aboutsummaryrefslogtreecommitdiff
path: root/lib
diff options
context:
space:
mode:
authorJakub Staszak <jstaszak@apple.com>2011-06-23 21:45:20 +0000
committerJakub Staszak <jstaszak@apple.com>2011-06-23 21:45:20 +0000
commit44eb49c2a191108df801977c8e3dc03466c6c02a (patch)
treeb51888831a9e6a115cf5d8c57d5c4664669eb322 /lib
parenta390a1aa48d8fa5085aa51b950f00d79dbb0c646 (diff)
Introduce BlockFrequency analysis for BasicBlocks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133766 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
-rw-r--r--lib/Analysis/Analysis.cpp1
-rw-r--r--lib/Analysis/BranchProbabilityInfo.cpp24
-rw-r--r--lib/Analysis/CMakeLists.txt1
3 files changed, 26 insertions, 0 deletions
diff --git a/lib/Analysis/Analysis.cpp b/lib/Analysis/Analysis.cpp
index e57ba78332..71e0a83269 100644
--- a/lib/Analysis/Analysis.cpp
+++ b/lib/Analysis/Analysis.cpp
@@ -23,6 +23,7 @@ void llvm::initializeAnalysis(PassRegistry &Registry) {
initializeAliasSetPrinterPass(Registry);
initializeNoAAPass(Registry);
initializeBasicAliasAnalysisPass(Registry);
+ initializeBlockFrequencyPass(Registry);
initializeBranchProbabilityInfoPass(Registry);
initializeCFGViewerPass(Registry);
initializeCFGPrinterPass(Registry);
diff --git a/lib/Analysis/BranchProbabilityInfo.cpp b/lib/Analysis/BranchProbabilityInfo.cpp
index 15059c733a..263ea2c26b 100644
--- a/lib/Analysis/BranchProbabilityInfo.cpp
+++ b/lib/Analysis/BranchProbabilityInfo.cpp
@@ -279,6 +279,21 @@ uint32_t BranchProbabilityInfo::getSumForBlock(BasicBlock *BB) const {
return Sum;
}
+uint32_t BranchProbabilityInfo::getBackSumForBlock(BasicBlock *BB) const {
+ uint32_t Sum = 0;
+
+ for (pred_iterator I = pred_begin(BB), E = pred_end(BB); I != E; ++I) {
+ BasicBlock *Pred = *I;
+ uint32_t Weight = getEdgeWeight(Pred, BB);
+ uint32_t PrevSum = Sum;
+
+ Sum += Weight;
+ assert(Sum > PrevSum); (void) PrevSum;
+ }
+
+ return Sum;
+}
+
bool BranchProbabilityInfo::isEdgeHot(BasicBlock *Src, BasicBlock *Dst) const {
// Hot probability is at least 4/5 = 80%
uint32_t Weight = getEdgeWeight(Src, Dst);
@@ -345,6 +360,15 @@ getEdgeProbability(BasicBlock *Src, BasicBlock *Dst) const {
return BranchProbability(N, D);
}
+BranchProbability BranchProbabilityInfo::
+getBackEdgeProbability(BasicBlock *Src, BasicBlock *Dst) const {
+
+ uint32_t N = getEdgeWeight(Src, Dst);
+ uint32_t D = getBackSumForBlock(Dst);
+
+ return BranchProbability(N, D);
+}
+
raw_ostream &
BranchProbabilityInfo::printEdgeProbability(raw_ostream &OS, BasicBlock *Src,
BasicBlock *Dst) const {
diff --git a/lib/Analysis/CMakeLists.txt b/lib/Analysis/CMakeLists.txt
index 1a975bf4a5..ab846a26b4 100644
--- a/lib/Analysis/CMakeLists.txt
+++ b/lib/Analysis/CMakeLists.txt
@@ -6,6 +6,7 @@ add_llvm_library(LLVMAnalysis
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp
+ BlockFrequency.cpp
BranchProbabilityInfo.cpp
CFGPrinter.cpp
CaptureTracking.cpp