On Sat, Sep 7, 2024 at 7:08 PM Jeff Law <jeffreya...@gmail.com> wrote: > > > > On 9/6/24 5:32 AM, Jin Ma wrote: > > In the process of DF to SI, we generally use "unsigned_fix" rather than > > "truncate" for conversion. Although this has no effect in general, > > unexpected ICE often occurs when precise semantic analysis is required. > > > > gcc/ChangeLog: > > > > * config/riscv/riscv.md: Change "truncate" to "unsigned_fix" for > > the Zfa extension on rv32. > > > > gcc/testsuite/ChangeLog: > > > > * gcc.target/riscv/zfa-fmovh-fmovp-bug.c: New test. > This doesn't look correct. > > fmv.x.w just moves the bits from one place to another, no conversion. > > So I don't see how the original pattern was correct. Using truncate on > an FP mode source isn't defined. But I also don't think the updated > pattern is correct either. > jeff
Having matching pattern for these Zfa moves seems pointless because the optimization that utilizes the instructions in riscv_split_doubleword_move() uses: gen_movdfsisi3_rv32(), gen_movsidf2_low_rv32() and gen_movsidf2_high_rv32(). In the XTheadFmv pattern, we use unspec, so the pattern won't match. I think this should be done for Zfa as well.
