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93ce8e1087
As of today, Android's libcxx is missing C++17's std::function's CTAD added in e1eabcdfad89f67ae575b0c86aa4a72d277378b4. This leads to InferIntRangeCommon.cpp to fail to compile. This commit makes the template parameter of std::function in that function explicit, therefore avoiding CTAD. While LLVM/MLIR's requirement is C++17, the rest of the code builds fine so hopefully this is acceptable.
700 lines
28 KiB
C++
700 lines
28 KiB
C++
//===- InferIntRangeCommon.cpp - Inference for common ops ------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file contains implementations of range inference for operations that are
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// common to both the `arith` and `index` dialects to facilitate reuse.
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//
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//===----------------------------------------------------------------------===//
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#include "mlir/Interfaces/Utils/InferIntRangeCommon.h"
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#include "mlir/Interfaces/InferIntRangeInterface.h"
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#include "llvm/ADT/ArrayRef.h"
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#include "llvm/ADT/STLExtras.h"
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#include "llvm/Support/Debug.h"
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#include <iterator>
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#include <optional>
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using namespace mlir;
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#define DEBUG_TYPE "int-range-analysis"
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//===----------------------------------------------------------------------===//
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// General utilities
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//===----------------------------------------------------------------------===//
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/// Function that evaluates the result of doing something on arithmetic
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/// constants and returns std::nullopt on overflow.
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using ConstArithFn =
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function_ref<std::optional<APInt>(const APInt &, const APInt &)>;
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using ConstArithStdFn =
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std::function<std::optional<APInt>(const APInt &, const APInt &)>;
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/// Compute op(minLeft, minRight) and op(maxLeft, maxRight) if possible,
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/// If either computation overflows, make the result unbounded.
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static ConstantIntRanges computeBoundsBy(ConstArithFn op, const APInt &minLeft,
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const APInt &minRight,
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const APInt &maxLeft,
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const APInt &maxRight, bool isSigned) {
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std::optional<APInt> maybeMin = op(minLeft, minRight);
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std::optional<APInt> maybeMax = op(maxLeft, maxRight);
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if (maybeMin && maybeMax)
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return ConstantIntRanges::range(*maybeMin, *maybeMax, isSigned);
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return ConstantIntRanges::maxRange(minLeft.getBitWidth());
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}
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/// Compute the minimum and maximum of `(op(l, r) for l in lhs for r in rhs)`,
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/// ignoring unbounded values. Returns the maximal range if `op` overflows.
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static ConstantIntRanges minMaxBy(ConstArithFn op, ArrayRef<APInt> lhs,
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ArrayRef<APInt> rhs, bool isSigned) {
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unsigned width = lhs[0].getBitWidth();
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APInt min =
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isSigned ? APInt::getSignedMaxValue(width) : APInt::getMaxValue(width);
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APInt max =
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isSigned ? APInt::getSignedMinValue(width) : APInt::getZero(width);
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for (const APInt &left : lhs) {
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for (const APInt &right : rhs) {
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std::optional<APInt> maybeThisResult = op(left, right);
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if (!maybeThisResult)
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return ConstantIntRanges::maxRange(width);
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APInt result = std::move(*maybeThisResult);
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min = (isSigned ? result.slt(min) : result.ult(min)) ? result : min;
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max = (isSigned ? result.sgt(max) : result.ugt(max)) ? result : max;
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}
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}
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return ConstantIntRanges::range(min, max, isSigned);
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}
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//===----------------------------------------------------------------------===//
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// Ext, trunc, index op handling
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//===----------------------------------------------------------------------===//
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ConstantIntRanges
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mlir::intrange::inferIndexOp(const InferRangeFn &inferFn,
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ArrayRef<ConstantIntRanges> argRanges,
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intrange::CmpMode mode) {
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ConstantIntRanges sixtyFour = inferFn(argRanges);
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SmallVector<ConstantIntRanges, 2> truncated;
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llvm::transform(argRanges, std::back_inserter(truncated),
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[](const ConstantIntRanges &range) {
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return truncRange(range, /*destWidth=*/indexMinWidth);
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});
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ConstantIntRanges thirtyTwo = inferFn(truncated);
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ConstantIntRanges thirtyTwoAsSixtyFour =
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extRange(thirtyTwo, /*destWidth=*/indexMaxWidth);
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ConstantIntRanges sixtyFourAsThirtyTwo =
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truncRange(sixtyFour, /*destWidth=*/indexMinWidth);
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LLVM_DEBUG(llvm::dbgs() << "Index handling: 64-bit result = " << sixtyFour
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<< " 32-bit = " << thirtyTwo << "\n");
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bool truncEqual = false;
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switch (mode) {
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case intrange::CmpMode::Both:
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truncEqual = (thirtyTwo == sixtyFourAsThirtyTwo);
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break;
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case intrange::CmpMode::Signed:
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truncEqual = (thirtyTwo.smin() == sixtyFourAsThirtyTwo.smin() &&
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thirtyTwo.smax() == sixtyFourAsThirtyTwo.smax());
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break;
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case intrange::CmpMode::Unsigned:
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truncEqual = (thirtyTwo.umin() == sixtyFourAsThirtyTwo.umin() &&
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thirtyTwo.umax() == sixtyFourAsThirtyTwo.umax());
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break;
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}
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if (truncEqual)
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// Returing the 64-bit result preserves more information.
