public inbox for gcc-cvs@sourceware.org help / color / mirror / Atom feed
From: Jeff Law <law@gcc.gnu.org> To: gcc-cvs@gcc.gnu.org Subject: [gcc r13-4119] RISC-V: Optimize RVV epilogue logic. Date: Thu, 17 Nov 2022 04:01:50 +0000 (GMT) [thread overview] Message-ID: <20221117040150.9636539484B2@sourceware.org> (raw) https://gcc.gnu.org/g:a62d957342e3e9ee9bda812f737279f1166e03ba commit r13-4119-ga62d957342e3e9ee9bda812f737279f1166e03ba Author: Jia-Wei Chen <jiawei@iscas.ac.cn> Date: Wed Nov 16 22:58:54 2022 -0500 RISC-V: Optimize RVV epilogue logic. Sometimes "step1 -= scalable_frame" will cause adjust equal to zero. And it will generate additional redundant instruction "addi sp,sp,0". Add checking segement to skip that case. This testcase mix exist spill-1.c and adding new fun to check if there have redundant addi intructions. Idea provided by Jeff Law. gcc/ChangeLog: * config/riscv/riscv.cc (riscv_expand_epilogue): Do not emit useless add sp, sp, 0 instrutions. gcc/testsuite/ChangeLog: * gcc.target/riscv/rvv/base/spill-sp-adjust.c: New test. Diff: --- gcc/config/riscv/riscv.cc | 34 ++++++++++++---------- .../gcc.target/riscv/rvv/base/spill-sp-adjust.c | 13 +++++++++ 2 files changed, 32 insertions(+), 15 deletions(-) diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc index e36ff05695a..ed8ba833c8d 100644 --- a/gcc/config/riscv/riscv.cc +++ b/gcc/config/riscv/riscv.cc @@ -5204,25 +5204,29 @@ riscv_expand_epilogue (int style) step1 -= scalable_frame; } - /* Get an rtx for STEP1 that we can add to BASE. */ - rtx adjust = GEN_INT (step1.to_constant ()); - if (!SMALL_OPERAND (step1.to_constant ())) + /* Get an rtx for STEP1 that we can add to BASE. + Skip if adjust equal to zero. */ + if (step1.to_constant () != 0) { - riscv_emit_move (RISCV_PROLOGUE_TEMP (Pmode), adjust); - adjust = RISCV_PROLOGUE_TEMP (Pmode); - } - - insn = emit_insn ( - gen_add3_insn (stack_pointer_rtx, stack_pointer_rtx, adjust)); + rtx adjust = GEN_INT (step1.to_constant ()); + if (!SMALL_OPERAND (step1.to_constant ())) + { + riscv_emit_move (RISCV_PROLOGUE_TEMP (Pmode), adjust); + adjust = RISCV_PROLOGUE_TEMP (Pmode); + } - rtx dwarf = NULL_RTX; - rtx cfa_adjust_rtx = gen_rtx_PLUS (Pmode, stack_pointer_rtx, - GEN_INT (step2)); + insn = emit_insn (gen_add3_insn (stack_pointer_rtx, + stack_pointer_rtx, + adjust)); + rtx dwarf = NULL_RTX; + rtx cfa_adjust_rtx = gen_rtx_PLUS (Pmode, stack_pointer_rtx, + GEN_INT (step2)); - dwarf = alloc_reg_note (REG_CFA_DEF_CFA, cfa_adjust_rtx, dwarf); - RTX_FRAME_RELATED_P (insn) = 1; + dwarf = alloc_reg_note (REG_CFA_DEF_CFA, cfa_adjust_rtx, dwarf); + RTX_FRAME_RELATED_P (insn) = 1; - REG_NOTES (insn) = dwarf; + REG_NOTES (insn) = dwarf; + } } else if (frame_pointer_needed) { diff --git a/gcc/testsuite/gcc.target/riscv/rvv/base/spill-sp-adjust.c b/gcc/testsuite/gcc.target/riscv/rvv/base/spill-sp-adjust.c new file mode 100644 index 00000000000..f8c9f6313e8 --- /dev/null +++ b/gcc/testsuite/gcc.target/riscv/rvv/base/spill-sp-adjust.c @@ -0,0 +1,13 @@ +/* { dg-do compile } */ +/* { dg-options "-march=rv64gcv" } */ + +#include "spill-1.c" + +void +spill_sp_adjust (int8_t *v) +{ + vint8mf8_t v1 = *(vint8mf8_t*)v; +} + +/* Make sure we do not have a useless SP adjustment. */ +/* { dg-final { scan-assembler-not "addi\tsp,sp,0" } } */
reply other threads:[~2022-11-17 4:01 UTC|newest] Thread overview: [no followups] expand[flat|nested] mbox.gz Atom feed
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20221117040150.9636539484B2@sourceware.org \ --to=law@gcc.gnu.org \ --cc=gcc-cvs@gcc.gnu.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).