From: Christoph Muellner <christoph.muellner@vrull.eu>
To: libc-alpha@sourceware.org, Palmer Dabbelt <palmer@dabbelt.com>,
Darius Rad <darius@bluespec.com>,
Andrew Waterman <andrew@sifive.com>, DJ Delorie <dj@redhat.com>,
Vineet Gupta <vineetg@rivosinc.com>,
Kito Cheng <kito.cheng@sifive.com>,
Jeff Law <jeffreyalaw@gmail.com>,
Philipp Tomsich <philipp.tomsich@vrull.eu>,
Heiko Stuebner <heiko.stuebner@vrull.eu>
Cc: "Christoph Müllner" <christoph.muellner@vrull.eu>
Subject: [RFC PATCH 07/19] riscv: hart-features: Add fast_unaligned property
Date: Tue, 7 Feb 2023 01:16:06 +0100 [thread overview]
Message-ID: <20230207001618.458947-8-christoph.muellner@vrull.eu> (raw)
In-Reply-To: <20230207001618.458947-1-christoph.muellner@vrull.eu>
From: Christoph Müllner <christoph.muellner@vrull.eu>
Having fast unaligned accesses opens the door for a performance
optimizations. Let's add this property to the hart-features
so that this property can be queried using the environment
variable RISCV_RT_FAST_UNALIGNED (e.g. by setting it to "1").
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
---
sysdeps/unix/sysv/linux/riscv/hart-features.c | 19 +++++++++++++++++++
sysdeps/unix/sysv/linux/riscv/hart-features.h | 5 +++++
2 files changed, 24 insertions(+)
diff --git a/sysdeps/unix/sysv/linux/riscv/hart-features.c b/sysdeps/unix/sysv/linux/riscv/hart-features.c
index 6de41a26cc..b3b7955534 100644
--- a/sysdeps/unix/sysv/linux/riscv/hart-features.c
+++ b/sysdeps/unix/sysv/linux/riscv/hart-features.c
@@ -326,6 +326,22 @@ parse_rt_cboz_blocksize (struct hart_features *hart_features)
hart_features->cboz_blocksize = v;
}
+/* Parse RISCV_RT_FAST_UNALIGNED and store value. */
+static inline void
+parse_rt_fast_unaligned (struct hart_features *hart_features)
+{
+ hart_features->rt_fast_unaligned = NULL;
+ hart_features->fast_unaligned = 0;
+
+ const char *s = simple_getenv ("RISCV_RT_FAST_UNALIGNED");
+ if (s == NULL)
+ return;
+
+ uint64_t v = _dl_strtoul (s, NULL);
+ hart_features->rt_fast_unaligned = s;
+ hart_features->fast_unaligned = v;
+}
+
/* Discover hart features and store them. */
static inline void
init_hart_features (struct hart_features *hart_features)
@@ -334,4 +350,7 @@ init_hart_features (struct hart_features *hart_features)
parse_rt_march (hart_features);
parse_rt_cbom_blocksize (hart_features);
parse_rt_cboz_blocksize (hart_features);
+
+ /* Parse tuning properties. */
+ parse_rt_fast_unaligned (hart_features);
}
diff --git a/sysdeps/unix/sysv/linux/riscv/hart-features.h b/sysdeps/unix/sysv/linux/riscv/hart-features.h
index dd94685676..b2cefd5748 100644
--- a/sysdeps/unix/sysv/linux/riscv/hart-features.h
+++ b/sysdeps/unix/sysv/linux/riscv/hart-features.h
@@ -34,6 +34,9 @@
#define HAVE_CBOZ_BLOCKSIZE(n) \
(GLRO (dl_riscv_hart_features).cboz_blocksize == n)
+#define HAVE_FAST_UNALIGNED() \
+ (GLRO (dl_riscv_hart_features).fast_unaligned != 0)
+
struct hart_features
{
const char* rt_march;
@@ -48,6 +51,8 @@ struct hart_features
unsigned cbom_blocksize;
const char* rt_cboz_blocksize;
unsigned cboz_blocksize;
+ const char* rt_fast_unaligned;
+ unsigned fast_unaligned;
};
#endif /* _CPU_FEATURES_RISCV_H */
--
2.39.1
next prev parent reply other threads:[~2023-02-07 0:16 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-07 0:15 [RFC PATCH 00/19] riscv: ifunc support with optimized mem*/str*/cpu_relax routines Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 01/19] Inhibit early libcalls before ifunc support is ready Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 02/19] riscv: LEAF: Use C_LABEL() to construct the asm name for a C symbol Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 03/19] riscv: Add ENTRY_ALIGN() macro Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 04/19] riscv: Add hart feature run-time detection framework Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 05/19] riscv: Introduction of ISA extensions Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 06/19] riscv: Adding ISA string parser for environment variables Christoph Muellner
2023-02-07 6:20 ` David Abdurachmanov
2023-02-07 0:16 ` Christoph Muellner [this message]
2023-02-07 0:16 ` [RFC PATCH 08/19] riscv: Add (empty) ifunc framework Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 09/19] riscv: Add ifunc support for memset Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 10/19] riscv: Add accelerated memset routines for RV64 Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 11/19] riscv: Add ifunc support for memcpy/memmove Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 12/19] riscv: Add accelerated memcpy/memmove routines for RV64 Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 13/19] riscv: Add ifunc support for strlen Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 14/19] riscv: Add accelerated strlen routine Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 15/19] riscv: Add ifunc support for strcmp Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 16/19] riscv: Add accelerated strcmp routines Christoph Muellner
2023-02-07 11:57 ` Xi Ruoyao
2023-02-07 14:15 ` Christoph Müllner
2023-03-31 5:06 ` Jeff Law
2023-03-31 12:31 ` Adhemerval Zanella Netto
2023-03-31 14:30 ` Jeff Law
2023-03-31 14:48 ` Adhemerval Zanella Netto
2023-03-31 17:19 ` Palmer Dabbelt
2023-03-31 14:32 ` Jeff Law
2023-02-07 0:16 ` [RFC PATCH 17/19] riscv: Add ifunc support for strncmp Christoph Muellner
2023-02-07 0:16 ` [RFC PATCH 18/19] riscv: Add an optimized strncmp routine Christoph Muellner
2023-02-07 1:19 ` Noah Goldstein
2023-02-08 15:13 ` Philipp Tomsich
2023-02-08 17:55 ` Palmer Dabbelt
2023-02-08 19:48 ` Adhemerval Zanella Netto
2023-02-08 18:04 ` Noah Goldstein
2023-02-07 0:16 ` [RFC PATCH 19/19] riscv: Add __riscv_cpu_relax() to allow yielding in busy loops Christoph Muellner
2023-02-07 0:23 ` Andrew Waterman
2023-02-07 0:29 ` Christoph Müllner
2023-02-07 2:59 ` [RFC PATCH 00/19] riscv: ifunc support with optimized mem*/str*/cpu_relax routines Kito Cheng
2023-02-07 16:40 ` Adhemerval Zanella Netto
2023-02-07 17:16 ` DJ Delorie
2023-02-07 19:32 ` Philipp Tomsich
2023-02-07 21:14 ` DJ Delorie
2023-02-08 11:26 ` Christoph Müllner
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