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return sixtyFour;
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ConstantIntRanges merged = sixtyFour.rangeUnion(thirtyTwoAsSixtyFour);
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return merged;
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}
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ConstantIntRanges mlir::intrange::extRange(const ConstantIntRanges &range,
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unsigned int destWidth) {
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APInt umin = range.umin().zext(destWidth);
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APInt umax = range.umax().zext(destWidth);
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APInt smin = range.smin().sext(destWidth);
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APInt smax = range.smax().sext(destWidth);
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return {umin, umax, smin, smax};
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}
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ConstantIntRanges mlir::intrange::extUIRange(const ConstantIntRanges &range,
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unsigned destWidth) {
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APInt umin = range.umin().zext(destWidth);
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APInt umax = range.umax().zext(destWidth);
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return ConstantIntRanges::fromUnsigned(umin, umax);
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}
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ConstantIntRanges mlir::intrange::extSIRange(const ConstantIntRanges &range,
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unsigned destWidth) {
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APInt smin = range.smin().sext(destWidth);
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APInt smax = range.smax().sext(destWidth);
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return ConstantIntRanges::fromSigned(smin, smax);
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}
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ConstantIntRanges mlir::intrange::truncRange(const ConstantIntRanges &range,
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unsigned int destWidth) {
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// If you truncate the first four bytes in [0xaaaabbbb, 0xccccbbbb],
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// the range of the resulting value is not contiguous ind includes 0.
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// Ex. If you truncate [256, 258] from i16 to i8, you validly get [0, 2],
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// but you can't truncate [255, 257] similarly.
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bool hasUnsignedRollover =
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range.umin().lshr(destWidth) != range.umax().lshr(destWidth);
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APInt umin = hasUnsignedRollover ? APInt::getZero(destWidth)
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: range.umin().trunc(destWidth);
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APInt umax = hasUnsignedRollover ? APInt::getMaxValue(destWidth)
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: range.umax().trunc(destWidth);
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// Signed post-truncation rollover will not occur when either:
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// - The high parts of the min and max, plus the sign bit, are the same
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// - The high halves + sign bit of the min and max are either all 1s or all 0s
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// and you won't create a [positive, negative] range by truncating.
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// For example, you can truncate the ranges [256, 258]_i16 to [0, 2]_i8
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// but not [255, 257]_i16 to a range of i8s. You can also truncate
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// [-256, -256]_i16 to [-2, 0]_i8, but not [-257, -255]_i16.
