
diff --git a/mlir/test/Dialect/LLVMIR/roundtrip.mlir b/mlir/test/Dialect/LLVMIR/roundtrip.mlir
index 682780c5f0a7df..f96f7d7fecae5a 100644
--- a/mlir/test/Dialect/LLVMIR/roundtrip.mlir
+++ b/mlir/test/Dialect/LLVMIR/roundtrip.mlir
@@ -325,6 +325,19 @@ func.func @casts(%arg0: i32, %arg1: i64, %arg2: vector<4xi32>,
   llvm.return
 }
 
+// CHECK-LABEL: @nneg_casts
+// CHECK-SAME: (%[[I32:.*]]: i32, %[[I64:.*]]: i64, %[[V4I32:.*]]: vector<4xi32>, %[[V4I64:.*]]: vector<4xi64>, %[[PTR:.*]]: !llvm.ptr)
+func.func @nneg_casts(%arg0: i32, %arg1: i64, %arg2: vector<4xi32>,
+                %arg3: vector<4xi64>, %arg4: !llvm.ptr) {
+// CHECK:  = llvm.zext nneg %[[I32]] : i32 to i64
+  %0 = llvm.zext nneg %arg0 : i32 to i64
+// CHECK:  = llvm.zext nneg %[[V4I32]] : vector<4xi32> to vector<4xi64>
+  %4 = llvm.zext nneg %arg2 : vector<4xi32> to vector<4xi64>
+// CHECK: %[[FLOAT:.*]] = llvm.uitofp nneg %[[I32]] : i32 to f32
+  %7 = llvm.uitofp nneg %arg0 : i32 to f32
+  llvm.return
+}
+
 // CHECK-LABEL: @vect
 func.func @vect(%arg0: vector<4xf32>, %arg1: i32, %arg2: f32, %arg3: !llvm.vec<2 x ptr>) {
 // CHECK:  = llvm.extractelement {{.*}} : vector<4xf32>
diff --git a/mlir/test/Target/LLVMIR/Import/nneg.ll b/mlir/test/Target/LLVMIR/Import/nneg.ll
new file mode 100644
index 00000000000000..07756b9f706bdb
--- /dev/null
+++ b/mlir/test/Target/LLVMIR/Import/nneg.ll
@@ -0,0 +1,10 @@
+; RUN: mlir-translate -import-llvm -split-input-file %s | FileCheck %s
+
+; CHECK-LABEL: @nnegflag_inst
+define void @nnegflag_inst(i32 %arg1) {
+  ; CHECK: llvm.zext nneg %{{.*}} : i32 to i64
+  %1 = zext nneg i32 %arg1 to i64
+  ; CHECK: llvm.uitofp nneg %{{.*}} : i32 to f32
+  %2 = uitofp nneg i32 %arg1 to float
+  ret void
+}
diff --git a/mlir/test/Target/LLVMIR/nneg.mlir b/mlir/test/Target/LLVMIR/nneg.mlir
new file mode 100644
index 00000000000000..8afa765a510e24
--- /dev/null
+++ b/mlir/test/Target/LLVMIR/nneg.mlir
@@ -0,0 +1,10 @@
+// RUN: mlir-translate -mlir-to-llvmir %s | FileCheck %s
+
+// CHECK-LABEL: define void @nnegflag_func
+llvm.func @nnegflag_func(%arg0: i32) {
+  // CHECK: %{{.*}} = zext nneg i32 %{{.*}} to i64
+  %0 = llvm.zext nneg %arg0 : i32 to i64
+  // CHECK: %{{.*}} = uitofp nneg i32 %{{.*}} to float
+  %1 = llvm.uitofp nneg %arg0 : i32 to f32
+  llvm.return
+}

gysit

Thanks!

