[LLHD] Replace llhd.neg with comb.sub (#1654) (#1678)

* [LLHD] Replace llhd.neg with comb.sub (#1654) * [LLHD][test] remove repeated test for `comb.sub`
llvm · Aug 31, 2021 · 34832f4 · 34832f4
1 parent ba9c344
commit 34832f4
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diff --git a/include/circt/Dialect/LLHD/IR/ArithmeticOps.td b/include/circt/Dialect/LLHD/IR/ArithmeticOps.td
@@ -10,33 +10,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-def LLHD_NegOp : LLHD_ArithmeticOrBitwiseOp<"neg", []> {
-  let summary = "Negate a value.";
-  let description = [{
-    The operand and result always have the same type. The type has to be a
-    signless integer of any width. Although, only signless integers are
-    allowed, this instruction applies two's complement negation of the
-    integer, basically treating it as a signed integer.
-
-    Syntax:
-
-    ```
-    neg-op ::= ssa-id `=` `llhd.neg` ssa-value attr-dict `:` type
-    ```
-
-    Example:
-
-    ```mlir
-    %0 = llhd.const 42 : i32
-    %1 = llhd.neg %0 : i32
-    ```
-  }];
-
-  let arguments = (ins HWIntegerType:$value);
-
-  let hasFolder = 1;
-}
-
 def LLHD_EqOp : LLHD_Op<"eq", [
     NoSideEffect,
     Commutative,

diff --git a/lib/Conversion/LLHDToLLVM/LLHDToLLVM.cpp b/lib/Conversion/LLHDToLLVM/LLHDToLLVM.cpp
@@ -2062,30 +2062,6 @@ struct CombParityOpConversion : public ConvertToLLVMPattern {
 
 } // namespace
 
-namespace {
-/// Convert a NegOp to LLVM dialect.
-struct NegOpConversion : public ConvertToLLVMPattern {
-  explicit NegOpConversion(MLIRContext *ctx, LLVMTypeConverter &typeConverter)
-      : ConvertToLLVMPattern(llhd::NegOp::getOperationName(), ctx,
-                             typeConverter) {}
-
-  LogicalResult
-  matchAndRewrite(Operation *op, ArrayRef<Value> operands,
-                  ConversionPatternRewriter &rewriter) const override {
-    NegOpAdaptor transformed(operands);
-
-    auto negOne = rewriter.create<LLVM::ConstantOp>(
-        op->getLoc(), transformed.value().getType(),
-        rewriter.getI32IntegerAttr(-1));
-    rewriter.replaceOpWithNewOp<LLVM::MulOp>(op, transformed.value().getType(),
-                                             negOne, transformed.value());
-
-    return success();
-  }
-};
-
-} // namespace
-
 namespace {
 /// Convert an EqOp to LLVM dialect.
 struct EqOpConversion : public ConvertToLLVMPattern {
@@ -2856,8 +2832,7 @@ void circt::populateLLHDToLLVMConversionPatterns(LLVMTypeConverter &converter,
       converter);
 
   // Arithmetic conversion patterns.
-  patterns.add<NegOpConversion, EqOpConversion, NeqOpConversion>(ctx,
-                                                                 converter);
+  patterns.add<EqOpConversion, NeqOpConversion>(ctx, converter);
   patterns.add<CombAddOpConversion, CombSubOpConversion, CombMulOpConversion,
                CombDivUOpConversion, CombDivSOpConversion, CombModUOpConversion,
                CombModSOpConversion, CombICmpOpConversion, CombSExtOpConversion,

diff --git a/lib/Dialect/LLHD/Export/TranslateToVerilog.cpp b/lib/Dialect/LLHD/Export/TranslateToVerilog.cpp
@@ -311,8 +311,6 @@ LogicalResult VerilogPrinter::printOperation(Operation *inst,
 
     return success();
   }
-  if (auto op = dyn_cast<llhd::NegOp>(inst))
-    return printUnaryOp(inst, "-", indentAmount);
   if (auto op = dyn_cast<comb::AddOp>(inst))
     return printVariadicOp(inst, "+", indentAmount);
   if (auto op = dyn_cast<comb::SubOp>(inst))

diff --git a/lib/Dialect/LLHD/IR/LLHDOps.cpp b/lib/Dialect/LLHD/IR/LLHDOps.cpp
@@ -199,14 +199,6 @@ OpFoldResult llhd::ConstOp::fold(ArrayRef<Attribute> operands) {
   return value();
 }
 
