Introduction to performance optimization using Intel SW tools - ответы
Количество вопросов - 252
What is CPU speed?
How many threads could enter the critical section at a time?
What qualities does shared memory systems have?
What are necessary conditions for auto-parallelization?
Internal representation is
What is the part of the syntax analysis in the compiler?
During the VTune analysis some of the functions is missed. Why could it happened?
What are disadvantages of the procedural-level optimizations?
CPU timer speed is
What criteria of connecting statements into a list inside Intel compiler
Choose the code resulting to the loop peeling for:p = 10; for (i=0; i<10; ++i) { y[i] = x[i] + x[p]; p = i;}
Static call graph is
What platforms are supported by Intel compilers?
What parallel library does Intel compiler use?
SSA-form is:
SSE is:
Choose the characteristic corresponding to distributed memory systems:
What are locks and waits for?
This command line parameter is used to enable inter-file optimization
Superscalarity is
How data dependencies are used in the code generation?
What types multiprocessor systems could be divided into?
What is the goals of ALU
Dynamic data is useful when
Tree of expressions is
Interference graph is built
What is an automatic parallelization propose?
What is constant folding?
Dynamic profiler differs from static
Basic blocks are contained by
Memory, which is directly accessed by processor is
Modern Intel processors are
Choose the wrong statement
Superscalarity is
Superscalar is
In a fully-associative memory
Vectorization is parallelization technique when
Number of units could be sent to the processor at once is
What kind of information is obtainable via VTune?
What operation system VTune supports?
What analysis types are included in VTune?
What event corresponds processor clock ticks?
What is critical code?
What compilers Intel® provides?
Data flow analysis is
Dominance frontier is
May one compiler have two different Front Ends?
What is the part of the syntax analysis in the compiler?
How the statements are connected inside the Intel compiler
Nodes of control flow graph are
Def-use graph nodes are
Constants in expressions tree
Choose the scalar optimization:
The dependency between S1 and S2 persist if
Choose code fragments which are good for optimizing
Why performance is improved when invariant is moved out of the loop?
Why performance could be increased after the loop distribution?
What is loop unrolling for?
When full loop unrolling is applicable?
Required condition for dependency between S1 and S2 are the following:
When the dependence <S1,S2> is true dependence
Normalized loops are used to?
Is there any dependence in this code?DO I=1,N S1 A(I)=… S2 …=A(I)END DO
What is FLOW dependency?
Loop vectorization is
Which of the following command line options will build a binary for any processor?
What is vector instruction for the compiler?
How many xmm registers does emm64t support?
Packed data type operations are
What is /Qvec-report used for?
What is the processor core?
What disadvantages does non-uniform memory access systems have?
What are multi-threading applications pros?
What kind of optimization is the auto-parallelization?
What directive suggest the compiler to not parallelize following loop?
What directive will force compiler to parallelize following loop if it is safe?
What is OpenMP?
How parallelization in Intel compiler is implemented?
How prefetch can be invoked?
When using OpenMP variables behave as follows:
What pragma is used to parallelize loop:
What could be performed to save the last state of the variable into master thread after the parallel block?
What directive is used to create synchronization point?
What directive marks sequential execution block?
What option used to determine multi-thread iteration distribution?
What of the following could be considered as a good style of programming?
What is the aim when the program is divided into functions and procedures?
What are disadvantages of the procedural-level optimizations?
What is node in call graph?
Dynamical call graph
What kind of interprocedural optimization is used by default?
Points to analysis is
What are disadvantages of inlining?
What is taken into account during the memory disambiguation?
What is demanded by ANSI aliasing?
How compiler determines a case when it is better to perform inlining?
What could be used to force function inline?
What is partial inlining?
What is the source for branch prediction in static profiler
Choose the correct statement(s)
Register allocation includes
What instruction scheduling is useful for?
What are the aims for the structure splitting?
How dynamic linked list memory placement can be improved?
The advantages of SSA form:
Control flow graph
Bandwidth is
What size do xmm registers have?
When the linked list is stored inside the memory
SIMD is:
What directive is used to avoid incorrect concurrent usage of the lval variable?
What option is used to disable inline?
What of the following is required to execute vector operation?
How developer could drive inlining process?
Which of the following is required to keep the equation equivalence
What is loop invariant?
What interprocedural optimization is specific to C++?
Basic blocks are
For parallelization it is required to:
How does instruction planning performed?
What identifier is not reserved for OpenMP:
What is VTune™ Performance Analyzer for?
How auto-parallelization is connected with other optimizations in Intel compiler?
SSA is
Linked list worse than array for
What is ANTI dependency?
