diff --git a/llvm/include/llvm/IR/FixedPointBuilder.h b/llvm/include/llvm/IR/FixedPointBuilder.h
new file mode 100644
--- /dev/null
+++ b/llvm/include/llvm/IR/FixedPointBuilder.h
@@ -0,0 +1,406 @@
+//===- llvm/FixedPointBuilder.h - Builder for fixed-point ops ---*- 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 defines the FixedPointBuilder class, which is used as a convenient
+// way to lower fixed-point arithmetic operations to LLVM IR.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_IR_FIXEDPOINTBUILDER_H
+#define LLVM_IR_FIXEDPOINTBUILDER_H
+
+#include "llvm/ADT/APFixedPoint.h"
+#include "llvm/IR/Constant.h"
+#include "llvm/IR/Constants.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/InstrTypes.h"
+#include "llvm/IR/Instruction.h"
+#include "llvm/IR/IntrinsicInst.h"
+#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/Type.h"
+#include "llvm/IR/Value.h"
+
+namespace llvm {
+
+template <class IRBuilderTy> class FixedPointBuilder {
+  IRBuilderTy &B;
+
+  Value *Convert(Value *Src, const FixedPointSemantics &SrcSema,
+                 const FixedPointSemantics &DstSema, bool DstIsInteger) {
+    unsigned SrcWidth = SrcSema.getWidth();
+    unsigned DstWidth = DstSema.getWidth();
+    unsigned SrcScale = SrcSema.getScale();
+    unsigned DstScale = DstSema.getScale();
+    bool SrcIsSigned = SrcSema.isSigned();
+    bool DstIsSigned = DstSema.isSigned();
+
+    Type *DstIntTy = B.getIntNTy(DstWidth);
+
+    Value *Result = Src;
+    unsigned ResultWidth = SrcWidth;
+
+    // Downscale.
+    if (DstScale < SrcScale) {
+      // When converting to integers, we round towards zero. For negative
+      // numbers, right shifting rounds towards negative infinity. In this case,
+      // we can just round up before shifting.
+      if (DstIsInteger && SrcIsSigned) {
+        Value *Zero = Constant::getNullValue(Result->getType());
+        Value *IsNegative = B.CreateICmpSLT(Result, Zero);
+        Value *LowBits = ConstantInt::get(
+            B.getContext(), APInt::getLowBitsSet(ResultWidth, SrcScale));
+        Value *Rounded = B.CreateAdd(Result, LowBits);
+        Result = B.CreateSelect(IsNegative, Rounded, Result);
+      }
+
+      Result = SrcIsSigned
+                   ? B.CreateAShr(Result, SrcScale - DstScale, "downscale")
+                   : B.CreateLShr(Result, SrcScale - DstScale, "downscale");
+    }
+
+    if (!DstSema.isSaturated()) {
+      // Resize.
+      Result = B.CreateIntCast(Result, DstIntTy, SrcIsSigned, "resize");
+
+      // Upscale.
+      if (DstScale > SrcScale)
+        Result = B.CreateShl(Result, DstScale - SrcScale, "upscale");
+    } else {
+      // Adjust the number of fractional bits.
+      if (DstScale > SrcScale) {
+        // Compare to DstWidth to prevent resizing twice.
+        ResultWidth = std::max(SrcWidth + DstScale - SrcScale, DstWidth);
+        Type *UpscaledTy = B.getIntNTy(ResultWidth);
+        Result = B.CreateIntCast(Result, UpscaledTy, SrcIsSigned, "resize");
+        Result = B.CreateShl(Result, DstScale - SrcScale, "upscale");
+      }
+
+      // Handle saturation.
+      bool LessIntBits = DstSema.getIntegralBits() < SrcSema.getIntegralBits();
+      if (LessIntBits) {
+        Value *Max = ConstantInt::get(
+            B.getContext(),
+            APFixedPoint::getMax(DstSema).getValue().extOrTrunc(ResultWidth));
+        Value *TooHigh = SrcIsSigned ? B.CreateICmpSGT(Result, Max)
+                                     : B.CreateICmpUGT(Result, Max);
+        Result = B.CreateSelect(TooHigh, Max, Result, "satmax");
+      }
+      // Cannot overflow min to dest type if src is unsigned since all fixed
+      // point types can cover the unsigned min of 0.
