similar to: [LLVMdev] Overflow trap

On Aug 9, 2010, at 10:44 AM, Peter S. Housel wrote: > Several instruction set architectures include arithmetic operations that can trap on overflow, or support this feature with a separate trap-on-overflow-flag instruction (such as the x86 INTO instruction). > > > I am adding a back-end to the Open Dylan compiler to generate LLVM IR. The original back-end, which generates x86

After chatting on IRC, Peter wants a very specific interrupt (int4 on x86). I suggested he add a new llvm.x86.int(i32) intrinsic, and use the existing branch on llvm.sadd.with.overflow intrinsic. The x86 backend can then turn jo+int4 into into when reasonable. -Chris On Aug 9, 2010, at 5:45 PM, Chris Lattner wrote: > > On Aug 9, 2010, at 10:44 AM, Peter S. Housel wrote: > >>

The enclosed patch adds a llvm.x86.int(i8) intrinsic expanding to the INT or INT3 instruction as appropriate. I haven't yet figured out the best way to select for the INTO instruction across basic blocks (hints would be welcome), but that can be added later with no changes in semantics. -Peter- On Aug 9, 2010, at 6:05 PM, Chris Lattner wrote: > After chatting on IRC, Peter wants a very

Hi Pete, > Or do you mean that the result of an add may not even be defined? In that case would reading it be considered UB in the case where the overflow bit was set? Yeah, this is the case I'm worried about: that for example sadd.with.overflow(INT_MAX, 1) might be designed to return { poison, true } instead of giving a useful result in the first element of the struct. John

Hi, all. I have noticed that LLVM supports some Intrinsic Functions such as *"** llvm.sadd.with.overflow"* described in http://llvm.org/docs/LangRef.html#int_sadd_overflow. We can use these functions and needn't define the function bodies. For example, I can manually insert codes: * %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b) %sum = extractvalue

CGP also relies on the add being a simple two's complement add, since it will transform define void @test1(i64 %a, i64 %b, i64* %res_i64, i1* %res_i1) { entry: %add = add i64 %b, %a %cmp = icmp ult i64 %add, %a store i1 %cmp, i1* %res_i1 store i64 %add, i64* %res_i64 ret void } to define void @test1(i64 %a, i64 %b, i64* %res_i64, i1* %res_i1) { entry: %uadd.overflow = call

Hi guys, I just noticed that the LLVM has some node for signed/unsigned type( like udiv, sdiv), but why the ADD, SUB do not have the counter part sadd, uadd? best kevin

I'm interested in using @llvm.experimental.vector.reduce.smax/umax to implement runtime overflow checking for vectors. Here's an example checked addition, without vectors, and then I'll follow the example with what I would do for checked addition with vectors. Frontend code (zig): export fn entry() void { var a: i32 = 1; var b: i32 = 2; var x = a + b; } LLVM IR code:

The IR update to allow vector types was here: https://reviews.llvm.org/D57090 ...we didn't update the docs at that time because it was not clear what the backend would do with that, but that might've changed with some of the more recent patches. On Sat, Feb 9, 2019 at 1:42 AM Craig Topper via llvm-dev < llvm-dev at lists.llvm.org> wrote: > I don't think I understand your

On Sat, Feb 9, 2019 at 6:25 PM Simon Pilgrim <llvm-dev at redking.me.uk> wrote: > The add/sub (+mul) overflow intrinsics are being updated to support > vectors to match the related add/sub saturation intrinsics. We haven't > updated the docs yet as legalization, vectorization and various minor bits > of plumbing still need to be finished before it can be officially supported

Hello, We are looking to adjust the font size of the axis annotation on the graph that results from use of the metaplot() function. Metaplot seems to respond to cex and cex.lab to change those graphical parameters, but it doesn't respond to cex.axis. Is there a way to work around this by creating a customized x-axis, and if so, how? Thanks for all your help. Syntax is below. Best, Dawn

Hi everyone, We seem to have allowed our documented target-independent intrinsics to acquire a somewhat-haphazard naming system, and I think we should standardize on one convention. All of the intrinsics have 'llvm.' as a prefix, and some also have some additional prefix 'llvm.dbg.', 'llvm.eh.', 'llvm.experimental.', etc., but after that we lose consistency. When

Hi Devs, Consider below testcase. $cat test.cpp #include <vector> #include<type_traits> typedef int _int4 __attribute__((vector_size(16))); typedef union{ int data[4]; struct {int x, y, z, w;}; _int4 vec; } int4; typedef int4 int3; int main() { static_assert(std::alignment_of<int4>::value <= alignof(max_align_t), "over aligned!"); } $clang++ -m32 error:

Hello r users, I have to deal with int8 data with R. AFAIK R does only handle int4 with `as.integer` function [1]. I wonder: 1. what is the better approach to handle int8 ? `as.character` ? `as.numeric` ? 2. is there any plan to handle int8 in the future ? As you might know, int4 is to small to deal with earth population right now. Thanks for you ideas, int8 eg: human_id

Is there any good reason for using DW_FORM_data1 for the DW_AT_language attribute of DW_TAG_compile_unit? This prevents using language codes in the DW_LANG_lo_user=0x8000 to DW_LANG_hi_user=0xffff range. I think the obvious change to use DW_FORM_data2 in line 1897 of lib/CodeGen/AsmPrinter/DwarfDebug.cpp should fix it. Or, if there are binary compatibility issues, the abbrev form could be chosen

The new pragmatic Rails Cookbook has a drag and drop sorting recipe. Does anyone know if this works with 1.0? I''ve followed the recipe (i think), and I can drag but when I drop everything goes back the way it was. It seems that the sort logic doesn''t get invoked. I put this code in my view: <%= sortable_element ''task-list'' , :url => {

On Tue Nov 04 2014 at 12:43:05 PM Peter S. Housel <housel at acm.org> wrote: > On 11/04/2014 07:04 AM, Robinson, Paul wrote: > >> From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] > On Behalf Of Sean Silva > >> > >> You haven't established that you really need this. AFAIK Apple's linker > >> doesn't need this

>> In other words, abandoning overflow detection makes the >> duplication of types redundant, while requiring it would be a >> great burden on CPUs that don't have overflow exception hardware. > >Yes, you're right. This has been a desired change for quite some time >now. Unfortunately, its a huge impact to nearly every part of LLVM. We >will

Philip Reames and I are debating the semantics of x.with.overflow and I wanted to see if I could get a ruling here: My read of the langref is that the overflow bit and the result of the operation are independent of each other. In other words, we can count on the result of add.with.overflow being the same as the result of a (non-nsw) add, even in the case where an overflow occurs. Is that

On Wed, 2010-05-05 at 13:22 -0700, Nathan Jeffords wrote: > > The important point here is that the COFF MCSection needs to > have the right level of semantic information. In fact, > MCSection is the place that I'd start for COFF bringup. > > OK, I see that now. The current isolation > between TargetLoweringObjectFile ->