From 11d5ffa108983d5d9742f0aad23f80c691f285ee Mon Sep 17 00:00:00 2001
From: Andrea Pellegrini <andrea.pellegrini@gmail.com>
Date: Tue, 22 Jan 2013 00:13:28 -0600
Subject: o3 cpu: fix zero reg problem There was an issue w/ the rename logic,
which would assign a previous physical register to the ZeroReg architectural
register in x86. This issue was giving problems for instructions squashed in
threads w/ ID different from 0, sometimes allowing non-mispredicted
instructions to obtain a value different from zero when reading the zeroReg.
---
src/cpu/o3/rename_map.cc | 1 +
1 file changed, 1 insertion(+)
(limited to 'src/cpu')
diff --git a/src/cpu/o3/rename_map.cc b/src/cpu/o3/rename_map.cc
index 8508071b4..57caa76be 100644
--- a/src/cpu/o3/rename_map.cc
+++ b/src/cpu/o3/rename_map.cc
@@ -158,6 +158,7 @@ SimpleRenameMap::rename(RegIndex arch_reg)
} else {
// Otherwise return the zero register so nothing bad happens.
renamed_reg = intZeroReg;
+ prev_reg = intZeroReg;
}
} else if (arch_reg < numLogicalRegs) {
// Record the current physical register that is renamed to the
--
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