-//===----------------------------------------------------------------------===//
-// NegOp
-//===----------------------------------------------------------------------===//
-
-OpFoldResult llhd::NegOp::fold(ArrayRef<Attribute> operands) {
-  return constFoldUnaryOp<IntegerAttr>(operands, [](APInt a) { return -a; });
-}
-
 //===----------------------------------------------------------------------===//
 // EqOp
 //===----------------------------------------------------------------------===//

diff --git a/test/Conversion/LLHDToLLVM/convert_arithmetic.mlir b/test/Conversion/LLHDToLLVM/convert_arithmetic.mlir
@@ -1,22 +1,6 @@
 // NOTE: Assertions have been autogenerated by utils/generate-test-checks.py
 // RUN: circt-opt %s --convert-llhd-to-llvm | FileCheck %s
 
-// CHECK-LABEL:   llvm.func @convert_neg(
-// CHECK-SAME:                           %[[VAL_0:.*]]: i1,
-// CHECK-SAME:                           %[[VAL_1:.*]]: i32) {
-// CHECK:           %[[VAL_2:.*]] = llvm.mlir.constant(-1 : i32) : i1
-// CHECK:           %[[VAL_3:.*]] = llvm.mul %[[VAL_2]], %[[VAL_0]] : i1
-// CHECK:           %[[VAL_4:.*]] = llvm.mlir.constant(-1 : i32) : i32
-// CHECK:           %[[VAL_5:.*]] = llvm.mul %[[VAL_4]], %[[VAL_1]] : i32
-// CHECK:           llvm.return
-// CHECK:         }
-func @convert_neg(%i1 : i1, %i32 : i32) {
-    %0 = llhd.neg %i1 : i1
-    %1 = llhd.neg %i32 : i32
-
-    return
-}
-
 // CHECK-LABEL:   llvm.func @convert_eq(
 // CHECK-SAME:                          %[[VAL_0:.*]]: i32,
 // CHECK-SAME:                          %[[VAL_1:.*]]: i32) -> i1 {

diff --git a/test/Dialect/LLHD/Canonicalization/arithmetic.mlir b/test/Dialect/LLHD/Canonicalization/arithmetic.mlir
@@ -1,15 +1,5 @@
 // RUN: circt-opt %s -canonicalize='top-down=true region-simplify=true' | FileCheck %s
 
-// CHECK-LABEL: @check_neg_folding
-func @check_neg_folding() -> (i16) {
-  // CHECK-NEXT: %[[NEG:.*]] = llhd.const -5 : i16
-  %a = llhd.const 5 : i16
-  %0 = llhd.neg %a : i16
-
-  // CHECK-NEXT: return %[[NEG]] : i16
-  return %0 : i16
-}
-
 // CHECK-LABEL: @check_eq_folding
 // CHECK-SAME: %[[VAL_0:.*]]: i64,
 // CHECK-SAME: %[[VAL_1:.*]]: i1,

diff --git a/test/Dialect/LLHD/Export/verilog_arithmetic.mlir b/test/Dialect/LLHD/Export/verilog_arithmetic.mlir
@@ -4,8 +4,6 @@
 llhd.entity @check_arithmetic() -> () {
   // CHECK-NEXT: wire [63:0] _[[A:.*]] = 64'd42;
   %a = llhd.const 42 : i64
-  // CHECK-NEXT: wire [63:0] _{{.*}} = -_[[A]];
-  %0 = llhd.neg %a : i64
 
   // CHECK-NEXT: wire [63:0] _{{.*}} = _[[A]];
   %1 = comb.add %a : i64

diff --git a/test/Dialect/LLHD/IR/arithmetic.mlir b/test/Dialect/LLHD/IR/arithmetic.mlir
@@ -5,9 +5,6 @@
 // CHECK-SAME: %[[ARR:.*]]: !hw.array<3xi32>
 // CHECK-SAME: %[[TUP:.*]]: !hw.struct<foo: i1, bar: i2, baz: i3>
 func @check_arithmetic(%a : i64, %array : !hw.array<3xi32>, %tup : !hw.struct<foo: i1, bar: i2, baz: i3>) -> () {
-  // CHECK-NEXT: %{{.*}} = llhd.neg %[[A]] : i64
-  %0 = llhd.neg %a : i64
-
   // CHECK-NEXT: %{{.*}} = llhd.neq %[[A]], %[[A]] : i64
   %2 = llhd.neq %a, %a : i64
   // CHECK-NEXT: %{{.*}} = llhd.neq %[[ARR]], %[[ARR]] : !hw.array<3xi32>