What is condition for vectorization?
When the dependence <S1,S2> is output-dependence
Basic block is
Vectorization is
Leafs in expressions tree
Dynamic call graph is
What is inlining?
System bus used for
Superscalar is
Time latency (for RAM) is
In out-of-order execution instructions scheduled according
What is the requirements of VTune?
What is profiling?
What event corresponds wrong branch prediction?
What may be cause of ineffective resource utilization?
What is the functions of the compiler Front End ?
Expression is
To know what variables could be used inside the block, it is necessary to estimate:
Choose the correct statements
Operations in a expressions tree
"Dead code" may be caused by
What is the Loop Stream Detector for?
Loop invariant code motion
What optimization is inverse for loop fusion?
How loop unrolling is provided?
Choose the correct statements for the code: DO I=1,N S1 A(I) = B(I) + 1 S2 B(I+1) = A(I) – 5END DO
When the dependency <S1,S2> is anti-dependence?
What is iteration vector?
What is OUTPUT dependency?
May four different variables became components of the same vector after the vectorization?
What is happened to zero bits in packed data type?
What seriously limit modern system performance?
What qualities does distributed memory systems have?
What disadvantages does distributed memory systems have?
What are multi-threading applications cons?
What information does /Qpar-report3 output?
Is it hard to measure optimization profitability?
What directive will force compiler to parallelize following loop?
OpenMP uses the following model of parallel execution:
As a default all variables except local function variables and loop iterators are add to
How global variables usage affects?
Why call graph may be considered as not full?
Aliasing could be occurred between
When permutation transformations are not allowed?
Static profiler used
What is required for dynamic profiling
Dynamic memory allocation is bad for
Choose the correct statement(s)
What of the following is schedule type?
What of the following will not cause any change in processor performance?
What are normalized loops?
x86 speed factors are
What is required for most of the loop optimizations
What qualities does non-uniform memory access systems have?
Pipeline is
What is corresponding entity for the interference graph colors?
What abilities does VTune has?
What is passed as an argument to loop parallelizing function in Intel compiler?
What information is corresponding to vertexes in a call graph?
What conditions can prevent vectorization?
Statement M dominates N if
This command line parameter is used to disable interprocedural optimizations
What is variable scope?
nowait directive is used for:
What is used to send data between the processor and the memory or between the processor and the devices?
Cache levels differ by
Type of cache, where any memory block could be loaded into any part of the cache
VTune supports:
What are functions of the Hotspots?
Set Uses[b] contains:
SSA-form is
Statements could be arranged
Choose the correct statements
What is packed data type?
Choose the characteristic corresponding to non-uniform memory access systems:
What is loop parallelizing function in Intel compiler?
What directive is used to mark a piece of code to be executed by master thread only?
What benefits would give correct code formatting?
What is - ansi-alias for?
Dynamic memory allocation
Choose the correct statement(s)
Why is the pointer chasing useful?
The ability to perform multiple operations at a tick is
What cons does prefetch has?
Dynamic profiler benefits are
Transforming optimization keeps the equation equivalence if
What is required for loop dependency between S1 и S2 in a nested set?
Why register access latency is lower than RAM?
What is __declspec(align(n)) pragma used for?
Registers are
What is loop peeling?
To convert a compiler to different internal representation it is necessary to correct
What of the following could be considered as a bad style of programming?
Choose the correct statement
Hardware prefetching used for
What could be the reason for loosing performance while processing a big loop?
Is there any dependence in this code?DO I=1,N S1 A(I+1) =F(I) S2 F(I+1) = A(I)END DO
MMX technology provides:
What size do ymm registers have?
What is __alignof__ used for?
What disadvantages does shared memory systems have?
What is "prefetch"?
OpenMP is:
Schedule clause accepts the following arguments:
What of the following is schedule type?
What are disadvantages of the procedural-level optimizations?
What is the goals of inlining?
What is used to suggest function for inline?
What is function cloning?
What disadvantage does static profiler has?
How structure field reordering could affect the application performance?
What is input data for syntax analysis?
What is memory diambiguation?
Choose the correct statements for this code: S1 PI = 3.14S2 R = 5S3 AREA = PI*R **2
Loop optimizations are:
Choose the characteristic corresponding to shared memory systems:
The Control Unit functions are
Number of ticks, required to transfer one unit from the memory is
Choose scalar optimizations
Dependency is
What is alias analysis?
Basic blocks are
What is the meaning of restrict attribute at pointer definition in С/С++?
Why it is recommended to arrange fields in structure by decrease of their size?
Array is better than linked list for
What part of the compiler depends on a language most?