similar to: [LLVMdev] Exception handling question

2010/1/22 Duncan Sands <baldrick at free.fr> > Hi James, > > > I've been trying to get a minimal test function to work, which simply >> invokes _Unwind_RaiseException with a single clean-up landing pad. However. >> when I run it my personality function is not getting called - >> _Unwind_RaiseException simply returns apparently doing nothing. Looking at

Hi James, > I've been trying to get a minimal test function to work, which simply > invokes _Unwind_RaiseException with a single clean-up landing pad. > However. when I run it my personality function is not getting called - > _Unwind_RaiseException simply returns apparently doing nothing. Looking > at the x86-64 assembly output from llc, I can see this is happening >

2010/1/22 James Williams <junk at giantblob.com> > > > 2010/1/22 Duncan Sands <baldrick at free.fr> > > Hi James, >> >> >> I've been trying to get a minimal test function to work, which simply >>> invokes _Unwind_RaiseException with a single clean-up landing pad. However. >>> when I run it my personality function is not getting

On Jan 21, 2010, at 3:50 PM, James Williams wrote: > Hi, > > I'm trying to get exception handling working in my compiler targetting LLVM. I've been working from the LLVM exception handling documentation (including http://llvm.org/docs/ExceptionHandling.html and http://wiki.llvm.org/HowTo:_Build_JIT_based_Exception_mechanism) and looking at g++-llvm's output. > >

Hi Duncan et al, Our linker guy brought up a problem with how we pad out our exception tables. Right now we pad them out like this: .section __DATA,__gcc_except_tab .align 2 GCC_except_table13: .byte 0x0 #< --- hun? .byte 0x0 #< --- hun? Lexception13: .byte 0xFF .byte 0x0 .byte 0xB2, 0x1 > Here are his comments: The problem is that the linker parses FDE which gives it

Hi, In GCC there is one useful option -dp (or -dP for more verbose output) to annotate assembler with instruction patterns, that was used when assembler was generated. For example: double test(long long s) { return s; } gcc -S -dp -O0 test.c test: .LFB0: .cfi_startproc pushq %rbp # 18 *pushdi2_rex64/1 [length = 1] .cfi_def_cfa_offset 16 movq %rsp, %rbp # 19 *movdi_1_rex64/2

Bill, ooops, yes, I described the meaning of "throw(A)" backwards, but I still think my example shows why you cannot merge LandingpadInst while inlining because multiple filter-lists on a LandingpadInst don't make sense. Perhaps I'm reading your original spec wrong, perhaps I'm mis-reading Duncan's emails, but I read them to mean that your syntax supports

On 02.03.2012, at 09:20, Konstantin Vladimirov wrote: > Hi, > > In GCC there is one useful option -dp (or -dP for more verbose output) > to annotate assembler with instruction patterns, that was used when > assembler was generated. For example: The internal "-mllvm -show-mc-inst" option is probably as close as you can get. $ clang -S -O0 test.c -mllvm -show-mc-inst -o

Hey everybody! I have been using llvm 2.8 (i know ancient history!) for a backend that i was implementing. I have been trying to port my patches to latest llvm (svn build) lately but i have one problem as far as the Exception Handling mechanism is concerned. It seems that there are no Exception Tables generated any more such as the one below: .section .gcc_except_table,"a", at

Moving this month old RFC to llvmdev. Not sure why I sent this to cfe-dev in the first place... --- Based on code review discussion from John, he thinks filter expressions should be emitted into the body of the function with the try, rather than being outlined by the frontend. Instead of having the frontend create filter functions, we would use labels in place of typeinfo. The IR would look

Duncan Sands wrote: > Hi Nicolas, > > >> In order to have exceptions for non-call instructions (such as sdiv, >> load or stores), I'm modifying codegen so that it generates a BeginLabel >> and an EndLabel between the "may throwing" instruction. This is what the >> codegen of an InvokeInst does. >> > > the rule is that all

Hi Nicolas, > In order to have exceptions for non-call instructions (such as sdiv, > load or stores), I'm modifying codegen so that it generates a BeginLabel > and an EndLabel between the "may throwing" instruction. This is what the > codegen of an InvokeInst does. the rule is that all instructions between eh begin labelN and eh end labelN must unwind to the same

Hi Yiannis, > I have been using llvm 2.8 (i know ancient history!) for a backend that i was > implementing. I have been trying to port my patches to latest llvm (svn build) > lately but i have one problem as far as the Exception Handling mechanism is > concerned. It seems that there are no Exception Tables generated any more such > as the one below: got some example bitcode for

hi: maybe this should not be here! the test code: eh3.cpp int main() { try { throw 34; } catch (int) { } catch (char) { } catch (bool) { } } compile with g++ -S -dA eh3.cpp -o eh3.s the except table of the eh3.s 106 .section .gcc_except_table,"a", at progbits 107 .align 4 108 .LLSDA2: 109

On 09/02/2011 05:58 PM, Duncan Sands wrote: > Hi Yiannis, > >> I have been using llvm 2.8 (i know ancient history!) for a backend that i was >> implementing. I have been trying to port my patches to latest llvm (svn build) >> lately but i have one problem as far as the Exception Handling mechanism is >> concerned. It seems that there are no Exception Tables generated

Thank you Frits! I noticed the following lines in the dwarf output (run with -O2): .uleb128 40 # Offset .byte 134 # DW_CFA_offset + Reg (6) .uleb128 4 # Offset .byte 135 # DW_CFA_offset + Reg (7) .uleb128 3 # Offset .byte 131 # DW_CFA_offset + Reg (3)

On Feb 5, 2010, at 4:00 PM, Duncan Sands wrote: > Hi Bill, > >> It looks like your goal is to keep the 32-bit pointers in the call-site table 4-byte aligned. Here is another solution, instead of having two labels at the start of the LSDA (with pad bytes between them), have no pad bytes and instead use an unnormalized uleb128 for the call-site table length. By unnormalized, I mean one

Hi, I'm investigating the size of Clang's generated binaries relative to GCC, when targeting Android, and I've noticed that Clang's exception tables are much larger -- the .ARM.extab section is about 2.5 times as large in two examples. I noticed a couple of differences between Clang and GCC: 1. *ULEB128 encoding.* In the call site table, GCC encodes offsets using a ULEB128

On Fri, Jan 21, 2011 at 2:48 PM, Vijayaraghavan Murali <m.vijay at nus.edu.sg> wrote: > I just wish to know if other than manually comparing the llc generated > code with the source program, is there any other way of knowing which > variables in the program are mapped to which registers? I was not able > to find any suitable option for the same, so I'm wondering if there is a

Motivation: Many optimizations duplicate code. E.g. loop unroller duplicates the loop body, GVN duplicates computation, etc. The duplicated code will share the same debug info with the original code. For SamplePGO, the debug info is used to present the profile. Code duplication will affect profile accuracy. Taking loop unrolling for example: #1 foo(); #2 for (i = 0; i < N; i++) { #3 bar();