From: Matthias Braun <matze@braunis.de>
Date: Mon, 5 Dec 2016 08:15:57 +0000 (+0000)
Subject: TableGen/AsmMatcherEmitter: Trust that stable_sort works
X-Git-Tag: llvmorg-4.0.0-rc1~3009
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=ec0b0b548e1cfbe9ea4e9d3fc1c0f68e753818a0;p=platform%2Fupstream%2Fllvm.git

TableGen/AsmMatcherEmitter: Trust that stable_sort works

A debug build of AsmMatcherEmitter would use a quadratic algorithm to
check whether std::stable_sort() actually sorted. Let's hope the authors
of our C++ standard library did that testing for us. Removing the check
gives a 3x speedup in the X86 case.

llvm-svn: 288655
---

diff --git a/llvm/utils/TableGen/AsmMatcherEmitter.cpp b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
index a403ab7..a8a984d 100644
--- a/llvm/utils/TableGen/AsmMatcherEmitter.cpp
+++ b/llvm/utils/TableGen/AsmMatcherEmitter.cpp
@@ -2719,16 +2719,6 @@ void AsmMatcherEmitter::run(raw_ostream &OS) {
                       const std::unique_ptr<MatchableInfo> &b){
                      return *a < *b;});
 
-#ifndef NDEBUG
-  // Verify that the table is now sorted
-  for (auto I = Info.Matchables.begin(), E = Info.Matchables.end(); I != E;
-       ++I) {
-    for (auto J = I; J != E; ++J) {
-      assert(!(**J < **I));
-    }
-  }
-#endif // NDEBUG
-
   DEBUG_WITH_TYPE("instruction_info", {
       for (const auto &MI : Info.Matchables)
         MI->dump();