BasicBlockInfo - Information about the offset and size of a single basic block. More...

#include "Target/ARM/ARMBasicBlockInfo.h"

Collaboration diagram for llvm::BasicBlockInfo:

Public Member Functions
	BasicBlockInfo ()=default

unsigned	internalKnownBits () const
	Compute the number of known offset bits internally to this block. More...

unsigned	postOffset (unsigned LogAlign=0) const
	Compute the offset immediately following this block. More...

unsigned	postKnownBits (unsigned LogAlign=0) const
	Compute the number of known low bits of postOffset. More...

Public Attributes
unsigned	Offset = 0
	Offset - Distance from the beginning of the function to the beginning of this basic block. More...

unsigned	Size = 0
	Size - Size of the basic block in bytes. More...

uint8_t	KnownBits = 0
	KnownBits - The number of low bits in Offset that are known to be exact. More...

uint8_t	Unalign = 0
	Unalign - When non-zero, the block contains instructions (inline asm) of unknown size. More...

uint8_t	PostAlign = 0
	PostAlign - When non-zero, the block terminator contains a .align directive, so the end of the block is aligned to 1 << PostAlign bytes. More...

Detailed Description

BasicBlockInfo - Information about the offset and size of a single basic block.

Definition at line 37 of file ARMBasicBlockInfo.h.

Constructor & Destructor Documentation

◆ BasicBlockInfo()

llvm::BasicBlockInfo::BasicBlockInfo ( )

default

Member Function Documentation

◆ internalKnownBits()

unsigned llvm::BasicBlockInfo::internalKnownBits ( ) const

inline

Compute the number of known offset bits internally to this block.

This number should be used to predict worst case padding when splitting the block.

Definition at line 75 of file ARMBasicBlockInfo.h.

References llvm::tgtok::Bits, llvm::countTrailingZeros(), KnownBits, and Unalign.

Referenced by CompareMBBNumbers(), getUnconditionalBrDisp(), postKnownBits(), and postOffset().

◆ postKnownBits()

unsigned llvm::BasicBlockInfo::postKnownBits ( unsigned LogAlign = 0 ) const

inline

Compute the number of known low bits of postOffset.

If this block contains inline asm, the number of known bits drops to the instruction alignment. An aligned terminator may increase the number of know bits. If LogAlign is given, also consider the alignment of the next block.

Definition at line 101 of file ARMBasicBlockInfo.h.

References internalKnownBits(), and llvm::max().

◆ postOffset()

unsigned llvm::BasicBlockInfo::postOffset ( unsigned LogAlign = 0 ) const

inline

Compute the offset immediately following this block.

If LogAlign is specified, return the offset the successor block will get if it has this alignment.

Definition at line 87 of file ARMBasicBlockInfo.h.

References internalKnownBits(), llvm::max(), Size, and llvm::UnknownPadding().

Referenced by CompareMBBNumbers(), and getUnconditionalBrDisp().

Member Data Documentation

◆ KnownBits

uint8_t llvm::BasicBlockInfo::KnownBits = 0

KnownBits - The number of low bits in Offset that are known to be exact.

The remaining bits of Offset are an upper bound.

Definition at line 58 of file ARMBasicBlockInfo.h.

Referenced by internalKnownBits().

◆ Offset

unsigned llvm::BasicBlockInfo::Offset = 0

Offset - Distance from the beginning of the function to the beginning of this basic block.

Offsets are computed assuming worst case padding before an aligned block. This means that subtracting basic block offsets always gives a conservative estimate of the real distance which may be smaller.

Because worst case padding is used, the computed offset of an aligned block may not actually be aligned.

Definition at line 47 of file ARMBasicBlockInfo.h.

Referenced by branchMaxOffsets(), and CompareMBBNumbers().