diff --git a/lib/Target/SystemZ/README.txt b/lib/Target/SystemZ/README.txt index cd367d60bab..5bfe1747464 100644 --- a/lib/Target/SystemZ/README.txt +++ b/lib/Target/SystemZ/README.txt @@ -43,11 +43,6 @@ We don't use the BRANCH ON INDEX instructions. -- -We might want to use BRANCH ON CONDITION for conditional indirect calls -and conditional returns. - --- - We don't use the TEST DATA CLASS instructions. -- @@ -166,3 +161,16 @@ If needed, we can support 16-byte atomics using LPQ, STPQ and CSDG. We might want to model all access registers and use them to spill 32-bit values. + +-- + +We might want to use 'j .+2' as a trap instruction, like gcc does. It can +also be made conditional like the return instruction, allowing us to utilize +compare-and-trap and load-and-trap instructions. + +-- + +We might want to use the 'overflow' condition of eg. AR to support +llvm.sadd.with.overflow.i32 and related instructions - the generated code +for signed overflow check is currently quite bad. This would improve +the results of using -ftrapv.