+      if (SrcIsSigned && (LessIntBits || !DstIsSigned)) {
+        Value *Min = ConstantInt::get(
+            B.getContext(),
+            APFixedPoint::getMin(DstSema).getValue().extOrTrunc(ResultWidth));
+        Value *TooLow = B.CreateICmpSLT(Result, Min);
+        Result = B.CreateSelect(TooLow, Min, Result, "satmin");
+      }
+
+      // Resize the integer part to get the final destination size.
+      if (ResultWidth != DstWidth)
+        Result = B.CreateIntCast(Result, DstIntTy, SrcIsSigned, "resize");
+    }
+    return Result;
+  }
+
+  /// Get the common semantic for two semantics, with the added imposition that
+  /// saturated padded types retain the padding bit.
+  FixedPointSemantics
+  getCommonBinopSemantic(const FixedPointSemantics &LHSSema,
+                         const FixedPointSemantics &RHSSema) {
+    auto C = LHSSema.getCommonSemantics(RHSSema);
+    bool BothPadded =
+        LHSSema.hasUnsignedPadding() && RHSSema.hasUnsignedPadding();
+    return FixedPointSemantics(
+        C.getWidth() + (unsigned)(BothPadded && C.isSaturated()), C.getScale(),
+        C.isSigned(), C.isSaturated(), BothPadded);
+  }
+
+public:
+  FixedPointBuilder(IRBuilderTy &Builder) : B(Builder) {}
+
+  /// Convert an integer value representing a fixed-point number from one
+  /// fixed-point semantic to another fixed-point semantic.
+  /// \p Src     - The source value
+  /// \p SrcSema - The fixed-point semantic of the source value
+  /// \p DstSema - The resulting fixed-point semantic
+  Value *CreateFixedToFixed(Value *Src, const FixedPointSemantics &SrcSema,
+                            const FixedPointSemantics &DstSema) {
+    return Convert(Src, SrcSema, DstSema, false);
+  }
+
+  /// Convert an integer value representing a fixed-point number to an integer
+  /// with the given bit width and signedness.
+  /// \p Src         - The source value
+  /// \p SrcSema     - The fixed-point semantic of the source value
+  /// \p DstWidth    - The bit width of the result value
+  /// \p DstIsSigned - The signedness of the result value
+  Value *CreateFixedToInteger(Value *Src, const FixedPointSemantics &SrcSema,
+                              unsigned DstWidth, bool DstIsSigned) {
+    return Convert(
+        Src, SrcSema,
+        FixedPointSemantics::GetIntegerSemantics(DstWidth, DstIsSigned), true);
+  }
+
+  /// Convert an integer value with the given signedness to an integer value
+  /// representing the given fixed-point semantic.
+  /// \p Src         - The source value
+  /// \p SrcIsSigned - The signedness of the source value
+  /// \p DstSema     - The resulting fixed-point semantic
+  Value *CreateIntegerToFixed(Value *Src, unsigned SrcIsSigned,
+                              const FixedPointSemantics &DstSema) {
+    return Convert(Src,
+                   FixedPointSemantics::GetIntegerSemantics(
+                       Src->getType()->getScalarSizeInBits(), SrcIsSigned),
+                   DstSema, false);
+  }
+
+  /// Add two fixed-point values and return the result in their common semantic.
+  /// \p LHS     - The left hand side
+  /// \p LHSSema - The semantic of the left hand side
+  /// \p RHS     - The right hand side
+  /// \p RHSSema - The semantic of the right hand side
+  Value *CreateAdd(Value *LHS, const FixedPointSemantics &LHSSema,
+                   Value *RHS, const FixedPointSemantics &RHSSema) {
+    auto CommonSema = getCommonBinopSemantic(LHSSema, RHSSema);
+    bool UseSigned = CommonSema.isSigned() || CommonSema.hasUnsignedPadding();
+
+    Value *WideLHS = CreateFixedToFixed(LHS, LHSSema, CommonSema);
+    Value *WideRHS = CreateFixedToFixed(RHS, RHSSema, CommonSema);
+
+    Value *Result;
+    if (CommonSema.isSaturated()) {
+      Intrinsic::ID IID = UseSigned ? Intrinsic::sadd_sat : Intrinsic::uadd_sat;
+      Result = B.CreateBinaryIntrinsic(IID, WideLHS, WideRHS);
+    } else {
+      Result = B.CreateAdd(WideLHS, WideRHS);
+    }
+
+    return CreateFixedToFixed(Result, CommonSema,
+                              LHSSema.getCommonSemantics(RHSSema));
+  }
+
+  /// Subtract two fixed-point values and return the result in their common
+  /// semantic.