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// You can also truncate [-130, 0]_i16 to i8 because -130_i16 (0xff7e)
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// will truncate to 0x7e, which is greater than 0
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APInt sminHighPart = range.smin().ashr(destWidth - 1);
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APInt smaxHighPart = range.smax().ashr(destWidth - 1);
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bool hasSignedOverflow =
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(sminHighPart != smaxHighPart) &&
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!(sminHighPart.isAllOnes() &&
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(smaxHighPart.isAllOnes() || smaxHighPart.isZero())) &&
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!(sminHighPart.isZero() && smaxHighPart.isZero());
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APInt smin = hasSignedOverflow ? APInt::getSignedMinValue(destWidth)
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: range.smin().trunc(destWidth);
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APInt smax = hasSignedOverflow ? APInt::getSignedMaxValue(destWidth)
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: range.smax().trunc(destWidth);
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return {umin, umax, smin, smax};
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}
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//===----------------------------------------------------------------------===//
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// Addition
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//===----------------------------------------------------------------------===//
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ConstantIntRanges
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mlir::intrange::inferAdd(ArrayRef<ConstantIntRanges> argRanges,
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OverflowFlags ovfFlags) {
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const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
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ConstArithStdFn uadd = [=](const APInt &a,
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const APInt &b) -> std::optional<APInt> {
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bool overflowed = false;
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APInt result = any(ovfFlags & OverflowFlags::Nuw)
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? a.uadd_sat(b)
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: a.uadd_ov(b, overflowed);
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return overflowed ? std::optional<APInt>() : result;
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};
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ConstArithStdFn sadd = [=](const APInt &a,
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const APInt &b) -> std::optional<APInt> {
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bool overflowed = false;
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APInt result = any(ovfFlags & OverflowFlags::Nsw)
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? a.sadd_sat(b)
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: a.sadd_ov(b, overflowed);
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return overflowed ? std::optional<APInt>() : result;
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};
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ConstantIntRanges urange = computeBoundsBy(
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uadd, lhs.umin(), rhs.umin(), lhs.umax(), rhs.umax(), /*isSigned=*/false);
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ConstantIntRanges srange = computeBoundsBy(
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sadd, lhs.smin(), rhs.smin(), lhs.smax(), rhs.smax(), /*isSigned=*/true);
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return urange.intersection(srange);
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}
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//===----------------------------------------------------------------------===//
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// Subtraction
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//===----------------------------------------------------------------------===//
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ConstantIntRanges
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mlir::intrange::inferSub(ArrayRef<ConstantIntRanges> argRanges,
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OverflowFlags ovfFlags) {
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const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
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ConstArithStdFn usub = [=](const APInt &a,
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const APInt &b) -> std::optional<APInt> {
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bool overflowed = false;
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APInt result = any(ovfFlags & OverflowFlags::Nuw)
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? a.usub_sat(b)
