search for: jumptables

Hi all, I'm a beginner in LLVM. I read a paper recently, and I'm trying to use LLVM jumptable in 3.5. When I compile the .bc file into .s file, I tried to use the different jumptable type: all, single, ... e.g. clang -c -emit-llvm test.c llc test.bc -jump-table-type=full -o test-full.s llc test.bc -jump-table-type=single -o test-single.s The tested C source code is like: void foo() {

Hello everyone, I'm new to LLVM (which is a really great project by the way) and I hope this is the right place for my question. In the LLVM Language Reference Manual I found the "jumptable" function attribute, which seems to be exactly what I need for my project (where I want to add one level of indirection to every function call), but I have trouble figuring out, how to use

Hi, this is a proposal for the implementation of CFI-icall [1] with ThinLTO. Jumptables are generated in the merged module. To generate a jumptable, we need a list of functions with !type annotations, including (in non-cross-dso mode) external functions. Unfortunately, LLVM IR does not preserve unused function declarations, and we don’t want to copy the actual function bodies to the m...

On Wed, Apr 02, 2014 at 05:28:04PM -0700, Tom Roeder wrote: > On Fri, Mar 21, 2014 at 1:46 PM, Peter Collingbourne <peter at pcc.me.uk>wrote: > > > On Fri, Mar 21, 2014 at 12:54:07PM -0700, Tom Roeder wrote: > > > On Fri, Mar 21, 2014 at 12:15 PM, Peter Collingbourne <peter at pcc.me.uk> > > wrote: > > > >> The way I've implemented it (see

...nks for sending this out. A few comments below. > > On Mon, May 15, 2017 at 5:17 PM, Evgenii Stepanov via llvm-dev > <llvm-dev at lists.llvm.org> wrote: >> >> Hi, >> >> this is a proposal for the implementation of CFI-icall [1] with ThinLTO. >> >> Jumptables are generated in the merged module. To generate a >> jumptable, we need a list of functions with !type annotations, >> including (in non-cross-dso mode) external functions. Unfortunately, >> LLVM IR does not preserve unused function declarations, and we don’t >> want to copy...

On Thu, Apr 03, 2014 at 06:54:55PM -0700, Reid Kleckner wrote: > I think it's a little scary to assume things about LLVM's x86 code > generation. I haven't really finished the codegen side of the change, but > I'm pretty sure in it's current state it will emit extra loads and stores, > even if they are unnecessary. Right, I had similar concerns. Now that I've

...y 15, 2017 at 5:17 PM, Evgenii Stepanov via llvm-dev > >> <llvm-dev at lists.llvm.org> wrote: > >>> > >>> Hi, > >>> > >>> this is a proposal for the implementation of CFI-icall [1] with > ThinLTO. > >>> > >>> Jumptables are generated in the merged module. To generate a > >>> jumptable, we need a list of functions with !type annotations, > >>> including (in non-cross-dso mode) external functions. Unfortunately, > >>> LLVM IR does not preserve unused function declarations, and we...

On Fri, Mar 21, 2014 at 12:54:07PM -0700, Tom Roeder wrote: > On Fri, Mar 21, 2014 at 12:15 PM, Peter Collingbourne <peter at pcc.me.uk> wrote: > >> The way I've implemented it (see the patch I sent to llvm-commits > >> yesterday), it's not just metadata: the intrinsic lowers to the > >> jumptable entry code given above. The CFI pass then generates a

...on an out-of-tree embedded back-end. Our primary goal is code size, secondary performance. We've recently implemented an optimization that we believe others could use. It's about time to contribute back. ------------------------------------------------------- JumpMaps: a generalization of JumpTables JumpTables produce fast and small code but have a limitation - they only work if case values are easy to compute from the variable being switch()ed. To overcome this limitation we introduce a {key,value} structure - a JumpMap. Simplifying somewhat, LLVM would currently generate a sequential if-els...

JumpMap lowering is nearly identical to that of JumpTables with the exception of lack of range-check basic-block. We introduce JumpMapInfo structure which follows the same flow as JumpTableInfo and is finally emitted by AsmPrinter. There are many ways a Target may want to encode jumpmaps (deltas, compression, relative vs absolute), so we plan to keep this...

...nclude "llvm/Support/Compiler.h" #include "llvm/Support/Mangler.h" #include "llvm/Support/MathExtras.h" #include "llvm/Support/raw_ostream.h" #include <cctype> +#include <sstream> using namespace llvm; +extern cl::opt<bool> FlagOutlineJumpTables; +cl::opt<std::string> FlagJumpTableSection("jumptable-section", + cl::init(".data.jtab")); + STATISTIC(EmittedInsts, "Number of machine instrs printed"); namespace { @@ -139,6 +145,7 @@ /// EmitMachineConstantPo...

