From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 2066) id C399F3858D1E; Tue, 20 Dec 2022 03:59:41 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org C399F3858D1E DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1671508781; bh=Fja28YxVSFgVl5bkbxX268hRxEH4btg36C0tyi3srso=; h=From:To:Subject:Date:From; b=OgUH8L0CoHXy5LVie11O/vA4lfO8lg3JDN5ZnaYYWYJFWb/EPk+1QcdPdMUHgTZlP 5b//sJ4SOnDlJ7gqGLtSi7bUSJr0GPGiefdzjy7W11or1sZhYfoAoWlA0zdewrfiAl Vi1IJq2uCC0VB7mr8A422sG5PP36LGBauFW/svu0= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Jiu Fu Guo To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-4803] rs6000: Optimize cmp on rotated 16bits constant X-Act-Checkin: gcc X-Git-Author: Jiufu Guo X-Git-Refname: refs/heads/master X-Git-Oldrev: d2ef2327bb357da9d4cff8111e15547441b74c99 X-Git-Newrev: 1060cd2ad00b5174f4f8ef8ca3d8c283e321ffca Message-Id: <20221220035941.C399F3858D1E@sourceware.org> Date: Tue, 20 Dec 2022 03:59:41 +0000 (GMT) List-Id: https://gcc.gnu.org/g:1060cd2ad00b5174f4f8ef8ca3d8c283e321ffca commit r13-4803-g1060cd2ad00b5174f4f8ef8ca3d8c283e321ffca Author: Jiufu Guo Date: Tue Dec 20 11:43:57 2022 +0800 rs6000: Optimize cmp on rotated 16bits constant Hi, When checking eq/ne with a constant which has only 16bits, it can be optimized to check the rotated data. By this, the constant building is optimized. As the example in PR103743: For "in == 0x8000000000000000LL", this patch generates: rotldi 3,3,1 ; cmpldi 0,3,1 instead of: li 9,-1 ; rldicr 9,9,0,0 ; cmpd 0,3,9 Compare with previous version: https://gcc.gnu.org/pipermail/gcc-patches/2022-August/600475.html. This patch refactor the code according to review comments. e.g. updating function names/comments/code. This patch pass bootstrap and regtest on ppc64 and ppc64le. Is it ok for trunk? Thanks for comments! BR, Jeff(Jiufu) PR target/103743 gcc/ChangeLog: * config/rs6000/rs6000-protos.h (can_be_rotated_to_lowbits): New. (can_be_rotated_to_positive_16bits): New. (can_be_rotated_to_negative_15bits): New. * config/rs6000/rs6000.cc (can_be_rotated_to_lowbits): New definition. (can_be_rotated_to_positive_16bits): New definition. (can_be_rotated_to_negative_15bits): New definition. * config/rs6000/rs6000.md (*rotate_on_cmpdi): New define_insn_and_split. (eqne): Move earlier. gcc/testsuite/ChangeLog: * gcc.target/powerpc/pr103743.c: New test. * gcc.target/powerpc/pr103743_1.c: New test. Diff: --- gcc/config/rs6000/rs6000-protos.h | 3 + gcc/config/rs6000/rs6000.cc | 65 ++++++++++++++++++ gcc/config/rs6000/rs6000.md | 66 ++++++++++++++++++- gcc/testsuite/gcc.target/powerpc/pr103743.c | 52 +++++++++++++++ gcc/testsuite/gcc.target/powerpc/pr103743_1.c | 95 +++++++++++++++++++++++++++ 5 files changed, 280 insertions(+), 1 deletion(-) diff --git a/gcc/config/rs6000/rs6000-protos.h b/gcc/config/rs6000/rs6000-protos.h index d0d89320ef6..8355621d4ed 100644 --- a/gcc/config/rs6000/rs6000-protos.h +++ b/gcc/config/rs6000/rs6000-protos.h @@ -35,6 +35,9 @@ extern bool xxspltib_constant_p (rtx, machine_mode, int *, int *); extern int vspltis_shifted (rtx); extern HOST_WIDE_INT const_vector_elt_as_int (rtx, unsigned int); extern bool macho_lo_sum_memory_operand (rtx, machine_mode); +extern bool can_be_rotated_to_lowbits (unsigned HOST_WIDE_INT, int, int *); +extern bool can_be_rotated_to_positive_16bits (HOST_WIDE_INT); +extern bool can_be_rotated_to_negative_15bits (HOST_WIDE_INT); extern int num_insns_constant (rtx, machine_mode); extern int small_data_operand (rtx, machine_mode); extern bool mem_operand_gpr (rtx, machine_mode); diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc index 9318ef151c9..e074e8f7bdf 100644 --- a/gcc/config/rs6000/rs6000.cc +++ b/gcc/config/rs6000/rs6000.cc @@ -14950,6 +14950,71 @@ rs6000_reverse_condition (machine_mode mode, enum rtx_code code) return reverse_condition (code); } +/* Check if C (as 64bit integer) can be rotated to a constant which constains + nonzero bits at the LOWBITS low bits only. + + Return true if C can be rotated to such constant. If so, *ROT is written + to the number by which C is rotated. + Return false otherwise. */ + +bool +can_be_rotated_to_lowbits (unsigned HOST_WIDE_INT c, int lowbits, int *rot) +{ + int clz = HOST_BITS_PER_WIDE_INT - lowbits; + + /* case a. 0..0xxx: already at least clz zeros. */ + int lz = clz_hwi (c); + if (lz >= clz) + { + *rot = 0; + return true; + } + + /* case b. 0..0xxx0..0: at least clz zeros. */ + int tz = ctz_hwi (c); + if (lz + tz >= clz) + { + *rot = HOST_BITS_PER_WIDE_INT - tz; + return true; + } + + /* case c. xx10.....0xx: rotate 'clz - 1' bits first, then check case b. + ^bit -> Vbit, , then zeros are at head or tail. + 00...00xxx100, 'clz - 1' >= 'bits of xxxx'. */ + const int rot_bits = lowbits + 1; + unsigned HOST_WIDE_INT rc = (c >> rot_bits) | (c << (clz - 1)); + tz = ctz_hwi (rc); + if (clz_hwi (rc) + tz >= clz) + { + *rot = HOST_BITS_PER_WIDE_INT - (tz + rot_bits); + return true; + } + + return false; +} + +/* Check if C (as 64bit integer) can be rotated to a positive 16bits constant + which contains 48bits leading zeros and 16bits of any value. */ + +bool +can_be_rotated_to_positive_16bits (HOST_WIDE_INT c) +{ + int rot = 0; + bool res = can_be_rotated_to_lowbits (c, 16, &rot); + return res && rot > 0; +} + +/* Check if C (as 64bit integer) can be rotated to a negative 15bits constant + which contains 49bits leading ones and 15bits of any value. */ + +bool +can_be_rotated_to_negative_15bits (HOST_WIDE_INT c) +{ + int rot = 0; + bool res = can_be_rotated_to_lowbits (~c, 15, &rot); + return res && rot > 0; +} + /* Generate a compare for CODE. Return a brand-new rtx that represents the result of the compare. */ diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md index 6011f5bf76a..3cae64a264a 100644 --- a/gcc/config/rs6000/rs6000.md +++ b/gcc/config/rs6000/rs6000.md @@ -7765,6 +7765,71 @@ "xscvdpsp %x0,%x1" [(set_attr "type" "fp")]) + +(define_code_iterator eqne [eq ne]) + +;; "i == C" ==> "rotl(i,N) == rotl(C,N)" +(define_insn_and_split "*rotate_on_cmpdi" + [(set (pc) + (if_then_else (eqne (match_operand:DI 1 "gpc_reg_operand" "r") + (match_operand:DI 2 "const_int_operand" "n")) + (label_ref (match_operand 0 "")) + (pc))) + (clobber (match_scratch:DI 3 "=r")) + (clobber (match_scratch:CCUNS 4 "=y"))] + "TARGET_POWERPC64 && num_insns_constant (operands[2], DImode) > 1 + && (can_be_rotated_to_positive_16bits (INTVAL (operands[2])) + || can_be_rotated_to_negative_15bits (INTVAL (operands[2])))" + "#" + "&& 1" + [(pc)] +{ + bool sgn = false; + unsigned HOST_WIDE_INT C = INTVAL (operands[2]); + int rot; + + /* cmpldi */ + if (!can_be_rotated_to_lowbits (C, 16, &rot)) + { + /* cmpdi */ + sgn = true; + bool res = can_be_rotated_to_lowbits (~C, 15, &rot); + gcc_assert (res); + } + + rtx n = GEN_INT (rot); + + /* i' = rotl (i, n) */ + rtx op0 = can_create_pseudo_p () ? gen_reg_rtx (DImode) : operands[3]; + emit_insn (gen_rtx_SET (op0, gen_rtx_ROTATE (DImode, operands[1], n))); + + /* C' = rotl (C, n) */ + rtx op1 = GEN_INT ((C << rot) | (C >> (HOST_BITS_PER_WIDE_INT - rot))); + + /* i' == C' */ + machine_mode comp_mode = sgn ? CCmode : CCUNSmode; + rtx cc = can_create_pseudo_p () ? gen_reg_rtx (comp_mode) : operands[4]; + PUT_MODE (cc, comp_mode); + emit_insn (gen_rtx_SET (cc, gen_rtx_COMPARE (comp_mode, op0, op1))); + rtx cmp = gen_rtx_ (CCmode, cc, const0_rtx); + rtx loc_ref = gen_rtx_LABEL_REF (VOIDmode, operands[0]); + emit_jump_insn (gen_rtx_SET (pc_rtx, + gen_rtx_IF_THEN_ELSE (VOIDmode, cmp, + loc_ref, pc_rtx))); + + /* Keep the probability info for the prediction of the branch insn. */ + rtx note = find_reg_note (curr_insn, REG_BR_PROB, 0); + if (note) + { + profile_probability prob + = profile_probability::from_reg_br_prob_note (XINT (note, 0)); + + add_reg_br_prob_note (get_last_insn (), prob); + } + + DONE; +}) + ;; Split a load of a large constant into the appropriate two-insn ;; sequence. @@ -13463,7 +13528,6 @@ ;; rs6000_legitimate_combined_insn prevents combine creating any of ;; the ctr insns. -(define_code_iterator eqne [eq ne]) (define_code_attr bd [(eq "bdz") (ne "bdnz")]) (define_code_attr bd_neg [(eq "bdnz") (ne "bdz")]) diff --git a/gcc/testsuite/gcc.target/powerpc/pr103743.c b/gcc/testsuite/gcc.target/powerpc/pr103743.c new file mode 100644 index 00000000000..41c686bb4cb --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/pr103743.c @@ -0,0 +1,52 @@ +/* { dg-options "-O2" } */ +/* { dg-do compile { target has_arch_ppc64 } } */ + +/* { dg-final { scan-assembler-times {\mcmpldi\M} 10 } } */ +/* { dg-final { scan-assembler-times {\mcmpdi\M} 4 } } */ +/* { dg-final { scan-assembler-times {\mrotldi\M} 14 } } */ + +int foo (int a); + +int __attribute__ ((noinline)) udi_fun (unsigned long long in) +{ + if (in == (0x8642000000000000ULL)) + return foo (1); + if (in == (0x7642000000000000ULL)) + return foo (12); + if (in == (0x8000000000000000ULL)) + return foo (32); + if (in == (0x8700000000000091ULL)) + return foo (33); + if (in == (0x8642FFFFFFFFFFFFULL)) + return