similar to: [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.

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 Tom, Matt, I'm running into strange issues with the cos test (piglit generated_tests/cl/builtin/math/builtin-float-cos-1.0.generated.c) I have been seeing random failures (incorrect results) for some time and tried to investigate. the weird part is that the failures are not 100% reproducible, sometimes the tests pass, or partly pass (it's usually float8 and float16 subtests that

Hi All, The following code : void hexagon2( int *a, int *res ) { int i = 100; while ( i-- ) { *res++ = *a++; } } gets compiled as a sub-optimal Software loop on LLVM 9.0 instead of a Hardware loop, whereas it was compiled as a Hardware Loop in LLVM 7.0. This is the final assembly code generated by LLVM 9.0 : .text .file "main.c" .globl hexagon2 // --

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

When zig updated to llvm 5 we started hitting this assertion: zig: /home/andy/downloads/llvm-project/llvm/include/llvm/Support/Casting.h:106: static bool llvm::isa_impl_cl<To, const From*>::doit(const From*) [with To = llvm::Instruction; From = llvm::Value]: Assertion `Val && "isa<> used on a null pointer"' failed. I wonder if however this was caused by an

Can you please open a bug on bugzilla and attach the ir testcase? Your fix doesn't look right (just hiding the assertion failure) On Sep 17, 2017 10:45 AM, "Andrew Kelley via llvm-dev" < llvm-dev at lists.llvm.org> wrote: > What do you think about this patch? > > --- a/llvm/lib/Transforms/Scalar/NewGVN.cpp > +++ b/llvm/lib/Transforms/Scalar/NewGVN.cpp > @@

So, 90% of the time I've seen this, it was memory corruption, usually use after free. I know I fixed one after 5.0 branched. You should compile with address sanitizer enabled, and I suspect you will find the issue quicky. If not, we really need ir that reproduces it. On Sun, Sep 17, 2017, 12:27 PM Andrew Kelley via llvm-dev < llvm-dev at lists.llvm.org> wrote: > I think I forgot to

Hi Tom, Thanks for taking the time to answer this. On 11-01-16 18:10, Tom Stellard wrote: > On Mon, Jan 11, 2016 at 12:07:14PM +0100, Hans de Goede wrote: >> Hi, >> >> After a few distractions I'm back to work on the llvm tgsi backend. I've >> added clang integration and I can now compile a simple opencl program >> to something which sort of looks like

The PNaCl project has implemented various IR simplification passes that simplify LLVM IR by lowering complex features to simpler features. We'd like to upstream some of these IR passes to LLVM. We'd like to explore if this acceptable, and if so, how we should go about doing this. The immediate reason is that Emscripten is reusing PNaCl's IR passes for its new "fastcomp"

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

On 07/04/2013 01:39 PM, Stéphane Letz wrote: > Hi, > > Our DSL can generate C or directly generate LLVM IR. With LLVM 3.3, we can vectorize the C produced code using clang with -O3, or clang with -O1 then opt -O3 -vectorize-loops. But the same program generating LLVM IR version cannot be vectorized with opt -O3 -vectorize-loops. So our guess is that our generated LLVM IR lacks some

Hi, Our DSL can generate C or directly generate LLVM IR. With LLVM 3.3, we can vectorize the C produced code using clang with -O3, or clang with -O1 then opt -O3 -vectorize-loops. But the same program generating LLVM IR version cannot be vectorized with opt -O3 -vectorize-loops. So our guess is that our generated LLVM IR lacks some informations that are needed by the vectorization passes to

Hi, After a few distractions I'm back to work on the llvm tgsi backend. I've added clang integration and I can now compile a simple opencl program to something which sort of looks like tgsi. You can find my latest work on this here: http://cgit.freedesktop.org/~jwrdegoede/llvm http://cgit.freedesktop.org/~jwrdegoede/clang (the latter may still need to sync) I've a little test

The Hexagon part is fixed in r364790. -- Krzysztof Parzyszek kparzysz at quicinc.com<mailto:kparzysz at quicinc.com> LLVM compiler development From: llvm-dev <llvm-dev-bounces at lists.llvm.org> On Behalf Of Joan Lluch via llvm-dev Sent: Sunday, June 30, 2019 2:04 PM To: llvm-dev <llvm-dev at lists.llvm.org> Subject: [EXT] [llvm-dev] [hexagon][PowerPC] code regression

Hi, On 22-02-16 13:41, Samuel Pitoiset wrote: > Hi there, > > On 02/22/2016 12:26 PM, Hans de Goede wrote: <snip> >> So back to the problem of getting OpenCL(ish) code to work again with >> the recent mesa changes. For starters I would like to get: >> >> src/gallium/tests/trivial/compute.c and then the test with mask 8, >> test_input_global() to work

Hello all again, take 2. Over in D68651 I would like to make code that attempt to saturate an value (using higher bitwidth integers) use a saturating intrinsic instead. Something like this: https://godbolt.org/z/9knBnP As can be seen, the unsigned cases are already being matched to llvm.uadd.sat intrinsics. I am hoping to extend that to the signed cases. This has numerous benefits including

Hi, On 22-02-16 14:04, Samuel Pitoiset wrote: > > On 02/22/2016 01:46 PM, Hans de Goede wrote: >> Hi, >> >> On 22-02-16 13:41, Samuel Pitoiset wrote: >>> Hi there, >>> >>> On 02/22/2016 12:26 PM, Hans de Goede wrote: >> >> <snip> >> >>>> So back to the problem of getting OpenCL(ish) code to work again with

I suggest that LLVM needs intrinsics for add/sub with carry, e.g. declare {T, i1} @llvm.addc.T(T %a, T %b, i1 c) The current multiprecision clang intrinsics example: void foo(unsigned *x, unsigned *y, unsigned *z) { unsigned carryin = 0; unsigned carryout; z[0] = __builtin_addc(x[0], y[0], carryin, &carryout); carryin = carryout; z[1] = __builtin_addc(x[1], y[1],

Hi, On 13-11-15 19:51, Tom Stellard wrote: > On Fri, Nov 13, 2015 at 02:46:52PM +0100, Hans de Goede wrote: >> Hi All, >> >> So as discussed I've started working on a TGSI backend for >> llvm to use as a way to get compute going on nouveau (and other gpu-s). >> >> I'm still learning all the ins and outs of llvm so I do not have >> much to show