similar to: why clang compile local to global

> On Dec 27, 2016, at 11:09 PM, liuyu11 at ict.ac.cn via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > Hello,everyone: > I want to known how to let clang compile my local array to local variables: > I have the code : > int main() > { > int a[3]={1,2,3}; > > int b=7; > int c=8; > int d=9; > int e=10; > int f=11; >

Ok, now I think I've found a bug: Consider this C code: void bar(int b) { int a[10]; memset(a, b, 10); } which generates this IR code: define dso_local void @bar(i32 %b) #0 { entry: %b.addr = alloca i32, align 4 %a = alloca [10 x i32], align 16 store i32 %b, i32* %b.addr, align 4 %arraydecay = getelementptr inbounds [10 x i32], [10 x i32]* %a, i64 0, i64 0 %0 = bitcast i32*

Hi, I was looking into the semantics of GEP inbounds and some BasicAA rules and I'm wondering if it's valid in LLVM IR to allocate more than half of the address space with a global variable or an alloca. If that's a scenario want to consider, then we have problems :) Consider this C code (32 bits): #include <string.h> char obj[0x80000008]; char f() { char *p = obj +

Many thanks for the pointer! I missed that bug report since the title was about GVN. If there's interest in supporting this feature I can help since we've formalized most of BasicAA. I can easily verify if proposed changes are correct. (I'll release the code soon). Nuno Quoting Björn Pettersson A <bjorn.a.pettersson at ericsson.com>: > Hi Nuno. > I can't

The frontend code is a pretty simple for loop, that counts from i = 0; i != 10; i += 1 It gets optimized into and endless loop. export fn entry() void { var array: [10]Bar = undefined; var x = for (array) |elem, i| { if (i == 1) break elem; } else bar2(); } Here's the generated IR: ; ModuleID = 'test' source_filename = "test" target datalayout =

Hi Duncan, >> #include<stdio.h> >> #include<string.h> >> >> int main(int argc, char** argv){ >> >> char a[8] = "aaaaaaa"; >> char b[8] = "bbbbbbb"; >> >> char *c = (char*) malloc(sizeof(char)*(strlen(a)+strlen(b)+1)); >> memcpy(c, a, strlen(a)); >> memcpy(c + strlen(a), b, strlen(b) + 1); >>

Hi Pablo, I can reproduce this with the supplied IR. It is related to the use of __memcpy_chk. As far as I can see it is a bug in lli or the LLVM code generators. Can you please open a bugreport, attaching the LLVM IR. Ciao, Duncan. On 23/01/12 17:00, Pablo Barrio wrote: > Hi Duncan, >>> #include<stdio.h> >>> #include<string.h> >>> >>> int

Below is attached a full IR module that can reproduce this issue, but the part to notice is this: %Foo96Bits = type <{ i24, i24, i24, i24 }> define internal fastcc i16 @main.0.1() unnamed_addr #2 !dbg !113 { Entry: %value = alloca %Foo96Bits, align 1 %b = alloca i24, align 4 %0 = bitcast %Foo96Bits* %value to i8*, !dbg !129 call void @llvm.memcpy.p0i8.p0i8.i64(i8* %0, i8* bitcast

Hi I am upgrading my clang fork from 5.0 to 6.0 and I am hit by this error: Access type node must be a valid scalar type %4 = load %"struct.Foo::p.test1::"*, %"struct.Foo::p.test1::"** %_param.addr, align 8, !tbaa !16 !16 = !{!15, !15, i64 0} !15 = !{!"p.test1::", !13, i64 0, !13, i64 8} It looks like !16 is referencing !15, which is a struct. !13 is !13 =

Yes, I know this works peachy keen for char arrays. I'm looking at (which is hard to express in C) something like void foo () { int bar[20] = { 42, 42, ..., 42 }; } I don't want to do a memcopy of the 20 element constant array, and memset doesn't work here. I want an intrinsic that copys the scalar int constant 42 to each element of the int array. bagel On 11/10/2016 03:30

