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From: Max Filippov <jcmvbkbc@gcc.gnu.org> To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-1032] xtensa: Make one_cmplsi2 optimizer-friendly Date: Thu, 9 Jun 2022 22:10:20 +0000 (GMT) [thread overview] Message-ID: <20220609221020.D7CD3382B5DF@sourceware.org> (raw) https://gcc.gnu.org/g:9777d446e2148ef9a6e9f35db3f4eab99ee8812c commit r13-1032-g9777d446e2148ef9a6e9f35db3f4eab99ee8812c Author: Takayuki 'January June' Suwa <jjsuwa_sys3175@yahoo.co.jp> Date: Sun May 29 19:46:16 2022 +0900 xtensa: Make one_cmplsi2 optimizer-friendly In Xtensa ISA, there is no single machine instruction that calculates unary bitwise negation. But a few optimizers assume that bitwise negation can be done by a single insn. As a result, '((x < 0) ? ~x : x)' cannot be optimized to '(x ^ (x >> 31))' ever before, for example. This patch relaxes such limitation, by putting the insn expansion off till the split pass. gcc/ChangeLog: * config/xtensa/xtensa.md (one_cmplsi2): Rearrange as an insn_and_split pattern. gcc/testsuite/ChangeLog: * gcc.target/xtensa/one_cmpl_abs.c: New. Diff: --- gcc/config/xtensa/xtensa.md | 26 ++++++++++++++++++-------- gcc/testsuite/gcc.target/xtensa/one_cmpl_abs.c | 9 +++++++++ 2 files changed, 27 insertions(+), 8 deletions(-) diff --git a/gcc/config/xtensa/xtensa.md b/gcc/config/xtensa/xtensa.md index abf4ad10346..fd80fdd52eb 100644 --- a/gcc/config/xtensa/xtensa.md +++ b/gcc/config/xtensa/xtensa.md @@ -556,16 +556,26 @@ (set_attr "mode" "SI") (set_attr "length" "3")]) -(define_expand "one_cmplsi2" - [(set (match_operand:SI 0 "register_operand" "") - (not:SI (match_operand:SI 1 "register_operand" "")))] +(define_insn_and_split "one_cmplsi2" + [(set (match_operand:SI 0 "register_operand" "=a") + (not:SI (match_operand:SI 1 "register_operand" "r")))] "" + "#" + "&& can_create_pseudo_p ()" + [(set (match_dup 2) + (const_int -1)) + (set (match_dup 0) + (xor:SI (match_dup 1) + (match_dup 2)))] { - rtx temp = gen_reg_rtx (SImode); - emit_insn (gen_movsi (temp, constm1_rtx)); - emit_insn (gen_xorsi3 (operands[0], temp, operands[1])); - DONE; -}) + operands[2] = gen_reg_rtx (SImode); +} + [(set_attr "type" "arith") + (set_attr "mode" "SI") + (set (attr "length") + (if_then_else (match_test "TARGET_DENSITY") + (const_int 5) + (const_int 6)))]) (define_insn "negsf2" [(set (match_operand:SF 0 "register_operand" "=f") diff --git a/gcc/testsuite/gcc.target/xtensa/one_cmpl_abs.c b/gcc/testsuite/gcc.target/xtensa/one_cmpl_abs.c new file mode 100644 index 00000000000..608f65fd777 --- /dev/null +++ b/gcc/testsuite/gcc.target/xtensa/one_cmpl_abs.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-O1" } */ + +int one_cmpl_abs(int a) +{ + return a < 0 ? ~a : a; +} + +/* { dg-final { scan-assembler-not "bgez" } } */
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