Make block placement deterministic
We fail to produce bit-to-bit matching stage2 and stage3 compiler in PGO
bootstrap build. The reason is because LoopBlockSet is of SmallPtrSet type
whose iterating order depends on the pointer value.
This patch fixes this issue by changing to use SmallSetVector.
Differential Revision: http://reviews.llvm.org/D26634
llvm-svn: 287148
diff --git a/llvm/lib/CodeGen/MachineBlockPlacement.cpp b/llvm/lib/CodeGen/MachineBlockPlacement.cpp
index 2f43d2c..32c0bcf 100644
--- a/llvm/lib/CodeGen/MachineBlockPlacement.cpp
+++ b/llvm/lib/CodeGen/MachineBlockPlacement.cpp
@@ -264,7 +264,7 @@
namespace {
class MachineBlockPlacement : public MachineFunctionPass {
/// \brief A typedef for a block filter set.
- typedef SmallPtrSet<MachineBasicBlock *, 16> BlockFilterSet;
+ typedef SmallSetVector<MachineBasicBlock *, 16> BlockFilterSet;
/// \brief work lists of blocks that are ready to be laid out
SmallVector<MachineBasicBlock *, 16> BlockWorkList;
@@ -1512,7 +1512,7 @@
}
for (MachineBasicBlock *ChainBB : LoopChain) {
dbgs() << " ... " << getBlockName(ChainBB) << "\n";
- if (!LoopBlockSet.erase(ChainBB)) {
+ if (!LoopBlockSet.remove(ChainBB)) {
// We don't mark the loop as bad here because there are real situations
// where this can occur. For example, with an unanalyzable fallthrough
// from a loop block to a non-loop block or vice versa.
@@ -1928,7 +1928,7 @@
// Handle the filter set
if (BlockFilter) {
- BlockFilter->erase(RemBB);
+ BlockFilter->remove(RemBB);
}
// Remove the block from loop info.