diff options
Diffstat (limited to '0226-Backport-SME-riscv-Add-support-for-strlen-inline-exp.patch')
| -rw-r--r-- | 0226-Backport-SME-riscv-Add-support-for-strlen-inline-exp.patch | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/0226-Backport-SME-riscv-Add-support-for-strlen-inline-exp.patch b/0226-Backport-SME-riscv-Add-support-for-strlen-inline-exp.patch new file mode 100644 index 0000000..94d1277 --- /dev/null +++ b/0226-Backport-SME-riscv-Add-support-for-strlen-inline-exp.patch @@ -0,0 +1,142 @@ +From 637e6469f2225b6f6f6b0c84b4e7abcd8dfd7ca4 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Christoph=20M=C3=BCllner?= <christoph.muellner@vrull.eu> +Date: Wed, 28 Sep 2022 11:19:06 +0200 +Subject: [PATCH 127/157] [Backport][SME] riscv: Add support for strlen inline + expansion +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Reference: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=df48285b2484eb4f8e0570c566677114eb0e553a + +Note: Only introduce the definitions of function +emit_likely_jump_insn and emit_unlikely_jump_insn, +and drop others. + +This patch implements the expansion of the strlen builtin for RV32/RV64 +for xlen-aligned aligned strings if Zbb or XTheadBb instructions are available. +The inserted sequences are: + +rv32gc_zbb (RV64 is similar): + add a3,a0,4 + li a4,-1 +.L1: lw a5,0(a0) + add a0,a0,4 + orc.b a5,a5 + beq a5,a4,.L1 + not a5,a5 + ctz a5,a5 + srl a5,a5,0x3 + add a0,a0,a5 + sub a0,a0,a3 + +rv64gc_xtheadbb (RV32 is similar): + add a4,a0,8 +.L2: ld a5,0(a0) + add a0,a0,8 + th.tstnbz a5,a5 + beqz a5,.L2 + th.rev a5,a5 + th.ff1 a5,a5 + srl a5,a5,0x3 + add a0,a0,a5 + sub a0,a0,a4 + +This allows to inline calls to strlen(), with optimized code for +xlen-aligned strings, resulting in the following benefits over +a call to libc: +* no call/ret instructions +* no stack frame allocation +* no register saving/restoring +* no alignment test + +The inlining mechanism is gated by a new switch ('-minline-strlen') +and by the variable 'optimize_size'. + +Tested using the glibc string tests. + +Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu> + +gcc/ChangeLog: + + * config.gcc: Add new object riscv-string.o. + riscv-string.cc. + * config/riscv/riscv-protos.h (riscv_expand_strlen): + New function. + * config/riscv/riscv.md (strlen<mode>): New expand INSN. + * config/riscv/riscv.opt: New flag 'minline-strlen'. + * config/riscv/t-riscv: Add new object riscv-string.o. + * config/riscv/thead.md (th_rev<mode>2): Export INSN name. + (th_rev<mode>2): Likewise. + (th_tstnbz<mode>2): New INSN. + * doc/invoke.texi: Document '-minline-strlen'. + * emit-rtl.cc (emit_likely_jump_insn): New helper function. + (emit_unlikely_jump_insn): Likewise. + * rtl.h (emit_likely_jump_insn): New prototype. + (emit_unlikely_jump_insn): Likewise. + * config/riscv/riscv-string.cc: New file. + +gcc/testsuite/ChangeLog: + + * gcc.target/riscv/xtheadbb-strlen-unaligned.c: New test. + * gcc.target/riscv/xtheadbb-strlen.c: New test. + * gcc.target/riscv/zbb-strlen-disabled-2.c: New test. + * gcc.target/riscv/zbb-strlen-disabled.c: New test. + * gcc.target/riscv/zbb-strlen-unaligned.c: New test. + * gcc.target/riscv/zbb-strlen.c: New test. +--- + gcc/emit-rtl.cc | 24 ++++++++++++++++++++++++ + gcc/rtl.h | 2 ++ + 2 files changed, 26 insertions(+) + +diff --git a/gcc/emit-rtl.cc b/gcc/emit-rtl.cc +index 1e02ae254..2df5ff414 100644 +--- a/gcc/emit-rtl.cc ++++ b/gcc/emit-rtl.cc +@@ -5163,6 +5163,30 @@ emit_jump_insn (rtx x) + return last; + } + ++/* Make an insn of code JUMP_INSN with pattern X, ++ add a REG_BR_PROB note that indicates very likely probability, ++ and add it to the end of the doubly-linked list. */ ++ ++rtx_insn * ++emit_likely_jump_insn (rtx x) ++{ ++ rtx_insn *jump = emit_jump_insn (x); ++ add_reg_br_prob_note (jump, profile_probability::very_likely ()); ++ return jump; ++} ++ ++/* Make an insn of code JUMP_INSN with pattern X, ++ add a REG_BR_PROB note that indicates very unlikely probability, ++ and add it to the end of the doubly-linked list. */ ++ ++rtx_insn * ++emit_unlikely_jump_insn (rtx x) ++{ ++ rtx_insn *jump = emit_jump_insn (x); ++ add_reg_br_prob_note (jump, profile_probability::very_unlikely ()); ++ return jump; ++} ++ + /* Make an insn of code CALL_INSN with pattern X + and add it to the end of the doubly-linked list. */ + +diff --git a/gcc/rtl.h b/gcc/rtl.h +index 488016bb4..a0db225cb 100644 +--- a/gcc/rtl.h ++++ b/gcc/rtl.h +@@ -3333,6 +3333,8 @@ extern rtx_note *emit_note_after (enum insn_note, rtx_insn *); + extern rtx_insn *emit_insn (rtx); + extern rtx_insn *emit_debug_insn (rtx); + extern rtx_insn *emit_jump_insn (rtx); ++extern rtx_insn *emit_likely_jump_insn (rtx); ++extern rtx_insn *emit_unlikely_jump_insn (rtx); + extern rtx_insn *emit_call_insn (rtx); + extern rtx_code_label *emit_label (rtx); + extern rtx_jump_table_data *emit_jump_table_data (rtx); +-- +2.33.0 + |