From 46c71906bcee9981e7a331ed35dcf9b8297c2f78 Mon Sep 17 00:00:00 2001 From: Chad Rosier Date: Mon, 6 Jul 2015 14:46:34 +0000 Subject: [PATCH] Fix a bug in the A57FPLoadBalancing register tracking/scavenger. The code in AArch64A57FPLoadBalancing::scavengeRegister() to handle dead defs was not correctly handling aliased registers. E.g. if the dead def was of D2, then S2 was not being marked as unavailable, so it could potentially be used across a live-range in which it would be clobbered. Patch by Geoff Berry ! Phabricator: http://reviews.llvm.org/D10900 llvm-svn: 241449 --- lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp b/lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp index bffd9e6e8c7..9d6dbd641a1 100644 --- a/lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp +++ b/lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp @@ -510,9 +510,17 @@ int AArch64A57FPLoadBalancing::scavengeRegister(Chain *G, Color C, if (J.isRegMask()) AvailableRegs.clearBitsNotInMask(J.getRegMask()); - if (J.isReg() && J.isDef() && AvailableRegs[J.getReg()]) { - assert(J.isDead() && "Non-dead def should have been removed by now!"); - AvailableRegs.reset(J.getReg()); + if (J.isReg() && J.isDef()) { + MCRegAliasIterator AI(J.getReg(), TRI, /*IncludeSelf=*/true); + if (J.isDead()) + for (; AI.isValid(); ++AI) + AvailableRegs.reset(*AI); +#ifndef NDEBUG + else + for (; AI.isValid(); ++AI) + assert(!AvailableRegs[*AI] && + "Non-dead def should have been removed by now!"); +#endif } } }