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: a.usub_ov(b, overflowed);
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return overflowed ? std::optional<APInt>() : result;
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};
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ConstArithStdFn ssub = [=](const APInt &a,
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const APInt &b) -> std::optional<APInt> {
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bool overflowed = false;
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APInt result = any(ovfFlags & OverflowFlags::Nsw)
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? a.ssub_sat(b)
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: a.ssub_ov(b, overflowed);
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return overflowed ? std::optional<APInt>() : result;
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};
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ConstantIntRanges urange = computeBoundsBy(
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usub, lhs.umin(), rhs.umax(), lhs.umax(), rhs.umin(), /*isSigned=*/false);
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ConstantIntRanges srange = computeBoundsBy(
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ssub, lhs.smin(), rhs.smax(), lhs.smax(), rhs.smin(), /*isSigned=*/true);
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return urange.intersection(srange);
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}
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//===----------------------------------------------------------------------===//
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// Multiplication
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//===----------------------------------------------------------------------===//
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ConstantIntRanges
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mlir::intrange::inferMul(ArrayRef<ConstantIntRanges> argRanges,
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OverflowFlags ovfFlags) {
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const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
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ConstArithStdFn umul = [=](const APInt &a,
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const APInt &b) -> std::optional<APInt> {
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bool overflowed = false;
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APInt result = any(ovfFlags & OverflowFlags::Nuw)
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? a.umul_sat(b)
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: a.umul_ov(b, overflowed);
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return overflowed ? std::optional<APInt>() : result;
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};
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ConstArithStdFn smul = [=](const APInt &a,
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const APInt &b) -> std::optional<APInt> {
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bool overflowed = false;
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APInt result = any(ovfFlags & OverflowFlags::Nsw)
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? a.smul_sat(b)
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: a.smul_ov(b, overflowed);
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return overflowed ? std::optional<APInt>() : result;
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};
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ConstantIntRanges urange =
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minMaxBy(umul, {lhs.umin(), lhs.umax()}, {rhs.umin(), rhs.umax()},
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/*isSigned=*/false);
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ConstantIntRanges srange =
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minMaxBy(smul, {lhs.smin(), lhs.smax()}, {rhs.smin(), rhs.smax()},
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/*isSigned=*/true);
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return urange.intersection(srange);
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}
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//===----------------------------------------------------------------------===//
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// DivU, CeilDivU (Unsigned division)
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//===----------------------------------------------------------------------===//
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/// Fix up division results (ex. for ceiling and floor), returning an APInt
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/// if there has been no overflow
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using DivisionFixupFn = function_ref<std::optional<APInt>(
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const APInt &lhs, const APInt &rhs, const APInt &result)>;
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static ConstantIntRanges inferDivURange(const ConstantIntRanges &lhs,
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const ConstantIntRanges &rhs,
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DivisionFixupFn fixup) {
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const APInt &lhsMin = lhs.umin(), &lhsMax = lhs.umax(), &rhsMin = rhs.umin(),
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&rhsMax = rhs.umax();
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if (!rhsMin.isZero()) {
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auto udiv = [&fixup](const APInt &a,
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const APInt &b) -> std::optional<APInt> {
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return fixup(a, b, a.udiv(b));
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};
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return minMaxBy(udiv, {lhsMin, lhsMax}, {rhsMin, rhsMax},
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/*isSigned=*/false);
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}
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// Otherwise, it's possible we might divide by 0.
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return ConstantIntRanges::maxRange(rhsMin.getBitWidth());
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}
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ConstantIntRanges
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mlir::intrange::inferDivU(ArrayRef<ConstantIntRanges> argRanges) {
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return inferDivURange(argRanges[0], argRanges[1],
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[](const APInt &lhs, const APInt &rhs,
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const APInt &result) { return result; });
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}
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ConstantIntRanges
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mlir::intrange::inferCeilDivU(ArrayRef<ConstantIntRanges> argRanges) {
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const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
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DivisionFixupFn ceilDivUIFix =
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[](const APInt &lhs, const APInt &rhs,
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const APInt &result) -> std::optional<APInt> {
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if (!lhs.urem(rhs).isZero()) {
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bool overflowed = false;
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APInt corrected =
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result.uadd_ov(APInt(result.getBitWidth(), 1), overflowed);
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return overflowed ? std::optional<APInt>() : corrected;
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}
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return result;
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};
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return inferDivURange(lhs, rhs, ceilDivUIFix);
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}
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//===----------------------------------------------------------------------===//
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// DivS, CeilDivS, FloorDivS (Signed division)
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//===----------------------------------------------------------------------===//
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static ConstantIntRanges inferDivSRange(const ConstantIntRanges &lhs,
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const ConstantIntRanges &rhs,
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DivisionFixupFn fixup) {
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const APInt &lhsMin = lhs.smin(), &lhsMax = lhs.smax(), &rhsMin = rhs.smin(),
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&rhsMax = rhs.smax();
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bool canDivide = rhsMin.isStrictlyPositive() || rhsMax.isNegative();
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if (canDivide) {
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auto sdiv = [&fixup](const APInt &a,
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const APInt &b) -> std::optional<APInt> {
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bool overflowed = false;
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APInt result = a.sdiv_ov(b, overflowed);
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return overflowed ? std::optional<APInt>() : fixup(a, b, result);
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};
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return minMaxBy(sdiv, {lhsMin, lhsMax}, {rhsMin, rhsMax},
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/*isSigned=*/true);
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}
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return ConstantIntRanges::maxRange(rhsMin.getBitWidth());
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}
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ConstantIntRanges
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mlir::intrange::inferDivS(ArrayRef<ConstantIntRanges> argRanges) {
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return inferDivSRange(argRanges[0], argRanges[1],
