Displaying 20 results from an estimated 2000 matches similar to: "[LLVMdev] preserving an implicit def between basic blocks"
2008 Jul 12
3
[LLVMdev] Little bug in LoopInfo after Rotate?
Hello, I have two for loops (one inside the other), that after indvars,
looprotate, etc. (the important here is the loop rotate), is similar to this
(I've stripped the real operations):
define i32 @f() nounwind {
entry:
br label %bb1
bb1: ; preds = %bb3, %bb1, %entry
%i.0.reg2mem.0.ph = phi i32 [ 0, %entry ], [ %i.0.reg2mem.0.ph, %bb1 ],
[ %indvar.next9, %bb3 ] ;
2009 Jun 09
1
Problem : solving a equation with R , fail with uniroot function
Hi ,
I would like to know if a R function have the same behaviour than the matlab
solve function.
I tried something with uniroot but I have some problems:
The equation I need to solve is :
exp(c0-r0)*(bb0+x)*(bb1-x)=(bb0+x+1)(bb1-x-1)
So I tried this:
STEP 1: my function test
test <- function(x,bb0=-3,bb1=5,c0=2,r0=0) {
+ ((exp(c0-r0)*(bb0+x)*(bb1-x))/((bb0+x+1)(bb1-x-1))-1)}
STEP 2:
>
2012 Jul 25
2
[LLVMdev] Question about an unusual jump instruction
Dear all,
I'm working on an exploratory backend on llvm. In the instruction set I'm using
I have an instruction (called DECJNZ) that decrements a register and, if the
decremented value is not zero, jumps (with a relative jump) to a given offset.
I've described in tablegen this instruction as follow:
def DECJNZ : Instruction {
let Namespace = "MyTarget";
let
2012 Jul 25
0
[LLVMdev] Question about an unusual jump instruction
On Wed, Jul 25, 2012 at 12:48 AM, Michele Scandale
<michele.scandale at gmail.com> wrote:
> Dear all,
>
> I'm working on an exploratory backend on llvm. In the instruction set I'm using
> I have an instruction (called DECJNZ) that decrements a register and, if the
> decremented value is not zero, jumps (with a relative jump) to a given offset.
>
> I've
2005 Jun 08
2
policy or rules
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Dear all,
I''m a bit confused on the rules and would like your help.
I''ve 4 NIC,
eth0 --> WAN (net)
eth1 --> OSPF1 (bb1)
eth2 --> OSPF2 (bb2)
I would like to enable all the icmp function (ping and traceroute)
Wonder what effect will the following policy make.
bb0 all ACCEPT info
bb1
2013 Oct 10
2
[LLVMdev] Are there implicit rules or conventions for an llvm frontend to generate llvm IR?
Hi, this question might be a bit silly: apart from the language
reference(http://llvm.org/docs/LangRef.html#switch-instruction) page, are
there additional rules for a regular llvm frontend to generate llvm IRs?
There are a few cases that I got from clang/llvm-gcc/dragonegg when
compiling *C* source code into llvm IR:
1. It seems that there is ONLY ONE ReturnInst(and NO InvokeInst) for such
llvm
2017 Feb 06
2
Adding Extended-SSA to LLVM
On Sun, Feb 5, 2017 at 3:41 PM, Nuno Lopes <nunoplopes at sapo.pt> wrote:
> Thanks for the answers! The plan makes sense to me.
>
> Regarding phis, what about diamonds, e.g.:
>
>
> define i32 @f(i32 %x) {
> br .., label %bb0, label %bb1
> bb0:
> %cmp = icmp sge i32 %x, 0 ; x > 0
> br i1 %cmp, label %bb2, label %bb3
> bb1:
> %x2 = add nsw
2013 Oct 10
0
[LLVMdev] Are there implicit rules or conventions for an llvm frontend to generate llvm IR?
On 10/10/13 10:43 AM, Hongxu Chen wrote:
> Hi, this question might be a bit silly: apart from the language
> reference(http://llvm.org/docs/LangRef.html#switch-instruction) page, are
> there additional rules for a regular llvm frontend to generate llvm IRs?
>
> There are a few cases that I got from clang/llvm-gcc/dragonegg when
> compiling *C* source code into llvm IR:
>
>
2013 Oct 10
1
[LLVMdev] Are there implicit rules or conventions for an llvm frontend to generate llvm IR?
On Fri, Oct 11, 2013 at 12:06 AM, John Criswell <criswell at illinois.edu>wrote:
> On 10/10/13 10:43 AM, Hongxu Chen wrote:
>
>> Hi, this question might be a bit silly: apart from the language
>> reference(http://llvm.org/**docs/LangRef.html#switch-**instruction<http://llvm.org/docs/LangRef.html#switch-instruction>)
>> page, are
>> there additional rules
2015 Feb 25
0
[LLVMdev] Jump Theading/GVN bug - moving discussion to llvm-dev
On 02/25/2015 10:41 AM, Rafael EspĂndola wrote:
>>> all the zero paths from entry to %a pass by %b.
>>
>> That is a graph-wise definition, sure.
