From 485f7b4a70eafc299b8e31cf37f3ef3c7e904592 Mon Sep 17 00:00:00 2001
From: Kostya Serebryany <kcc@google.com>
Date: Mon, 3 Dec 2012 15:00:33 +0000
Subject: [PATCH] [tsan] add CompactSizeClassMap as an alternative (more
 compact) size class map. Not used yet.

llvm-svn: 169128
---
 .../lib/sanitizer_common/sanitizer_allocator64.h   | 42 +++++++++++-----------
 .../tests/sanitizer_allocator64_test.cc            | 17 ++++++---
 2 files changed, 33 insertions(+), 26 deletions(-)

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_allocator64.h b/compiler-rt/lib/sanitizer_common/sanitizer_allocator64.h
index f045bde..e3a395b 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_allocator64.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_allocator64.h
@@ -30,7 +30,10 @@
 namespace __sanitizer {
 
 // Maps size class id to size and back.
-class DefaultSizeClassMap {
+template <uptr l0, uptr l1, uptr l2, uptr l3, uptr l4, uptr l5,
+          uptr s0, uptr s1, uptr s2, uptr s3, uptr s4,
+          uptr c0, uptr c1, uptr c2, uptr c3, uptr c4>
+class SplineSizeClassMap {
  private:
   // Here we use a spline composed of 5 polynomials of oder 1.
   // The first size class is l0, then the classes go with step s0
@@ -38,32 +41,12 @@ class DefaultSizeClassMap {
   // Steps should be powers of two for cheap division.
   // The size of the last size class should be a power of two.
   // There should be at most 256 size classes.
-  static const uptr l0 = 1 << 4;
-  static const uptr l1 = 1 << 9;
-  static const uptr l2 = 1 << 12;
-  static const uptr l3 = 1 << 15;
-  static const uptr l4 = 1 << 18;
-  static const uptr l5 = 1 << 21;
-
-  static const uptr s0 = 1 << 4;
-  static const uptr s1 = 1 << 6;
-  static const uptr s2 = 1 << 9;
-  static const uptr s3 = 1 << 12;
-  static const uptr s4 = 1 << 15;
-
   static const uptr u0 = 0  + (l1 - l0) / s0;
   static const uptr u1 = u0 + (l2 - l1) / s1;
   static const uptr u2 = u1 + (l3 - l2) / s2;
   static const uptr u3 = u2 + (l4 - l3) / s3;
   static const uptr u4 = u3 + (l5 - l4) / s4;
 
-  // Max cached in local cache blocks.
-  static const uptr c0 = 256;
-  static const uptr c1 = 64;
-  static const uptr c2 = 16;
-  static const uptr c3 = 4;
-  static const uptr c4 = 1;
-
  public:
   static const uptr kNumClasses = u4 + 1;
   static const uptr kMaxSize = l5;
@@ -99,13 +82,28 @@ class DefaultSizeClassMap {
   }
 };
 
+class DefaultSizeClassMap: public SplineSizeClassMap<
+  /* l: */1 << 4, 1 << 9,  1 << 12, 1 << 15, 1 << 18, 1 << 21,
+  /* s: */1 << 4, 1 << 6,  1 << 9,  1 << 12, 1 << 15,
+  /* c: */256,    64,      16,      4,       1> {
+ private:
+  COMPILER_CHECK(kNumClasses == 256);
+};
+
+class CompactSizeClassMap: public SplineSizeClassMap<
+  /* l: */1 << 3, 1 << 4,  1 << 7, 1 << 8, 1 << 12, 1 << 15,
+  /* s: */1 << 3, 1 << 4,  1 << 7, 1 << 8, 1 << 12,
+  /* c: */256,    64,      16,      4,       1> {
+ private:
+  COMPILER_CHECK(kNumClasses <= 32);
+};
+
 struct AllocatorListNode {
   AllocatorListNode *next;
 };
 
 typedef IntrusiveList<AllocatorListNode> AllocatorFreeList;
 
-
 // Space: a portion of address space of kSpaceSize bytes starting at
 // a fixed address (kSpaceBeg). Both constants are powers of two and
 // kSpaceBeg is kSpaceSize-aligned.
diff --git a/compiler-rt/lib/sanitizer_common/tests/sanitizer_allocator64_test.cc b/compiler-rt/lib/sanitizer_common/tests/sanitizer_allocator64_test.cc
index de7092f..de6491d 100644
--- a/compiler-rt/lib/sanitizer_common/tests/sanitizer_allocator64_test.cc
+++ b/compiler-rt/lib/sanitizer_common/tests/sanitizer_allocator64_test.cc
@@ -23,15 +23,16 @@ typedef
 typedef SizeClassAllocatorLocalCache<Allocator::kNumClasses, Allocator>
   AllocatorCache;
 
-TEST(SanitizerCommon, DefaultSizeClassMap) {
+template <class SizeClassMap>
+void TestSizeClassMap() {
+  typedef SizeClassMap SCMap;
 #if 0
   for (uptr i = 0; i < SCMap::kNumClasses; i++) {
-    printf("c%ld => %ld cached=%ld(%ld)\n",
-        i, SCMap::Size(i), SCMap::MaxCached(i) * SCMap::Size(i),
+    printf("c%ld => %ld (%lx) cached=%ld(%ld)\n",
+        i, SCMap::Size(i), SCMap::Size(i), SCMap::MaxCached(i) * SCMap::Size(i),
         SCMap::MaxCached(i));
   }
 #endif
-
   for (uptr c = 0; c < SCMap::kNumClasses; c++) {
     uptr s = SCMap::Size(c);
     CHECK_EQ(SCMap::ClassID(s), c);
@@ -52,6 +53,14 @@ TEST(SanitizerCommon, DefaultSizeClassMap) {
   }
 }
 
+TEST(SanitizerCommon, DefaultSizeClassMap) {
+  TestSizeClassMap<DefaultSizeClassMap>();
+}
+
+TEST(SanitizerCommon, CompactSizeClassMap) {
+  TestSizeClassMap<CompactSizeClassMap>();
+}
+
 TEST(SanitizerCommon, SizeClassAllocator64) {
   Allocator a;
   a.Init();
-- 
2.7.4