Commit 6b24442d authored Feb 09, 2018 by Will Deacon

arm64: lse: Pass -fomit-frame-pointer to out-of-line ll/sc atomics



In cases where x30 is used as a temporary in the out-of-line ll/sc atomics
(e.g. atomic_fetch_add), the compiler tends to put out a full stackframe,
which included pointing the x29 at the new frame.

Since these things aren't traceable anyway, we can pass -fomit-frame-pointer
to reduce the work when spilling. Since this is incompatible with -pg, we
also remove that from the CFLAGS for this file.

Signed-off-by: Will Deacon <will.deacon@arm.com>

parent 4e829b67

arch/arm64/lib/Makefile

+2 −1

Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@ CFLAGS_atomic_ll_sc.o := -fcall-used-x0 -ffixed-x1 -ffixed-x2 \
		-ffixed-x7 -fcall-saved-x8 -fcall-saved-x9 \
		-fcall-saved-x10 -fcall-saved-x11 -fcall-saved-x12 \
		-fcall-saved-x13 -fcall-saved-x14 -fcall-saved-x15 \
		-fcall-saved-x18
		-fcall-saved-x18 -fomit-frame-pointer
		CFLAGS_REMOVE_atomic_ll_sc.o := -pg

		lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o

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