https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64286
--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Untested patch (just tried it on the testcase so far). Trying to reduce the testcase now. --- gcc/ree.c.jj 2015-01-05 13:07:15.000000000 +0100 +++ gcc/ree.c 2015-01-09 18:08:30.820754926 +0100 @@ -1021,6 +1021,7 @@ add_removable_extension (const_rtx expr, different extension. FIXME: this obviously can be improved. */ for (def = defs; def; def = def->next) if ((idx = def_map[INSN_UID (DF_REF_INSN (def->ref))]) + && idx != -1U && (cand = &(*insn_list)[idx - 1]) && cand->code != code) { @@ -1032,6 +1033,51 @@ add_removable_extension (const_rtx expr, } return; } + else if (VECTOR_MODE_P (GET_MODE (XEXP (src, 0)))) + { + if (idx == 0) + { + struct df_link *ref_chain, *ref_link; + + ref_chain = DF_REF_CHAIN (def->ref); + for (ref_link = ref_chain; ref_link; ref_link = ref_link->next) + { + if (ref_link->ref == NULL + || DF_REF_INSN_INFO (ref_link->ref) == NULL) + { + idx = -1U; + break; + } + rtx_insn *use_insn = DF_REF_INSN (ref_link->ref); + const_rtx use_set; + if (use_insn == insn || DEBUG_INSN_P (use_insn)) + continue; + if (!(use_set = single_set (use_insn)) + || !REG_P (SET_DEST (use_set)) + || GET_MODE (SET_DEST (use_set)) != GET_MODE (dest) + || GET_CODE (SET_SRC (use_set)) != code + || !rtx_equal_p (XEXP (SET_SRC (use_set), 0), + XEXP (src, 0))) + { + idx = -1U; + break; + } + } + if (idx == -1U) + def_map[INSN_UID (DF_REF_INSN (def->ref))] = idx; + } + if (idx == -1U) + { + if (dump_file) + { + fprintf (dump_file, "Cannot eliminate extension:\n"); + print_rtl_single (dump_file, insn); + fprintf (dump_file, + " because some vector uses aren't extension\n"); + } + return; + } + } /* Then add the candidate to the list and insert the reaching definitions into the definition map. */