From e7561b8fe394cafda9303768f610632f12f34d29 Mon Sep 17 00:00:00 2001
From: Benjamin Kramer <benny.kra@googlemail.com>
Date: Sat, 20 Jun 2015 15:59:41 +0000
Subject: [PATCH] [PPC] Factor vector removal into a function and remove O(n^2)
 behavior.

No functionality change intended.

llvm-svn: 240222
---
 llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp | 42 ++++++++++++-----------------
 1 file changed, 17 insertions(+), 25 deletions(-)

diff --git a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
index e3814f7..5f9f9f2 100644
--- a/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelDAGToDAG.cpp
@@ -1301,12 +1301,9 @@ class BitPermutationSelector {
 
       // Now, remove all groups with this underlying value and rotation
       // factor.
-      for (auto I = BitGroups.begin(); I != BitGroups.end();) {
-        if (I->V == VRI.V && I->RLAmt == VRI.RLAmt)
-          I = BitGroups.erase(I);
-        else
-          ++I;
-      }
+      eraseMatchingBitGroups([VRI](const BitGroup &BG) {
+        return BG.V == VRI.V && BG.RLAmt == VRI.RLAmt;
+      });
     }
   }
 
@@ -1337,12 +1334,9 @@ class BitPermutationSelector {
       }
 
       // Now, remove all groups with this underlying value and rotation factor.
-      for (auto I = BitGroups.begin(); I != BitGroups.end();) {
-        if (I->V == VRI.V && I->RLAmt == VRI.RLAmt)
-          I = BitGroups.erase(I);
-        else
-          ++I;
-      }
+      eraseMatchingBitGroups([VRI](const BitGroup &BG) {
+        return BG.V == VRI.V && BG.RLAmt == VRI.RLAmt;
+      });
     }
 
     if (InstCnt) *InstCnt += BitGroups.size();
@@ -1544,7 +1538,7 @@ class BitPermutationSelector {
       // Repl32 true, but are trivially convertable to Repl32 false. Such a
       // group is trivially convertable if it overlaps only with the lower 32
       // bits, and the group has not been coalesced.
-      auto MatchingBG = [VRI](BitGroup &BG) {
+      auto MatchingBG = [VRI](const BitGroup &BG) {
         if (VRI.V != BG.V)
           return false;
 
@@ -1675,12 +1669,7 @@ class BitPermutationSelector {
 
       // Now, remove all groups with this underlying value and rotation
       // factor.
-      for (auto I = BitGroups.begin(); I != BitGroups.end();) {
-        if (MatchingBG(*I))
-          I = BitGroups.erase(I);
-        else
-          ++I;
-      }
+      eraseMatchingBitGroups(MatchingBG);
     }
   }
 
@@ -1740,12 +1729,10 @@ class BitPermutationSelector {
 
       // Now, remove all groups with this underlying value and rotation factor.
       if (Res)
-        for (auto I = BitGroups.begin(); I != BitGroups.end();) {
-          if (I->V == VRI.V && I->RLAmt == VRI.RLAmt && I->Repl32 == VRI.Repl32)
-            I = BitGroups.erase(I);
-          else
-            ++I;
-        }
+        eraseMatchingBitGroups([VRI](const BitGroup &BG) {
+          return BG.V == VRI.V && BG.RLAmt == VRI.RLAmt &&
+                 BG.Repl32 == VRI.Repl32;
+        });
     }
 
     // Because 64-bit rotates are more flexible than inserts, we might have a
@@ -1846,6 +1833,11 @@ class BitPermutationSelector {
     return nullptr;
   }
 
+  void eraseMatchingBitGroups(function_ref<bool(const BitGroup &)> F) {
+    BitGroups.erase(std::remove_if(BitGroups.begin(), BitGroups.end(), F),
+                    BitGroups.end());
+  }
+
   SmallVector<ValueBit, 64> Bits;
 
   bool HasZeros;
-- 
2.7.4