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Revision 3657cf5f363fd64aeaf06432e62e3960800927b0 authored by Andrew Adams on 26 January 2024, 17:26:12 UTC, committed by GitHub on 26 January 2024, 17:26:12 UTC 
Fix bounds_of_nested_lanes (#8039)
 
* Fix bounds_of_nested_lanes

bounds_of_nested_lanes assumed that one layer of nested vectorization
could be removed at a time. When faced with the expression:

min(ramp(x8(a), x8(b), 5), x40(27))

It panicked, because on the left hand side it reduced the bounds to
x8(a) ... x8(a) + x8(b) * 4, and on the right hand side it reduced the
bounds to 27. It then attempted to take a min of mismatched types.

In general we can't assume that binary operators on nested vectors have
the same nesting structure on both sides, so I just rewrote it to reduce
directly to a scalar.

Fixes #8038
1 parent 4590a09
Raw File
Monotonic.h 
#ifndef HALIDE_MONOTONIC_H
#define HALIDE_MONOTONIC_H

/** \file
 *
 * Methods for computing whether expressions are monotonic
 */
#include <iostream>
#include <string>

#include "Interval.h"
#include "Scope.h"

namespace Halide {
namespace Internal {

/** Find the bounds of the derivative of an expression. */
ConstantInterval derivative_bounds(const Expr &e, const std::string &var,
                                   const Scope<ConstantInterval> &scope = Scope<ConstantInterval>::empty_scope());

/**
 * Detect whether an expression is monotonic increasing in a variable,
 * decreasing, or unknown.
 */
enum class Monotonic { Constant,
                       Increasing,
                       Decreasing,
                       Unknown };
Monotonic is_monotonic(const Expr &e, const std::string &var,
                       const Scope<ConstantInterval> &scope = Scope<ConstantInterval>::empty_scope());
Monotonic is_monotonic(const Expr &e, const std::string &var, const Scope<Monotonic> &scope);

/** Emit the monotonic class in human-readable form for debugging. */
std::ostream &operator<<(std::ostream &stream, const Monotonic &m);

void is_monotonic_test();

}  // namespace Internal
}  // namespace Halide

#endif
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