diff options
| -rw-r--r-- | lib/Target/X86/X86InstrInfo.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/lib/Target/X86/X86InstrInfo.cpp b/lib/Target/X86/X86InstrInfo.cpp index a1bacbf0e6..7b39fb311c 100644 --- a/lib/Target/X86/X86InstrInfo.cpp +++ b/lib/Target/X86/X86InstrInfo.cpp @@ -724,6 +724,10 @@ X86InstrInfo::isCoalescableExtInstr(const MachineInstr &MI, case X86::MOVZX32rr8: case X86::MOVSX64rr8: case X86::MOVZX64rr8: + if (!TM.getSubtarget<X86Subtarget>().is64Bit()) + // It's not always legal to reference the low 8-bit of the larger + // register in 32-bit mode. + return false; case X86::MOVSX32rr16: case X86::MOVZX32rr16: case X86::MOVSX64rr16: |