search for: d45576

...ctually be to add those nodes, so that we can make an > informed decision. I've now implemented the above to handle all the currently supported STRICT_ FP nodes in the SystemZ back-end (at least for pre-z13 machines, I'm not supporting vector instructions yet): https://reviews.llvm.org/D45576 I've tested this using a hacked clang front-end that always uses constrained intrisincs in place of most regular FP operations, and it at least still passes the LNT test-suite. I'd appreciate any comments on whether this looks like an acceptable approach. In particular, I'd like to h...

...riants (e.g. for vector types) are > supported correctly through codegen (see e.g. > https://reviews.llvm.org/D46967). > > - Allow targets to correctly reflect constrained intrinsics > semantics at the MI level and final machine code generation > (see e.g. https://reviews.llvm.org/D45576). > > - Review all optimization and codegen passes to verify they > fully respect strict FP semantics. > > Once this is done, we can improve on the solution by: > > - Supporting mixing strict and non-strict FP operations > (would lift the LTO restriction). (Note: there seems...

..., it seems not all variants (e.g. for vector types) are supported correctly through codegen (see e.g. https://reviews.llvm.org/D46967). - Allow targets to correctly reflect constrained intrinsics semantics at the MI level and final machine code generation (see e.g. https://reviews.llvm.org/D45576). - Review all optimization and codegen passes to verify they fully respect strict FP semantics. Once this is done, we can improve on the solution by: - Supporting mixing strict and non-strict FP operations (would lift the LTO restriction). (Note: there seems to be still some "invent...

...tly through codegen (see e.g. > https://reviews.llvm.org/D46967 <https://reviews.llvm.org/D46967>). > > - Allow targets to correctly reflect constrained intrinsics > semantics at the MI level and final machine code generation > (see e.g. https://reviews.llvm.org/D45576 > <https://reviews.llvm.org/D45576>). > > - Review all optimization and codegen passes to verify they > fully respect strict FP semantics. > > Once this is done, we can improve on the solution by: > > - Supporting mixing strict and non-strict FP ope...

...types) are >> supported correctly through codegen (see e.g. >> https://reviews.llvm.org/D46967). >> >> - Allow targets to correctly reflect constrained intrinsics >> semantics at the MI level and final machine code generation >> (see e.g. https://reviews.llvm.org/D45576). >> >> - Review all optimization and codegen passes to verify they >> fully respect strict FP semantics. >> >> Once this is done, we can improve on the solution by: >> >> - Supporting mixing strict and non-strict FP operations >> (would lift the LTO...

Hi Andrew, sorry for the delay, I only now got some time to look into this a bit more. But I still have a number of questions of how to actually implement this in the back end. Looking at this bottom-up, starting with the behavior of the actual machine instructions, we have (at least on SystemZ) the following things to consider: A) Rounding mode Most FP arithmetic instructions use the