diff options
| -rw-r--r-- | lib/CodeGen/LiveRangeEdit.cpp | 7 | ||||
| -rw-r--r-- | test/CodeGen/X86/pr14098.ll | 23 |
2 files changed, 30 insertions, 0 deletions
diff --git a/lib/CodeGen/LiveRangeEdit.cpp b/lib/CodeGen/LiveRangeEdit.cpp index 0dfb084f1e..f8fbc7ddf0 100644 --- a/lib/CodeGen/LiveRangeEdit.cpp +++ b/lib/CodeGen/LiveRangeEdit.cpp @@ -96,6 +96,13 @@ bool LiveRangeEdit::allUsesAvailableAt(const MachineInstr *OrigMI, const VNInfo *OVNI = li.getVNInfoAt(OrigIdx); if (!OVNI) continue; + + // Don't allow rematerialization immediately after the original def. + // It would be incorrect if OrigMI redefines the register. + // See PR14098. + if (SlotIndex::isSameInstr(OrigIdx, UseIdx)) + return false; + if (OVNI != li.getVNInfoAt(UseIdx)) return false; } diff --git a/test/CodeGen/X86/pr14098.ll b/test/CodeGen/X86/pr14098.ll new file mode 100644 index 0000000000..6ce2449ab6 --- /dev/null +++ b/test/CodeGen/X86/pr14098.ll @@ -0,0 +1,23 @@ +; RUN: llc -mtriple i386-unknown-linux-gnu -relocation-model=pic -verify-machineinstrs < %s +; We used to crash on this. + +declare void @foo() +declare void @foo3(i1 %x) +define void @bar(i1 %a1, i16 %a2) nounwind align 2 { +bb0: + %a3 = trunc i16 %a2 to i8 + %a4 = lshr i16 %a2, 8 + %a5 = trunc i16 %a4 to i8 + br i1 %a1, label %bb1, label %bb2 +bb1: + br label %bb2 +bb2: + %a6 = phi i8 [ 3, %bb0 ], [ %a5, %bb1 ] + %a7 = phi i8 [ 9, %bb0 ], [ %a3, %bb1 ] + %a8 = icmp eq i8 %a6, 1 + call void @foo() + %a9 = icmp eq i8 %a7, 0 + call void @foo3(i1 %a9) + call void @foo3(i1 %a8) + ret void +} |