From: Chad Rosier <mcrosier@codeaurora.org>
Date: Mon, 24 Nov 2014 18:57:58 +0000 (+0000)
Subject: [AArch64] Fix clobber computation in A57LoadBalancing pass.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=6b3c567613204e01dc74452a4d37f7706548ddee;p=oota-llvm.git

[AArch64] Fix clobber computation in A57LoadBalancing pass.

Extremely difficult to reproduce, so no test case included.
PR21637

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222677 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp b/lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp
index 2503764a852..d4c742bb449 100644
--- a/lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp
+++ b/lib/Target/AArch64/AArch64A57FPLoadBalancing.cpp
@@ -481,10 +481,16 @@ int AArch64A57FPLoadBalancing::scavengeRegister(Chain *G, Color C,
     RS.forward(I);
     AvailableRegs &= RS.getRegsAvailable(TRI->getRegClass(RegClassID));
 
-    // Remove any registers clobbered by a regmask.
+    // Remove any registers clobbered by a regmask or any def register that is
+    // immediately dead.
     for (auto J : I->operands()) {
       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());
+      }
     }
   }