diff options
| -rw-r--r-- | lib/Target/X86/X86RegisterInfo.cpp | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/lib/Target/X86/X86RegisterInfo.cpp b/lib/Target/X86/X86RegisterInfo.cpp index 23242e3edf..c1ac9f3431 100644 --- a/lib/Target/X86/X86RegisterInfo.cpp +++ b/lib/Target/X86/X86RegisterInfo.cpp @@ -246,6 +246,17 @@ X86RegisterInfo::getMatchingSuperRegClass(const TargetRegisterClass *A, const TargetRegisterClass* X86RegisterInfo::getLargestLegalSuperClass(const TargetRegisterClass *RC) const{ + // Don't allow super-classes of GR8_NOREX. This class is only used after + // extrating sub_8bit_hi sub-registers. The H sub-registers cannot be copied + // to the full GR8 register class in 64-bit mode, so we cannot allow the + // reigster class inflation. + // + // The GR8_NOREX class is always used in a way that won't be constrained to a + // sub-class, so sub-classes like GR8_ABCD_L are allowed to expand to the + // full GR8 class. + if (RC == X86::GR8_NOREXRegisterClass) + return RC; + const TargetRegisterClass *Super = RC; TargetRegisterClass::sc_iterator I = RC->getSuperClasses(); do { |