similar to: [LLVMdev] Non-local DSE optimization

Hi, It looks like PDT.getRootNode() returns NULL for: define fastcc void @c974001__lengthy_calculation. 1736(%struct.FRAME.c974001* nocapture %CHAIN.185) noreturn { entry: br label %bb bb: br label %bb } Isn't it a bug in PostDominatorTree? Please note that this crashes: opt -postdomtree -debug dom_crash.bc I think this should be reported as a bug, -Jakub On Sep 3, 2009, at

Hi Jakub, interesting patch. I ran it over the Ada testsuite and this picked up some problems even without enabling dse-ssu. For example, "opt -inline -dse -domtree" crashes on the attached testcase. Ciao, Duncan. -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: dom_crash.ll URL:

Jakub Staszak wrote: > Hi, > > It looks like PDT.getRootNode() returns NULL for: > > define fastcc void @c974001__lengthy_calculation. > 1736(%struct.FRAME.c974001* nocapture %CHAIN.185) noreturn { > entry: > br label %bb > > bb: > br label %bb > } > > > Isn't it a bug in PostDominatorTree? > > Please note that this crashes: >

Hello, Bug is already fixed by Chris (see: http://llvm.org/bugs/show_bug.cgi?id=4915) . I added getRootNode() == NULL condition to my patch. It's not a great solution, but it is enough for now I think. New patch attached. -Jakub -------------- next part -------------- A non-text attachment was scrubbed... Name: dse_ssu-2.patch Type: application/octet-stream Size: 17762 bytes Desc: not

Here is an alternative proposal to Bill's. It is closer to what we already have (which can be seen as a good or a bad thing!), and is also closer to what gcc does. It is more incremental than Bill's and introduces fewer new concepts. Executive summary ----------------- Remove the personality and list of catches out of eh.selector and stick them directly on invoke instructions. The

Hi Bill, there are a couple of things I didn't understand about your proposal, for example how it interacts with inlining, whether it is feasible to do the "turn invoke-of-Unwind_Resume into a branch" optimization and also whether in "resumedest" you still plan to use _Unwind_Resume to continue unwinding up the stack. Could you please show what the LLVM IR would look like

This is a revision of the second exception handling proposal I sent out. You can see it here: http://lists.cs.uiuc.edu/pipermail/llvmdev/2010-November/036484.html After much discussion, there are some changes to the proposal – some significant and some minor. One major point, this proposal does not address the issue of catching an exception thrown from a non-invoke instruction. However if done

HI all, here is a llvm IR : invoke void @__cxa_throw(i8* %7, i8* bitcast (%struct.__fundamental_type_info_pseudo* @_ZTIi to i8*), void (i8*)* null) noreturn to label %invcont unwind label %lpad say I want to get the Invoke's Operand's name, I use getOperand(i)->getName(), it can work for that the Operand hasname, but some Operand hasn't name, So, My problem is how

Hi Duncan, >>are you trying to get the name "@_ZTIi" or "@__cxa_throw"? yes! i want get the name @_ZTi or @__cxa_throw, the latter @__cxa_throw i can get it throw value->getName(), but the @_ZTi it did n't has name! zhangzw thanks 2009/3/26 Duncan Sands <baldrick at free.fr>: > Hi zhangzw, > >> invoke void @__cxa_throw(i8* %7, i8*

Hi Bill, this proposal seems strangely complicated. I don't see the advantage of the dispatch instruction over just attaching the information to each invoke. Right now you have invoke void @_Z3foov() to label %invcont unwind label %catch.handlers catch.handlers: landingpad dispatch resume to label %... catches [ %struct.__fundamental_type_info_pseudo* @_ZTIi, label

Hi, catch_all.cpp: 1 int main() 2 { 3 try { 4 throw 34; 5 } 6 catch (...) {} 7 } llvm-gcc -O3 -S -emit-llvm catch_all.cpp -o catch_all.ll: 1 ; ModuleID = 'catch_all.cpp' 2 target datalayout =

On Dec 1, 2010, at 10:20 AM, Duncan Sands wrote: > Hi Bill, this proposal seems strangely complicated. I don't see the advantage > of the dispatch instruction over just attaching the information to each invoke. > Right now you have > > invoke void @_Z3foov() > to label %invcont unwind label %catch.handlers > > catch.handlers: landingpad > dispatch resume

Hi zhangzw, > invoke void @__cxa_throw(i8* %7, i8* bitcast > (%struct.__fundamental_type_info_pseudo* @_ZTIi to i8*), void (i8*)* > null) > noreturn to label %invcont unwind label %lpad > > say I want to get the Invoke's Operand's name are you trying to get the name "@_ZTIi" or "@__cxa_throw"? Ciao, Duncan.

Hi zhangzw, >> invoke void @__cxa_throw(i8* %7, i8* bitcast >> (%struct.__fundamental_type_info_pseudo* @_ZTIi to i8*), void (i8*)* >> null) >> noreturn to label %invcont unwind label %lpad > > >>are you trying to get the name "@_ZTIi" or "@__cxa_throw"? > > yes! i want get the name @_ZTi or @__cxa_throw, > the latter

Hi, I'm confused about the entry and exit blocks of an LLVM CFG. I understand that every CFG has one and only one entry block, and this is confirmed by the existence of the getEntryBlock function in the Function class. But what about exit (a.k.a. return) blocks? At first I assumed that LLVM CFGs have one and only one exit block, too, but the following code is a counter-example:

Hi John, >> Inlining >> -------- >> >> Many a plausible seeming exception handling scheme has fallen by the way-side >> because it interacts poorly with inlining. >> >> Here is how inlining would work with this scheme. It's pretty close to how >> it works right now. Suppose you have >> >> invoke void @foo() >>

On Dec 1, 2010, at 1:37 PM, Duncan Sands wrote: > Inlining > -------- > > Many a plausible seeming exception handling scheme has fallen by the way-side > because it interacts poorly with inlining. > > Here is how inlining would work with this scheme. It's pretty close to how > it works right now. Suppose you have > > invoke void @foo() > to

Hi Bill, > This is similar to my first proposal. yup, I still consider your first proposal to have been basically sound. But it also suffers from a major problem, > which stopped that proposal dead in its tracks. Namely, you have information in > one place which needs to be shared in two different, but possibly disjoint, > places: the type, filters, and personality information. In

On Dec 1, 2010, at 1:37 PM, Duncan Sands wrote: > Executive summary > ----------------- > > Remove the personality and list of catches out of eh.selector and stick them > directly on invoke instructions. > > The invoke instruction > ---------------------- > > The invoke instruction is modified by adding extra catch info to it: > > <result> = invoke

On Dec 2, 2010, at 2:21 AM, Duncan Sands wrote: > Hi Bill, > >> This is similar to my first proposal. > > yup, I still consider your first proposal to have been basically sound. > > But it also suffers from a major problem, >> which stopped that proposal dead in its tracks. Namely, you have information in >> one place which needs to be shared in two