diff options
| author |   mortimer <mortimer@openbsd.org> | 2018-06-22 12:01:07 +0000 |
|---|---|---|
| committer | mortimer <mortimer@openbsd.org> | 2018-06-22 12:01:07 +0000 |
| commit | aac92f18378ed3e3a0cf30f3c850ff4efe475631 (patch) | |
| tree | f8df4be0f0239d4f66322aa12cd754829a7572a8 | |
| parent | vmm(4): Be more careful when tearing down VMs, to avoid a possible race (diff) | |
| download | wireguard-openbsd-aac92f18378ed3e3a0cf30f3c850ff4efe475631.tar.xz wireguard-openbsd-aac92f18378ed3e3a0cf30f3c850ff4efe475631.zip | |
Emit trap alignment between basic blocks that are unrechable via
fallthrough. Avoids unnecessary jmp instructions in the middle
of functions and makes disassembly nicer to read.
ok guenther@ mlarkin@ deraadt@
| -rw-r--r-- | gnu/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/gnu/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/gnu/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp index cac872cada4..21bd72789cd 100644 --- a/gnu/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp +++ b/gnu/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp @@ -2684,11 +2684,15 @@ void AsmPrinter::EmitBasicBlockStart(const MachineBasicBlock &MBB) const { } } - // Emit an alignment directive for this block, if needed. - if (unsigned Align = MBB.getAlignment()) - EmitAlignment(Align); MCCodePaddingContext Context; setupCodePaddingContext(MBB, Context); + // Emit an alignment directive for this block, if needed. + if (unsigned Align = MBB.getAlignment()) { + if (Context.IsBasicBlockReachableViaFallthrough) + EmitAlignment(Align); + else + EmitTrapAlignment(Align); + } OutStreamer->EmitCodePaddingBasicBlockStart(Context); // If the block has its address taken, emit any labels that were used to |