Helper class that determines whether a list of integer comparisons can share a single predicate. More...

#include "Transforms/Vectorize/SLPVectorizer/SLPCompatibilityAnalysis.h"

Public Member Functions
bool	add (const Instruction *I)
	Intersects the convertible predicate set of the comparison lane `I` (an icmp or a trunc to i1) with the running set.
CmpInst::Predicate	getPredicate (const ICmpInst *Preferred) const
	Returns the shared predicate, preferring the predicate of `Preferred` when the whole list can use it, or BAD_ICMP_PREDICATE when the list cannot share a natively present predicate.

Static Public Member Functions
static CmpInst::Predicate	getSharedPredicate (ArrayRef< Value * > VL, const ICmpInst *Preferred)
	Returns the predicate the whole list can share, or BAD_ICMP_PREDICATE when it cannot share a natively present predicate.
static bool	isBitTest (const Instruction *I)
	Checks if the comparison lane `I` is the bit test of the single use and A, B != 0 or and A, B == 0, or trunc X to i1, which is and X, 1 != 0.
static bool	canConvertTo (const Instruction *I, CmpInst::Predicate Pred)
	Checks if the comparison lane `I` can be expressed with the predicate `Pred` by adjusting its constant operand.
static Constant *	getAdjustedConstant (const Instruction *I, CmpInst::Predicate Pred)
	Returns the adjusted constant operand expressing the comparison lane `I` with the predicate `Pred`, or nullptr if not convertible or if `I` is a compare already using `Pred`.

Detailed Description

Helper class that determines whether a list of integer comparisons can share a single predicate.

InstCombine canonicalizes single-element and single-complement range comparisons to eq/ne at the type boundaries (e.g. x <u 1 becomes x == 0); such lanes are interchangeable with the rest of the list by adjusting the compared constant. InstCombine also canonicalizes icmp ne (and X, 1), 0 to trunc X to i1, such lanes are treated as the original comparison or as icmp eq (and X, 1), 1.

Definition at line 143 of file SLPCompatibilityAnalysis.h.

Member Function Documentation

◆ add()

bool llvm::slpvectorizer::CmpSamePredicateHelper::add ( const Instruction * I )

Intersects the convertible predicate set of the comparison lane I (an icmp or a trunc to i1) with the running set.

Returns false when the intersection becomes empty.

Definition at line 465 of file SLPCompatibilityAnalysis.cpp.

References llvm::dyn_cast(), and I.

Referenced by getSharedPredicate().

◆ canConvertTo()

bool llvm::slpvectorizer::CmpSamePredicateHelper::canConvertTo	(	const Instruction *	I,
		CmpInst::Predicate	Pred )

static

Checks if the comparison lane I can be expressed with the predicate Pred by adjusting its constant operand.

Definition at line 495 of file SLPCompatibilityAnalysis.cpp.

References I, and llvm::CmpInst::isIntPredicate().

Referenced by getAdjustedConstant(), and llvm::slpvectorizer::getSameOpcode().

◆ getAdjustedConstant()

Constant * llvm::slpvectorizer::CmpSamePredicateHelper::getAdjustedConstant	(	const Instruction *	I,
		CmpInst::Predicate	Pred )

static

Returns the adjusted constant operand expressing the comparison lane I with the predicate Pred, or nullptr if not convertible or if I is a compare already using Pred.

Definition at line 500 of file SLPCompatibilityAnalysis.cpp.

References assert(), C(), canConvertTo(), llvm::dyn_cast(), llvm::slpvectorizer::getCmpBoundaryFamily(), llvm::slpvectorizer::getLaneConstantCmp(), I, llvm::CmpInst::ICMP_EQ, and llvm::isa().

Referenced by llvm::slpvectorizer::convertTo().

◆ getPredicate()

CmpInst::Predicate llvm::slpvectorizer::CmpSamePredicateHelper::getPredicate ( const ICmpInst * Preferred ) const

Returns the shared predicate, preferring the predicate of Preferred when the whole list can use it, or BAD_ICMP_PREDICATE when the list cannot share a natively present predicate.

Definition at line 473 of file SLPCompatibilityAnalysis.cpp.

References llvm::CmpInst::BAD_ICMP_PREDICATE, llvm::countr_zero(), llvm::CmpInst::getPredicate(), and llvm::CmpInst::ICMP_EQ.

Referenced by getSharedPredicate().