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Diffstat (limited to 'src/arch/x86/predecoder.cc')
| -rw-r--r-- | src/arch/x86/predecoder.cc | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/arch/x86/predecoder.cc b/src/arch/x86/predecoder.cc index 9d60089e3..620ab89ea 100644 --- a/src/arch/x86/predecoder.cc +++ b/src/arch/x86/predecoder.cc @@ -136,7 +136,10 @@ namespace X86ISA { uint8_t prefix = Prefixes[nextByte]; State nextState = PrefixState; - if(prefix) + // REX prefixes are only recognized in 64 bit mode. + if (prefix == RexPrefix && emi.mode.submode != SixtyFourBitMode) + prefix = 0; + if (prefix) consumeByte(); switch(prefix) { |