On Jul 2, 2009, at 10:48 AM, robert muth wrote: > I spend over a day trying to follow your suggestion. In the end I > was not successful. Here is what Iearned: > > After setting > > ARMJITInfo::hasCustomJumpTables -> true > setOperationAction for ISD::BR_JT -> Expand > > I needed to add a "brind" definition to ARMInstrInfo.td > I picked "bx" but to do a proper job one would have to take older > architectures > into account.. > The next thing was to to set >...

On Sat, Jun 6, 2009 at 4:51 PM, Evan Cheng<evan.cheng at apple.com> wrote: > +cl::opt<std::string> FlagJumpTableSection("jumptable-section", > +                                           cl::init(".data.jtab")); > + I thought it would be nice to group all the jumptables together. But as long as it stays configurable, I am fine to change the default to ".data". > Is this...

On Sun, Jun 7, 2009 at 11:53 PM, Evan Cheng <evan.cheng at apple.com> wrote: > > On Jun 7, 2009, at 6:59 AM, robert muth wrote: > >> On Sat, Jun 6, 2009 at 4:51 PM, Evan Cheng<evan.cheng at apple.com> >> wrote: >>> +cl::opt<std::string> FlagJumpTableSection("jumptable-section", >>> +                                           cl::init(".data.jtab")); >>> + >> >> I thought it would be nice to group all the jumptables together. >> But as long as it stays configurable, I am fine to change the d...

...default behavior, but you have implemented it without using > the existing code. Did you consider implementing it using the LLVM > defaults? > I spend over a day trying to follow your suggestion. In the end I was not successful. Here is what Iearned: After setting ARMJITInfo::hasCustomJumpTables -> true setOperationAction for ISD::BR_JT -> Expand I needed to add a "brind" definition to ARMInstrInfo.td I picked "bx" but to do a proper job one would have to take older architectures into account.. The next thing was to to set setOperationAction for ISD::JumpTable -...

On Thu, Mar 20, 2014 at 3:29 PM, Peter Collingbourne <peter at pcc.me.uk> wrote: > > On Mon, Mar 17, 2014 at 10:28:52AM -0700, Tom Roeder wrote: > > On Tue, Feb 25, 2014 at 5:41 PM, Eric Christopher <echristo at gmail.com>wrote: > > > > > On Mon, Feb 24, 2014 at 4:33 PM, Tom Roeder <tmroeder at google.com> wrote: > > > > > > > >

...at 11:53 PM, Evan Cheng <evan.cheng at apple.com> > wrote: >> >> On Jun 7, 2009, at 6:59 AM, robert muth wrote: >> >>> On Sat, Jun 6, 2009 at 4:51 PM, Evan Cheng<evan.cheng at apple.com> >>> wrote: >>>> +cl::opt<std::string> FlagJumpTableSection("jumptable-section", >>>> + >>>> cl::init(".data.jtab")); >>>> + >>> >>> I thought it would be nice to group all the jumptables together. >>> But as long as it stays...

...mpmap_find_i8, jumpmap_find_i16, jumpmap_find_i32, jumpmap_find_i64. > > We don't have any benchmarks for any of the in-tree targets yet. > > Witold > > > W dniu 2017-02-14 o 14:28, Witold Waligora via llvm-dev pisze: >> JumpMap lowering is nearly identical to that of JumpTables with the >> exception of lack of range-check basic-block. >> We introduce JumpMapInfo structure which follows the same flow as >> JumpTableInfo and is finally emitted by AsmPrinter. >> >> There are many ways a Target may want to encode jumpmaps (deltas, >> compre...

hello everyone, I few days ago I had some code (for the PyPy project) that llc - march=c converted to a switch statement and gcc compiled that nicely to a jumptable in the .s file. Now I try to reproduce when directly going from a .ll to a .s file. But I now see a long list of compare and jumps instead of the jumptable. Is there a transformation that does this if->switch(ing) or is

...cheng at apple.com> > > wrote: > >> > >> On Jun 7, 2009, at 6:59 AM, robert muth wrote: > >> > >>> On Sat, Jun 6, 2009 at 4:51 PM, Evan Cheng<evan.cheng at apple.com> > >>> wrote: > >>>> +cl::opt<std::string> FlagJumpTableSection("jumptable-section", > >>>> + > >>>> cl::init(".data.jtab")); > >>>> + > >>> > >>> I thought it would be nice to group all the jumptables together. > >>> But as long as it stays configurable,...