[llvm-commits] [PATCH] MachineRegisterInfo: Don't emit the same livein copy more than once

[Tom Stellard]

On Fri, Jan 27, 2012 at 02:56:03PM -0500, Tom Stellard wrote:
> ---
> 
> Is MachineRegisterInfo::EmitLiveInCopies() only meant to be called once
> per compile?  If I call it more than once, it emits duplicate copies
> which causes the live interval analysis to fail.
> 
>  lib/CodeGen/MachineRegisterInfo.cpp |    4 +++-
>  1 files changed, 3 insertions(+), 1 deletions(-)
> 
> diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp
> index 266ebf6..fc787f2 100644
> --- a/lib/CodeGen/MachineRegisterInfo.cpp
> +++ b/lib/CodeGen/MachineRegisterInfo.cpp
> @@ -227,7 +227,9 @@ MachineRegisterInfo::EmitLiveInCopies(MachineBasicBlock *EntryMBB,
>          // complicated by the debug info code for arguments.
>          LiveIns.erase(LiveIns.begin() + i);
>          --i; --e;
> -      } else {
> +        //Make sure we don't emit the same livein copies twice, in case this
> +        //function is called more than once.
> +      } else if (def_empty(LiveIns[i].second)) {
>          // Emit a copy.
>          BuildMI(*EntryMBB, EntryMBB->begin(), DebugLoc(),
>                  TII.get(TargetOpcode::COPY), LiveIns[i].second)
> -- 
> 1.7.6.4
> 
>

Reposting this as a diff that can be applied via patch -P0 for SVN
users.

-Tom
-------------- next part --------------
diff --git lib/CodeGen/MachineRegisterInfo.cpp lib/CodeGen/MachineRegisterInfo.cpp
index 6ec55247..749db2a 100644
--- lib/CodeGen/MachineRegisterInfo.cpp
+++ lib/CodeGen/MachineRegisterInfo.cpp
@@ -229,7 +229,9 @@ MachineRegisterInfo::EmitLiveInCopies(MachineBasicBlock *EntryMBB,
         // complicated by the debug info code for arguments.
         LiveIns.erase(LiveIns.begin() + i);
         --i; --e;
-      } else {
+        //Make sure we don't emit the same livein copies twice, in case this
+        //function is called more than once.
+      } else if (def_empty(LiveIns[i].second)) {
         // Emit a copy.
         BuildMI(*EntryMBB, EntryMBB->begin(), DebugLoc(),
                 TII.get(TargetOpcode::COPY), LiveIns[i].second)