[WebAssembly] Don't use range-based loop for a list that's being modified
The first instruction in a block is what the rend() iterator points to, so
if it moves, we need to re-evaluate rend() so that we continue to iterate
through the rest of the instructions.
llvm-svn: 256953
diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
index 89ef5cd..537c147 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
@@ -147,8 +147,10 @@
// block boundaries, and the blocks aren't ordered so the block visitation
// order isn't significant, but we may want to change this in the future.
for (MachineBasicBlock &MBB : MF) {
- for (MachineInstr &MI : reverse(MBB)) {
- MachineInstr *Insert = &MI;
+ // Don't use a range-based for loop, because we modify the list as we're
+ // iterating over it and the end iterator may change.
+ for (auto MII = MBB.rbegin(); MII != MBB.rend(); ++MII) {
+ MachineInstr *Insert = &*MII;
// Don't nest anything inside a phi.
if (Insert->getOpcode() == TargetOpcode::PHI)
break;
@@ -221,7 +223,7 @@
Insert = Def;
}
if (AnyStackified)
- ImposeStackOrdering(&MI);
+ ImposeStackOrdering(&*MII);
}
}