C Code Generation

1 2012 The MathWorks, Inc.

Latest Features in code generation

November 2013

Michael Donnenfeld,

Application Engineer

Code Generation

Systematics

2

C/C++ Coders

MATLAB Coder - Code from MATLAB

Portable code for numerical algorithms

Desktop applications (standalone, library)

Simulink Coder - Code from Simulink

Rapid prototyping or HIL applications

Real-time machines (xPC Target)

Embedded Coder Production optimized code

Embedded applications

MCU and DSP (fixed or float)

Code verification (in-the-loop)

Target-specific support (APIs and examples)

All coders generate portable code (ANSI/ISO C) by default.

C/C++

Gen

era

te

MATLAB and Simulink

Algorithm and System Design

Verify


Latest Features in MATLAB Coder

November 2013

5

fprintf, fopen, and fclose in

MATLAB Coder

Log data in generated code

6

load and coder.load

Use load to read data from MAT-files from within generated

MEX-files only

Use coder.load to read data from MAT-files and embed them

as constants

Access data stored in

MAT-files

7

Nonpersistent Handle Objects

Create an object and pass it to a subfunction

Create an object and assign it to a property of another object

Allocate and use an object repeatedly inside a loop

Create an object in a function and return it

Use more programming idioms with Handle objects

8

Structures Passed by Reference to

Entry-Point Functions

Reduce data copies for better performance

9

MEX C Code generation for parfor

Simplify integration with existing C code

Runtime errors handled using setjmp/longjmp rather than

try/catch

Generate code from parfor

loops in MEX C code

10

Build Tool Integration

A new panel Toolchain for toolchain-related settings.

Toolchain pulldown allows you select registered toolchains.

User can add their own.

Build Configuration pulldown allows to switch easily among

different configurations

Correspondingly, three new coder.config properties are added:

Toolchain

BuildConfiguration

CustomToolchainOptions

Allows users to choose

different toolchains and build

configurations

11

Optimize X = [X C]

This is a typical pattern of growing a vector but it

generates data copies in

previous releases

R2013a generates optimized code, improves RAM/ROM and

speed

for (i = 0; i < 10; i++) { ......................

for (i0 = 0; i0 < loop_ub; i0++) { b_x_data[i0] = (int8_T)x_data[i0];

} b_x_data[y_size[1]] = (int8_T)(1 + i);

....................... for (i0 = 0; i0 < x_size_idx_1; i0++) { x_data[i0] = (real_T)b_x_data[i0];

} ......................

}

for (i = 0; i < 10; i++) { x_data[y_size[1]] = 1.0 + (real_T)i;

x_size[1]++; }

R2012b

R2013a

coder.varsize(x',[1,10]); .

for i = 1 : 10 x = [x i];

end

codegen -config:lib grow_a_vec_pattern -args {} -report

concat

assign

12

For Use with Embedded Coder

13

Static Code Metrics Report

Target-independent analysis

Report showing:

