From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 7856) id 8E10B3857BAE; Wed, 6 Jul 2022 16:06:52 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 8E10B3857BAE Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Xi Ruoyao To: gcc-cvs@gcc.gnu.org Subject: [gcc(refs/users/xry111/heads/xry111/loongarch-div-opt)] loongarch: add alternatives for idiv insns to improve code generation X-Act-Checkin: gcc X-Git-Author: Xi Ruoyao X-Git-Refname: refs/users/xry111/heads/xry111/loongarch-div-opt X-Git-Oldrev: 9e0d5db3e04afd2d030ace4ccb5c1af5e9f05a8f X-Git-Newrev: 06bf853ae271eb138743d80b8a6085e9bdbe4d25 Message-Id: <20220706160652.8E10B3857BAE@sourceware.org> Date: Wed, 6 Jul 2022 16:06:52 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 06 Jul 2022 16:06:52 -0000 https://gcc.gnu.org/g:06bf853ae271eb138743d80b8a6085e9bdbe4d25 commit 06bf853ae271eb138743d80b8a6085e9bdbe4d25 Author: Xi Ruoyao Date: Wed Jul 6 13:45:55 2022 +0800 loongarch: add alternatives for idiv insns to improve code generation Currently in the description of LoongArch integer division instructions, the output is marked as earlyclobbered ('&'). It's necessary when loongarch_check_zero_div_p() because clobbering operand 2 (divisor) will make the checking for zero divisor impossible. But, for -mno-check-zero-division (the default of GCC >= 12.2 for optimized code), the output is not earlyclobbered at all. And, the read of operand 1 only occurs before clobbering the output. So we make three alternatives for an idiv instruction: * (=r,r,r): For -mno-check-zero-division. * (=&r,r,r): For -mcheck-zero-division. * (=&r,0,r): For -mcheck-zero-division, to explicitly allow patterns like "div.d $a0, $a0, $a1". gcc/ChangeLog: * config/loongarch/loongarch.cc (loongarch_check_zero_div_p): Remove static, for use in the machine description file. * config/loongarch/loongarch-protos.h: (loongarch_check_zero_div_p): Add prototype. * config/loongarch/loongarch.md (enabled): New attr. (*3): Add (=r,r,r) and (=&r,0,r) alternatives for idiv. Conditionally enable the alternatives using loongarch_check_zero_div_p. (di3_fake): Likewise. gcc/testsuite/ChangeLog: * gcc.target/loongarch/div-1.c: New test. * gcc.target/loongarch/div-2.c: New test. * gcc.target/loongarch/div-3.c: New test. Diff: --- gcc/config/loongarch/loongarch-protos.h | 1 + gcc/config/loongarch/loongarch.cc | 2 +- gcc/config/loongarch/loongarch.md | 28 ++++++++++++++++++++-------- gcc/testsuite/gcc.target/loongarch/div-1.c | 9 +++++++++ gcc/testsuite/gcc.target/loongarch/div-2.c | 9 +++++++++ gcc/testsuite/gcc.target/loongarch/div-3.c | 9 +++++++++ 6 files changed, 49 insertions(+), 9 deletions(-) diff --git a/gcc/config/loongarch/loongarch-protos.h b/gcc/config/loongarch/loongarch-protos.h index 2144c2421ed..2287fd3763c 100644 --- a/gcc/config/loongarch/loongarch-protos.h +++ b/gcc/config/loongarch/loongarch-protos.h @@ -130,6 +130,7 @@ extern bool loongarch_symbol_binds_local_p (const_rtx); extern const char *current_section_name (void); extern unsigned int current_section_flags (void); extern bool loongarch_use_ins_ext_p (rtx, HOST_WIDE_INT, HOST_WIDE_INT); +extern bool loongarch_check_zero_div_p (void); union loongarch_gen_fn_ptrs { diff --git a/gcc/config/loongarch/loongarch.cc b/gcc/config/loongarch/loongarch.cc index d72b256df51..bc56282c9a7 100644 --- a/gcc/config/loongarch/loongarch.cc +++ b/gcc/config/loongarch/loongarch.cc @@ -2104,7 +2104,7 @@ loongarch_load_store_insns (rtx mem, rtx_insn *insn) /* Return true if we need to trap on division by zero. */ -static bool +bool loongarch_check_zero_div_p (void) { /* if -m[no-]check-zero-division is given explicitly. */ diff --git a/gcc/config/loongarch/loongarch.md b/gcc/config/loongarch/loongarch.md index d3c809e25f3..b002eb2ac22 100644 --- a/gcc/config/loongarch/loongarch.md +++ b/gcc/config/loongarch/loongarch.md @@ -110,6 +110,8 @@ ;; ;; .................... +(define_attr "enabled" "no,yes" (const_string "yes")) + (define_attr "got" "unset,load" (const_string "unset")) @@ -763,26 +765,36 @@ }) (define_insn "*3" - [(set (match_operand:GPR 0 "register_operand" "=&r") - (any_div:GPR (match_operand:GPR 1 "register_operand" "r") - (match_operand:GPR 2 "register_operand" "r")))] + [(set (match_operand:GPR 0 "register_operand" "=r,&r,&r") + (any_div:GPR (match_operand:GPR 1 "register_operand" "r,r,0") + (match_operand:GPR 2 "register_operand" "r,r,r")))] "" { return loongarch_output_division (".\t%0,%1,%2", operands); } [(set_attr "type" "idiv") - (set_attr "mode" "")]) + (set_attr "mode" "") + (set (attr "enabled") + (if_then_else + (match_test "!!which_alternative == loongarch_check_zero_div_p()") + (const_string "yes") + (const_string "no")))]) (define_insn "di3_fake" - [(set (match_operand:SI 0 "register_operand" "=&r") - (any_div:SI (match_operand:DI 1 "register_operand" "r") - (match_operand:DI 2 "register_operand" "r")))] + [(set (match_operand:SI 0 "register_operand" "=r,&r,&r") + (any_div:SI (match_operand:DI 1 "register_operand" "r,r,0") + (match_operand:DI 2 "register_operand" "r,r,r")))] "" { return loongarch_output_division (".w\t%0,%1,%2", operands); } [(set_attr "type" "idiv") - (set_attr "mode" "SI")]) + (set_attr "mode" "SI") + (set (attr "enabled") + (if_then_else + (match_test "!!which_alternative == loongarch_check_zero_div_p()") + (const_string "yes") + (const_string "no")))]) ;; Floating point multiply accumulate instructions. diff --git a/gcc/testsuite/gcc.target/loongarch/div-1.c b/gcc/testsuite/gcc.target/loongarch/div-1.c new file mode 100644 index 00000000000..b1683f8535f --- /dev/null +++ b/gcc/testsuite/gcc.target/loongarch/div-1.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -mcheck-zero-division" } */ +/* { dg-final { scan-assembler "div.\[wd\]\t\\\$r4,\\\$r4,\\\$r5" } } */ + +long +div(long a, long b) +{ + return a / b; +} diff --git a/gcc/testsuite/gcc.target/loongarch/div-2.c b/gcc/testsuite/gcc.target/loongarch/div-2.c new file mode 100644 index 00000000000..4c2beb5b930 --- /dev/null +++ b/gcc/testsuite/gcc.target/loongarch/div-2.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -mno-check-zero-division" } */ +/* { dg-final { scan-assembler "div.\[wd\]\t\\\$r4,\\\$r5,\\\$r4" } } */ + +long +div(long a, long b) +{ + return b / a; +} diff --git a/gcc/testsuite/gcc.target/loongarch/div-3.c b/gcc/testsuite/gcc.target/loongarch/div-3.c new file mode 100644 index 00000000000..d25969263f5 --- /dev/null +++ b/gcc/testsuite/gcc.target/loongarch/div-3.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ +/* { dg-options "-O2 -mcheck-zero-division" } */ +/* { dg-final { scan-assembler-not "div.\[wd\]\t\\\$r4,\\\$r5,\\\$r4" } } */ + +long +div(long a, long b) +{ + return b / a; +}