Eliminate an assortment of undefined behavior.
Hopefully, this fixes the PPC64 buildbots.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185218 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/BlockFrequency.cpp b/lib/Support/BlockFrequency.cpp
index 6e4d6b1..8de517f 100644
--- a/lib/Support/BlockFrequency.cpp
+++ b/lib/Support/BlockFrequency.cpp
@@ -47,9 +47,13 @@
uint64_t x = W[1];
unsigned i;
+ // This is really a 64-bit division.
+ if (!x)
+ return y / D;
+
// This long division algorithm automatically saturates on overflow.
for (i = 0; i < 64 && x; ++i) {
- uint32_t t = (int)x >> 31;
+ uint32_t t = -((x >> 31) & 1); // Splat bit 31 to bits 0-31.
x = (x << 1) | (y >> 63);
y = y << 1;
if ((x | t) >= D) {