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[](const APInt &lhs, const APInt &rhs,
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const APInt &result) { return result; });
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}
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ConstantIntRanges
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mlir::intrange::inferCeilDivS(ArrayRef<ConstantIntRanges> argRanges) {
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const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
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DivisionFixupFn ceilDivSIFix =
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[](const APInt &lhs, const APInt &rhs,
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const APInt &result) -> std::optional<APInt> {
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if (!lhs.srem(rhs).isZero() && lhs.isNonNegative() == rhs.isNonNegative()) {
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bool overflowed = false;
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APInt corrected =
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result.sadd_ov(APInt(result.getBitWidth(), 1), overflowed);
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return overflowed ? std::optional<APInt>() : corrected;
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}
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return result;
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};
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return inferDivSRange(lhs, rhs, ceilDivSIFix);
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}
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ConstantIntRanges
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mlir::intrange::inferFloorDivS(ArrayRef<ConstantIntRanges> argRanges) {
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const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
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DivisionFixupFn floorDivSIFix =
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[](const APInt &lhs, const APInt &rhs,
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const APInt &result) -> std::optional<APInt> {
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if (!lhs.srem(rhs).isZero() && lhs.isNonNegative() != rhs.isNonNegative()) {
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bool overflowed = false;
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APInt corrected =
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result.ssub_ov(APInt(result.getBitWidth(), 1), overflowed);
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return overflowed ? std::optional<APInt>() : corrected;
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}
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return result;
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};
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return inferDivSRange(lhs, rhs, floorDivSIFix);
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}
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//===----------------------------------------------------------------------===//
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// Signed remainder (RemS)
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//===----------------------------------------------------------------------===//
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ConstantIntRanges
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mlir::intrange::inferRemS(ArrayRef<ConstantIntRanges> argRanges) {
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const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
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const APInt &lhsMin = lhs.smin(), &lhsMax = lhs.smax(), &rhsMin = rhs.smin(),
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&rhsMax = rhs.smax();
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unsigned width = rhsMax.getBitWidth();
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APInt smin = APInt::getSignedMinValue(width);
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APInt smax = APInt::getSignedMaxValue(width);
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// No bounds if zero could be a divisor.
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bool canBound = (rhsMin.isStrictlyPositive() || rhsMax.isNegative());
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if (canBound) {
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APInt maxDivisor = rhsMin.isStrictlyPositive() ? rhsMax : rhsMin.abs();
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bool canNegativeDividend = lhsMin.isNegative();
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bool canPositiveDividend = lhsMax.isStrictlyPositive();
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APInt zero = APInt::getZero(maxDivisor.getBitWidth());
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APInt maxPositiveResult = maxDivisor - 1;
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APInt minNegativeResult = -maxPositiveResult;
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smin = canNegativeDividend ? minNegativeResult : zero;
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smax = canPositiveDividend ? maxPositiveResult : zero;
