It is possible to due copy propagation for all operations, even the one that have side effects or clobber arguments (it only concerns input arguments). That said, the call operation should be handled differently due to the variable number of arguments.
Reviewed-by: Richard Henderson <[email protected]> Signed-off-by: Aurelien Jarno <[email protected]> --- tcg/optimize.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/tcg/optimize.c b/tcg/optimize.c index 1904b39..aeb2225 100644 --- a/tcg/optimize.c +++ b/tcg/optimize.c @@ -378,8 +378,15 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, op = gen_opc_buf[op_index]; def = &tcg_op_defs[op]; /* Do copy propagation */ - if (!(def->flags & (TCG_OPF_CALL_CLOBBER | TCG_OPF_SIDE_EFFECTS))) { - assert(op != INDEX_op_call); + if (op == INDEX_op_call) { + int nb_oargs = args[0] >> 16; + int nb_iargs = args[0] & 0xffff; + for (i = nb_oargs + 1; i < nb_oargs + nb_iargs + 1; i++) { + if (temps[args[i]].state == TCG_TEMP_COPY) { + args[i] = find_better_copy(s, args[i]); + } + } + } else { for (i = def->nb_oargs; i < def->nb_oargs + def->nb_iargs; i++) { if (temps[args[i]].state == TCG_TEMP_COPY) { args[i] = find_better_copy(s, args[i]); -- 1.7.10.4
