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authorLinus Torvalds <torvalds@linux-foundation.org>2019-09-21 09:47:19 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-09-21 09:47:19 -0700
commit227c3e9eb5cf3552c2cc83225df6d14adb05f8e8 (patch)
tree529caf68f7c4a670813ecddb718e5118ce3cef70 /init
parent56c631f5aec35117b0b5862a09a447a72dfbd678 (diff)
parent32ee8230b2b06c50f583e14fcd174d7d2edb52f5 (diff)
Merge tag 'compiler-attributes-for-linus-v5.4' of git://github.com/ojeda/linux
Pull asm inline support from Miguel Ojeda: "Make use of gcc 9's "asm inline()" (Rasmus Villemoes): gcc 9+ (and gcc 8.3, 7.5) provides a way to override the otherwise crude heuristic that gcc uses to estimate the size of the code represented by an asm() statement. From the gcc docs If you use 'asm inline' instead of just 'asm', then for inlining purposes the size of the asm is taken as the minimum size, ignoring how many instructions GCC thinks it is. For compatibility with older compilers, we obviously want a #if [understands asm inline] #define asm_inline asm inline #else #define asm_inline asm #endif But since we #define the identifier inline to attach some attributes, we have to use an alternate spelling of that keyword. gcc provides both __inline__ and __inline, and we currently #define both to inline, so they all have the same semantics. We have to free up one of __inline__ and __inline, and the latter is by far the easiest. The two x86 changes cause smaller code gen differences than I'd expect, but I think we do want the asm_inline thing available sooner or later, so this is just to get the ball rolling" * tag 'compiler-attributes-for-linus-v5.4' of git://github.com/ojeda/linux: x86: bug.h: use asm_inline in _BUG_FLAGS definitions x86: alternative.h: use asm_inline for all alternative variants compiler-types.h: add asm_inline definition compiler_types.h: don't #define __inline lib/zstd/mem.h: replace __inline by inline staging: rtl8723bs: replace __inline by inline
Diffstat (limited to 'init')
-rw-r--r--init/Kconfig3
1 files changed, 3 insertions, 0 deletions
diff --git a/init/Kconfig b/init/Kconfig
index f4534c58342d..7020238fd263 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -33,6 +33,9 @@ config CC_HAS_ASM_GOTO
config TOOLS_SUPPORT_RELR
def_bool $(success,env "CC=$(CC)" "LD=$(LD)" "NM=$(NM)" "OBJCOPY=$(OBJCOPY)" $(srctree)/scripts/tools-support-relr.sh)
+config CC_HAS_ASM_INLINE
+ def_bool $(success,echo 'void foo(void) { asm inline (""); }' | $(CC) -x c - -c -o /dev/null)
+
config CC_HAS_WARN_MAYBE_UNINITIALIZED
def_bool $(cc-option,-Wmaybe-uninitialized)
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