search for: instrumented

...re instrumentation. It has >> significant impact on instrumentation runtime performance. In addition, it >> tends to produce larger binary and profile data file. Our internal C++ >> benchmarks shows that FE based instrumentation degrades the performance >> (compared to non-instrumented version) by 58.3%, and in some extreme cases, >> the application speed/throughput decreases by 95% (21x runtime slowdown). >> >> Running the instrumented binary too slow is not desirable in PGO for the >> following reasons: >> * This slows down already lengthy build...

...add these passes during -O3 regardless of whether we are doing > PGO). > >> > > The pipeline change is very PGO specific. I expect it has very little > impact on regular compilations: > 1) LLVM's bottom up inliner is already iterative. > 2) The performance impact (on instrumented build) can be 4x large -- > which is unlikely for any nonPGO pipeline change. > With respect to adding extra passes, I'm actually more concerned about the non-instrumented build, for which Rong did not show any data. For example, will users find their program is X% faster than no PGO wit...

...ortunities to optimize the code before instrumentation. It has significant impact on instrumentation runtime performance. In addition, it tends to produce larger binary and profile data file. Our internal C++ benchmarks shows that FE based instrumentation degrades the performance (compared to non-instrumented version) by 58.3%, and in some extreme cases, the application speed/throughput decreases by 95% (21x runtime slowdown). Running the instrumented binary too slow is not desirable in PGO for the following reasons: * This slows down already lengthy build time. In the worst case, the instrumented b...

...{ id: 2, address: 0x000000000041DAFA, function: 0x000000000041D4F0, kind: function-exit, always-instrument: false, function-name: '' } - { id: 3, address: 0x000000000041E570, function: 0x000000000041E570, kind: function-enter, always-in ...... ...... Does the map mean that no function is instrumented? Should I change my commands? BTW, after instrumentation could I run the binary and get trace directly? Here is the link to current documentation: https://llvm.org/docs/XRay.html Thank you all, Yushan -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lis...

Hello, I have some questions about removing the instrumented instructions at runtime. Assume I instrument some instructions by using some transformation passes. At runtime, I just need those instrumented instructions at the beginning, and I would like to remove instrumented instructions at runtime to reduce overhead. Does anyone know how to do this by us...

Hello all, I have developed a instrumented pass which insert some variables between the original variables, as well as insert some code into the original source code. just like: ============= original source code ============= int a[10]; void fun1 () { // some source code here } ========================================= ==========...

...trumentation. In contrast, CSI inserts a standard collection of instrumentation hooks into the program-under-test. Each CSI-tool is implemented as a library that defines relevant hooks, and the remaining hooks are "nulled" out and elided during link-time optimization (LTO), resulting in instrumented runtimes on par with custom instrumentation. CSI allows many compiler-based tools to be written as simple libraries without modifying the compiler, greatly lowering the bar for developing dynamic-analysis tools. ================ Motivation ================ Key to understanding and improving t...

> Assume I instrument some instructions by using some transformation passes. > At runtime, I just need those instrumented instructions at the beginning, > and I would like to remove instrumented instructions at runtime to reduce > overhead. At the beginning of what? You mean at the time of program starup? Then after detecting/collecting whatever you want, you would like to remove those instrumented instructi...

...ntrast, CSI inserts a standard > collection of instrumentation hooks into the program-under-test. Each > CSI-tool is implemented as a library that defines relevant hooks, and the > remaining hooks are "nulled" out and elided during link-time optimization > (LTO), resulting in instrumented runtimes on par with custom > instrumentation. CSI allows many compiler-based tools to be written as > simple libraries without modifying the compiler, greatly lowering the bar > for > developing dynamic-analysis tools. > > ================ > Motivation > ================ &...

