similar to: [RFC] Canonicalization of unsigned subtraction with saturation

Displaying 20 results from an estimated 1000 matches similar to: "[RFC] Canonicalization of unsigned subtraction with saturation"

2017 May 16
2
[RFC] Canonicalization of unsigned subtraction with saturation
On 5/16/2017 6:30 AM, Sanjay Patel wrote: > Thanks for posting this question, Julia. > > I had a similar question about a signed min/max variant here: > http://lists.llvm.org/pipermail/llvm-dev/2016-November/106868.html > > The 2nd version in each case contains a canonical max/min > representation in IR, and this could enable more IR analysis. > A secondary advantage is
2020 Jun 15
5
[RFC] Integer Intrinsics for abs, in unsigned/signed min/max
Hello all. This is a proposal to introduce 5 new integer intrinsics: * absolute value * signed min * signed max * unsigned min * unsigned max This is motivated by the fact that we keep working around not having these intrinsics, and that constantly leads us into having more workarounds, and causes infinite combine loops. Here's a (likely incomplete!) list of motivational bugs: infinite
2006 Aug 08
9
Handling userland char ** pointers
I''ve been trying to get access to a userland string that''s behind a second level pointer using DTrace, but I can''t seem to get it to work. I started with the example on the Team DTrace Tips and Tricks slides: trace(copyinstr(*(uintptr_t *)copyin(arg0, curpsinfo->pr_dmodel == PR_MODEL_ILP32 ? 4 : 8))); And when I couldn''t get it to work, I started
2024 May 23
1
No RID Set found for this server. Can't self-allocate
The Samba ports are not filtered. The firewall is between STG-DC and SAMBADC (both of them sync correctly). The sync problems happen in VIG-DC3, which is behind the same firewall of STG-DC. Here's nmap output (SAMBADC is 172.16.50.9): root at vig-dc3:~# nmap -Pn 172.16.50.9 Starting Nmap 7.93 ( https://nmap.org ) at 2024-05-23 08:22 UTC Nmap scan report for SAMBADC.ugt.ldap (172.16.50.9)
2008 Oct 07
3
vectorized sub, gsub, grep, etc.
R pattern-matching and replacement functions are vectorized: they can operate on vectors of targets. However, they can only use one pattern and replacement. Here is code to apply a different pattern and replacement for every target. My question: can it be done better? sub2 <- function(pattern, replacement, x) { len <- length(x) if (length(pattern) == 1) pattern <-
2011 Aug 01
2
[LLVMdev] "icmp sgt" when it should be "ugt" ?
Hello, while writing a new LLVM backend I have observed that in some cases the optimizer produces an "icmp sgt i32 %a, 0" where I would have expected an "icmp ugt i32 %a, 0". For example when I feed "opt -O3 -S ..." (LLVM 2.9, Windows) with ------------------------------------------------------------------------ target datalayout = "E-p:32:32:32"
2013 Nov 16
16
[PATCH] BTRFS-PROG: recursively subvolume snapshot and delete
Hi All, the following patches implement the recursively snapshotting and deleting of a subvolume. To snapshot recursively you must pass the -R switch: # btrfs subvolume create sub1 Create subvolume ''./sub1'' # btrfs subvolume create sub1/sub2 Create subvolume ''sub1/sub2'' # btrfs subvolume snapshot -R sub1 sub1-snap Create a snapshot of
2011 Aug 01
0
[LLVMdev] "icmp sgt" when it should be "ugt" ?
Icmp sgt is correct. Note that "ugt x, 0" is the same as "x != 0" which is not what you want. -Chris On Aug 1, 2011, at 9:11 AM, Jonas Gefele <llvm.org at schrieb.de> wrote: > Hello, > > while writing a new LLVM backend I have observed that in some cases the > optimizer produces an "icmp sgt i32 %a, 0" where I would have expected an >
2006 Nov 01
1
How to rsync only specified subdirectories in the source folder?
