Re: [PATCH] rtl-optimization/110587 - remove quadratic regno_in_use_p
On 7/25/23 09:40, Richard Biener wrote: The following removes the code checking whether a noop copy is between something involved in the return sequence composed of a SET and USE. Instead of checking for this special-case the following makes us only ever remove noop copies between pseudos - which is the case that is necessary for IRA/LRA interfacing to function according to the comment. That makes looking for the return reg special case unnecessary, reducing the compile-time in LRA non-specific to zero for the testcase. Bootstrapped and tested on x86_64-unknown-linux-gnu with all languages and {,-m32}. OK? Richard, sorry for the delay with the answer. I was on vacation. There is a lot of history of changes of the code. I believe your change is right. I don't think that RTL will ever contain noop return move insn involving the return hard register especially after removing hard reg propagation couple years ago, at least IRA/LRA do not generate such insns during its work. So the patch is OK for me. I specially like that the big part of code is removed. No code, no problem (including performance one). Thank you for the patch. PR rtl-optimization/110587 * lra-spills.cc (return_regno_p): Remove. (regno_in_use_p): Likewise. (lra_final_code_change): Do not remove noop moves between hard registers. --- gcc/lra-spills.cc | 69 +-- 1 file changed, 1 insertion(+), 68 deletions(-) diff --git a/gcc/lra-spills.cc b/gcc/lra-spills.cc index 3a7bb7e8cd9..fe58f162d05 100644 --- a/gcc/lra-spills.cc +++ b/gcc/lra-spills.cc @@ -705,72 +705,6 @@ alter_subregs (rtx *loc, bool final_p) return res; }
Re: [PATCH] rtl-optimization/110587 - remove quadratic regno_in_use_p
On 7/31/23 04:53, Richard Biener via Gcc-patches wrote: On Tue, 25 Jul 2023, Richard Biener wrote: The following removes the code checking whether a noop copy is between something involved in the return sequence composed of a SET and USE. Instead of checking for this special-case the following makes us only ever remove noop copies between pseudos - which is the case that is necessary for IRA/LRA interfacing to function according to the comment. That makes looking for the return reg special case unnecessary, reducing the compile-time in LRA non-specific to zero for the testcase. Bootstrapped and tested on x86_64-unknown-linux-gnu with all languages and {,-m32}. OK? Ping. Thanks, Richard. PR rtl-optimization/110587 * lra-spills.cc (return_regno_p): Remove. (regno_in_use_p): Likewise. (lra_final_code_change): Do not remove noop moves between hard registers. OK jeff
Re: [PATCH] rtl-optimization/110587 - remove quadratic regno_in_use_p
On Tue, 25 Jul 2023, Richard Biener wrote: > The following removes the code checking whether a noop copy > is between something involved in the return sequence composed > of a SET and USE. Instead of checking for this special-case > the following makes us only ever remove noop copies between > pseudos - which is the case that is necessary for IRA/LRA > interfacing to function according to the comment. That makes > looking for the return reg special case unnecessary, reducing > the compile-time in LRA non-specific to zero for the testcase. > > Bootstrapped and tested on x86_64-unknown-linux-gnu with > all languages and {,-m32}. > > OK? Ping. > Thanks, > Richard. > > PR rtl-optimization/110587 > * lra-spills.cc (return_regno_p): Remove. > (regno_in_use_p): Likewise. > (lra_final_code_change): Do not remove noop moves > between hard registers. > --- > gcc/lra-spills.cc | 69 +-- > 1 file changed, 1 insertion(+), 68 deletions(-) > > diff --git a/gcc/lra-spills.cc b/gcc/lra-spills.cc > index 3a7bb7e8cd9..fe58f162d05 100644 > --- a/gcc/lra-spills.cc > +++ b/gcc/lra-spills.cc > @@ -705,72 +705,6 @@ alter_subregs (rtx *loc, bool final_p) >return res; > } > > -/* Return true if REGNO is used for return in the current > - function. */ > -static bool > -return_regno_p (unsigned int regno) > -{ > - rtx outgoing = crtl->return_rtx; > - > - if (! outgoing) > -return false; > - > - if (REG_P (outgoing)) > -return REGNO (outgoing) == regno; > - else if (GET_CODE (outgoing) == PARALLEL) > -{ > - int i; > - > - for (i = 0; i < XVECLEN (outgoing, 0); i++) > - { > - rtx x = XEXP (XVECEXP (outgoing, 0, i), 0); > - > - if (REG_P (x) && REGNO (x) == regno) > - return true; > - } > -} > - return false; > -} > - > -/* Return true if REGNO is in one of subsequent USE after INSN in the > - same BB. */ > -static bool > -regno_in_use_p (rtx_insn *insn, unsigned int regno) > -{ > - static lra_insn_recog_data_t id; > - static struct lra_static_insn_data *static_id; > - struct lra_insn_reg *reg; > - int i, arg_regno; > - basic_block bb = BLOCK_FOR_INSN (insn); > - > - while ((insn = next_nondebug_insn (insn)) != NULL_RTX) > -{ > - if (BARRIER_P (insn) || bb != BLOCK_FOR_INSN (insn)) > - return false; > - if (! INSN_P (insn)) > - continue; > - if (GET_CODE (PATTERN (insn)) == USE > - && REG_P (XEXP (PATTERN (insn), 0)) > - && regno == REGNO (XEXP (PATTERN (insn), 0))) > - return true; > - /* Check that the regno is not modified. */ > - id = lra_get_insn_recog_data (insn); > - for (reg = id->regs; reg != NULL; reg = reg->next) > - if (reg->type != OP_IN && reg->regno == (int) regno) > - return false; > - static_id = id->insn_static_data; > - for (reg = static_id->hard_regs; reg != NULL; reg = reg->next) > - if (reg->type != OP_IN && reg->regno == (int) regno) > - return false; > - if (id->arg_hard_regs != NULL) > - for (i = 0; (arg_regno = id->arg_hard_regs[i]) >= 0; i++) > - if ((int) regno == (arg_regno >= FIRST_PSEUDO_REGISTER > - ? arg_regno : arg_regno - FIRST_PSEUDO_REGISTER)) > - return false; > -} > - return false; > -} > - > /* Final change of pseudos got hard registers into the corresponding > hard registers and removing temporary clobbers. */ > void > @@ -821,8 +755,7 @@ lra_final_code_change (void) > if (NONJUMP_INSN_P (insn) && GET_CODE (pat) == SET > && REG_P (SET_SRC (pat)) && REG_P (SET_DEST (pat)) > && REGNO (SET_SRC (pat)) == REGNO (SET_DEST (pat)) > - && (! return_regno_p (REGNO (SET_SRC (pat))) > - || ! regno_in_use_p (insn, REGNO (SET_SRC (pat) > + && REGNO (SET_SRC (pat)) >= FIRST_PSEUDO_REGISTER) > { > lra_invalidate_insn_data (insn); > delete_insn (insn); >
[PATCH] rtl-optimization/110587 - remove quadratic regno_in_use_p
The following removes the code checking whether a noop copy is between something involved in the return sequence composed of a SET and USE. Instead of checking for this special-case the following makes us only ever remove noop copies between pseudos - which is the case that is necessary for IRA/LRA interfacing to function according to the comment. That makes looking for the return reg special case unnecessary, reducing the compile-time in LRA non-specific to zero for the testcase. Bootstrapped and tested on x86_64-unknown-linux-gnu with all languages and {,-m32}. OK? Thanks, Richard. PR rtl-optimization/110587 * lra-spills.cc (return_regno_p): Remove. (regno_in_use_p): Likewise. (lra_final_code_change): Do not remove noop moves between hard registers. --- gcc/lra-spills.cc | 69 +-- 1 file changed, 1 insertion(+), 68 deletions(-) diff --git a/gcc/lra-spills.cc b/gcc/lra-spills.cc index 3a7bb7e8cd9..fe58f162d05 100644 --- a/gcc/lra-spills.cc +++ b/gcc/lra-spills.cc @@ -705,72 +705,6 @@ alter_subregs (rtx *loc, bool final_p) return res; } -/* Return true if REGNO is used for return in the current - function. */ -static bool -return_regno_p (unsigned int regno) -{ - rtx outgoing = crtl->return_rtx; - - if (! outgoing) -return false; - - if (REG_P (outgoing)) -return REGNO (outgoing) == regno; - else if (GET_CODE (outgoing) == PARALLEL) -{ - int i; - - for (i = 0; i < XVECLEN (outgoing, 0); i++) - { - rtx x = XEXP (XVECEXP (outgoing, 0, i), 0); - - if (REG_P (x) && REGNO (x) == regno) - return true; - } -} - return false; -} - -/* Return true if REGNO is in one of subsequent USE after INSN in the - same BB. */ -static bool -regno_in_use_p (rtx_insn *insn, unsigned int regno) -{ - static lra_insn_recog_data_t id; - static struct lra_static_insn_data *static_id; - struct lra_insn_reg *reg; - int i, arg_regno; - basic_block bb = BLOCK_FOR_INSN (insn); - - while ((insn = next_nondebug_insn (insn)) != NULL_RTX) -{ - if (BARRIER_P (insn) || bb != BLOCK_FOR_INSN (insn)) - return false; - if (! INSN_P (insn)) - continue; - if (GET_CODE (PATTERN (insn)) == USE - && REG_P (XEXP (PATTERN (insn), 0)) - && regno == REGNO (XEXP (PATTERN (insn), 0))) - return true; - /* Check that the regno is not modified. */ - id = lra_get_insn_recog_data (insn); - for (reg = id->regs; reg != NULL; reg = reg->next) - if (reg->type != OP_IN && reg->regno == (int) regno) - return false; - static_id = id->insn_static_data; - for (reg = static_id->hard_regs; reg != NULL; reg = reg->next) - if (reg->type != OP_IN && reg->regno == (int) regno) - return false; - if (id->arg_hard_regs != NULL) - for (i = 0; (arg_regno = id->arg_hard_regs[i]) >= 0; i++) - if ((int) regno == (arg_regno >= FIRST_PSEUDO_REGISTER - ? arg_regno : arg_regno - FIRST_PSEUDO_REGISTER)) - return false; -} - return false; -} - /* Final change of pseudos got hard registers into the corresponding hard registers and removing temporary clobbers. */ void @@ -821,8 +755,7 @@ lra_final_code_change (void) if (NONJUMP_INSN_P (insn) && GET_CODE (pat) == SET && REG_P (SET_SRC (pat)) && REG_P (SET_DEST (pat)) && REGNO (SET_SRC (pat)) == REGNO (SET_DEST (pat)) - && (! return_regno_p (REGNO (SET_SRC (pat))) - || ! regno_in_use_p (insn, REGNO (SET_SRC (pat) + && REGNO (SET_SRC (pat)) >= FIRST_PSEUDO_REGISTER) { lra_invalidate_insn_data (insn); delete_insn (insn); -- 2.35.3