foo (46); + if (in == (0x7642FFFFFFFFFFFFULL)) + return foo (51); + if (in == (0x7567000000ULL)) + return foo (9); + if (in == (0xFFF8567FFFFFFFFFULL)) + return foo (19); + + return 0; +} + +int __attribute__ ((noinline)) di_fun (long long in) +{ + if (in == (0x8642000000000000LL)) + return foo (1); + if (in == (0x7642000000000000LL)) + return foo (12); + if (in == (0x8000000000000000LL)) + return foo (32); + if (in == (0x8700000000000091LL)) + return foo (33); + if (in == (0x8642FFFFFFFFFFFFLL)) + return foo (46); + if (in == (0x7642FFFFFFFFFFFFLL)) + return foo (51); + if (in == (0x7567000000LL)) + return foo (9); + if (in == (0xFFF8567FFFFFFFFFLL)) + return foo (19); + + return 0; +} diff --git a/gcc/testsuite/gcc.target/powerpc/pr103743_1.c b/gcc/testsuite/gcc.target/powerpc/pr103743_1.c new file mode 100644 index 00000000000..e128aae7574 --- /dev/null +++ b/gcc/testsuite/gcc.target/powerpc/pr103743_1.c @@ -0,0 +1,95 @@ +/* { dg-do run } */ +/* { dg-options "-O2 -std=c99" } */ + +int +foo (int a) +{ + return a + 6; +} + +int __attribute__ ((noipa)) udi_fun (unsigned long long in) +{ + if (in == (0x8642000000000000ULL)) + return foo (1); + if (in == (0x7642000000000000ULL)) + return foo (12); + if (in == (0x8000000000000000ULL)) + return foo (32); + if (in == (0x8700000000000091ULL)) + return foo (33); + if (in == (0x8642FFFFFFFFFFFFULL)) + return foo (46); + if (in == (0x7642FFFFFFFFFFFFULL)) + return foo (51); + if (in == (0x7567000000ULL)) + return foo (9); + if (in == (0xFFF8567FFFFFFFFFULL)) + return foo (19); + + return 0; +} + +int __attribute__ ((noipa)) di_fun (long long in) +{ + if (in == (0x8642000000000000LL)) + return foo (1); + if (in == (0x7642000000000000LL)) + return foo (12); + if (in == (0x8000000000000000LL)) + return foo (32); + if (in == (0x8700000000000091LL)) + return foo (33); + if (in == (0x8642FFFFFFFFFFFFLL)) + return foo (46); + if (in == (0x7642FFFFFFFFFFFFLL)) + return foo (51); + return 0; +} + +int +main () +{ + int e = 0; + if (udi_fun (6) != 0) + e++; + if (udi_fun (0x8642000000000000ULL) != foo (1)) + e++; + if (udi_fun (0x7642000000000000ULL) != foo (12)) + e++; + if (udi_fun (0x8000000000000000ULL) != foo (32)) + e++; + if (udi_fun (0x8700000000000091ULL) != foo (33)) + e++; + if (udi_fun (0x8642FFFFFFFFFFFFULL) != foo (46)) + e++; + if (udi_fun (0x7642FFFFFFFFFFFFULL) != foo (51)) + e++; + if (udi_fun (0x7567000000ULL) != foo (9)) + e++; + if (udi_fun (0xFFF8567FFFFFFFFFULL) != foo (19)) + e++; + + if (di_fun (6) != 0) + e++; + if (di_fun (0x8642000000000000LL) != foo (1)) + e++; + if (di_fun (0x7642000000000000LL) != foo (12)) + e++; + if (di_fun (0x8000000000000000LL) != foo (32)) + e++; + if (di_fun (0x8700000000000091LL) != foo (33)) + e++; + if (di_fun (0x8642FFFFFFFFFFFFLL) != foo (46)) + e++; + if (di_fun (0x7642FFFFFFFFFFFFLL) != foo (51)) + e++; + if (udi_fun (0x7567000000LL) != foo (9)) + e++; + if (udi_fun (0xFFF8567FFFFFFFFFLL) != foo (19)) + e++; + + if (e) + __builtin_abort (); + return 0; +} +