On Tue, 2023-09-19 at 14:29 +0530, Ajit Agarwal wrote:
> This new version of patch 7 use improve ree pass for rs6000 target
> using defined ABI interfaces.
> Bootstrapped and regtested on power64-linux-gnu.
You should drop the "4/4" in subject if it does not depends on other
non-committed patches. Otherwise you should send all the non-committed
dependencies in a series.
If you just have the 4/4 there without {1..3}/4, people will believe
this is an incomplete patch submission and likely ignore it.
> Review comments incorporated.
>
> Thanks & Regards
> Ajit
>
> ree: Improve ree pass for rs6000 target using defined abi interfaces
>
> For rs6000 target we see redundant zero and sign extension and done to
> improve ree pass to eliminate such redundant zero and sign extension
> using defined ABI interfaces.
>
> 2023-09-19 Ajit Kumar Agarwal <aagar...@linux.ibm.com>
>
> gcc/ChangeLog:
>
> * ree.cc (combine_reaching_defs): Use of zero_extend and
> sign_extend
> defined abi interfaces.
> (add_removable_extension): Use of defined abi interfaces for
> no
> reaching defs.
> (abi_extension_candidate_return_reg_p): New function.
> (abi_extension_candidate_p): New function.
> (abi_extension_candidate_argno_p): New function.
> (abi_handle_regs_without_defs_p): New function.
> (abi_target_promote_function_mode): New function.
>
> gcc/testsuite/ChangeLog:
>
> * g++.target/powerpc/zext-elim-3.C
> ---
> gcc/ree.cc | 148
> +++++++++++++++++-
> .../g++.target/powerpc/zext-elim-3.C | 13 ++
> 2 files changed, 158 insertions(+), 3 deletions(-)
> create mode 100644 gcc/testsuite/g++.target/powerpc/zext-elim-3.C
>
> diff --git a/gcc/ree.cc b/gcc/ree.cc
> index fc04249fa84..79fc54f38a3 100644
> --- a/gcc/ree.cc
> +++ b/gcc/ree.cc
> @@ -514,7 +514,8 @@ get_uses (rtx_insn *insn, rtx reg)
> if (REGNO (DF_REF_REG (def)) == REGNO (reg))
> break;
>
> - gcc_assert (def != NULL);
> + if (def == NULL)
> + return NULL;
>
> ref_chain = DF_REF_CHAIN (def);
>
> @@ -750,6 +751,122 @@ get_extended_src_reg (rtx src)
> return src;
> }
>
> +/* Return TRUE if target mode is equal to source mode of zero_extend
> + or sign_extend otherwise false. */
> +
> +static bool
> +abi_target_promote_function_mode (machine_mode mode)
> +{
> + int unsignedp;
> + machine_mode tgt_mode
> + = targetm.calls.promote_function_mode (NULL_TREE, mode,
> &unsignedp,
> + NULL_TREE, 1);
> +
> + if (tgt_mode == mode)
> + return true;
> + else
> + return false;
> +}
> +
> +/* Return TRUE if the candidate insn is zero extend and regno is
> + a return registers. */
> +
> +static bool
> +abi_extension_candidate_return_reg_p (rtx_insn *insn, int regno)
> +{
> + rtx set = single_set (insn);
> +
> + if (GET_CODE (SET_SRC (set)) != ZERO_EXTEND)
> + return false;
> +
> + if (targetm.calls.function_value_regno_p (regno))
> + return true;
> +
> + return false;
> +}
> +
> +/* Return TRUE if reg source operand of zero_extend is argument
> registers
> + and not return registers and source and destination operand are
> same
> + and mode of source and destination operand are not same. */
> +
> +static bool
> +abi_extension_candidate_p (rtx_insn *insn)
> +{
> + rtx set = single_set (insn);
> +
> + if (GET_CODE (SET_SRC (set)) != ZERO_EXTEND)
> + return false;
> +
> + machine_mode dst_mode = GET_MODE (SET_DEST (set));
> + rtx orig_src = XEXP (SET_SRC (set), 0);
> +
> + if (!FUNCTION_ARG_REGNO_P (REGNO (orig_src))
> + || abi_extension_candidate_return_reg_p (insn, REGNO
> (orig_src)))
> + return false;
> +
> + /* Mode of destination and source of zero_extend should be
> different. */
> + if (dst_mode == GET_MODE (orig_src))
> + return false;
> +
> + /* REGNO of source and destination of zero_extend should be same.