+  /// \p LHS     - The left hand side
+  /// \p LHSSema - The semantic of the left hand side
+  /// \p RHS     - The right hand side
+  /// \p RHSSema - The semantic of the right hand side
+  Value *CreateSub(Value *LHS, const FixedPointSemantics &LHSSema,
+                   Value *RHS, const FixedPointSemantics &RHSSema) {
+    auto CommonSema = getCommonBinopSemantic(LHSSema, RHSSema);
+    bool UseSigned = CommonSema.isSigned() || CommonSema.hasUnsignedPadding();
+
+    Value *WideLHS = CreateFixedToFixed(LHS, LHSSema, CommonSema);
+    Value *WideRHS = CreateFixedToFixed(RHS, RHSSema, CommonSema);
+
+    Value *Result;
+    if (CommonSema.isSaturated()) {
+      Intrinsic::ID IID = UseSigned ? Intrinsic::ssub_sat : Intrinsic::usub_sat;
+      Result = B.CreateBinaryIntrinsic(IID, WideLHS, WideRHS);
+    } else {
+      Result = B.CreateSub(WideLHS, WideRHS);
+    }
+
+    // Subtraction can end up below 0 for padded unsigned operations, so emit
+    // an extra clamp in that case.
+    if (CommonSema.isSaturated() && CommonSema.hasUnsignedPadding()) {
+      Constant *Zero = Constant::getNullValue(Result->getType());
+      Result =
+          B.CreateSelect(B.CreateICmpSLT(Result, Zero), Zero, Result, "satmin");
+    }
+
+    return CreateFixedToFixed(Result, CommonSema,
+                              LHSSema.getCommonSemantics(RHSSema));
+  }
+
+  /// Multiply two fixed-point values and return the result in their common
+  /// semantic.
+  /// \p LHS     - The left hand side
+  /// \p LHSSema - The semantic of the left hand side
+  /// \p RHS     - The right hand side
+  /// \p RHSSema - The semantic of the right hand side
+  Value *CreateMul(Value *LHS, const FixedPointSemantics &LHSSema,
+                   Value *RHS, const FixedPointSemantics &RHSSema) {
+    auto CommonSema = getCommonBinopSemantic(LHSSema, RHSSema);
+    bool UseSigned = CommonSema.isSigned() || CommonSema.hasUnsignedPadding();
+
+    Value *WideLHS = CreateFixedToFixed(LHS, LHSSema, CommonSema);
+    Value *WideRHS = CreateFixedToFixed(RHS, RHSSema, CommonSema);
+
+    Intrinsic::ID IID;
+    if (CommonSema.isSaturated()) {
+      IID = UseSigned ? Intrinsic::smul_fix_sat : Intrinsic::umul_fix_sat;
+    } else {
+      IID = UseSigned ? Intrinsic::smul_fix : Intrinsic::umul_fix;
+    }
+    Value *Result = B.CreateIntrinsic(
+        IID, {WideLHS->getType()},
+        {WideLHS, WideRHS, B.getInt32(CommonSema.getScale())});
+
+    return CreateFixedToFixed(Result, CommonSema,
+                              LHSSema.getCommonSemantics(RHSSema));
+  }
+
+  /// Divide two fixed-point values and return the result in their common
+  /// semantic.