>> So, this is an interesting definition, and maybe this is part of the source
>> of the problem.
>>
>> For SSA, at least GCC requires that both "definition block dominates use
>> block" (which
2015 Feb 25
4
[LLVMdev] Jump Theading/GVN bug - moving discussion to llvm-dev
>> all the zero paths from entry to %a pass by %b.
>
>
> That is a graph-wise definition, sure.
> So, this is an interesting definition, and maybe this is part of the source
> of the problem.
>
> For SSA, at least GCC requires that both "definition block dominates use
> block" (which would be true here), *and*
> that "definition appears before use in
2011 Nov 21
1
[LLVMdev] Fwd: Order of Basic Blocks
---------- Forwarded message ----------
From: Ryan Taylor <ryta1203 at gmail.com>
Date: Mon, Nov 21, 2011 at 10:30 AM
Subject: Re: [LLVMdev] Order of Basic Blocks
To: Benjamin Kramer <benny.kra at googlemail.com>
This worked, though the RPO_iterator apparently wasn't what I was looking
for anyways, it seems it doesn't rreally go top->down.
I have a simple example code,
2012 Dec 26
2
[LLVMdev] Can simplifycfg kill llvm.lifetime intrinsics?
> Ok, suppose you have the following code:
> BB1:
> llvm.lifetime.start(%a)
> store to %a
> llvm.lifetime.end(%a)
> br %BB2
>
> BB2:
> <some code>
> br %BB1
>
> If you remove the first "llvm.lifetime.start", then when you enter
> %BB1 for the second time, your "store to %a" can be considered invalid,
> as you've
2011 Nov 10
3
[LLVMdev] Alternate instruction sequences
On Wed, 09 Nov 2011 09:27:30 -0800, Devang Patel wrote:
> On Nov 9, 2011, at 12:52 AM, cafxx wrote:
>
>> I was wondering, is there any way to express in the IR that an
>> instruction/instruction sequence/basic
>> block/region/function/module/whatever is an alternate version of
>> another?
>
> There is not a way to represent --- instruction I1 is an alternative
2017 Feb 05
3
Adding Extended-SSA to LLVM
On Sun, Feb 5, 2017 at 12:25 PM, Nuno Lopes <nunoplopes at sapo.pt> wrote:
> Hi Daniel,
>
> Many thanks for working on this!
> SSI/e-SSA is the only way I'm aware of for doing efficient sparse
> analyses, so I'm definitely in favor of adding support for it in LLVM!
>
> I read the discussion so far and did a cursory review of the patches, and
> I have just a
2010 Nov 05
0
[LLVMdev] Basic block liveouts
They cannot be found like the live in values because different values may be
live out.
For instance the psudocode may look like:
BB0:
vreg1 = rand()
if( vreg1 > .5 ) goto BB1;
else goto BB2;
BB1:
vreg 2 = rand();
EAX = copy vreg2;
Return
BB2:
vreg 3 = rand() * rand()'
EAX = copy vreg3;
Return
On Fri, Nov 5, 2010 at 7:41 AM, s Last namerc <srcsrc84 at yahoo.com>
2014 Jul 26
2
[LLVMdev] Finding previous emitted instruction
Hi All,
For various obscure reasons I'd like to detect the condition when X86 CALL
instruction immediately precedes a function epilogue in the final emitted
code, and insert a NOP between them if that happens.
My initial attempt at it looked like this:
MachineBasicBlock& MBB;
MachineBasicBlock::iterator MBBI; <-- points to where the epilogue would
be inserted
if (MBBI != MBB.begin()
2015 Feb 24
3
[LLVMdev] Jump Theading/GVN bug - moving discussion to llvm-dev
On 24 February 2015 at 02:05, Chandler Carruth <chandlerc at google.com> wrote:
> Will try to reply to the larger thread again soon, but a quick reply on a
> bit of a tangent...
>
> On Mon, Feb 23, 2015 at 8:45 PM, Hal Finkel <hfinkel at anl.gov> wrote:
>>
>> 2. Should unreachable code be allowed to contain nonsense (like
>> instructions that depend on
2016 May 11
2
[LLVMdev] Improving the quality of debug locations / DbgValueHistoryCalculator
> On May 11, 2016, at 1:12 PM, Francois Pichet <pichet2000 at gmail.com> wrote:
>
> Hello,
>
> Regarding the problem of debug range for optimized code.
> Currently a DEBUG_VALUE will be inserted after the <def>vregX
> DEBUG_VALUE are only valid until the end of the current MachineBasicBlock. That's the main problem.
> Why not simply iterate over all uses
2011 Jun 12
1
[LLVMdev] Doubt on phi nodes
Hi all,
I have a doubt on the usage of phi nodes in LLVM: if I define a value in
a bb, are phi nodes needed in the blocks that are dominated by the bb
where the value is defined?
As an example consider the following trivial example:
// BB0
A = 5;
if (condition) { // BB1
B = 2;
} else { // BB2
B = 1;
}
// BB3
is a phi node required for A in BB3?
b.r.,
Carlo Alberto Ferraris
--------------