Lines of code

Global RAM estimate

Stack size estimate

Cyclomatic complexity estimate

See estimated code metrics

at code generation time

14

Code Replacement Library Report

Improves discoverability of code replacement library usage in

generated code

Provides traceability of used function back to MATLAB

function that triggered the

replacement

Find code replacement

functions used in generated

code

See next slide

15

Code Replacement Library Traceability

Aids in debugging code replacement library entries

Provides information for why CRL entry was not used for

replacement by a particular

MATLAB function

Discover why code

replacement functions were

not used in generated code


Latest Features in MATLAB Coder

November 2013

17

Code Generation Support for

Statistics Toolbox functions

betacdf

betainv

betapdf

betarnd

betastat

binocdf

binoinv

binopdf

binornd

binostat

cdf

chi2cdf

chi2inv

chi2pdf

chi2rnd

chi2stat

evcdf

evinv

evpdf

evrnd

evstat

expcdf

expinv

exppdf

exprnd

expstat

fcdf

finv

fpdf

frnd

fstat

gamcdf

gaminv

gampdf

gamrnd

gamstat

geocdf

geoinv

geomean

geopdf

geornd

geostat

gevcdf

gevinv

gevpdf

gevrnd

gevstat

gpcdf

gpinv

gppdf

gprnd

gpstat

harmmean

hygecdf

hygeinv

hygepdf

hygernd

hygestat

icdf

iqr

kurtosis

logncdf

logninv

lognpdf

lognrnd

lognstat

mad

mnpdf

moment

nancov

nanmax

nanmean

nanmedian

nanmin

nanstd

nansum

nanvar

nbincdf

nbininv

nbinpdf

pdf

poisscdf

poissinv

poisspdf

poissrnd

poisstat

prctile

quantile

randg

random

raylcdf

raylinv

raylpdf

raylrnd

raylstat

skewness

tcdf

tinv

tpdf

trnd

tstat

unidcdf

unidinv

unidpdf

unidrnd

unidstat

unifcdf

unifinv

unifpdf

unifrnd

unifstat

wblcdf

wblinv

wblpdf

wblrnd

wblstat

zscore

nbinrnd

nbinstat

ncfcdf

ncfinv

ncfpdf

ncfrnd

ncfstat

nctcdf

nctinv

nctpdf

nctrnd

nctstat

ncx2cdf

ncx2rnd

ncx2stat

normcdf

norminv

normpdf

normrnd

normstat

Use 100+ Statistics Toolbox functions

18


Phased Array System Toolbox functions

aictest

albersheim

ambgfun

aperture2gain

az2broadside

azel2phitheta

azel2phithetap

at

azel2uv

azel2uvpat

azelaxes

beat2range

billingsleyicm

broadside2az

cart2sphvec

cbfweights

circpol2pol

dechirp

delayseq

depressionang

dop2speed

dopsteeringvec

effearthradius

espritdoa

fspl

gain2aperture

global2localcoord

grazingang

horizonrange

lcmvweights

local2globalcoord

mdltest

mvdrweights

noisepow

npwgnthresh

phitheta2azel

phitheta2azelpat

phitheta2uv

phitheta2uvpat

physconst

pol2circpol

polellip

polloss

polratio

polsignature

pulsint

radareqpow

radareqrng

radareqsnr

radarvcd

radialspeed

range2beat

range2bw

range2time

rangeangle

rdcoupling

rocpfa

rocsnr

rootmusicdoa

rotx

roty

rotz

sensorcov

sensorsig

shnidman

speed2dop

sph2cartvec

spsmooth

steervec

stokes

stretchfreq2rng

surfacegamma

surfclutterrcs

systemp

time2range

unigrid

uv2azel

uv2azelpat

uv2phitheta

uv2phithetapat

val2ind

Use 80+ functions

19


Phased Array System Toolbox functions

phased.CosineAntennaElement

phased.CrossedDipoleAntennaElement

phased.CustomAntennaElement

phased.CustomMicrophoneElement

phased.IsotropicAntennaElementIsotropic

phased.OmnidirectionalMicrophoneElement

phased.ShortDipoleAntennaElement

phased.ULA

phased.URA

phased.ConformalArray

phased.PartitionedArray

phased.ReplicatedSubarray

phased.SteeringVector

phased.ArrayGain

phased.ArrayResponse

phased.ElementDelay

phased.Collector

phased.Radiator

phased.WidebandCollector

phased.LinearFMWaveformLinear

phased.PhaseCodedWaveform

phased.RectangularWaveform

phased.SteppedFMWaveform

phased.FMCWWaveform

phased.MatchedFilter

phased.Transmitter

phased.ReceiverPreamp

phased.PhaseShiftBeamformer

phased.LCMVBeamformer

phased.MVDRBeamformer

phased.SubbandPhaseShiftBeamformer

phased.FrostBeamformer

phased.TimeDelayBeamformer

phased.TimeDelayLCMVBeamformer

phased.SteeringVector

phased.SumDifferenceMonopulseTracker

phased.SumDifferenceMonopulseTracker2D

phased.BeamscanEstimator

phased.BeamscanEstimator2D

phased.MVDREstimator

Use 50+ System objects

phased.MVDREstimator2D

phased.RootMUSICEstimator

phased.RootWSFEstimator