+  /// \p LHS     - The left hand side
+  /// \p LHSSema - The semantic of the left hand side
+  /// \p RHS     - The right hand side
+  /// \p RHSSema - The semantic of the right hand side
+  Value *CreateDiv(Value *LHS, const FixedPointSemantics &LHSSema,
+                   Value *RHS, const FixedPointSemantics &RHSSema) {
+    auto CommonSema = getCommonBinopSemantic(LHSSema, RHSSema);
+    bool UseSigned = CommonSema.isSigned() || CommonSema.hasUnsignedPadding();
+
+    Value *WideLHS = CreateFixedToFixed(LHS, LHSSema, CommonSema);
+    Value *WideRHS = CreateFixedToFixed(RHS, RHSSema, CommonSema);
+
+    Intrinsic::ID IID;
+    if (CommonSema.isSaturated()) {
+      IID = UseSigned ? Intrinsic::sdiv_fix_sat : Intrinsic::udiv_fix_sat;
+    } else {
+      IID = UseSigned ? Intrinsic::sdiv_fix : Intrinsic::udiv_fix;
+    }
+    Value *Result = B.CreateIntrinsic(
+        IID, {WideLHS->getType()},
+        {WideLHS, WideRHS, B.getInt32(CommonSema.getScale())});
+
+    return CreateFixedToFixed(Result, CommonSema,
+                              LHSSema.getCommonSemantics(RHSSema));
+  }
+
+  /// Left shift a fixed-point value by an unsigned integer value. The integer
+  /// value can be any bit width.
+  /// \p LHS     - The left hand side
+  /// \p LHSSema - The semantic of the left hand side
+  /// \p RHS     - The right hand side
+  Value *CreateShl(Value *LHS, const FixedPointSemantics &LHSSema, Value *RHS) {
+    bool UseSigned = LHSSema.isSigned() || LHSSema.hasUnsignedPadding();
+
+    RHS = B.CreateIntCast(RHS, LHS->getType(), /*IsSigned=*/false);
+
+    Value *Result;
+    if (LHSSema.isSaturated()) {
+      Intrinsic::ID IID = UseSigned ? Intrinsic::sshl_sat : Intrinsic::ushl_sat;
+      Result = B.CreateBinaryIntrinsic(IID, LHS, RHS);
+    } else {
+      Result = B.CreateShl(LHS, RHS);
+    }
+
+    return Result;
+  }
+
+  /// Right shift a fixed-point value by an unsigned integer value. The integer
+  /// value can be any bit width.
+  /// \p LHS     - The left hand side
+  /// \p LHSSema - The semantic of the left hand side
+  /// \p RHS     - The right hand side
+  Value *CreateShr(Value *LHS, const FixedPointSemantics &LHSSema, Value *RHS) {
+    RHS = B.CreateIntCast(RHS, LHS->getType(), false);
+
+    return LHSSema.isSigned() ? B.CreateAShr(LHS, RHS) : B.CreateLShr(LHS, RHS);
+  }
+
+  /// Compare two fixed-point values for equality.
+  /// \p LHS     - The left hand side
+  /// \p LHSSema - The semantic of the left hand side
+  /// \p RHS     - The right hand side
+  /// \p RHSSema - The semantic of the right hand side
+  Value *CreateEQ(Value *LHS, const FixedPointSemantics &LHSSema,
+                  Value *RHS, const FixedPointSemantics &RHSSema) {
+    auto CommonSema = getCommonBinopSemantic(LHSSema, RHSSema);
+
+    Value *WideLHS = CreateFixedToFixed(LHS, LHSSema, CommonSema);
+    Value *WideRHS = CreateFixedToFixed(RHS, RHSSema, CommonSema);
+
+    return B.CreateICmpEQ(WideLHS, WideRHS);
+  }
+
+  /// Compare two fixed-point values for inequality.
+  /// \p LHS     - The left hand side
+  /// \p LHSSema - The semantic of the left hand side
+  /// \p RHS     - The right hand side
+  /// \p RHSSema - The semantic of the right hand side
+  Value *CreateNE(Value *LHS, const FixedPointSemantics &LHSSema,
+                  Value *RHS, const FixedPointSemantics &RHSSema) {
+    auto CommonSema = getCommonBinopSemantic(LHSSema, RHSSema);
+
+    Value *WideLHS = CreateFixedToFixed(LHS, LHSSema, CommonSema);
+    Value *WideRHS = CreateFixedToFixed(RHS, RHSSema, CommonSema);
+
+    return B.CreateICmpNE(WideLHS, WideRHS);
+  }
+
+  /// Compare two fixed-point values as LHS < RHS.
