[llvm] r206072 - [RegAllocGreedy][Last Chance Recoloring] Addition of

Quentin Colombet qcolombet at apple.com
Fri Apr 11 14:53:49 PDT 2014


On Apr 11, 2014, at 2:49 PM, Hal Finkel <hfinkel at anl.gov> wrote:

> ----- Original Message -----
>> From: "Quentin Colombet" <qcolombet at apple.com>
>> To: llvm-commits at cs.uiuc.edu
>> Sent: Friday, April 11, 2014 4:39:45 PM
>> Subject: [llvm] r206072 - [RegAllocGreedy][Last Chance Recoloring] Addition of
>> 
>> Author: qcolombet
>> Date: Fri Apr 11 16:39:44 2014
>> New Revision: 206072
>> 
>> URL: http://llvm.org/viewvc/llvm-project?rev=206072&view=rev
>> Log:
>> [RegAllocGreedy][Last Chance Recoloring] Addition of
>> -fexhaustive-register-search option to allow an exhaustive search
>> during last
>> chance recoloring.
>> 
>> This is related to PR18747
>> 
>> Patch by MAYUR PANDEY <mayur.p at samsung.com>.
>> 
>> Modified:
>>    llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp
>>    llvm/trunk/test/CodeGen/X86/ragreedy-last-chance-recoloring.ll
>> 
>> Modified: llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp?rev=206072&r1=206071&r2=206072&view=diff
>> ==============================================================================
>> --- llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp (original)
>> +++ llvm/trunk/lib/CodeGen/RegAllocGreedy.cpp Fri Apr 11 16:39:44
>> 2014
>> @@ -73,6 +73,11 @@ static cl::opt<unsigned> LastChanceRecol
>>              " interference at a time"),
>>     cl::init(8));
>> 
>> +static cl::opt<bool>
>> +ExhaustiveSearch("fexhaustive-register-search", cl::NotHidden,
> 
> We don't normally name these things with a 'f' in front inside LLVM proper. That's a Clang thing ;)
> 
Good point!
I’ll remove it.

-Quentin

> -Hal
> 
>> +                 cl::desc("Exhaustive Search for registers bypassing
>> the depth "
>> +                          "and interference cutoffs of last chance
>> recoloring"));
>> +
>> // FIXME: Find a good default for this flag and remove the flag.
>> static cl::opt<unsigned>
>> CSRFirstTimeCost("regalloc-csr-first-time-cost",
>> @@ -1932,7 +1937,7 @@ RAGreedy::mayRecolorAllInterferences(uns
>>     // If there is LastChanceRecoloringMaxInterference or more
>>     interferences,
>>     // chances are one would not be recolorable.
>>     if
>>     (Q.collectInterferingVRegs(LastChanceRecoloringMaxInterference)
>>> =
>> -        LastChanceRecoloringMaxInterference) {
>> +        LastChanceRecoloringMaxInterference && !ExhaustiveSearch) {
>>       DEBUG(dbgs() << "Early abort: too many interferences.\n");
>>       CutOffInfo |= CO_Interf;
>>       return false;
>> @@ -2005,7 +2010,7 @@ unsigned RAGreedy::tryLastChanceRecolori
>>   // We may want to reconsider that if we end up with a too large
>>   search space
>>   // for target with hundreds of registers.
>>   // Indeed, in that case we may want to cut the search space
>>   earlier.
>> -  if (Depth >= LastChanceRecoloringMaxDepth) {
>> +  if (Depth >= LastChanceRecoloringMaxDepth && !ExhaustiveSearch) {
>>     DEBUG(dbgs() << "Abort because max depth has been reached.\n");
>>     CutOffInfo |= CO_Depth;
>>     return ~0u;
>> @@ -2139,14 +2144,17 @@ unsigned RAGreedy::selectOrSplit(LiveInt
>>   if (Reg == ~0U && (CutOffInfo != CO_None)) {
>>     uint8_t CutOffEncountered = CutOffInfo & (CO_Depth | CO_Interf);
>>     if (CutOffEncountered == CO_Depth)
>> -      Ctx.emitError(
>> -          "register allocation failed: maximum depth for recoloring
>> reached");
>> +      Ctx.emitError("register allocation failed: maximum depth for
>> recoloring "
>> +                    "reached. Use -fexhaustive-register-search to
>> skip "
>> +                    "cutoffs");
>>     else if (CutOffEncountered == CO_Interf)
>>       Ctx.emitError("register allocation failed: maximum
>>       interference for "
>> -                    "recoloring reached");
>> +                    "recoloring reached. Use
>> -fexhaustive-register-search "
>> +                    "to skip cutoffs");
>>     else if (CutOffEncountered == (CO_Depth | CO_Interf))
>>       Ctx.emitError("register allocation failed: maximum
>>       interference and "
>> -                    "depth for recoloring reached");
>> +                    "depth for recoloring reached. Use "
>> +                    "-fexhaustive-register-search to skip cutoffs");
>>   }
>>   return Reg;
>> }
>> 
>> Modified:
>> llvm/trunk/test/CodeGen/X86/ragreedy-last-chance-recoloring.ll
>> URL:
>> http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/ragreedy-last-chance-recoloring.ll?rev=206072&r1=206071&r2=206072&view=diff
>> ==============================================================================
>> --- llvm/trunk/test/CodeGen/X86/ragreedy-last-chance-recoloring.ll
>> (original)
>> +++ llvm/trunk/test/CodeGen/X86/ragreedy-last-chance-recoloring.ll
>> Fri Apr 11 16:39:44 2014
>> @@ -8,6 +8,10 @@
>> ; RUN: not llc -regalloc=greedy -relocation-model=pic
>> -lcr-max-interf=1  < %s 2>&1 | FileCheck %s
>> --check-prefix=CHECK-INTERF
>> ; Test whether failure due to cutoff for interference is reported
>> 
>> +; RUN: llc -regalloc=greedy -relocation-model=pic -lcr-max-interf=1
>> -lcr-max-depth=0 -fexhaustive-register-search < %s > %t 2>&1
>> +; RUN: FileCheck --input-file=%t %s --check-prefix=CHECK-EXHAUSTIVE
>> +; Test whether fexhaustive-register-search can bypass the depth and
>> interference cutoffs of last chance recoloring
>> +
>> target datalayout =
>> "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128-n8:16:32-S128"
>> target triple = "i386-apple-macosx"
>> 
>> @@ -20,6 +24,7 @@ target triple = "i386-apple-macosx"
>> ; CHECK-NOT: ran out of registers during register allocation
>> ; CHECK-INTERF: error: register allocation failed: maximum
>> interference for recoloring reached
>> ; CHECK-DEPTH: error: register allocation failed: maximum depth for
>> recoloring reached
>> +; CHECK-EXHAUSTIVE-NOT: error: register allocation failed: maximum
>> {{depth|interference}} for recoloring reached
>> define void @fp_dh_f870bf31fd8ffe068450366e3f05389a(i8* %arg) #0 {
>> bb:
>>   indirectbr i8* undef, [label %bb85, label %bb206]
>> 
>> 
>> _______________________________________________
>> llvm-commits mailing list
>> llvm-commits at cs.uiuc.edu
>> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>> 
> 
> -- 
> Hal Finkel
> Assistant Computational Scientist
> Leadership Computing Facility
> Argonne National Laboratory

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20140411/58f39499/attachment.html>


More information about the llvm-commits mailing list