ARMv8.1 adds instructions for atomic compare-and-swap with optional
memory ordering specifiers. This patch series adds the instructions to
GCC, making them available with -march=armv8.1-a or with
-march=armv8-a+lse, and using them to implement the __sync and __atomic
builtins.
This patch adds an internal TARGET_LSE macro, to check target support
for the atomic instructions.
Subsequent patches
- add and use atomic compare-and-swap instructions;
- add tests for the compare-and-swap;
Tested the series for aarch64-none-linux-gnu with native bootstrap and make
check and for aarch64-none-elf with cross-compiled check-gcc. Also tested
aarch64-none-elf with cross-compiled check-gcc on an emulator that supports
ARMv8.1.
Ok for trunk?
Matthew
2015-08-12 Matthew Wahab <matthew.wa...@arm.com>
* config/aarch64/aarch64.h (AARCH64_ISA_LSE): New.
(TARGET_LSE): New.
>From 50a71e7572de7eb47c7913ae3d0984cd61f8d425 Mon Sep 17 00:00:00 2001
From: Matthew Wahab <matthew.wa...@arm.com>
Date: Mon, 20 Jul 2015 12:42:52 +0100
Subject: [PATCH 1/3] Add LSE flag testing macro.
Change-Id: I4bfeb5ec617f13026fb7dcd28a9b5c7efa4c1719
---
gcc/config/aarch64/aarch64.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index 721927f..d6c7a74 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -156,6 +156,7 @@ extern unsigned aarch64_architecture_version;
#define AARCH64_ISA_CRYPTO (aarch64_isa_flags & AARCH64_FL_CRYPTO)
#define AARCH64_ISA_FP (aarch64_isa_flags & AARCH64_FL_FP)
#define AARCH64_ISA_SIMD (aarch64_isa_flags & AARCH64_FL_SIMD)
+#define AARCH64_ISA_LSE (aarch64_isa_flags & AARCH64_FL_LSE)
/* Crypto is an optional extension to AdvSIMD. */
#define TARGET_CRYPTO (TARGET_SIMD && AARCH64_ISA_CRYPTO)
@@ -163,6 +164,9 @@ extern unsigned aarch64_architecture_version;
/* CRC instructions that can be enabled through +crc arch extension. */
#define TARGET_CRC32 (AARCH64_ISA_CRC)
+/* Atomic instructions that can be enabled through the +lse extension. */
+#define TARGET_LSE (AARCH64_ISA_LSE)
+
/* Make sure this is always defined so we don't have to check for ifdefs
but rather use normal ifs. */
#ifndef TARGET_FIX_ERR_A53_835769_DEFAULT
--
1.9.1
