The new tree-cfg.c checking in r278245 tripped on folds of ALTIVEC_BUILTIN_VPERM_*, which were using gimple_convert rather than VIEW_CONVERT_EXPR to reinterpret the contents of a vector as a different type.
Spot-tested on powerpc64-linux-gnu. OK to install? Richard (There are actually two bugs in PR92515, this only fixes one of them.) 2019-11-15 Richard Sandiford <richard.sandif...@arm.com> gcc/ PR target/92515 * config/rs6000/rs6000-call.c (rs6000_gimple_fold_builtin): Use VIEW_CONVERT_EXPR to reinterpret vectors as different types. Index: gcc/config/rs6000/rs6000-call.c =================================================================== --- gcc/config/rs6000/rs6000-call.c 2019-11-14 14:49:32.629684201 +0000 +++ gcc/config/rs6000/rs6000-call.c 2019-11-15 10:00:03.413590914 +0000 @@ -6173,13 +6173,16 @@ rs6000_gimple_fold_builtin (gimple_stmt_ // convert arg0 and arg1 to match the type of the permute // for the VEC_PERM_EXPR operation. tree permute_type = (TREE_TYPE (permute)); - tree arg0_ptype = gimple_convert (&stmts, loc, permute_type, arg0); - tree arg1_ptype = gimple_convert (&stmts, loc, permute_type, arg1); + tree arg0_ptype = gimple_build (&stmts, loc, VIEW_CONVERT_EXPR, + permute_type, arg0); + tree arg1_ptype = gimple_build (&stmts, loc, VIEW_CONVERT_EXPR, + permute_type, arg1); tree lhs_ptype = gimple_build (&stmts, loc, VEC_PERM_EXPR, permute_type, arg0_ptype, arg1_ptype, permute); // Convert the result back to the desired lhs type upon completion. - tree temp = gimple_convert (&stmts, loc, TREE_TYPE (lhs), lhs_ptype); + tree temp = gimple_build (&stmts, loc, VIEW_CONVERT_EXPR, + TREE_TYPE (lhs), lhs_ptype); gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT); g = gimple_build_assign (lhs, temp); gimple_set_location (g, loc);