> */
> + if (REGNO (SET_DEST (set)) != REGNO (orig_src))
> + return false;
> +
> + return true;
> +}
> +
> +/* Return TRUE if the candidate insn is zero extend and regno is
> + an argument registers. */
> +
> +static bool
> +abi_extension_candidate_argno_p (rtx_code code, int regno)
> +{
> + if (code != ZERO_EXTEND && code != SIGN_EXTEND)
> + return false;
> +
> + if (FUNCTION_ARG_REGNO_P (regno))
> + return true;
> +
> + return false;
> +}
> +
> +/* Return TRUE if the candidate insn doesn't have defs and have
> + * uses without RTX_BIN_ARITH/RTX_COMM_ARITH/RTX_UNARY rtx class. */
> +
> +static bool
> +abi_handle_regs_without_defs_p (rtx_insn *insn)
> +{
> + if (side_effects_p (PATTERN (insn)))
> + return false;
> +
> + struct df_link *uses = get_uses (insn, SET_DEST (PATTERN (insn)));
> +
> + if (!uses)
> + return false;
> +
> + for (df_link *use = uses; use; use = use->next)
> + {
> + if (!use->ref)
> + return false;
> +
> + if (BLOCK_FOR_INSN (insn) != BLOCK_FOR_INSN (DF_REF_INSN (use-
> >ref)))
> + return false;
> +
> + rtx_insn *use_insn = DF_REF_INSN (use->ref);
> +
> + if (GET_CODE (PATTERN (use_insn)) == SET)
> + {
> + rtx_code code = GET_CODE (SET_SRC (PATTERN (use_insn)));
> +
> + if (GET_RTX_CLASS (code) == RTX_BIN_ARITH
> + || GET_RTX_CLASS (code) == RTX_COMM_ARITH
> + || GET_RTX_CLASS (code) == RTX_UNARY)
> + return false;
> + }
> + }
> + return true;
> +}
> +
> /* This function goes through all reaching defs of the source
> of the candidate for elimination (CAND) and tries to combine
> the extension with the definition instruction. The changes
> @@ -770,6 +887,11 @@ combine_reaching_defs (ext_cand *cand, const_rtx
> set_pat, ext_state *state)
>
> state->defs_list.truncate (0);
> state->copies_list.truncate (0);
> + rtx orig_src = XEXP (SET_SRC (cand->expr),0);
> +
> + if (abi_extension_candidate_p (cand->insn)
> + && (!get_defs (cand->insn, orig_src, NULL)))
> + return abi_handle_regs_without_defs_p (cand->insn);
>
> outcome = make_defs_and_copies_lists (cand->insn, set_pat, state);
>
> @@ -1036,6 +1158,15 @@ combine_reaching_defs (ext_cand *cand,
> const_rtx set_pat, ext_state *state)
> }
> }
>
> + rtx insn_set = single_set (cand->insn);
> +
> + machine_mode mode = (GET_MODE (XEXP (SET_SRC (insn_set), 0)));
> +
> + bool promote_p = abi_target_promote_function_mode (mode);
> +
> + if (promote_p)
> + return true;
> +
> if (merge_successful)
> {
> /* Commit the changes here if possible
> @@ -1112,6 +1243,7 @@ add_removable_extension (const_rtx expr,
> rtx_insn *insn,
> rtx reg = XEXP (src, 0);
> struct df_link *defs, *def;
> ext_cand *cand;
> + defs = get_defs (insn, reg, NULL);
>
> /* Zero-extension of an undefined value is partly defined (it's
> completely undefined for sign-extension, though). So if
> there exists
> @@ -1131,9 +1263,14 @@ add_removable_extension (const_rtx expr,
> rtx_insn *insn,
> }
>
> /* Second, make sure we can get all the reaching definitions.
> */
> - defs = get_defs (insn, reg, NULL);
> if (!defs)
> {
> + if (abi_extension_candidate_argno_p (code, REGNO (reg)))
> + {
> + ext_cand e = {expr, code, mode, insn};
> + insn_list->safe_push (e);
> + return;
> + }
> if (dump_file)
> {
> fprintf (dump_file, "Cannot eliminate extension:\n");
> @@ -1321,7 +1458,8 @@ find_and_remove_re (void)
> && (REGNO (SET_DEST (set)) != REGNO (XEXP (SET_SRC
> (set), 0))))
> {
> reinsn_copy_list.safe_push (curr_cand->insn);
> - reinsn_copy_list.safe_push (state.defs_list[0]);
> + if (state.defs_list.length () != 0)
> + reinsn_copy_list.safe_push (state.defs_list[0]);
> }
> reinsn_del_list.safe_push (curr_cand->insn);
> state.modified[INSN_UID (curr_cand->insn)].deleted = 1;
> @@ -1345,6 +1483,10 @@ find_and_remove_re (void)
> for (unsigned int i = 0; i < reinsn_copy_list.length (); i += 2)
> {
> rtx_insn *curr_insn = reinsn_copy_list[i];
> +
> + if ((i+1) >= reinsn_copy_list.length ())
> + continue;
> +
> rtx_insn *def_insn = reinsn_copy_list[i + 1];
>
> /* Use the mode of the destination of the defining insn
> diff --git a/gcc/testsuite/g++.target/powerpc/zext-elim-3.C
> b/gcc/testsuite/g++.target/powerpc/zext-elim-3.C
> new file mode 100644
> index 00000000000..5a050df06ff
> --- /dev/null
> +++ b/gcc/testsuite/g++.target/powerpc/zext-elim-3.C
> @@ -0,0 +1,13 @@
> +/* { dg-options "-mcpu=power9 -O2" } */
> +
> +void *memset(void *b, int c, unsigned long len)
> +{
> + unsigned long i;
> +
> + for (i = 0; i < len; i++)
> + ((unsigned char *)b)[i] = c;
> +
> + return b;
> +}
> +
> +/* { dg-final { scan-assembler-not "\mrlwinm\M" } } */
--
Xi Ruoyao <xry...@xry111.site>
School of Aerospace Science and Technology, Xidian University
