From 0e96ea5c3eb5904e5dc2f3d414e2aba361933b87 Mon Sep 17 00:00:00 2001
From: Nathan Chancellor <nathan@kernel.org>
Date: Tue, 25 Jan 2022 15:19:24 -0700
Subject: [PATCH] MIPS: Loongson64: Clean up use of cc-ifversion
This Makefile checks that GCC is 4.9 or newer, which is redundant after
commit 76ae847497bc ("Documentation: raise minimum supported version of
GCC to 5.1"), so cc-option can be removed.
Clang does not support -march=loongson3a so it needs to continue to use
-march=mips64r2, which no longer needs cc-option because all supported
clang versions recognize this flag.
-march=loonson3a can be used unconditionally with GCC because the
minimum supported GCC version has been bumped past 4.9.0, which won't
have the bug mentioned in the comment. The _MIPS_ISA macro redefinition
can be removed at the same time for the same reason.
Suggested-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
---
arch/mips/loongson64/Platform | 21 +++------------------
1 file changed, 3 insertions(+), 18 deletions(-)
diff --git a/arch/mips/loongson64/Platform b/arch/mips/loongson64/Platform
index 3e660d6d3c2b..f2a08a185ee2 100644
--- a/arch/mips/loongson64/Platform
+++ b/arch/mips/loongson64/Platform
@@ -5,24 +5,9 @@
cflags-$(CONFIG_CPU_LOONGSON64) += -Wa,--trap
-#
-# binutils from v2.25 on and gcc starting from v4.9.0 treat -march=loongson3a
-# as MIPS64 R2; older versions as just R1. This leaves the possibility open
-# that GCC might generate R2 code for -march=loongson3a which then is rejected
-# by GAS. The cc-option can't probe for this behaviour so -march=loongson3a
-# can't easily be used safely within the kbuild framework.
-#
-ifeq ($(call cc-ifversion, -ge, 0409, y), y)
- ifeq ($(call ld-ifversion, -ge, 22500, y), y)
- cflags-$(CONFIG_CPU_LOONGSON64) += \
- $(call cc-option,-march=loongson3a -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
- else
- cflags-$(CONFIG_CPU_LOONGSON64) += \
- $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
- endif
-else
- cflags-$(CONFIG_CPU_LOONGSON64) += \
- $(call cc-option,-march=mips64r2,-mips64r2 -U_MIPS_ISA -D_MIPS_ISA=_MIPS_ISA_MIPS64)
+ifdef CONFIG_CPU_LOONGSON64
+cflags-$(CONFIG_CC_IS_GCC) += -march=loongson3a
+cflags-$(CONFIG_CC_IS_CLANG) += -march=mips64r2
endif
# Some -march= flags enable MMI instructions, and GCC complains about that