An upcoming patch adds a match.pd rule that folds pow(pow(x,y),z) to pow(x,y*z). This fold can reuse the existing pow gimple statement and simply replace the operands with x and y*z. However, the y*z itself requires a separate gimple statement and the code wasn't prepared to handle that.
Tested on x86_64-linux-gnu, aarch64-linux-gnu and arm-linux-gnueabi. OK to install? Thanks, Richard gcc/ * gimple-fold.c (replace_stmt_with_simplification): Allow calls to have nonempty sequences. diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index 1869c09..4b9b782 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -3365,7 +3365,14 @@ replace_stmt_with_simplification (gimple_stmt_iterator *gsi, } if (i < 3) gcc_assert (ops[i] == NULL_TREE); - gcc_assert (gimple_seq_empty_p (*seq)); + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "gimple_simplified to "); + if (!gimple_seq_empty_p (*seq)) + print_gimple_seq (dump_file, *seq, 0, TDF_SLIM); + print_gimple_stmt (dump_file, gsi_stmt (*gsi), 0, TDF_SLIM); + } + gsi_insert_seq_before (gsi, *seq, GSI_SAME_STMT); return true; } else if (!inplace)