https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112993
--- Comment #1 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Kewen Lin <li...@gcc.gnu.org>: https://gcc.gnu.org/g:3f6e6d4b408a26f69816f18d88dde4d983677488 commit r15-2083-g3f6e6d4b408a26f69816f18d88dde4d983677488 Author: Kewen Lin <li...@linux.ibm.com> Date: Wed Jul 17 00:14:18 2024 -0500 expr: Allow same precision modes conversion between {ibm_extended, ieee_quad}_format With some historical reasons, rs6000 defines KFmode, TFmode and IFmode to have different mode precisions, but it causes some issues and needs some workarounds such as PR112993. So we are going to make all rs6000 128 bit scalar FP modes have 128 bit precision. Be prepared for that, this patch is to make function convert_mode_scalar allow same precision FP modes conversion if their underlying formats are ibm_extended_format and ieee_quad_format respectively, just like the existing special treatment on arm_bfloat_half_format <-> ieee_half_format. It also factors out all the relevant checks into a lambda function. Besides, similar to ieee fp16 -> bfloat conversion, it adopts trunc_optab rather than sext_optab for ibm128 to ieee128 conversion. PR target/112993 gcc/ChangeLog: * expr.cc (convert_mode_scalar): Allow same precision conversion between scalar floating point modes if whose underlying format is ibm_extended_format or ieee_quad_format, and refactor assertion with new lambda function acceptable_same_precision_modes. Use trunc_optab rather than sext_optab for ibm128 to ieee128 conversion. * optabs-libfuncs.cc (gen_trunc_conv_libfunc): Use trunc_optab rather than sext_optab for ibm128 to ieee128 conversion.
