From 08e79990a0a8c40e1ebed0b8f90f993ea792cac7 Mon Sep 17 00:00:00 2001 From: Quentin Colombet Date: Tue, 26 Apr 2016 23:14:29 +0000 Subject: [MachineBasicBlock] Take advantage of the partially dead information. Thanks to that information we wouldn't lie on a register being live whereas it is not. llvm-svn: 267622 --- llvm/lib/CodeGen/MachineBasicBlock.cpp | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'llvm/lib/CodeGen/MachineBasicBlock.cpp') diff --git a/llvm/lib/CodeGen/MachineBasicBlock.cpp b/llvm/lib/CodeGen/MachineBasicBlock.cpp index 8b3f01fe58c..58e71bbe2e2 100644 --- a/llvm/lib/CodeGen/MachineBasicBlock.cpp +++ b/llvm/lib/CodeGen/MachineBasicBlock.cpp @@ -1208,8 +1208,15 @@ MachineBasicBlock::computeRegisterLiveness(const TargetRegisterInfo *TRI, if (Info.DeadDef) return LQR_Dead; // Register is (at least partially) live after a def. - if (Info.Defined) - return LQR_Live; + if (Info.Defined) { + if (!Info.PartialDeadDef) + return LQR_Live; + // As soon as we saw a partial definition (dead or not), + // we cannot tell if the value is partial live without + // tracking the lanemasks. We are not going to do this, + // so fall back on the remaining of the analysis. + break; + } // Register is dead after a full kill or clobber and no def. if (Info.Killed || Info.Clobbered) return LQR_Dead; -- cgit v1.2.3