similar to: [LLVMdev] interesting possible compiler bug

On 1 October 2012 18:34, reed kotler <rkotler at mips.com> wrote: > This code is essentially from an LTP test ( http://ltp.sourceforge.net/). > > > #include <stdlib.h> > > int main() { > void *curr; > > do { > curr = malloc(1); > } while (curr); > > return 0; > > } > > If you compile it with no optimization, it will keep

>>>>> On Mon, 1 Oct 2012 19:40:58 -0700, Nick Lewycky <nlewycky at google.com> said: > On 1 October 2012 18:34, reed kotler <rkotler at mips.com> wrote: > This code is essentially from an LTP test ( > http://ltp.sourceforge.net/ ). > #include <stdlib.h> > int main() {   void  *curr; >   do {     curr =

They have been discussing this for a solid two days on the C committee list with many pro and con opinions, all supported by various parts of the standard or other sources. My personal opinion is that it's only a bug if some real program can be made to fail because of this. If I were writing this test case for LPT, I would call an external function and pass the value curr to it. If I

For what it's worth, I will be at the social tonight, and am happy to discuss this paper. I'm a co-author and the instigator the work here to clarify the spec and allow a large number of exciting optimizations on code that have previously not be employed merely because of the use of malloc rather than (for example) alloca. On Thu, Oct 4, 2012 at 4:40 PM, reed kotler <rkotler at

On 2 Oct 2012, at 03:40, Nick Lewycky wrote: > As far as I know, this optimization is legal. Fix the test with a volatile pointer: Why would that be required? malloc() is defined by the standard to return a pointer that is distinct from any other valid pointer, or NULL. Any optimisation that makes any assumptions about its next value is invalid. > int main() { > volatile char

I've sent this issue to some friends on the C++ committee. The first response I received indicates that the person thinks the optimizer is within it's rights to optimize away the call to malloc. Here are some points, extracted from the response: "There is no observable behavior (a technical term in the standard) that violates requirements of the standard. In particular, malloc in

David Chisnall wrote: > On 2 Oct 2012, at 03:40, Nick Lewycky wrote: > >> As far as I know, this optimization is legal. Fix the test with a volatile pointer: > > Why would that be required? It isn't. My suggestion for fixing the test is to make use of the returned pointer in a fashion that the compiler is forbidden to elide it: make it an observable side-effect using

See also this proposal for the next C++ committee meeting, which aims to clarify this case and others like it: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3433.html On Tue, Oct 2, 2012 at 9:49 AM, Reed Kotler <rkotler at mips.com> wrote: > I've sent this issue to some friends on the C++ committee. > > The first response I received indicates that the person thinks

We have tested latest xen on VT platform with Intel 915/E8500 chipset.Here is the test summary. Issues: - IA-32 VMX guest will hang when booting on IA-32PAE host with acpi=1 and apic=1.(Bug 594) - Failed to created VMX after tens of VMXs have been created & destroyed on IA-32e.(Bug593) IA-32: Build&Boot SMP xen0 without problem Can bootup unmodified IA-32 2.4/2.6 linux in VMX

We have tested the latest xen on VT platform with Intel 915/E8500 chipset. Here is the test summary: Issues: - Cannot boot Windows 2000 - Only one CPU is detected in SMP dom0 - Destroying VMX with 4G memory may make xend hang on IA-32e IA-32: + Build&Boot UP xen0 without problem + Can bootup unmodified IA-32 2.4/2.6 linux in VMX domain + Can bootup unmodified IA-32 WindowsXP SP1/SP2

DMA-related logic is separated from the virtqueue_add_packed(). DMA address will be saved as sg->dma_address, then virtqueue_add_packed() will use it directly. Unmap operation will be simpler. The purpose of this is to facilitate subsequent support to receive dma address mapped by drivers. Signed-off-by: Xuan Zhuo <xuanzhuo at linux.alibaba.com> --- drivers/virtio/virtio_ring.c | 37

We have test latest xen on VT platform with Intel 915 chipset and Here is the test summary: IA32: Build&Boot SMP xen0 without problem Can startup unmodified 2.4/2.6 linux on VMX domain Can startup VMX & Xen with different configuration Part of LTP runs well in VMX domain(2.6) IA32E: Build&Boot SMP xen0 without problem Can startup unmodified 2.6 linux on

This patch adds a simple callback framework. Modified loadfile and floadfile to look for callbacks and call them if present Supports multiple callbacks Modified com32/modules/linux.c to demonstrate functionality (it's a little more complicated than it should be just to demonstrate multiple callbacks). Add progress argument to display a percentage indicator when loading. Example boot:

Dear all, I'm currently working on the automated program analysis tool AProVE (http://aprove.informatik.rwth-aachen.de/) and would like to use LLVM for analysis of C programs. I have the following example C program dealing with simple lists of integers: ------------ start C example ------------- #include<stdlib.h> struct list_el { int val; struct list_el * next; }; typedef

DMA-related logic is separated from the virtqueue_add_vring_packed() to prepare for subsequent support for premapped. DMA address will be saved as sg->dma_address, then virtqueue_add_vring_packed() will use it directly. If it is a premapped scene, the transmitted sgs should have saved DMA address in dma_address, and in virtio core, we need to pass virtqueue_map_sgs(). Signed-off-by: Xuan

We have tested latest xen on VT platform with Intel 915/E8500 chipset.Here is the test summary. issues: - No bocking issues. IA-32: Build&Boot SMP xen0 without problem Can bootup unmodified IA-32 2.4/2.6 linux in VMX domain Can bootup unmodified IA-32 WindowsXP SP1/SP2 in VMX domain Can bootup VMX & XenU with different memory size(VMX:128MB,256MB,512MB.XenU:256MB)

Change code to use list_entry api. And removed comment suggesting that change. Signed-off-by: Abhishek Kane <v-abkane at microsoft.com> Signed-off-by: K.Y. Srinivasan <kys at microsoft.com> Signed-off-by: Hank Janssen <hjanssen at microsoft.com> --- drivers/staging/hv/channel_mgmt.c | 17 +++++++++-------- 1 files changed, 9 insertions(+), 8 deletions(-) diff --git

Change code to use list_entry api. And removed comment suggesting that change. Signed-off-by: Abhishek Kane <v-abkane at microsoft.com> Signed-off-by: K.Y. Srinivasan <kys at microsoft.com> Signed-off-by: Hank Janssen <hjanssen at microsoft.com> --- drivers/staging/hv/channel_mgmt.c | 17 +++++++++-------- 1 files changed, 9 insertions(+), 8 deletions(-) diff --git

With this patch, x86 and x86-64 share ioport.c, fixing LTP iopl and ioperm testcase failures (on both). We found an iopl testcase failing even on x86 xenlinux. Now x86-64 xenlinux should have the same results regarding the LTP testcases (as far as we tested). Signed-off-by: Li B Xin <li.b.xin@intel.com> Signed-off-by: Jun Nakajima <jun.nakajima@intel.com> Jun --- Intel Open Source

Extend the guestfs_inspect_list_applications2 API call to work on Arch Linux guest images. --- src/inspect-apps.c | 125 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 125 insertions(+) diff --git a/src/inspect-apps.c b/src/inspect-apps.c index b62b432..b7a3b0e 100644 --- a/src/inspect-apps.c +++ b/src/inspect-apps.c @@ -60,6 +60,7 @@ static struct