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From: Emil Renner Berthing <kernel@esmil.dk>
To: Ley Foon Tan <lftan.linux@gmail.com>,
	Matteo Croce <mcroce@linux.microsoft.com>
Cc: Emil Renner Berthing <kernel@esmil.dk>,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-arch@vger.kernel.org,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Akira Tsukamoto <akira.tsukamoto@gmail.com>,
	Drew Fustini <drew@beagleboard.org>,
	Bin Meng <bmeng.cn@gmail.com>,
	David Laight <David.Laight@aculab.com>,
	Guo Ren <guoren@kernel.org>, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v5 3/3] riscv: optimized memset
Date: Mon,  6 Dec 2021 21:37:03 +0100	[thread overview]
Message-ID: <20211206203703.67597-1-kernel@esmil.dk> (raw)
In-Reply-To: <CAFiDJ5-OJzWWR0hSZDsuAmxzxTE7cRR9Bsetpfh5vvrTxzkKPw@mail.gmail.com>

Hi Ley Foon,

You're right it doesn't boot for me either when building with

  make ARCH=riscv LLVM=1

The following patch fixes it for me though. In hindsigt it's perhaps a
bit surprising it works without -ffreestanding in GCC.

/Emil

---
 arch/riscv/lib/Makefile | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index e33263cc622a..6dfa919d4cd6 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -4,4 +4,9 @@ lib-$(CONFIG_MMU)	+= uaccess.o
 lib-$(CONFIG_64BIT)	+= tishift.o
 lib-$(CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE) += string.o
 
+# string.o implements standard library functions like memset/memcpy etc.
+# Use -ffreestanding to ensure that the compiler does not try to "optimize"
+# them into calls to themselves.
+CFLAGS_string.o := -ffreestanding
+
 obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
-- 
2.34.1


WARNING: multiple messages have this Message-ID (diff)
From: Emil Renner Berthing <kernel@esmil.dk>
To: Ley Foon Tan <lftan.linux@gmail.com>,
	Matteo Croce <mcroce@linux.microsoft.com>
Cc: Emil Renner Berthing <kernel@esmil.dk>,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-arch@vger.kernel.org,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Akira Tsukamoto <akira.tsukamoto@gmail.com>,
	Drew Fustini <drew@beagleboard.org>,
	Bin Meng <bmeng.cn@gmail.com>,
	David Laight <David.Laight@aculab.com>,
	Guo Ren <guoren@kernel.org>, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v5 3/3] riscv: optimized memset
Date: Mon,  6 Dec 2021 21:37:03 +0100	[thread overview]
Message-ID: <20211206203703.67597-1-kernel@esmil.dk> (raw)
In-Reply-To: <CAFiDJ5-OJzWWR0hSZDsuAmxzxTE7cRR9Bsetpfh5vvrTxzkKPw@mail.gmail.com>

Hi Ley Foon,

You're right it doesn't boot for me either when building with

  make ARCH=riscv LLVM=1

The following patch fixes it for me though. In hindsigt it's perhaps a
bit surprising it works without -ffreestanding in GCC.

/Emil

---
 arch/riscv/lib/Makefile | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index e33263cc622a..6dfa919d4cd6 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -4,4 +4,9 @@ lib-$(CONFIG_MMU)	+= uaccess.o
 lib-$(CONFIG_64BIT)	+= tishift.o
 lib-$(CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE) += string.o
 
+# string.o implements standard library functions like memset/memcpy etc.
+# Use -ffreestanding to ensure that the compiler does not try to "optimize"
+# them into calls to themselves.
+CFLAGS_string.o := -ffreestanding
+
 obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
-- 
2.34.1


_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

  reply	other threads:[~2021-12-06 20:37 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-29 17:22 [PATCH v5 0/3] riscv: optimized mem* functions Matteo Croce
2021-09-29 17:22 ` Matteo Croce
2021-09-29 17:22 ` [PATCH v5 1/3] riscv: optimized memcpy Matteo Croce
2021-09-29 17:22   ` Matteo Croce
2021-09-30  1:24   ` Guo Ren
2021-09-30  1:24     ` Guo Ren
2021-09-30  1:36     ` Matteo Croce
2021-09-30  1:36       ` Matteo Croce
2021-09-30 19:43       ` Vineet Gupta
2021-09-30 19:43         ` Vineet Gupta
2021-10-01  8:06         ` David Laight
2021-10-01  8:06           ` David Laight
2021-10-01 11:23   ` Pavel Machek
2021-10-01 11:23     ` Pavel Machek
2021-10-02 17:20     ` Matteo Croce
2021-10-02 17:20       ` Matteo Croce
2021-09-29 17:22 ` [PATCH v5 2/3] riscv: optimized memmove Matteo Croce
2021-09-29 17:22   ` Matteo Croce
2021-09-29 17:22 ` [PATCH v5 3/3] riscv: optimized memset Matteo Croce
2021-09-29 17:22   ` Matteo Croce
2021-11-25 10:56   ` Ley Foon Tan
2021-11-25 10:56     ` Ley Foon Tan
2021-12-06 20:37     ` Emil Renner Berthing [this message]
2021-12-06 20:37       ` Emil Renner Berthing

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