phased.ESPRITEstimator

phased.BeamspaceESPRITEstimator

phased.STAPSMIBeamformer

phased.DPCACanceller

phased.ADPCACanceller

phased.AngleDopplerResponse

phased.CFARDetector

phased.MatchedFilter

phased.RangeDopplerResponse

phased.StretchProcessor

phased.TimeVaryingGain

phased.FreeSpace

phased.RadarTarget

phased.ConstantGammaClutter

phased.BarrageJammer

phased.Platform

20

Multicore parfor Support for

Standalone Code Generation

Requires C/C++ compiler supporting OpenMP

rand works with parfor

Use parfor to generate parallel C/C++ code using OpenMP

>> coderdemo_contrast_enhancer

22

Generate Built-In C Types

Improved readability of the

generated code

Use built-in C types in the generated code

Make generated code look more like handwritten code

Revert to old behavior if desired

23

Code Generation Support for 64-Bit Data

Types

Use int64 and uint64 data types

for code generation

Generate multiword code for

hardware target not having 64-

bit integer C type

Leverage long long C Type

24

For Use with Embedded Coder

25

Software-in-the-Loop (SIL) Verification

Reuse MATLAB tests to exercise standalone source code compiled for

host computer

Integrate SIL verification with the existing Project verification tool and command-line utility coder.runTest

Step through generated code in Microsoft Visual Studio debugger during SIL testing when using coder.runTest

Verify numerical behavior of

generated source code through

software-in-the-loop testing


Embedded Coder and Simulink Coder

Features for R2013a

November 2013

28

User-directed Buffer merging at Root IO

Allows Reusable (CSC) buffer specification at Simulink model

root IO

Reusable buffers are reused in the generated code (buffers are

merged for a pair of specified

root input and output)

Feature-controlled

Facilitates user-guided

in-place optimization in the

generated code

slfeature(ReuseReusableCSCAtRootIO, 1)

abc = Simulink.Signal; abc.CoderInfo.StorageClass = 'Custom';

abc.CoderInfo.CustomStorageClass = 'Reusable';

Reuse of abc

29

Easily Run Generated Code in

the Microsoft Visual C++ Source

Level Debugger

Supports top-model and Model block SIL

Automatically compiles generated code with

debug symbols

Automatically launches MSVC and adds breakpoints at entry

point functions in generated

code

Step through the generated

code in the MSVC debugger

during SIL simulations

30

Reduce verification time by simulating

SIL components together

Simulate Multiple SIL

Model Blocks Within a

Top Model

Multiple Model blocks

can now simulate in SIL

mode at the same time

Reduces the number of

simulations required to

simulate all components

in SIL mode.

31

Easily Review Function Execution Times

for Code Running on Embedded Hardware

Call-site instrumentation to measure execution time of

functions in the generated code

Now includes initialization, shared utility and math library

functions

Configurable units for reporting of measured execution times

Comprehensive measurement

of function call execution

times

rtwdemo_sil_topmodel

Default units are

nanoseconds

32

Create Comparison Plots for Function

Execution Times

Results automatically imported into Simulation

Data Inspector

Use extensive capabilities to plot execution times and

to manage and compare

runs

Faster alternative to the command line API

View code execution times in

Simulation Data Inspector

rtwdemo_sil_topmodel

33

Define an Execution Profiling Timer via

Code Replacement Library (CRL)

CRL is now the recommended approach

to specify a timer for

execution profiling

You can use the command line API or the crtool graphical user

interface

Use the Code Replacement

Tool to define a hardware-

specific timer

rtwdemo_custom_pil_script

34

Code Replacement Library (CRL) used

to enable custom multi-core targeting

Used with the Concurrent Execution modeling capability

Customize data transfer code to the specific RTOS

environment

Functions Mutex Destroy

Mutex Init Mutex Lock

Mutex Unlock Semaphore Destroy

Semaphore Init Semaphore Post Semaphore Wait

void mReusableRTB_SubsystemTID0(real_T rtu_In1,

rtB_Subsystem_mReusableRTB *localB,

rtDW_Subsystem_mReusableRTB *localDW)

