Optimize 96-bit division a little bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@136222 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/BlockFrequency.cpp b/lib/Support/BlockFrequency.cpp
index 0bc7840..a63bf83 100644
--- a/lib/Support/BlockFrequency.cpp
+++ b/lib/Support/BlockFrequency.cpp
@@ -46,8 +46,9 @@
uint64_t div96bit(uint64_t W[2], uint32_t D) {
uint64_t y = W[0];
uint64_t x = W[1];
+ int i;
- for (int i = 1; i <= 64; ++i) {
+ for (i = 1; i <= 64 && x; ++i) {
uint32_t t = (int)x >> 31;
x = (x << 1) | (y >> 63);
y = y << 1;
@@ -57,7 +58,7 @@
}
}
- return y;
+ return y << (64 - i + 1);
}
}