From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1923) id 744523857B93; Tue, 15 Nov 2022 14:02:39 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 744523857B93 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1668520959; bh=VV9Z1d5mmvBKcbVJLFSyFW9tWPMTflPIAzZr0iUQnH4=; h=From:To:Subject:Date:From; b=yN3cvRVtlP2cEARzjObYxLWzK/AEkMQfoJ/mJ9O0+0Y2ZVFzsHWi6V3VE9U2Wig5D NgTkfkCQVXfe1JItDqDu3n9RMNmXBZG9B03j2EZ5f5n6yzT29kDfASah3XgrHK40QH KDx9RQ0Wy24YJEfnSDYSyPRMGdO8x4KI68XGiF4s= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Philipp Tomsich To: gcc-cvs@gcc.gnu.org Subject: [gcc(refs/vendors/vrull/heads/for-upstream)] RISC-V: Split "(a & (1UL << bitno)) ? 0 : 1" to bext + xori X-Act-Checkin: gcc X-Git-Author: Philipp Tomsich X-Git-Refname: refs/vendors/vrull/heads/for-upstream X-Git-Oldrev: c4af9ca07ccb5ae4085284a242d082fc4e7176d1 X-Git-Newrev: 0533c214155dc1493eb5d972cd20b0c18d532edd Message-Id: <20221115140239.744523857B93@sourceware.org> Date: Tue, 15 Nov 2022 14:02:39 +0000 (GMT) List-Id: https://gcc.gnu.org/g:0533c214155dc1493eb5d972cd20b0c18d532edd commit 0533c214155dc1493eb5d972cd20b0c18d532edd Author: Philipp Tomsich Date: Thu May 12 15:11:20 2022 +0200 RISC-V: Split "(a & (1UL << bitno)) ? 0 : 1" to bext + xori We avoid reassociating "(~(a >> BIT_NO)) & 1" into "((~a) >> BIT_NO) & 1" by splitting it into a zero-extraction (bext) and an xori. This both avoids burning a register on a temporary and generates a sequence that clearly captures 'extract bit, then invert bit'. This change improves the previously generated srl a0,a0,a1 not a0,a0 andi a0,a0,1 into bext a0,a0,a1 xori a0,a0,1 Signed-off-by: Philipp Tomsich gcc/ChangeLog: * config/riscv/bitmanip.md: Add split covering "(a & (1 << BIT_NO)) ? 0 : 1". gcc/testsuite/ChangeLog: * gcc.target/riscv/zbs-bext.c: Add testcases. * gcc.target/riscv/zbs-bexti.c: Add testcases. Series-to: gcc-patches@gcc.gnu.org Series-cc: Kito Cheng Series-cc: Palmer Dabbelt Series-cc: Vineet Gupta Series-cc: Christoph Muellner Series-cc: Jeff Law Diff: --- gcc/config/riscv/bitmanip.md | 13 +++++++++++++ gcc/testsuite/gcc.target/riscv/zbs-bext.c | 10 ++++++++-- gcc/testsuite/gcc.target/riscv/zbs-bexti.c | 10 ++++++++-- 3 files changed, 29 insertions(+), 4 deletions(-) diff --git a/gcc/config/riscv/bitmanip.md b/gcc/config/riscv/bitmanip.md index a5170baceaf..d639760e1e2 100644 --- a/gcc/config/riscv/bitmanip.md +++ b/gcc/config/riscv/bitmanip.md @@ -685,3 +685,16 @@ "TARGET_ZBS" [(set (match_dup 0) (zero_extract:GPR (match_dup 1) (const_int 1) (match_dup 2))) (set (match_dup 0) (plus:GPR (match_dup 0) (const_int -1)))]) + +;; Split for "(a & (1 << BIT_NO)) ? 0 : 1": +;; We avoid reassociating "(~(a >> BIT_NO)) & 1" into "((~a) >> BIT_NO) & 1", +;; so we don't have to use a temporary. Instead we extract the bit and then +;; invert bit 0 ("a ^ 1") only. +(define_split + [(set (match_operand:X 0 "register_operand") + (and:X (not:X (lshiftrt:X (match_operand:X 1 "register_operand") + (subreg:QI (match_operand:X 2 "register_operand") 0))) + (const_int 1)))] + "TARGET_ZBS" + [(set (match_dup 0) (zero_extract:X (match_dup 1) (const_int 1) (match_dup 2))) + (set (match_dup 0) (xor:X (match_dup 0) (const_int 1)))]) diff --git a/gcc/testsuite/gcc.target/riscv/zbs-bext.c b/gcc/testsuite/gcc.target/riscv/zbs-bext.c index 8de9c5a167c..a8aadb60390 100644 --- a/gcc/testsuite/gcc.target/riscv/zbs-bext.c +++ b/gcc/testsuite/gcc.target/riscv/zbs-bext.c @@ -23,16 +23,22 @@ long bext64_1(long a, char bitno) long bext64_2(long a, char bitno) { - return (a & (1UL << bitno)) ? 0 : -1; + return (a & (1UL << bitno)) ? 0 : 1; } long bext64_3(long a, char bitno) +{ + return (a & (1UL << bitno)) ? 0 : -1; +} + +long bext64_4(long a, char bitno) { return (a & (1UL << bitno)) ? -1 : 0; } /* { dg-final { scan-assembler-times "bexti\t" 1 } } */ -/* { dg-final { scan-assembler-times "bext\t" 4 } } */ +/* { dg-final { scan-assembler-times "bext\t" 5 } } */ +/* { dg-final { scan-assembler-times "xori\t|snez\t" 1 } } */ /* { dg-final { scan-assembler-times "addi\t" 1 } } */ /* { dg-final { scan-assembler-times "neg\t" 1 } } */ /* { dg-final { scan-assembler-not "andi" } } */ \ No newline at end of file diff --git a/gcc/testsuite/gcc.target/riscv/zbs-bexti.c b/gcc/testsuite/gcc.target/riscv/zbs-bexti.c index 30b69c9bc3e..c15098eb6cc 100644 --- a/gcc/testsuite/gcc.target/riscv/zbs-bexti.c +++ b/gcc/testsuite/gcc.target/riscv/zbs-bexti.c @@ -12,14 +12,20 @@ long bexti64_1(long a, char bitno) long bexti64_2(long a, char bitno) { - return (a & (1UL << BIT_NO)) ? 0 : -1; + return (a & (1UL << BIT_NO)) ? 0 : 1; } long bexti64_3(long a, char bitno) +{ + return (a & (1UL << BIT_NO)) ? 0 : -1; +} + +long bexti64_4(long a, char bitno) { return (a & (1UL << BIT_NO)) ? -1 : 0; } -/* { dg-final { scan-assembler-times "bexti\t" 3 } } */ +/* { dg-final { scan-assembler-times "bexti\t" 4 } } */ +/* { dg-final { scan-assembler-times "xori\t|snez\t" 1 } } */ /* { dg-final { scan-assembler-times "addi\t" 1 } } */ /* { dg-final { scan-assembler-times "neg\t" 1 } } */