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// Special case: sweeping out a contiguous range in N/[modulus].
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if (rhsMin == rhsMax) {
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if ((lhsMax - lhsMin).ult(maxDivisor)) {
|
|
APInt minRem = lhsMin.srem(maxDivisor);
|
|
APInt maxRem = lhsMax.srem(maxDivisor);
|
|
if (minRem.sle(maxRem)) {
|
|
smin = minRem;
|
|
smax = maxRem;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return ConstantIntRanges::fromSigned(smin, smax);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Unsigned remainder (RemU)
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
ConstantIntRanges
|
|
mlir::intrange::inferRemU(ArrayRef<ConstantIntRanges> argRanges) {
|
|
const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
|
|
const APInt &rhsMin = rhs.umin(), &rhsMax = rhs.umax();
|
|
|
|
unsigned width = rhsMin.getBitWidth();
|
|
APInt umin = APInt::getZero(width);
|
|
APInt umax = APInt::getMaxValue(width);
|
|
|
|
if (!rhsMin.isZero()) {
|
|
umax = rhsMax - 1;
|
|
// Special case: sweeping out a contiguous range in N/[modulus]
|
|
if (rhsMin == rhsMax) {
|
|
const APInt &lhsMin = lhs.umin(), &lhsMax = lhs.umax();
|
|
if ((lhsMax - lhsMin).ult(rhsMax)) {
|
|
APInt minRem = lhsMin.urem(rhsMax);
|
|
APInt maxRem = lhsMax.urem(rhsMax);
|
|
if (minRem.ule(maxRem)) {
|
|
umin = minRem;
|
|
umax = maxRem;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return ConstantIntRanges::fromUnsigned(umin, umax);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Max and min (MaxS, MaxU, MinS, MinU)
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
ConstantIntRanges
|
|
mlir::intrange::inferMaxS(ArrayRef<ConstantIntRanges> argRanges) {
|
|
const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
|
|
|
|
const APInt &smin = lhs.smin().sgt(rhs.smin()) ? lhs.smin() : rhs.smin();
|
|
const APInt &smax = lhs.smax().sgt(rhs.smax()) ? lhs.smax() : rhs.smax();
|
|
return ConstantIntRanges::fromSigned(smin, smax);
|
|
}
|
|
|
|
ConstantIntRanges
|
|
mlir::intrange::inferMaxU(ArrayRef<ConstantIntRanges> argRanges) {
|
|
const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
|
|
|
|
const APInt &umin = lhs.umin().ugt(rhs.umin()) ? lhs.umin() : rhs.umin();
|
|
const APInt &umax = lhs.umax().ugt(rhs.umax()) ? lhs.umax() : rhs.umax();
|
|
return ConstantIntRanges::fromUnsigned(umin, umax);
|
|
}
|
|
|
|
ConstantIntRanges
|
|
mlir::intrange::inferMinS(ArrayRef<ConstantIntRanges> argRanges) {
|
|
const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
|
|
|
|
const APInt &smin = lhs.smin().slt(rhs.smin()) ? lhs.smin() : rhs.smin();
|
|
const APInt &smax = lhs.smax().slt(rhs.smax()) ? lhs.smax() : rhs.smax();
|
|
return ConstantIntRanges::fromSigned(smin, smax);
|
|
}
|
|
|
|
ConstantIntRanges
|
|
mlir::intrange::inferMinU(ArrayRef<ConstantIntRanges> argRanges) {
|
|
const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
|
|
|
|
const APInt &umin = lhs.umin().ult(rhs.umin()) ? lhs.umin() : rhs.umin();
|
|
const APInt &umax = lhs.umax().ult(rhs.umax()) ? lhs.umax() : rhs.umax();
|
|
return ConstantIntRanges::fromUnsigned(umin, umax);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Bitwise operators (And, Or, Xor)
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
/// "Widen" bounds - if 0bvvvvv??? <= a <= 0bvvvvv???,
|
|
/// relax the bounds to 0bvvvvv000 <= a <= 0bvvvvv111, where vvvvv are the bits
|
|
/// that both bonuds have in common. This gives us a consertive approximation
|
|
/// for what values can be passed to bitwise operations.
|
|
static std::tuple<APInt, APInt>
|
|
widenBitwiseBounds(const ConstantIntRanges &bound) {
|
|
APInt leftVal = bound.umin(), rightVal = bound.umax();
|
|
unsigned bitwidth = leftVal.getBitWidth();
|
|
unsigned differingBits = bitwidth - (leftVal ^ rightVal).countl_zero();
|
|
leftVal.clearLowBits(differingBits);
|
|
rightVal.setLowBits(differingBits);
|
|
return std::make_tuple(std::move(leftVal), std::move(rightVal));
|
|
}
|
|
|
|
ConstantIntRanges
|
|
mlir::intrange::inferAnd(ArrayRef<ConstantIntRanges> argRanges) {
|
|
auto [lhsZeros, lhsOnes] = widenBitwiseBounds(argRanges[0]);
|
|
auto [rhsZeros, rhsOnes] = widenBitwiseBounds(argRanges[1]);
|
|
auto andi = [](const APInt &a, const APInt &b) -> std::optional<APInt> {
|
|
return a & b;
|
|
};
|
|
return minMaxBy(andi, {lhsZeros, lhsOnes}, {rhsZeros, rhsOnes},
|
|
/*isSigned=*/false);
|
|
}
|
|
|
|
ConstantIntRanges
|
|
mlir::intrange::inferOr(ArrayRef<ConstantIntRanges> argRanges) {
|
|
auto [lhsZeros, lhsOnes] = widenBitwiseBounds(argRanges[0]);
|
|
auto [rhsZeros, rhsOnes] = widenBitwiseBounds(argRanges[1]);
|
|
auto ori = [](const APInt &a, const APInt &b) -> std::optional<APInt> {
|
|
return a | b;
|
|
};
|
|
return minMaxBy(ori, {lhsZeros, lhsOnes}, {rhsZeros, rhsOnes},
|
|
/*isSigned=*/false);
|
|
}
|
|
|
|
ConstantIntRanges
|
|
mlir::intrange::inferXor(ArrayRef<ConstantIntRanges> argRanges) {
|
|
auto [lhsZeros, lhsOnes] = widenBitwiseBounds(argRanges[0]);
|
|
auto [rhsZeros, rhsOnes] = widenBitwiseBounds(argRanges[1]);
|
|
auto xori = [](const APInt &a, const APInt &b) -> std::optional<APInt> {
|
|
return a ^ b;
|
|
};
|
|
return minMaxBy(xori, {lhsZeros, lhsOnes}, {rhsZeros, rhsOnes},
|
|
