similar to: [LLVMdev] [PATCH] Protection against stack-based memory corruption errors using SafeStack

plain text document attachment (xx-paravirt-irqs.patch) Interrupt updates for paravirt ops. Signed-off-by: Steven Rostedt srostedt@redhat.com Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Index: clean-start/arch/x86_64/ia32/ia32entry.S =================================================================== --- clean-start.orig/arch/x86_64/ia32/ia32entry.S +++

plain text document attachment (xx-paravirt-irqs.patch) Interrupt updates for paravirt ops. Signed-off-by: Steven Rostedt srostedt@redhat.com Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Index: clean-start/arch/x86_64/ia32/ia32entry.S =================================================================== --- clean-start.orig/arch/x86_64/ia32/ia32entry.S +++

One more interesting thing I have noticed is as following : In sqlite3 code consider 3 functions namely sqlite3Update, sqlite3Select and sqlite3Where begin sqlite3WhereBegin is called by both functions sqlite3Update and sqlite3Select but according to CallGraphSCC sqlite3Update is codegen before in that case during RegMask propagation phase default regmask is used for call site of

On Sun, May 11, 2014 at 8:19 AM, Stephan Tolksdorf <st at quanttec.com> wrote: > Hi, > > When clang/LLVM can't prove that a noexcept function only contains > non-throwing code, it seems to insert an explicit exception handler that > calls std::terminate. Why doesn't clang leave it to the eh personality > function to call std::terminate when an exception is thrown

I should mention a couple of useful self-explanatory LLVM flags for triage: -enable-misched=false -verify-misched -Andy On Oct 15, 2013, at 4:43 PM, Eric Christopher <echristo at gmail.com> wrote: > Grats on the work, a long time coming! > > Beware the incoming register allocation bugs ;) > > -eric > > On Tue, Oct 15, 2013 at 4:33 PM, Andrew Trick <atrick at

*NOTE* IIRC compiling this with -O0 on x86-64 can yield the wrong result since clang will emit shifts and on intel shifts are mod the register size: ===== .section __TEXT,__text,regular,pure_instructions .globl _ror .align 4, 0x90 _ror: ## @ror .cfi_startproc ## BB#0: pushq %rbp Ltmp2: .cfi_def_cfa_offset 16 Ltmp3: .cfi_offset %rbp, -16 movq %rsp, %rbp

Hi LLVM and GCC developers, My sincere thanks will goto: * Duncan, the core developer of llvm-gcc and dragonegg http://llvm.org/devmtg/2009-10/Sands_LLVMGCCPlugin.pdf * David, the innovator and developer of GCC https://dmalcolm.fedorapeople.org/gcc/global-state/requirements.html and others who give me kind response for teaching me patiently and carefully about how to migrate GCC v4.8.x to

Hi, Recently 10% performance regression on an important benchmark showed up after we integrated https://reviews.llvm.org/rL318299. The analysis showed that rL318299 triggered loop rotation on an multi exits loop, and the loop rotation introduced code layout issue. The performance regression is a side-effect of rL318299. I got two testcases a.ll and b.ll attached to illustrate the problem. a.ll

On Mon, Dec 18, 2017 at 5:46 PM Xinliang David Li <davidxl at google.com> wrote: > The introduction of cleanup.cond block in b.ll without loop-rotation > already makes the layout worse than a.ll. > > > Without introducing cleanup.cond block, the layout out is > > entry->while.cond -> while.body->ret > > All the arrows are hot fall through edges which is

Hi Devs, consider below testcase $cat test.cpp constexpr int product() { return 10*20; } int main() { const int x = product(); return 0; } $./clang test.cpp -std=c++11 -S $./clang -v clang version 9.0.0 Target: x86_64-unknown-linux-gnu $cat test.s main: .cfi_startproc # %bb.0: pushq %rbp .cfi_def_cfa_offset 16 .cfi_offset %rbp, -16 movq

On 2/7/2017 20:02, Kostya Serebryany wrote: > ... > > My understanding is that BNDCU is the cheapest possible instruction, > just like XOR or ADD, > so the overhead should be relatively small. > Still my guesstimate would be >= 5% since stores are very numerous. > And such overhead will be on top of whatever overhead SafeStack has. > Do you have any measurements to

Hello, With GCC, it is possible to compile GIMPLE from an object file back to assembly. With Dragonegg, it seems to be a NOP. (See below for a comparison.) This appears it could be a nice way to mix the strengths of GCC and LLVM. If it worked.. Should it? Thanks, Marcus [mdaniels at dn002 dragonegg]$ cat hello.c #include <stdio.h> int hello () { printf ("Hello

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

Hi Kostya, >On Wed, Nov 12, 2014 at 2:50 AM, Volodymyr Kuznetsov <vova.kuznetsov at epfl.ch >> wrote: > >> Dear LLVM developers, >> >> We've applied the feedback we received on Phabricator on the SafeStack >> patches, >> > >Did you investigate the possibility of moving the transformation from >codegen to the LLVM level, i.e. the same level

Hello all, Here's a new version of the paravirt_ops x86_64 patch. With this message, I'm sending an incremental patch. The complete patches can be found , from now on, at http://et.redhat.com/~gcosta/paravirt_ops/ The main aim of this new update, is to fix a critical bug, namely, Rusty's name. However, I took the opportunity to write some new less important pieces of code,

Hello all, Here's a new version of the paravirt_ops x86_64 patch. With this message, I'm sending an incremental patch. The complete patches can be found , from now on, at http://et.redhat.com/~gcosta/paravirt_ops/ The main aim of this new update, is to fix a critical bug, namely, Rusty's name. However, I took the opportunity to write some new less important pieces of code,

Hmm. This looks like the backend conservatively giving up early on merging. It looks like you're running clang 5.02. There have been some improvements to the backend's memory aliasing and store merging that have landed since. Can you check if this is fixed in a newer version? -Nirav On Tue, Sep 11, 2018 at 2:21 PM, Andres Freund <andres at anarazel.de> wrote: > Hi, > >

Carl, See clang/lib/CodeGen/TargetInfo.cpp. // FIXME: mingw64-gcc emits 128-bit struct as i128 if (Size <= 128 && (Size & (Size - 1)) == 0) return ABIArgInfo::getDirect(llvm::IntegerType::get(getVMContext(), Size)); It was my workaround, sorry. Please check to tweak the clause (128 to 64) and lemme

Hi, Thank you, it is just what I need. But... it doesn't work for me: $ clang -S -O0 test.c -mllvm -show-mc-inst error: unknown argument: '-show-mc-inst' $ clang --version clang version 1.1 (branches/release_27) Target: x86_64-pc-linux-gnu Thread model: posix May be I need LLVM with higher version, or mention something in configure options? On Fri, Mar 2, 2012 at 4:32 PM,

Hi, I would like to use SafeStack sanitize option on ARM platform. Since Linux libc does not implement such functionality (in opposite to FreeBSD or Android), I need to use SafeStack compiler RT library. Unfortunately I've noticed that libclang_rt.safestack is not compiled/built for ARM platform. Looking into cmake file: "set(ALL_SAFESTACK_SUPPORTED_ARCH ${X86} ${X86_64} ${ARM64}