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Hi Quentin,<br>
<br>
After Simple Register Coalescing.<br>
<br>
<tt>thanks,<br>
<br>
Jonas<br>
</tt><br>
<div class="moz-cite-prefix">On 2015-04-17 18:52, Quentin Colombet
wrote:<br>
</div>
<blockquote
cite="mid:21041C84-341E-487A-BA92-23B4AB5AB3E0@apple.com"
type="cite">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
Hi Jonas,
<div class=""><br class="">
</div>
<div class="">When is the MachineVerifier complaining?</div>
<div class="">I mean after which pass?</div>
<div class=""><br class="">
</div>
<div class="">Thanks,</div>
<div class="">-Quentin</div>
<div class=""><br class="">
<div>
<blockquote type="cite" class="">
<div class="">On Apr 17, 2015, at 7:17 AM, Jonas Paulsson
<<a moz-do-not-send="true"
href="mailto:jonas.paulsson@ericsson.com" class="">jonas.paulsson@ericsson.com</a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<div bgcolor="#FFFFFF" text="#000000" class=""> Hi,<br
class="">
<br class="">
thanks for answering, but the COPY is there already from
after isel. It is a copy of a subreg, after a a call
returning 64 bits.<br class="">
<br class="">
<tt class=""> call
<ga:@safe_div_func_uint64_t_u_u></tt><tt
class=""><br class="">
</tt><tt class=""> %vreg45<def> = COPY %r0</tt><tt
class=""><br class="">
</tt><tt class=""> %vreg46<def> = COPY %r1</tt><tt
class=""><br class="">
</tt><tt class=""> %vreg3<def> = COPY
%vreg46
<<<<<<<<<<<<<<<<<<</tt><tt
class=""><br class="">
</tt><tt class=""> ST %vreg46, %vreg0</tt><tt
class=""><br class="">
</tt><tt class=""> ST %vreg46, %vreg1</tt><tt
class=""><br class="">
</tt><tt class=""> brr_uncond <BB#4></tt><tt
class=""><br class="">
</tt><br class="">
Does this ring any bell? Could there be any place that
misses something about the resulting LiveInterval due to
a phys reg copy?<br class="">
<br class="">
thanks<br class="">
<br class="">
/Jonas<br class="">
<br class="">
PS Quentin, as I said I could not reproduce this error
on any in-tree target.<br class="">
</div>
</div>
</blockquote>
<div><br class="">
</div>
<div>Ah right.</div>
<br class="">
<blockquote type="cite" class="">
<div class="">
<div bgcolor="#FFFFFF" text="#000000" class=""> <br
class="">
<br class="">
<div class="moz-cite-prefix">On 2015-04-17 01:25,
Quentin Colombet wrote:<br class="">
</div>
<blockquote
cite="mid:8FCC1A54-0FFC-4B6E-AB06-3376FDBCB0F5@apple.com"
type="cite" class=""> Hi Jonas,
<div class=""><br class="">
</div>
<div class="">Could you file a PR with your test case
please?</div>
<div class=""><br class="">
</div>
<div class="">Thanks,</div>
<div class="">-Quentin<br class="">
<div class="">
<blockquote type="cite" class="">
<div class="">On Apr 16, 2015, at 3:50 PM,
Andrew Trick <<a moz-do-not-send="true"
href="mailto:atrick@apple.com" class="">atrick@apple.com</a>>
wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<blockquote type="cite" style="font-family:
Helvetica; font-size: 12px; font-style:
normal; font-variant: normal; font-weight:
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text-indent: 0px; text-transform: none;
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-webkit-text-stroke-width: 0px;" class=""><br
class="Apple-interchange-newline">
On Apr 16, 2015, at 6:58 AM, Jonas Paulsson
<<a moz-do-not-send="true"
href="mailto:jonas.paulsson@ericsson.com"
class="">jonas.paulsson@ericsson.com</a>>
wrote:<br class="">
<br class="">
Hi,<br class="">
<br class="">
I have come across a csmith generated test
case that made the MachineVerifier spit out:<br
class="">
<br class="">
*** Bad machine code: Multiple connected
components in live interval ***<br class="">
<br class="">
Having looked at what this might mean, it
seems that
ConnectedVNInfoEqClasses::Classify() was
called on the LI in question by the
verifier, and that it returned two
equivalence classes, instead of just one,
which is demanded by the verifier. Does this
mean that there should never be<br class="">
any ValNos in a LiveInterval that are not
connected? In other words should such an LI
never exist, but rather two different LIs?<br