+  /// \p LHS     - The left hand side
+  /// \p LHSSema - The semantic of the left hand side
+  /// \p RHS     - The right hand side
+  /// \p RHSSema - The semantic of the right hand side
+  Value *CreateLT(Value *LHS, const FixedPointSemantics &LHSSema,
+                  Value *RHS, const FixedPointSemantics &RHSSema) {
+    auto CommonSema = getCommonBinopSemantic(LHSSema, RHSSema);
+
+    Value *WideLHS = CreateFixedToFixed(LHS, LHSSema, CommonSema);
+    Value *WideRHS = CreateFixedToFixed(RHS, RHSSema, CommonSema);
+
+    return CommonSema.isSigned() ? B.CreateICmpSLT(WideLHS, WideRHS)
+                                 : B.CreateICmpULT(WideLHS, WideRHS);
+  }
+
+  /// Compare two fixed-point values as LHS <= RHS.
+  /// \p LHS     - The left hand side
+  /// \p LHSSema - The semantic of the left hand side
+  /// \p RHS     - The right hand side
+  /// \p RHSSema - The semantic of the right hand side
+  Value *CreateLE(Value *LHS, const FixedPointSemantics &LHSSema,
+                  Value *RHS, const FixedPointSemantics &RHSSema) {
+    auto CommonSema = getCommonBinopSemantic(LHSSema, RHSSema);
+
+    Value *WideLHS = CreateFixedToFixed(LHS, LHSSema, CommonSema);
+    Value *WideRHS = CreateFixedToFixed(RHS, RHSSema, CommonSema);
+
+    return CommonSema.isSigned() ? B.CreateICmpSLE(WideLHS, WideRHS)
+                                 : B.CreateICmpULE(WideLHS, WideRHS);
+  }
+
+  /// Compare two fixed-point values as LHS > RHS.
+  /// \p LHS     - The left hand side
+  /// \p LHSSema - The semantic of the left hand side
+  /// \p RHS     - The right hand side
+  /// \p RHSSema - The semantic of the right hand side
+  Value *CreateGT(Value *LHS, const FixedPointSemantics &LHSSema,
+                  Value *RHS, const FixedPointSemantics &RHSSema) {
+    auto CommonSema = getCommonBinopSemantic(LHSSema, RHSSema);
+
+    Value *WideLHS = CreateFixedToFixed(LHS, LHSSema, CommonSema);
+    Value *WideRHS = CreateFixedToFixed(RHS, RHSSema, CommonSema);
+
+    return CommonSema.isSigned() ? B.CreateICmpSGT(WideLHS, WideRHS)
+                                 : B.CreateICmpUGT(WideLHS, WideRHS);
+  }
+
+  /// Compare two fixed-point values as LHS >= RHS.
+  /// \p LHS     - The left hand side
+  /// \p LHSSema - The semantic of the left hand side
+  /// \p RHS     - The right hand side
+  /// \p RHSSema - The semantic of the right hand side
+  Value *CreateGE(Value *LHS, const FixedPointSemantics &LHSSema,
+                  Value *RHS, const FixedPointSemantics &RHSSema) {
+    auto CommonSema = getCommonBinopSemantic(LHSSema, RHSSema);
+
+    Value *WideLHS = CreateFixedToFixed(LHS, LHSSema, CommonSema);
+    Value *WideRHS = CreateFixedToFixed(RHS, RHSSema, CommonSema);
+
+    return CommonSema.isSigned() ? B.CreateICmpSGE(WideLHS, WideRHS)
+                                 : B.CreateICmpUGE(WideLHS, WideRHS);
+  }
+};
+
+} // end namespace llvm
+
+#endif // LLVM_IR_FIXEDPOINTBUILDER_H
diff --git a/llvm/include/llvm/module.modulemap b/llvm/include/llvm/module.modulemap
--- a/llvm/include/llvm/module.modulemap
+++ b/llvm/include/llvm/module.modulemap
@@ -253,6 +253,7 @@
   module IR_CFG { header "IR/CFG.h" export * }
   module IR_ConstantRange { header "IR/ConstantRange.h" export * }
   module IR_Dominators { header "IR/Dominators.h" export * }
+  module IR_FixedPointBuilder { header "IR/FixedPointBuilder.h" export * }
   module Analysis_PostDominators { header "Analysis/PostDominators.h" export * }
   module Analysis_DomTreeUpdater { header "Analysis/DomTreeUpdater.h" export * }
   module IR_IRBuilder { header "IR/IRBuilder.h" export * }