[llvm-commits] [llvm] r64369 - in /llvm/trunk: lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp test/CodeGen/ARM/2008-11-19-ScavengerAssert.ll test/CodeGen/X86/2008-08-05-SpillerBug.ll

[Evan Cheng]

Author: evancheng
Date: Thu Feb 12 02:59:45 2009
New Revision: 64369

URL: http://llvm.org/viewvc/llvm-project?rev=64369&view=rev
Log:
Replace one of burr scheduling heuristic with something more sensible. Now calcMaxScratches simply compute the number of true data dependencies. This actually improve a couple of tests in dejagnu suite as many tests in llvm nightly test suite.

Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
    llvm/trunk/test/CodeGen/ARM/2008-11-19-ScavengerAssert.ll
    llvm/trunk/test/CodeGen/X86/2008-08-05-SpillerBug.ll

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp?rev=64369&r1=64368&r2=64369&view=diff

==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp Thu Feb 12 02:59:45 2009
@@ -916,7 +916,7 @@
     if (PredSethiUllman > SethiUllmanNumber) {
       SethiUllmanNumber = PredSethiUllman;
       Extra = 0;
-    } else if (PredSethiUllman == SethiUllmanNumber && !I->isCtrl())
+    } else if (PredSethiUllman == SethiUllmanNumber)
       ++Extra;
   }
 
@@ -1070,24 +1070,13 @@
 }
 
 /// calcMaxScratches - Returns an cost estimate of the worse case requirement
-/// for scratch registers. Live-in operands and live-out results don't count
-/// since they are "fixed".
+/// for scratch registers, i.e. number of data dependencies.
 static unsigned calcMaxScratches(const SUnit *SU) {
   unsigned Scratches = 0;
   for (SUnit::const_pred_iterator I = SU->Preds.begin(), E = SU->Preds.end();
-       I != E; ++I) {
+       I != E; ++I)
     if (I->isCtrl()) continue;  // ignore chain preds
-    if (!I->getSUnit()->getNode() ||
-        I->getSUnit()->getNode()->getOpcode() != ISD::CopyFromReg)
       Scratches++;
-  }
-  for (SUnit::const_succ_iterator I = SU->Succs.begin(), E = SU->Succs.end();
-       I != E; ++I) {
-    if (I->isCtrl()) continue;  // ignore chain succs
-    if (!I->getSUnit()->getNode() ||
-        I->getSUnit()->getNode()->getOpcode() != ISD::CopyToReg)
-      Scratches += 10;
-  }
   return Scratches;
 }
 
@@ -1120,10 +1109,7 @@
   if (LDist != RDist)
     return LDist < RDist;
 
-  // Intuitively, it's good to push down instructions whose results are
-  // liveout so their long live ranges won't conflict with other values
-  // which are needed inside the BB. Further prioritize liveout instructions
-  // by the number of operands which are calculated within the BB.
+  // How many registers becomes live when the node is scheduled.
   unsigned LScratch = calcMaxScratches(left);
   unsigned RScratch = calcMaxScratches(right);
   if (LScratch != RScratch)

Modified: llvm/trunk/test/CodeGen/ARM/2008-11-19-ScavengerAssert.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/ARM/2008-11-19-ScavengerAssert.ll?rev=64369&r1=64368&r2=64369&view=diff

==============================================================================
--- llvm/trunk/test/CodeGen/ARM/2008-11-19-ScavengerAssert.ll (original)
+++ llvm/trunk/test/CodeGen/ARM/2008-11-19-ScavengerAssert.ll Thu Feb 12 02:59:45 2009
@@ -1,4 +1,5 @@
 ; RUN: llvm-as < %s | llc -mtriple=arm-apple-darwin9
+; RUN: llvm-as < %s | llc -mtriple=arm-apple-darwin9 -stats |& grep asm-printer | grep 186
 
 	%"struct.Adv5::Ekin<3>" = type <{ i8 }>
 	%"struct.Adv5::X::Energyflux<3>" = type { double }

Modified: llvm/trunk/test/CodeGen/X86/2008-08-05-SpillerBug.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2008-08-05-SpillerBug.ll?rev=64369&r1=64368&r2=64369&view=diff

==============================================================================
--- llvm/trunk/test/CodeGen/X86/2008-08-05-SpillerBug.ll (original)
+++ llvm/trunk/test/CodeGen/X86/2008-08-05-SpillerBug.ll Thu Feb 12 02:59:45 2009
@@ -1,4 +1,4 @@
-; RUN: llvm-as < %s | llc -mtriple=i386-apple-darwin -disable-fp-elim -stats -info-output-file - | grep {Number of dead stores elided} | count 1
+; RUN: llvm-as < %s | llc -mtriple=i386-apple-darwin -disable-fp-elim -stats |& grep asm-printer | grep 57
 ; PR2568
 
 @g_3 = external global i16		; <i16*> [#uses=1]