{

int8_T wrBufIdx;

/* RateTransition: '/IntegF2S' */

mySemTake((void**)&(localDW->IntegF2S_SEMAPHORE));

wrBufIdx = (int8_T)(localDW->IntegF2S_LstBufWR + 1);

if (wrBufIdx == 3) {

wrBufIdx = 0;

}

mySemGive((void**)&(localDW->IntegF2S_SEMAPHORE));

}


Embedded Coder and Simulink Coder

Features for R2013b

November 2013

36

/* Model step function */

void add3_64bit_step(void)

{

Y = U + 3ULL;

}

/* rtwtypes.h */

typedef long long int64_T;

C99 long long available in Code Generation

Exploit C compilers long long (when available)

Enhance simulation accuracy

Speed up Windows64 accelerated simulation

64-bit multiword on 40-bit DSPs

Generate code for 64-bit data

types on 32-bit targets

37

Lean Generated C Code Using Long Long

~100 lines with just 32 bit long

~3 lines Code with 64 bit long long

38

Single Default Data Type Option for

Underspecified Signals

Option to set up default data type in a Simulink model as

single instead of double

Controls data type propagation rules to use double or single for

inherited data types

Avoid the introduction of double data types for embedded

designs that target single-

precision processors

Specify default floating-point

data type for under-specified

signals

39

Avoid Stowaway Doubles

Mixed single precision and integer (or fixed-point)

now always limit math to singles (avoid doubles).

New Design: Strict Singles yPB2 = (real32_T)U5 * U6;

ySF2 = (real32_T)U5 * U6;

Old Design: Stowaway doubles yPB2 = (real32_T)((real_T)U5 * U6);

ySF2 = (real32_T)((real_T)U5 * U6);

Math Mixed Single and Int32

40

Model Advisor Check for Single-Precision Designs

Finds use of doubles that

may be hidden deep in model

41

System Function with Return Argument

real_T sys(real_T in1, real_T in2)

{

return in1 + in2;

}

void model(void)

{

rtb_sum = sys(U.In1, U.In2);

Y.out = rtbsum + U.In3;

}

void sys(real_T in1, real_T in2, real_T *out)

{

*out = in1 + in2;

}

Void model(void)

{

sys(U.In1, U.In2, &rtb_sum);

Y.out = rtb_sum + U.In3;

}

Subsystem function may return one

of its scalar outputs as a return

argument when it is packaged to

generate non-reusable function

with arguments.

R2013a R2013b

42

Simplified Makefile generation for ert.tlc

and grt.tlc targets

Toolchain

Build Configuration

43

ARM Cortex-M Optimized Code

Example: Code Replacement Library enables FIR filter code to use ARM

CMSIS DSP library: arm_fir_f32() Provides order of magnitude performance

improvements for ARM Cortex-M cores

Includes STMicroelectronics Discovery Board basic blockset (ADC, GPIO)

44

New Targets in R2013a and R2013b

Educational Simulink targets

Raspberry Pi

Gumstix Overo

Embedded Coder targets

ARM Cortex-M

STM32F4-Discovery board (ARM Cortex-M4)

Xilinx Zynq (ARM Cortex-A9)

HDL Coder FPGA targets

Xilinx Zynq (FPGA fabric)

Xilinx-based Software-Defined Radio

45

Average Global RAM Reduction Since R2008b

(Using 70+ Industry Models)

Rela

tive to

R2

00

8b

Code Report

Global RAM Usage

46

Unnecessary Data Copy Reduction Since

R2008b (Using 70+ Industry Models)

MathWorks has developed a target-independent method to measure data copies, which helps prioritize our code efficiency efforts

Rela

tive to

R2

00

8b

Data Copy Measurement

47

Thank you

C Code Generation

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