[LLVMdev] problem with loopinfo

[Wei Jiang]

I will. I am working on another part currently, so if somebody have 
encountered the same problem before or know how to solve it, please let me 
know. Thanks.
-Wei
----- Original Message ----- 
From: "Chris Lattner" <sabre at nondot.org>
To: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu>
Sent: Thursday, June 15, 2006 4:03 PM
Subject: Re: [LLVMdev] problem with loopinfo


> On Thu, 15 Jun 2006, Wei Jiang wrote:
>> I did run the indvars pass, but it seemed that it didn't work.
>
> Then you'll have to trace through and find out why it's failing...
>
> -Chris
>
>> ----- Original Message ----- From: "Chris Lattner" <sabre at nondot.org>
>> To: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu>
>> Sent: Thursday, June 15, 2006 3:35 PM
>> Subject: Re: [LLVMdev] problem with loopinfo
>>
>>
>>> On Thu, 15 Jun 2006, Wei Jiang wrote:
>>>> hi,
>>>>    The loopinfo pass failed to recognize the Tripcount of a simple 
>>>> program constructed by me, can you help me to figure out why this 
>>>> happened? Thanks.
>>>>    The C program and corresponding .ll files are shown below. I used 
>>>> llvm1.7 to develop my own pass, and want to use the loop information.
>>>
>>> What passes are you running before your pass?  trip count information is 
>>> generally only available after the "indvars" pass runs.
>>>
>>> -Chris
>>>
>>>> Test.c:
>>>> #include "stdio.h"
>>>> #define N 40
>>>> void func1() {
>>>>  int a[N];
>>>>  int i,j;
>>>>  for (i=0; i<N; i++) {
>>>>      if (i==0)
>>>>        a[i] = i*N;
>>>>      else
>>>>        a[i] = i*i;
>>>>  }
>>>> }
>>>>
>>>> Test.ll:
>>>> void %func1() {
>>>> entry:
>>>>        %a = alloca [40 x int]          ; <[40 x int]*> [#uses=1]
>>>>        br label %no_exit
>>>>
>>>> no_exit:                ; preds = %else, %then, %entry
>>>>        %i.0.0 = phi int [ 0, %entry ], [ %inc9, %then ], [ %inc, 
>>>> %else ] ; <int> [#uses=7]
>>>>        %tmp.4 = seteq int %i.0.0, 0            ; <bool> [#uses=1]
>>>>        %tmp.7 = getelementptr [40 x int]* %a, int 0, int %i.0.0 ; 
>>>> <int*> [#uses=2]
>>>>        br bool %tmp.4, label %then, label %else
>>>>
>>>> then:           ; preds = %no_exit
>>>>        %tmp.9 = mul int %i.0.0, 40             ; <int> [#uses=1]
>>>>        store int %tmp.9, int* %tmp.7
>>>>        %inc9 = add int %i.0.0, 1               ; <int> [#uses=2]
>>>>        %tmp.112 = setlt int %inc9, 40          ; <bool> [#uses=1]
>>>>        br bool %tmp.112, label %no_exit, label %return
>>>>
>>>> else:           ; preds = %no_exit
>>>>        %tmp.14 = mul int %i.0.0, %i.0.0                ; <int> 
>>>> [#uses=1]
>>>>        store int %tmp.14, int* %tmp.7
>>>>        %inc = add int %i.0.0, 1                ; <int> [#uses=2]
>>>>        %tmp.1 = setlt int %inc, 40             ; <bool> [#uses=1]
>>>>        br bool %tmp.1, label %no_exit, label %return
>>>>
>>>> return:         ; preds = %else, %then
>>>>        ret void
>>>> }
>>>>
>>>
>>> -Chris
>>>
>>> -- 
>>> http://nondot.org/sabre/
>>> http://llvm.org/
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
>>> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev
>>>
>>
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>
> -Chris
>
> -- 
> http://nondot.org/sabre/
> http://llvm.org/
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