--- a/js/src/jit/x86-shared/Assembler-x86-shared.cpp 2019-05-21 19:30:05.036892727 +0100 +++ b/js/src/jit/x86-shared/Assembler-x86-shared.cpp 2019-05-21 19:31:26.805437074 +0100 @@ -340,12 +340,14 @@ avxPresent = (xcr0EAX & xcr0SSEBit) && (xcr0EAX & xcr0AVXBit); } + if (maxSSEVersion >= SSE2) { // CMOV instruction are supposed to be supported by all CPU which have SSE2 // enabled. While this might be true, this is not guaranteed by any // documentation, nor AMD, nor Intel. static const int CMOVBit = 1 << 15; MOZ_RELEASE_ASSERT(flagsEDX & CMOVBit, "CMOVcc instruction is not recognized by this CPU."); + } static const int POPCNTBit = 1 << 23; popcntPresent = (flagsECX & POPCNTBit);