Dear List, I have some questions about some passes for LLVM that I'm thinking about but first I need to give a little background ... One of the things I do in my "day job" (large IT system performance analysis) is to figure out where to place diagnostic instrumentation within an application. The instrumentation I'm talking about here is the kind that is inserted into

...;header.h' struct X { int k; int getK() const { return k; } ... }; // In 'source.cpp' #include "header.h" ... X anX; ... int check = anX.getK(); Now the tiny accessor function which is usually trivially eliminated during inlining, is unnecessarily instrumented with the '__cyg_profile_func_enter' and '__cyg_profile_func_exit' calls, as well as the calling function. Magnify this by the expansion and inlining of many hundreds of such functions, and the overhead becomes very large. And unfortunately, it also hides the true cost of the compo...

...rts a standard >> collection of instrumentation hooks into the program-under-test. Each >> CSI-tool is implemented as a library that defines relevant hooks, and the >> remaining hooks are "nulled" out and elided during link-time optimization >> (LTO), resulting in instrumented runtimes on par with custom >> instrumentation. CSI allows many compiler-based tools to be written as >> simple libraries without modifying the compiler, greatly lowering the bar >> for >> developing dynamic-analysis tools. >> >> ================ >> Motiva...

Hi, I consider reducing the usage of blacklist in sanitizer instrumentation passes and doing the necessary work in frontend (Clang) instead. Some of it is already implemented: e.g. Clang will attach an attribute "sanitize_address" to function definition only if this function is not blacklisted. In this case we won't instrument the memory accesses in this function in ASan

...lly like to hear about how the performance of your optimized application changes when you turn pre-inlining on during the instrumentation step. You can experiment with this with -mllvm -disable-preinline. > My question is whether there are any mechanisms in LLVM to control what functions get instrumented; for instance ‘#pragma’s that can be added to the code, especially headers, that can be used to disable the instrumentation of large groups of functions. Or an option to remove the instrumentation during inlining? Not that I'm aware of. One option is to not pass -fprofile-blah into translatio...

Reid, Adding this kind of instrumentation pass would be very valuable in LLVM. We don't have any such thing at present, and there could be multiple uses for it. Joel Stanley did an MS thesis last year that could complement this kind of pass nicely. Joel's thesis was on dynamic performance instrumentation guided by explicit queries within the application (I will forward you a

Hello, I have a question regarding PGO instrumented BBs (I use IR-level instrumentation). It seems that instrumented BBs do not match between the two compilations for profile-gen and profile-use for some cases. Here is an example from SPECcpu 2006 lbm (a simple case consisting of just two modules). In the first compilation, we have 5 instrumentatio...

...rts a standard >> collection of instrumentation hooks into the program-under-test. Each >> CSI-tool is implemented as a library that defines relevant hooks, and the >> remaining hooks are "nulled" out and elided during link-time optimization >> (LTO), resulting in instrumented runtimes on par with custom >> instrumentation. CSI allows many compiler-based tools to be written as >> simple libraries without modifying the compiler, greatly lowering the bar >> for >> >> developing dynamic-analysis tools. >> >> ================ >&g...

On 2/24/13 10:07 AM, Lu Mitnick wrote: > Hello all, > > I have developed a instrumented pass which insert some variables > between the original variables, > as well as insert some code into the original source code. just like: > > ============= original source code ============= > > int a[10]; > > void fun1 () { > // some source code here > } > &...

Hi there, I hope to build a model Y ~ X1 + X2 + X3 + X4 with X1 has two instrumental variable A and B, and X2 has one instrumental variable A. I have searched the R site and mailling list, and known that the tsls() from sem package and ivreg() from AER package can deal with instrumental variable regression, however, I don't know how to formula the model. Any suggestion will be really

...-arcs w/o einline 310.560 (4) profile-generate 139.952 (5) profile-generate w/o einline 680.910 In GCC, -fprofile-generate does -fprofile-arcs as well as the value profiling. The above table shows that with value profile, the impact of pre-inlining is even larger for instrumented binary performance. Without value profiling, disabling pre-inlining increases runtime by 1.7x, while with value profiling, its impact is 3.9x increase in runtime. On Tue, Aug 11, 2015 at 10:11 PM, Sean Silva via llvm-dev < llvm-dev at lists.llvm.org> wrote: > > > On Tue, Aug 11,...