/*isSigned=*/false);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Shifts (Shl, ShrS, ShrU)
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
ConstantIntRanges
|
|
mlir::intrange::inferShl(ArrayRef<ConstantIntRanges> argRanges,
|
|
OverflowFlags ovfFlags) {
|
|
const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
|
|
const APInt &rhsUMin = rhs.umin(), &rhsUMax = rhs.umax();
|
|
|
|
// The signed/unsigned overflow behavior of shl by `rhs` matches a mul with
|
|
// 2^rhs.
|
|
ConstArithStdFn ushl = [=](const APInt &l,
|
|
const APInt &r) -> std::optional<APInt> {
|
|
bool overflowed = false;
|
|
APInt result = any(ovfFlags & OverflowFlags::Nuw)
|
|
? l.ushl_sat(r)
|
|
: l.ushl_ov(r, overflowed);
|
|
return overflowed ? std::optional<APInt>() : result;
|
|
};
|
|
ConstArithStdFn sshl = [=](const APInt &l,
|
|
const APInt &r) -> std::optional<APInt> {
|
|
bool overflowed = false;
|
|
APInt result = any(ovfFlags & OverflowFlags::Nsw)
|
|
? l.sshl_sat(r)
|
|
: l.sshl_ov(r, overflowed);
|
|
return overflowed ? std::optional<APInt>() : result;
|
|
};
|
|
|
|
ConstantIntRanges urange =
|
|
minMaxBy(ushl, {lhs.umin(), lhs.umax()}, {rhsUMin, rhsUMax},
|
|
/*isSigned=*/false);
|
|
ConstantIntRanges srange =
|
|
minMaxBy(sshl, {lhs.smin(), lhs.smax()}, {rhsUMin, rhsUMax},
|
|
/*isSigned=*/true);
|
|
return urange.intersection(srange);
|
|
}
|
|
|
|
ConstantIntRanges
|
|
mlir::intrange::inferShrS(ArrayRef<ConstantIntRanges> argRanges) {
|
|
const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
|
|
|
|
ConstArithFn ashr = [](const APInt &l,
|
|
const APInt &r) -> std::optional<APInt> {
|
|
return r.uge(r.getBitWidth()) ? std::optional<APInt>() : l.ashr(r);
|
|
};
|
|
|
|
return minMaxBy(ashr, {lhs.smin(), lhs.smax()}, {rhs.umin(), rhs.umax()},
|
|
/*isSigned=*/true);
|
|
}
|
|
|
|
ConstantIntRanges
|
|
mlir::intrange::inferShrU(ArrayRef<ConstantIntRanges> argRanges) {
|
|
const ConstantIntRanges &lhs = argRanges[0], &rhs = argRanges[1];
|
|
|
|
ConstArithFn lshr = [](const APInt &l,
|
|
const APInt &r) -> std::optional<APInt> {
|
|
return r.uge(r.getBitWidth()) ? std::optional<APInt>() : l.lshr(r);
|
|
};
|
|
return minMaxBy(lshr, {lhs.umin(), lhs.umax()}, {rhs.umin(), rhs.umax()},
|
|
/*isSigned=*/false);
|
|
}
|
|
|
|
//===----------------------------------------------------------------------===//
|
|
// Comparisons (Cmp)
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
static intrange::CmpPredicate invertPredicate(intrange::CmpPredicate pred) {
|
|
switch (pred) {
|
|
case intrange::CmpPredicate::eq:
|
|
return intrange::CmpPredicate::ne;
|
|
case intrange::CmpPredicate::ne:
|
|
return intrange::CmpPredicate::eq;
|
|
case intrange::CmpPredicate::slt:
|
|
return intrange::CmpPredicate::sge;
|
|
case intrange::CmpPredicate::sle:
|
|
return intrange::CmpPredicate::sgt;
|
|
case intrange::CmpPredicate::sgt:
|
|
return intrange::CmpPredicate::sle;
|
|
case intrange::CmpPredicate::sge:
|
|
return intrange::CmpPredicate::slt;
|
|
case intrange::CmpPredicate::ult:
|
|
return intrange::CmpPredicate::uge;
|
|
case intrange::CmpPredicate::ule:
|
|
return intrange::CmpPredicate::ugt;
|
|
case intrange::CmpPredicate::ugt:
|
|
return intrange::CmpPredicate::ule;
|
|
case intrange::CmpPredicate::uge:
|
|
return intrange::CmpPredicate::ult;
|
|
}
|
|
llvm_unreachable("unknown cmp predicate value");
|
|
}
|
|
|
|
static bool isStaticallyTrue(intrange::CmpPredicate pred,
|
|
const ConstantIntRanges &lhs,
|
|
const ConstantIntRanges &rhs) {
|
|
switch (pred) {
|
|
case intrange::CmpPredicate::sle:
|
|
return lhs.smax().sle(rhs.smin());
|
|
case intrange::CmpPredicate::slt:
|
|
return lhs.smax().slt(rhs.smin());
|
|
case intrange::CmpPredicate::ule:
|
|
return lhs.umax().ule(rhs.umin());
|
|
case intrange::CmpPredicate::ult:
|
|
return lhs.umax().ult(rhs.umin());
|
|
case intrange::CmpPredicate::sge:
|
|
return lhs.smin().sge(rhs.smax());
|
|
case intrange::CmpPredicate::sgt:
|
|
return lhs.smin().sgt(rhs.smax());
|
|
case intrange::CmpPredicate::uge:
|
|
return lhs.umin().uge(rhs.umax());
|
|
case intrange::CmpPredicate::ugt:
|
|
return lhs.umin().ugt(rhs.umax());
|
|
case intrange::CmpPredicate::eq: {
|
|
std::optional<APInt> lhsConst = lhs.getConstantValue();
|
|
std::optional<APInt> rhsConst = rhs.getConstantValue();
|
|
return lhsConst && rhsConst && lhsConst == rhsConst;
|
|
}
|
|
case intrange::CmpPredicate::ne: {
|
|
// While equality requires that there is an interpration of the preceeding
|
|
// computations that produces equal constants, whether that be signed or
|
|
// unsigned, statically determining inequality requires that neither
|
|
// interpretation produce potentially overlapping ranges.
|
|
bool sne = isStaticallyTrue(intrange::CmpPredicate::slt, lhs, rhs) ||
|
|
isStaticallyTrue(intrange::CmpPredicate::sgt, lhs, rhs);
|
|
bool une = isStaticallyTrue(intrange::CmpPredicate::ult, lhs, rhs) ||
|
|
isStaticallyTrue(intrange::CmpPredicate::ugt, lhs, rhs);
|
|
return sne && une;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
std::optional<bool> mlir::intrange::evaluatePred(CmpPredicate pred,
|
|
const ConstantIntRanges &lhs,
|
|
const ConstantIntRanges &rhs) {
|
|
if (isStaticallyTrue(pred, lhs, rhs))
|
|
return true;
|
|
if (isStaticallyTrue(invertPredicate(pred), lhs, rhs))
|
|
return false;
|
|
return std::nullopt;
|
|
}
|