similar to: [LLVMdev] Question about NoWrap flag for SCEVAddRecExpr

[+Arnold] > On Jun 10, 2015, at 1:29 PM, Sanjoy Das <sanjoy at playingwithpointers.com> wrote: > > [+CC Andy] > >> Can anyone familiar with ScalarRevolution tell me whether this is an >> expected behavior or a bug? > > Assuming you're talking about 2*k, this is a bug. ScalarEvolution > should be able to prove that {0,+,4} is <nsw> and

Hi, I'm using LLVM 2.7 right now, and I found "opt -std-compile-opts" has missed some opportunities for optimization: define void @spa.main() readonly { entry: %tmp = load i32* @dst-ip ; <i32> [#uses=3] %tmp1 = and i32 %tmp, -16777216 ; <i32> [#uses=1] %tmp2 = icmp eq i32 %tmp1, 167772160 ; <i1> [#uses=2]

The following piece of IR is a fixed point for opt -std-compile-opts/-O3: --- target datalayout = "e-p:64:64:64-S128-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f16:16:16-f32:32:32-f64:64:64-f128:128:128-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64" target triple = "x86_64-unknown-linux-gnu" ; Function Attrs: nounwind readonly define i32 @get32Bits(i8*

> On Jun 10, 2015, at 6:17 PM, Sanjoy Das <sanjoy at playingwithpointers.com> wrote: > > I'm not sure if inbounds can be used to prove <nuw>. If an object > %OBJ is allocated at address -1 then "gep inbounds %OBJ 1" is not > poison, but the underlying computation unsigned-overflows. I think that this should yield poison per langref because the signed

I am seeing the wf loop get optimized just fine with llvm 2.8 (and almost as good with head). I'm running on Mac OS X 10.6. I have an apple supplied llvm-gcc and a self compiled llvm 2.8. When I run $ llvm-gcc -emit-llvm -S M.c $ opt -O2 M.s | llvm-dis I see that: 1. Tail recursion has been eliminated from wf 2. The accesses to sp have been promoted to registers 3. The loop has

Hello, I've come across another example: I'm compiling with clang -S -emit-llvm -std=gnu99 -O3 clang version 2.9 (trunk 118238) Target: x86_64-unknown-linux-gnu Thread model: posix I take the code: int loops(int x) { int ret = 0; for(int i = 0; i < x; i++) { for(int j = 0; j < x; j++) { ret += 1; } } return ret; } and the

Hello, I want to compile a LLVM file into an executable running on ARM platform. I use LLVM 2.0 with the following command lines: llvm-as -f -o test.bc test.ll llc -march=arm -mcpu=arm1136j-s -mattr=+v6 -f -o test.s test.bc arm-linux-gnu-as -mcpu=arm1136j-s test.s With the last command, I obtain the following error: rd and rm should be different in mul The bad instruction is

Hi Nicolas (at least, I suspect your signing of your mail with "Anton" was not intentional :-p), > I assume that's the same as the online demo's "Show LLVM C++ API code" > option (http://llvm.org/demo/)? I've tried that with a structure containing > four floating-point components but it also appears to add them individually > using extract/insert. Maybe

Hi Mikael, You are obtaining warning, not an error, right? The most arm cores, including arm1136, can execute mul with rd = rm. So, you can ignore this warning. Lauro 2007/6/12, Peltier, Mikael <m-peltier at ti.com>: > > > > > Hello, > > > > I want to compile a LLVM file into an executable running on ARM platform. > > I use LLVM 2.0 with the following

Hello everybody, I have stumbled upon a test case (the attached module is a slightly reduced version) that shows extremely reduced performance on linux compared to windows when executed using LLVM's JIT. We narrowed the problem down to the actual code being generated, the source IR on both systems is the same. Try compiling the attached module: llc -O3 -filetype=asm -o BAD.s BAD.ll Under

Hi Matthijs, Yes, I've turned off the link-time optimizations (otherwise it just propagates my constant vectors and immediate prints the result). :-) Here's essentially what I try to generate: void add(float z[4], float x[4], float y[4]) { z[0] = x[0] + y[0]; z[1] = x[1] + y[1]; z[2] = x[2] + y[2]; z[3] = x[3] + y[3]; } And here's part of the output from the online

llvm does not automatically vectorize your scalar code (as least for now). You have to write gcc generic vector code or use vector builtins. Evan On May 8, 2008, at 1:46 PM, Nicolas Capens wrote: > Hi Matthijs, > > Yes, I've turned off the link-time optimizations (otherwise it just > propagates my constant vectors and immediate prints the result). :-) > > Here's

Hi, I want to clone a given function, and add an argument to it. I then want to add a call to that new function. I have a callInstruction CI, which I want to transform to call this new function, and to take a new argument. The code I added was as follows CI->getCalledFunction()->dump(); Function* DirectF = CloneFunction(CI->getCalledFunction());

Hi, Seems pass scalar-evolution+indvars fail to get the loop trip count of the following case: int foo(int x, int y, int lam[256], int alp[256]) { int i; int z = y; for (i = 255; i >= 0; i--) { z += x; lam[i] = alp[i]; } return z; } The final optimized ll code is : define i32 @foo(i32 %x, i32 %y, i32* %lam, i32* %alp) nounwind { entry: br label %bb bb:

On May 22, 2014, at 3:51 PM, Chandler Carruth <chandlerc at google.com> wrote: > > On Thu, May 22, 2014 at 4:42 PM, Louis Gerbarg <lgg at apple.com> wrote: > The problem that the above transform is technically illegal because “When indexing into a (optionally packed) structure, only i32 integer constants are allowed (when using a vector of indices they must all be the same

Hey Duncan, hey everybody else, I just stumbled upon a problem in the latest llvm-gcc trunk which is related to my previous problem with the 64bit ABI and structs: Given the following code: struct float3 { float x, y, z; }; extern "C" void __attribute__((noinline)) test(float3 a, float3* res) { res->y = a.y; } int main(void) { float3 a; float3 res; test(a,

I'm attempting to modify a parser generator to emit LLVM code instead of C. So far the experience has been trivial, but I am now running into an error regarding labels that I can't seem to solve. Situation 1: A label is used immediately after a void function call (l6 in this case): <snip> %tmp26 = load i32* @yybegin, align 4 %tmp27 = load i32* @yyend, align 4 call void

Recently I posted a patch to migrate certain GEPs between basic blocks in cases where doing so would improve the ability of instcombine to merge into more complicated addressing mode (r209049 and r209065). After some build to failures it was rolled back. I now have a patch that no longer causes the regressions I was seeing, but it also no longer can optimize the case I was trying to optimize. As

Hi Ralf, > I do not understand why this behaviour is required. What is the problem > in having a function receive a single struct-parameter with three floats > compared to two scalar parameters? > > source-code (C++): > struct Test3Float { float a, b, c; }; > void test(Test3Float param, Test3Float* result) { ... } if you compile this with GCC, you will see that it too

Uh, sorry, did not pay attention where I was replying ;) Hey Duncan, I do not understand why this behaviour is required. What is the problem in having a function receive a single struct-parameter with three floats compared to two scalar parameters? source-code (C++): struct Test3Float { float a, b, c; }; void test(Test3Float param, Test3Float* result) { ... } bitcode: