From: Jason@zx2c4.com (Jason A. Donenfeld)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm64: support __int128 on gcc 5+
Date: Tue, 31 Oct 2017 12:43:19 +0100 [thread overview]
Message-ID: <20171031114319.24436-1-Jason@zx2c4.com> (raw)
In-Reply-To: <CAHmME9pE+G0V-nyKchQyG03YXbPjGykL1xX0M8E544Rh7QrgOQ@mail.gmail.com>
Versions of gcc prior to gcc 5 emitted a __multi3 function call when
dealing with TI types, resulting in failures when trying to link to
libgcc, and more generally, horrible performance. However, since gcc 5,
the compiler supports actually emitting fast instructions, which means
we can at long last enable this option and receive the speedups.
The gcc commit that added proper Aarch64 support is:
https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=d1ae7bb994f49316f6f63e6173f2931e837a351d
This commit appears to be part of the gcc 5 release.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
arch/arm64/Makefile | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 939b310913cf..1f8a0fec6998 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -53,6 +53,8 @@ KBUILD_AFLAGS += $(lseinstr) $(brokengasinst)
KBUILD_CFLAGS += $(call cc-option,-mabi=lp64)
KBUILD_AFLAGS += $(call cc-option,-mabi=lp64)
+KBUILD_CFLAGS += $(call cc-ifversion, -ge, 0500, -DCONFIG_ARCH_SUPPORTS_INT128)
+
ifeq ($(CONFIG_CPU_BIG_ENDIAN), y)
KBUILD_CPPFLAGS += -mbig-endian
CHECKFLAGS += -D__AARCH64EB__
--
2.14.2
next prev parent reply other threads:[~2017-10-31 11:43 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-31 10:17 CONFIG_ARCH_SUPPORTS_INT128 for AArch64 Jason A. Donenfeld
2017-10-31 10:43 ` Mark Rutland
2017-10-31 11:17 ` Jason A. Donenfeld
2017-10-31 11:43 ` Jason A. Donenfeld [this message]
2017-10-31 11:51 ` [PATCH] arm64: support __int128 on gcc 5+ Will Deacon
2017-10-31 11:57 ` Jason A. Donenfeld
2017-10-31 12:17 ` Will Deacon
2017-10-31 12:18 ` Jason A. Donenfeld
2017-11-02 13:47 ` Will Deacon
2017-11-02 17:43 ` [PATCH v2] " Jason A. Donenfeld
2017-11-03 13:42 ` Will Deacon
2017-11-03 14:02 ` Ard Biesheuvel
2017-11-03 14:14 ` Jason A. Donenfeld
2017-11-03 14:18 ` [PATCH v3] " Jason A. Donenfeld
2017-11-06 9:31 ` [PATCH v4] " Jason A. Donenfeld
2017-11-06 15:59 ` Catalin Marinas
2017-11-06 16:14 ` Catalin Marinas
[not found] ` <CAHmME9p+ef-+fmdiO15LU7X3Sr-CDyngpPwKZN2FqOQmZNjLtg@mail.gmail.com>
2017-11-06 16:55 ` Ard Biesheuvel
2017-11-06 23:58 ` [PATCH v5] " Jason A. Donenfeld
2017-11-07 0:01 ` [PATCH v4] " Jason A. Donenfeld
2017-11-07 2:13 ` Will Deacon
2017-11-07 2:16 ` Jason A. Donenfeld
2017-11-02 20:24 ` [PATCH] " Jason A. Donenfeld
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