class="">
</blockquote>
<br style="font-family: Helvetica; font-size:
12px; font-style: normal; font-variant:
normal; font-weight: normal; letter-spacing:
normal; line-height: normal; orphans: auto;
text-align: start; text-indent: 0px;
text-transform: none; white-space: normal;
widows: auto; word-spacing: 0px;
-webkit-text-stroke-width: 0px;" class="">
<span style="font-family: Helvetica;
font-size: 12px; font-style: normal;
font-variant: normal; font-weight: normal;
letter-spacing: normal; line-height: normal;
orphans: auto; text-align: start;
text-indent: 0px; text-transform: none;
white-space: normal; widows: auto;
word-spacing: 0px;
-webkit-text-stroke-width: 0px; float: none;
display: inline !important;" class="">That’s
right. It looks like a copy was inserted,</span><br
style="font-family: Helvetica; font-size:
12px; font-style: normal; font-variant:
normal; font-weight: normal; letter-spacing:
normal; line-height: normal; orphans: auto;
text-align: start; text-indent: 0px;
text-transform: none; white-space: normal;
widows: auto; word-spacing: 0px;
-webkit-text-stroke-width: 0px;" class="">
<br style="font-family: Helvetica; font-size:
12px; font-style: normal; font-variant:
normal; font-weight: normal; letter-spacing:
normal; line-height: normal; orphans: auto;
text-align: start; text-indent: 0px;
text-transform: none; white-space: normal;
widows: auto; word-spacing: 0px;
-webkit-text-stroke-width: 0px;" class="">
<blockquote type="cite" style="font-family:
Helvetica; font-size: 12px; font-style:
normal; font-variant: normal; font-weight:
normal; letter-spacing: normal; line-height:
normal; orphans: auto; text-align: start;
text-indent: 0px; text-transform: none;
white-space: normal; widows: auto;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;" class="">%vreg3<def>
= COPY %vreg46<br class="">
</blockquote>
<br style="font-family: Helvetica; font-size:
12px; font-style: normal; font-variant:
normal; font-weight: normal; letter-spacing:
normal; line-height: normal; orphans: auto;
text-align: start; text-indent: 0px;
text-transform: none; white-space: normal;
widows: auto; word-spacing: 0px;
-webkit-text-stroke-width: 0px;" class="">
<br style="font-family: Helvetica; font-size:
12px; font-style: normal; font-variant:
normal; font-weight: normal; letter-spacing:
normal; line-height: normal; orphans: auto;
text-align: start; text-indent: 0px;
text-transform: none; white-space: normal;
widows: auto; word-spacing: 0px;
-webkit-text-stroke-width: 0px;" class="">
<span style="font-family: Helvetica;
font-size: 12px; font-style: normal;
font-variant: normal; font-weight: normal;
letter-spacing: normal; line-height: normal;
orphans: auto; text-align: start;
text-indent: 0px; text-transform: none;
white-space: normal; widows: auto;
word-spacing: 0px;
-webkit-text-stroke-width: 0px; float: none;
display: inline !important;" class="">breaking
the live interval, and a new LI was not
created. Maybe the splitter did it? You
would need to look at debug-only=regalloc.</span><br
style="font-family: Helvetica; font-size:
12px; font-style: normal; font-variant:
normal; font-weight: normal; letter-spacing:
normal; line-height: normal; orphans: auto;
text-align: start; text-indent: 0px;
text-transform: none; white-space: normal;
widows: auto; word-spacing: 0px;
-webkit-text-stroke-width: 0px;" class="">
<br style="font-family: Helvetica; font-size:
12px; font-style: normal; font-variant:
normal; font-weight: normal; letter-spacing:
normal; line-height: normal; orphans: auto;
text-align: start; text-indent: 0px;
text-transform: none; white-space: normal;
widows: auto; word-spacing: 0px;
-webkit-text-stroke-width: 0px;" class="">
<span style="font-family: Helvetica;
font-size: 12px; font-style: normal;
font-variant: normal; font-weight: normal;
letter-spacing: normal; line-height: normal;
orphans: auto; text-align: start;
text-indent: 0px; text-transform: none;
white-space: normal; widows: auto;
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display: inline !important;" class="">Andy</span><br
style="font-family: Helvetica; font-size:
12px; font-style: normal; font-variant:
normal; font-weight: normal; letter-spacing:
normal; line-height: normal; orphans: auto;
text-align: start; text-indent: 0px;
text-transform: none; white-space: normal;
widows: auto; word-spacing: 0px;
-webkit-text-stroke-width: 0px;" class="">
<br style="font-family: Helvetica; font-size:
12px; font-style: normal; font-variant:
normal; font-weight: normal; letter-spacing:
normal; line-height: normal; orphans: auto;
text-align: start; text-indent: 0px;
text-transform: none; white-space: normal;
widows: auto; word-spacing: 0px;
-webkit-text-stroke-width: 0px;" class="">
<blockquote type="cite" style="font-family:
Helvetica; font-size: 12px; font-style:
normal; font-variant: normal; font-weight:
normal; letter-spacing: normal; line-height:
normal; orphans: auto; text-align: start;
text-indent: 0px; text-transform: none;
white-space: normal; widows: auto;
word-spacing: 0px;
-webkit-text-stroke-width: 0px;" class=""><br
class="">
I have tried to run this on in-tree targets,
but unfortunately they did not reproduce the
condition.<br class="">
I will therefore try to explain:<br class="">
<br class="">
The options to llc are -optimize-regalloc
-O0. The function is meaningless - with -O3
it just returns zero.<br class="">
It contains two nested loops, with a call
inside the inner loop, which is a
CFG-diamond.<br class="">
<br class="">
The PHI-nodes look like this in the inner
loop:<br class="">
<br class="">
BB#5: // Inner loop header<br class="">
Predecessors according to CFG: BB#1 BB#4<br
class="">
vreg7<def> = PHI %vreg29,
<BB#1>, %vreg4, <BB#4><br
class="">
...<br class="">
Successors according to CFG: BB#2 BB#6<br
class="">
<br class="">
BB#2:<br class="">
Predecessors according to CFG: BB#5<br
class="">
...<br class="">
Successors according to CFG: BB#3 BB#4<br
class="">
<br class="">
BB#3:<br class="">
Predecessors according to CFG: BB#2<br
class="">
call()<br class="">
%vreg46<def> = COPY %return_reg<br
class="">
%vreg3<def> = COPY %vreg46;<br
class="">
use of %vreg 46<br class="">
<br class="">
Successors according to CFG: BB#4<br
class="">
<br class="">
BB#4:<br class="">
Predecessors according to CFG: BB#2 BB#3<br
class="">
%vreg4<def> = PHI %vreg7,
<BB#2>, %vreg3, <BB#3><br
class="">
Successors according to CFG: BB#5<br
class="">
<br class="">
The observation I made here is that %vreg7
and %vreg4 are sort of nested PHI nodes,
while there are no other users of the
registers than the PHI nodes themselves.
There is however a use of %vreg46, which
later gets coalesced with %vreg64, which
will include as well the two PHI nodes.<br
class="">
<br class="">
This is the code with the two equivalence
classes, when verifier aborts:<br class="">
<br class="">
2272B BB#1: derived from LLVM BB %bb3<br
class="">
Predecessors according to CFG:
BB#8<br class="">
2304B %vreg64<def> = mov 0<br
class="">
2448B jmp <BB#5><br class="">
Successors according to CFG: BB#5<br
class="">
<br class="">
2592B BB#3: derived from LLVM BB %bb6<br
class="">
Predecessors according to CFG:
BB#2<br class="">
2704B callr
<ga:@safe_div_func_uint64_t_u_u><br
class="">
2736B %vreg64<def> = COPY
%return_reg<br class="">
2768B use of %vreg64<br class="">
2784B use of %vreg64<br class="">
2816B jmp <BB#4><br class="">
Successors according to CFG: BB#4<br
class="">
<br class="">
*** Bad machine code: Multiple connected
components in live interval ***<br class="">
- function: func_61<br class="">
- interval: %vreg64
[2304r,2336r:0)[2736r,2784r:3) 0@2304r 1@x
2@x 3@2736r<br class="">
0: valnos 0<br class="">
1: valnos 1 2 3<br class="">
LLVM ERROR: Found 1 machine code errors.<br
class="">
<br class="">
Two small live ranges of %vreg64 (originated
from %vreg7 and %vreg4), which look ok to
me, but the verifier does not like it.<br
class="">
<br class="">
Can anyone give me any background or any
hint on what might be the problem here?<br
class="">
<br class="">
thanks,<br class="">
<br class="">
Jonas Paulsson<br class="">
<br class="">
<br class="">
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