6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-09-24 23:28:41 +00:00
Code Issues Projects Releases Wiki Activity

Add a division operator to BlockFrequency.

Browse Source 
Allow a BlockFrequency to be divided by a non-zero BranchProbability
with saturating arithmetic. This will be used to compute the frequency
of a loop header given the probability of leaving the loop.

Our long division algorithm already saturates on overflow, so that was a
freebie.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185184 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen
2013-06-28 18:23:42 +00:00
parent f52578c08c
commit d7648ff20f
3 changed files with 60 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

18
unittests/Support/BlockFrequencyTest.cpp
View File

@@ -52,6 +52,24 @@ TEST(BlockFrequencyTest, MaxToMax) {
EXPECT_EQ(Freq.getFrequency(), UINT64_MAX);
}
TEST(BlockFrequency, Divide) {
BlockFrequency Freq(0x3333333333333333ULL);
Freq /= BranchProbability(1, 2);
EXPECT_EQ(Freq.getFrequency(), 0x6666666666666666ULL);
}
TEST(BlockFrequencyTest, Saturate) {
BlockFrequency Freq(0x3333333333333333ULL);
Freq /= BranchProbability(100, 300);
EXPECT_EQ(Freq.getFrequency(), 0x9999999999999999ULL);
Freq /= BranchProbability(1, 2);
EXPECT_EQ(Freq.getFrequency(), UINT64_MAX);
Freq = 0x1000000000000000ULL;
Freq /= BranchProbability(10000, 160000);
EXPECT_EQ(Freq.getFrequency(), UINT64_MAX);
}
TEST(BlockFrequencyTest, ProbabilityCompare) {
BranchProbability A(4, 5);
BranchProbability B(4U << 29, 5U << 29);