Hi! I'm having some trouble with a pass I'm writing. I'm using DemotePHIToStack to remove all phi node in my code with this code (this is the first thing I do in my pass): // Erase phi node vector<PHINode*> phis; for (Function::iterator i=f->begin();i!=f->end();++i) { for(BasicBlock::iterator b=i->begin();b!=i->end();++b) {

> On Mar 1, 2015, at 7:53 AM, Björn Steinbrink <bsteinbr at gmail.com> wrote: > > On 2015.02.28 18:17:27 -0800, Philip Reames wrote: >>> On Feb 28, 2015, at 3:01 PM, Björn Steinbrink <bsteinbr at gmail.com> wrote: >>> 2015-02-28 23:50 GMT+01:00 Philip Reames <listmail at philipreames.com>: >>>>>> On Feb 28, 2015, at 2:30 PM, Björn

> On Feb 28, 2015, at 3:01 PM, Björn Steinbrink <bsteinbr at gmail.com> wrote: > > [This time without dropping the list, sorry] > > 2015-02-28 23:50 GMT+01:00 Philip Reames <listmail at philipreames.com>: > >>>> On Feb 28, 2015, at 2:30 PM, Björn Steinbrink <bsteinbr at gmail.com> wrote: >>>> >>>>> On 2015.02.28

In your original file, %6 is defined in if.end11 and is used in cond.end. if.end11 branches to cond.true and cond.false, both of which branch unconditionally to cond.end. Therefore %6 dominates its use. In your second file %18 is defined in end.11 and used in cond.end. However, end.11 no longer dominates cond.end because you have rewritten all branches to go through the switch statement in

[This time without dropping the list, sorry] 2015-02-28 23:50 GMT+01:00 Philip Reames <listmail at philipreames.com>: >> On Feb 28, 2015, at 2:30 PM, Björn Steinbrink <bsteinbr at gmail.com> wrote: >> >>> On 2015.02.28 14:23:02 -0800, Philip Reames wrote: >>>> On 02/28/2015 10:04 AM, Björn Steinbrink wrote: >>>> Hi, >>>>

Hi, I've been stuck with this problem for a while now, and my supervisor's starting to think it's a bug in lli, but I thought I'd ask here before going down that route. I have this code, which stores an array in my 'MainClass', and prints out an element of it. Note that the print statement is irrelevant here, it segfaults regardless, and this code has been run with -O2

So I removed the 'tail' from the call and try out different properties: - IntrNoMem: memset() and the intrinsic are both optimized away as expected - IntrWriteMem: memset() optimized away by DSE but the intrinsic isn't. I would expect both to be removed, since the intrinsic is now also a dead store. - IntrReadMem: memset() and the intrinsic are both optimized away *unexpectedly* (CSE

> On Feb 28, 2015, at 2:30 PM, Björn Steinbrink <bsteinbr at gmail.com> wrote: > >> On 2015.02.28 14:23:02 -0800, Philip Reames wrote: >>> On 02/28/2015 10:04 AM, Björn Steinbrink wrote: >>> Hi, >>> >>>> On 2015.02.28 10:53:35 -0600, Hal Finkel wrote: >>>> ----- Original Message ----- >>>>> From: "Philip

Hi Johannes, Thanks for your reply. I now see more clearly how things work with these properties. However, what would be an object whose address is potentially known by a callee? I suppose the intrinsic arguments and global variable? So IIUC, if not restricted by *only properties, an intrinsic could access to: - only its arguments if IntrArgMemOnly specified, - its arguments and the global

On 2015.02.28 14:23:02 -0800, Philip Reames wrote: > On 02/28/2015 10:04 AM, Björn Steinbrink wrote: > >Hi, > > > >On 2015.02.28 10:53:35 -0600, Hal Finkel wrote: > >>----- Original Message ----- > >>>From: "Philip Reames" <listmail at philipreames.com> > >>>>6. Use the lifetime.start/lifetime.end and >