similar to: [LLVMdev] About instrumenting/rewriting X86 instructions

Hi all, I plan to use LLVM to instrument/rewrite X86 instructions during the compilation of a program. For example, insert checking target instructions before jmp instructions, or rewrite a instruction to prevent code using a specific register. I think the work should be done at the CodeGen phase, but I'm not quite clear how can I start. Can anyone give me some suggestion? Thanks very much,

Hi all, I plan to use LLVM to instrument/rewrite X86 instructions during the compilation of a program. For example, insert checking target instructions before jmp instructions, or rewrite a instruction to prevent code using a specific register. I think the work should be done at the CodeGen phase, but I'm not quite clear how can I start. Can anyone give me some suggestions? Thanks very

On 7/23/19 8:42 PM, John McCall via llvm-dev wrote: > > On 21 Jul 2019, at 12:29, James Y Knight via llvm-dev wrote: > > Yes, indeed! > > The SBCL lisp compiler (not llvm based) used to emit functions > which would > return either via ret to the usual instruction after the call, or > else load > the return-address from the stack, then jump 2

I estimate some parameters and I want to print them (pretty) on my plot: # somehow estimated parameters z<-c(1.543523e+00, 1.23453e+00, 3.454000e+00) x<-seq(-1,1,length=100) plot(x,z[3]*x^2+z[2]*x+z[3],type="l", main="My nice plot of the estimated function") zs<-format(z,digits=4,scientific=FALSE,trim=TRUE) text(-0.9,7,expression(1.54*x^2)) # is

I am simulating an ANOVA model and get a strange behavior from the summary function. To be more specific: please run the following code and see for yourself: the summary()[["r.squared"]] values of two identical models are quite different!! ## 3 x 3 ANOVA of two factors x and z on outcome y s.size <- 300 # the sample size p.z <- c(0.25, 0.5, 0.25) # the probabilities of factor z ##

Hi, I'm using LLVM to convert expressions to native assembly, the problem is when LLVM compiles this code: define void @fn_0000000000000000(i8*, i8*, i8*) { bb: %res = alloca i32 %3 = load i32* %res %4 = bitcast i8* %0 to i32* %5 = load i32* %4 %6 = bitcast i8* %0 to i32* %7 = load i32* %6 %8 = xor i32 %5, %7 store volatile i32 %8, i32* %res %9 = load i32* %res %10 = icmp

Yes, indeed! The SBCL lisp compiler (not llvm based) used to emit functions which would return either via ret to the usual instruction after the call, or else load the return-address from the stack, then jump 2 bytes later (which would skip over either a nop or a short jmp at original target location). Which one it used depended upon whether the function was doing a multi-valued return (in which

Hi all, I am trying to do fitting of large sets of timeseries data, and error messages derail the process when I encounter a dataset that doesn't fit. I'd like to ignore those "misfits" and try another equation or move to the next dataset. Any ideas? (piece of code below) Thanks, --Warren ##The code looks something like this: attach(zf) x <- hours

Dear R-List, I?m new in R, so I hope my question is not to primitive, but I haven?t found a solution in the R-help. I?ve got a datatframe with 3 factors, called xf (9 levels), yf (9 levels), zf (3 levels) and one variable (rt): > xf yf zf rt > 1 1 1 67 > 1 1 1 56 > 1 1 1 60 [...] > 1 1 2 58 > 1 1 2 61 [...] > 9 1

From: Gene Cumm <gene.cumm at gmail.com> SYSLINUX/COMBOOT: Abstract searchdir and fix the opendir call Signed-off-by: Gene Cumm <gene.cumm at gmail.com> --- First, change comboot.inc such that INT 22h AX=0020h (opendir) is about as simple and similar in behavior to INT 22h AX=0006h (openfile). Next, rename the function searchdir to searchdir4any, create a new function called

Hi I have problem in tar command Can you help? tar -cv --exclude /var/named/chroot/proc/* -zf backup.tar.gz /var/named /var/named/chroot/proc/net/route /var/named/chroot/proc/net/udp /var/named/chroot/proc/net/tcp tar: Error exit delayed from previous errors Thank you Send instant messages to your online friends http://uk.messenger.yahoo.com

From: Gene Cumm <gene.cumm at gmail.com> COMBOOT API: Add calls for directory functions; Implement most only for FAT (SYSLINUX). Uses INT 22h AX= 001Fh, 0020h, 0021h and 0022h to prepare for the COM32 C functions getcwd(), opendir(), readdir(), and closedir(), respectively. INT22h, AX=001Fh will return a valid value for all variants. INT22h, AX= 0020h, 0021h, and 0022h are only

From: Gene Cumm <gene.cumm at gmail.com> COMBOOT API: Add calls for directory functions; Implement most only for FAT (SYSLINUX). Uses INT 22h AX= 001Eh, 001Fh, 0020h and 0021h to prepare for the COM32 C functions getcwd(), opendir(), readdir(), and closedir(), respectively. INT22h, AX=001Eh will return a valid value for all variants. INT22h, AX= 001Fh, 0020h, and 0021h are only

Hi Marc, I'm a bit confused. Isn't the standard compare (i.e. the one for a language like C) an ordered one? I tried converting some C code to LLVM C++ API code with the online demo, and it uses FCMP_OEQ. No, if you have: x = NaN y = NaN then the comparison: (x == y) is false. Which is what your seeing from your first post and is the standard IEEE expected behavior.

On Wed, Jan 13, 2016 at 06:25:21PM +0200, Michael S. Tsirkin wrote: > Which flag do you refer to, exactly? All the flags in rFLAGS which ADD modifies: OF,SF,ZF,AF,PF,CF -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply.

On Wed, Jan 13, 2016 at 06:25:21PM +0200, Michael S. Tsirkin wrote: > Which flag do you refer to, exactly? All the flags in rFLAGS which ADD modifies: OF,SF,ZF,AF,PF,CF -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply.

These instructions are prefix selected flavors of bsf and bsr respectively, and hence the presences of the F3 prefix must be handled in the emulation code in order to avoid running into problems on newer CPUs. Signed-off-by: Jan Beulich <jbeulich@suse.com> --- a/xen/arch/x86/x86_emulate/x86_emulate.c +++ b/xen/arch/x86/x86_emulate/x86_emulate.c @@ -1058,6 +1058,9 @@ static bool_t vcpu_has(

Dear LLVM developers, I am Shen, a PhD student at Lehigh Univ. PA. Now I am implementing a Program Dependence Graph(PDG) on LLVM. I have 4 passes here: 1. ProgramDependenceGraph (a *ModulePass *on the highest level) 2. DataDependenceGraph (a Intermediate *FunctionPass*). 3. FlowDependenceAnalysis Pass (a intermediate *FunctionPass*) which uses llvm built-in AliasAnalysis (-basicaa) 4.

On Thu, Feb 21, 2008 at 9:34 AM, Andrew Lenharth <andrewl at lenharth.org> wrote: > On 2/21/08, Torvald Riegel <torvald at se.inf.tu-dresden.de> wrote: > > why is the intrinsic name not CAS? And having another version that returns > > just a bool might be better in some cases ( 1. does CAS return the value on > > all architectures? 2. you can just jump based

Both ZF and PF will be set if unordered, so the code below is IEEE correct...you want to generate 'fcmp ueq' instead of 'fcmp oqe' This is the resulting x86 assembly code: movss xmm0,dword ptr [ecx+4] ucomiss xmm0,dword ptr [ecx+8] sete al setnp dl test dl,al mov edx,edi cmovne edx,ecx cmovne ecx,esi cmovne