From 05ce999134d9358cb781c9d8e64af0688d1a1e94 Mon Sep 17 00:00:00 2001 From: James Molloy Date: Sun, 14 Sep 2014 18:24:26 +0000 Subject: [PATCH] [A57FPLoadBalancing] Modify r217689 - actually we do need to check defs ... Just make sure we check uses first so we see the kill first. It turns out ignoring defs gives some pretty nasty runtime failures. I'm certain this is the fix but I'm still reducing a testcase. llvm-svn: 217735 --- .../lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/llvm/lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp b/llvm/lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp index d8bafc16fe16..98e4bc3e9235 100644 --- a/llvm/lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp +++ b/llvm/lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp @@ -582,7 +582,9 @@ scanInstruction(MachineInstr *MI, unsigned Idx, if (isMul(MI)) { - for (auto &I : MI->operands()) + for (auto &I : MI->uses()) + maybeKillChain(I, Idx, ActiveChains); + for (auto &I : MI->defs()) maybeKillChain(I, Idx, ActiveChains); // Create a new chain. Multiplies don't require forwarding so can go on any @@ -644,7 +646,9 @@ scanInstruction(MachineInstr *MI, unsigned Idx, // Non-MUL or MLA instruction. Invalidate any chain in the uses or defs // lists. - for (auto &I : MI->operands()) + for (auto &I : MI->uses()) + maybeKillChain(I, Idx, ActiveChains); + for (auto &I : MI->defs()) maybeKillChain(I, Idx, ActiveChains); } @@ -657,10 +661,6 @@ maybeKillChain(MachineOperand &MO, unsigned Idx, // determine if a chain should be ended and remove from ActiveChains. MachineInstr *MI = MO.getParent(); - if (MO.isReg() && MO.isDef()) - // We don't care about defs. We see them before uses, so reject them early. - return; - if (MO.isReg()) { // If this is a KILL of a current chain, record it.