Hack around a GCC ICE that was fixed in GCC 6.2

lib/Target/X86/AsmParser/X86AsmParser.cpp: In member function ‘void {anonymous}::X86AsmParser::SwitchMode(unsigned int)’:
lib/Target/X86/AsmParser/X86AsmParser.cpp:927:76:   in constexpr expansion of ‘AllModes.llvm::FeatureBitset::FeatureBitset(std::initializer_list<unsigned int>{((const unsigned int*)(& ._157)), 3u})’
include/llvm/MC/SubtargetFeature.h:56:12:   in constexpr expansion of ‘llvm::FeatureBitset::set(I)’
lib/Target/X86/AsmParser/X86AsmParser.cpp:927:76: internal compiler error: in fold_binary_loc, at fold-const.c:9921
     FeatureBitset AllModes({X86::Mode64Bit, X86::Mode32Bit, X86::Mode16Bit});
                                                                            ^

llvm-svn: 369852

1 files changed, 9 insertions, 3 deletions

diff --git a/llvm/include/llvm/MC/SubtargetFeature.h b/llvm/include/llvm/MC/SubtargetFeature.h
index 7ce27843c2c..defbc3c6472 100644
--- a/llvm/include/llvm/MC/SubtargetFeature.h
+++ b/llvm/include/llvm/MC/SubtargetFeature.h
@@ -62,17 +62,23 @@ public:
   }
 
   constexpr FeatureBitset &set(unsigned I) {
-    Bits[I / 64] |= uint64_t(1) << (I % 64);
+    // GCC <6.2 crashes if this is written in a single statement.
+    uint64_t NewBits = Bits[I / 64] | (uint64_t(1) << (I % 64));
+    Bits[I / 64] = NewBits;
     return *this;
   }
 
   constexpr FeatureBitset &reset(unsigned I) {
-    Bits[I / 64] &= ~(uint64_t(1) << (I % 64));
+    // GCC <6.2 crashes if this is written in a single statement.
+    uint64_t NewBits = Bits[I / 64] & ~(uint64_t(1) << (I % 64));
+    Bits[I / 64] = NewBits;
     return *this;
   }
 
   constexpr FeatureBitset &flip(unsigned I) {
-    Bits[I / 64] ^= uint64_t(1) << (I % 64);
+    // GCC <6.2 crashes if this is written in a single statement.
+    uint64_t NewBits = Bits[I / 64] ^ (uint64_t(1) << (I % 64));
+    Bits[I / 64] = NewBits;
     return *this;
   }