[AArch64] Instructions missing MayRaiseFPException flag

There are many instructions in the generated AArch64GenInstrInfo.inc which may raise a floating-point exception, but do not have the MayRaiseFPException flag. For example, consider FADDSrr (FADD single-precision register-to-register):

sed ‘/.* // Inst #[0-9]+ = FADDSrr/!d’ AArch64GenInstrInfo.inc

{ 1595, 3, 1, 4, 441, 0, 0x0ULL, nullptr, nullptr, OperandInfo212 }, // Inst #1595 = FADDSrr

The ISA reference clearly states

This instruction can generate a floating-point exception.


  1. Why doesn’t this instruction have the MayRaiseFPException flag?

  2. I would like to add the MayRaiseFPException flag to AArch64 instructions which may raise floating-point exceptions. Are there any objections?