Hi all, For example,if there is ten subdirectories named sub1~sub10(each including subdirectories and files too),and file1~file10,how can I rsync only sub2 and sub 3 to the target? /---- MyFolder |---------- sub1 |---------- sub2 |---------- sub3 |---------- sub4 |---------- sub5 |---------- sub6 |---------- sub7 |---------- sub8 |---------- sub9
2009 Jun 19
6
ssh security
Dear All, I have the following setup running perfectly OK for a long time CentOS release 5 (Final) sendmail-8.13.8-2.el5 MailScanner 4.76.25 bind-9.3.4-6.0.3.P1.el5_2 now i jus setup a centos box running BackupPC for backing up my my above mail server using ssh as per the instructions in backup pc site i had to enable sshd so i did it and everthing works perfect and backup works great as per my
2024 Sep 11
2
[Bug 3732] New: An integer underflow may occur due to arithmetic operation (unsigned subtraction) between values '0' and '67108864', where the first value comes from the expression 'h4 + b' and the second value comes from the expression '(1 << 26)'
https://bugzilla.mindrot.org/show_bug.cgi?id=3732 Bug ID: 3732 Summary: An integer underflow may occur due to arithmetic operation (unsigned subtraction) between values '0' and '67108864', where the first value comes from the expression 'h4 + b' and the second value comes from
2008 Feb 01
2
Aplication slow after migration
Hi, everybody! I have been using samab on Debian for years and I have recently migrated my file server from version 3.0.14a-3sarge2 to 3.0.24-6etch4. One or our applications stores its data in a shared folder. This data is distributed in over 29000 files of about 1k-40k and is so much slower when it runs on the new server. I have thoroughly revised both smb.conf files, but can't see
2015 Mar 27
2
[LLVMdev] `llvm.$op.with.overflow`, InstCombine and ScalarEvolution
> If we don't care about trying to optimize out overflow checks in > InstCombine, I'd go with moving the complexity to CGP. I think instcombine should optimize out overflow checks (as it does today) without introducing _with_overflow calls. Are there reasons why such an approach would not work? > However, I think > InstCombine is doing the right thing here by forming these.
2011 Apr 13
4
[LLVMdev] built-in longjmp and setjmp
On Apr 12, 2011, at 3:15 PM, Jim Grosbach wrote: > If you want an automated method, then using the source code re-writer interfaces in clang is probably a reasonable starting place. Just modifying the source code manually is probably easier, though, to be honest. > > As a moderate caveat to all of this, there are some bits of code out there that use these builtins that are very tightly
2006 Mar 23
1
comparative density estimates
I have two series of events over time and I want to construct a graph of the relative frequency/density of these events that allows their distributions to be sensibly compared. The events are the milestones items in my project on milestones in the history of data visualization [1], and I want to compare trends in Europe vs. North America. I decided to use a graph of two overlaid density
2011 Aug 02
3
[LLVMdev] "icmp sgt" when it should be "ugt" ?
Hi Eli, >>> Icmp sgt is correct. >> >> while ugt would be wrong, I think sgt is too! >> >> For example, suppose %buf is 0 and %bufLen is ~0U. Then %add.ptr is ~0U, and >> %cmp is true, so control branches to %if.then. However in the optimized version >> %cmp is false and control branches to %if.end. >> >> The GEP does have an inbounds
2009 Feb 13
2
extracting parts of words or extraxting letter to use in ifelse-func.
Hello I want to make some variables with the ifelse-function, but i don't know how to do it. I want to make these five variables; b2$PRRSvac <- ifelse(b2$status=='A' | b2$status=='Aa',1,0) b2$PRRSdk <- ifelse(b2$status=='B' | b2$status=='Bb',1,0) b2$sanVac <- ifelse(b2$status=='C' | b2$status=='sanAa',1,0) b2$sanDk <-
2013 May 15
2
animating plots over time with a slider
I have a population of subjects each with a variable which has been captured at a baseline date. Then for many subjects (but not all) an intervention has occurred and the variable has changed at one or more time points after the baseline date. So my dataset consists of a subject ID (x), which may appear several times or just once, a measure (y), and a date of observation (z). I would like to be
2011 Apr 13
0
[LLVMdev] built-in longjmp and setjmp
It seems straightforward to implement, if it just needs to be functionally correct. I have another question about setjmp/longjmp. When the following program is compiled and run with argument 10 (./a.out 10), should it print 10 or 23? I am asking this question because it prints 23 when compiled with gcc and prints 10 when compiled with clang. If it is supposed to return 23, it seems to me that
2014 May 13
2
[LLVMdev] Missed optimization opportunity in 3-way integer comparison case
While looking at what llvm writes for this testcase, I noticed that there is one redundant operation in resulting assembly. The second 'cmp' operation there is essentially identical to the first one, with reversed order of arguments. Therefore, it is not needed. This testcase is a simple integer comparison routine, similar to what qsort would take to sort an integer array. I think