LGTM modulo nit comments!

gysit · 2024-11-09T11:03:25Z

mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td

+                  Type resultType, list<Trait> traits = []> :
+    LLVM_Op<mnemonic, !listconcat([Pure], [DeclareOpInterfaceMethods<NonNegFlagInterface>], traits)>,
+    LLVM_Builder<"$res = builder.Create" # instName # "($arg, $_resultType, /*Name=*/\"\", op.getNonNeg());"> {
+  let arguments = (ins type:$arg,  UnitAttr:$nonNeg);


Suggested change

let arguments = (ins type:$arg, UnitAttr:$nonNeg);

let arguments = (ins type:$arg, UnitAttr:$nonNeg);

ultra nit:

gysit · 2024-11-09T11:05:31Z

mlir/test/Dialect/LLVMIR/roundtrip.mlir

+  %0 = llvm.zext nneg %arg0 : i32 to i64
+// CHECK:  = llvm.zext nneg %[[V4I32]] : vector<4xi32> to vector<4xi64>
+  %4 = llvm.zext nneg %arg2 : vector<4xi32> to vector<4xi64>
+// CHECK: %[[FLOAT:.*]] = llvm.uitofp nneg %[[I32]] : i32 to f32


Suggested change

// CHECK: %[[FLOAT:.*]] = llvm.uitofp nneg %[[I32]] : i32 to f32

// CHECK: = llvm.uitofp nneg %[[I32]] : i32 to f32

nit: I would drop the variable since it has no uses in this test.

gysit · 2024-11-09T11:08:08Z

mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp

@@ -146,6 +146,9 @@ static void printLLVMOpAttrs(OpAsmPrinter &printer, Operation *op,
  } else if (auto iface = dyn_cast<ExactFlagInterface>(op)) {
    printer.printOptionalAttrDict(filteredAttrs,
                                  /*elidedAttrs=*/{iface.getIsExactName()});
+  } else if (auto iface = dyn_cast<NonNegFlagInterface>(op)) {
+    printer.printOptionalAttrDict(filteredAttrs,


I suspect this is not needed since the operation does not use custom<LLVMOpAttrs>(attr-dict). It seems like this print/parseLLVMOpAttrs should only be used for the operations that use fast math flags. That can be cleaned up in a separate PR though.

I brief I would suggest to remove the NonNegFlagInterface here, except it is necessary for a reason I do not see right now?

This implementation is based on the existing one for the exact flag. If the nneg flag is set and the argument is negative, the result is a poison value.

[mlir][LLVM] Add nneg flag

581e190

This implementation is based on the existing one for the exact flag. If the nneg flag is set, and the argument is negative, the result is a poison value.

llvmbot added mlir:llvm mlir labels Nov 8, 2024

gysit approved these changes Nov 9, 2024

View reviewed changes

nit fixes

0d6fc68

gysit merged commit 89aaf2c into llvm:main Nov 11, 2024
8 checks passed

lfrenot deleted the mlir-llvm-nneg branch November 11, 2024 14:09

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

[mlir][LLVM] Add nneg flag #115498

[mlir][LLVM] Add nneg flag #115498

Uh oh!

lfrenot commented Nov 8, 2024

Uh oh!

llvmbot commented Nov 8, 2024 •

edited

Loading

Uh oh!

gysit left a comment

Uh oh!

gysit Nov 9, 2024

Uh oh!

lfrenot Nov 11, 2024

Uh oh!

gysit Nov 9, 2024

Uh oh!

lfrenot Nov 11, 2024

Uh oh!

gysit Nov 9, 2024

Uh oh!

lfrenot Nov 11, 2024

Uh oh!

Uh oh!

Uh oh!

	let arguments = (ins type:$arg, UnitAttr:$nonNeg);
	let arguments = (ins type:$arg, UnitAttr:$nonNeg);

	// CHECK: %[[FLOAT:.*]] = llvm.uitofp nneg %[[I32]] : i32 to f32
	// CHECK: = llvm.uitofp nneg %[[I32]] : i32 to f32

[mlir][LLVM] Add nneg flag #115498

[mlir][LLVM] Add nneg flag #115498

Uh oh!

Conversation

lfrenot commented Nov 8, 2024

Uh oh!

llvmbot commented Nov 8, 2024 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

gysit left a comment

Choose a reason for hiding this comment

Uh oh!

gysit Nov 9, 2024

Choose a reason for hiding this comment

Uh oh!

lfrenot Nov 11, 2024

Choose a reason for hiding this comment

Uh oh!

gysit Nov 9, 2024

Choose a reason for hiding this comment

Uh oh!

lfrenot Nov 11, 2024

Choose a reason for hiding this comment

Uh oh!

gysit Nov 9, 2024

Choose a reason for hiding this comment

Uh oh!

lfrenot Nov 11, 2024

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

llvmbot commented Nov 8, 2024 •

edited

Loading