Re: [PATCH 06/10] powerpc: remove GCC version check for UPD_CONSTR

From: Nathan Chancellor
Date: Fri Sep 10 2021 - 19:48:29 EST


On 9/10/2021 4:40 PM, Nick Desaulniers wrote:
Now that GCC 5.1 is the minimum supported version, we can drop this
workaround for older versions of GCC. This adversely affected clang,
too.

Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Segher Boessenkool <segher@xxxxxxxxxxxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: linuxppc-dev@xxxxxxxxxxxxxxxx
Signed-off-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
---
arch/powerpc/include/asm/asm-const.h | 10 ----------
1 file changed, 10 deletions(-)

diff --git a/arch/powerpc/include/asm/asm-const.h b/arch/powerpc/include/asm/asm-const.h
index 0ce2368bd20f..dbfa5e1e3198 100644
--- a/arch/powerpc/include/asm/asm-const.h
+++ b/arch/powerpc/include/asm/asm-const.h
@@ -12,16 +12,6 @@
# define ASM_CONST(x) __ASM_CONST(x)
#endif
-/*
- * Inline assembly memory constraint
- *
- * GCC 4.9 doesn't properly handle pre update memory constraint "m<>"
- *
- */
-#if defined(GCC_VERSION) && GCC_VERSION < 50000
-#define UPD_CONSTR ""
-#else
#define UPD_CONSTR "<>"
-#endif

The only reason this exists is because of commit 592bbe9c505d ("powerpc/uaccess: Don't use "m<>" constraint with GCC 4.9"). It is probably just worth sinking "<>" into all of the callsites and removing
UPD_CONSTR.

#endif /* _ASM_POWERPC_ASM_CONST_H */