[fpc-devel] x86_64 Optimizer Overhaul

[J. Gareth Moreton]

 That's interesting. Thanks for that. Time to get fixing.

 In the meantime I'm also fixing up the buggy optimisation that caused the
original crash on Linux... nothing against the contributor, but it looks
like some badly-copied code from the MovXX routine... it even still
mentions "movsx" in the comments!

 Hopefully this effort on the overhaul won't all be for naught.

 Gareth aka. Kit

 On Sun 02/12/18 23:21 , "Marģers ." margers.roked at inbox.lv sent:
 I run it no linux. Problem code part.

 type PLongData = ^TLongData;
       TLongData = array [0..100] of longint;

 function binarySearchLong ( sortedArray:PLongData; nLen,
toFind:longint):longint;
 var low, high, mid, l, h, m : longint;
 begin
     { Returns index of toFind in sortedArray, or -1 if not found}
     low := 0;
     high := nLen - 1;

     l := sortedArray^[low];
     h := sortedArray^[high];

     while ((l = toFind)) do
     begin
          mid := (low + high) shr 1;   { var "low" in register
r8d }
          m := sortedArray^[mid];

          if (m < toFind) then
          begin
               low := mid + 1;
               l := sortedArray^[low];

         { asm code generated
 -- with trunk
         lea     r8d,
[r11d+1H]                          
     mov  esi, r8d
 --end trunk
 -- with overhaul   it never set r8d to new value, but should
         lea     esi,
[r11d+1H]                          
 -- end  overhaul

         mov     r10d, dword
[rdi+rsi*4]                 
         jmp    
?_00144                                 

         }
          end else
          if (m > toFind) then
          begin
               high := mid - 1;
               h := sortedArray^[high];
          end else
          begin
             binarySearchLong:=mid;
             exit;
          end;
          
     end;

     if (sortedArray^[low] = toFind) then
     begin
          binarySearchLong:=low;
     end else
         binarySearchLong := -1; { Not found}
 end;

         ----- Reply to message -----
 Subject: Re: [fpc-devel] x86_64 Optimizer Overhaul
 Date: 2018. gada 2. decembris 23:32:36
 From:  J. Gareth Moreton 
 To:  FPC developers' list  Thanks for the feedback.  Do you have a
reproducible case, and does it fail on Linux or Windows?  I'll have a look
for the infinite loops in the meantime.   Gareth aka. Kit          
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