diff options
| -rw-r--r-- | lib/libthr/arch/amd64/Makefile.inc | 6 | ||||
| -rw-r--r-- | lib/libthr/arch/i386/Makefile.inc | 6 | ||||
| -rw-r--r-- | libexec/rtld-elf/amd64/Makefile.inc | 2 | ||||
| -rw-r--r-- | libexec/rtld-elf/i386/Makefile.inc | 2 | ||||
| -rw-r--r-- | share/mk/bsd.cpu.mk | 21 |
5 files changed, 35 insertions, 2 deletions
diff --git a/lib/libthr/arch/amd64/Makefile.inc b/lib/libthr/arch/amd64/Makefile.inc index e6d99ec..0ae764c 100644 --- a/lib/libthr/arch/amd64/Makefile.inc +++ b/lib/libthr/arch/amd64/Makefile.inc @@ -1,3 +1,9 @@ #$FreeBSD$ SRCS+= pthread_md.c _umtx_op_err.S + +# With the current compiler and libthr code, using SSE in libthr +# does not provide enough performance improvement to outweigh +# the extra context switch cost. This can measurably impact +# performance when the application also does not use enough SSE. +CFLAGS+=${CFLAGS_NO_SIMD} diff --git a/lib/libthr/arch/i386/Makefile.inc b/lib/libthr/arch/i386/Makefile.inc index 01290d5..81fb6bb 100644 --- a/lib/libthr/arch/i386/Makefile.inc +++ b/lib/libthr/arch/i386/Makefile.inc @@ -1,3 +1,9 @@ # $FreeBSD$ SRCS+= pthread_md.c _umtx_op_err.S + +# With the current compiler and libthr code, using SSE in libthr +# does not provide enough performance improvement to outweigh +# the extra context switch cost. This can measurably impact +# performance when the application also does not use enough SSE. +CFLAGS+=${CFLAGS_NO_SIMD} diff --git a/libexec/rtld-elf/amd64/Makefile.inc b/libexec/rtld-elf/amd64/Makefile.inc index 7528dbe..a09db6f 100644 --- a/libexec/rtld-elf/amd64/Makefile.inc +++ b/libexec/rtld-elf/amd64/Makefile.inc @@ -1,6 +1,6 @@ # $FreeBSD$ -CFLAGS+= -mno-mmx -mno-3dnow -mno-sse -mno-sse2 -mno-sse3 -msoft-float +CFLAGS+= ${CFLAGS_NO_SIMD} -msoft-float # Uncomment this to build the dynamic linker as an executable instead # of a shared library: #LDSCRIPT= ${.CURDIR}/${MACHINE_CPUARCH}/elf_rtld.x diff --git a/libexec/rtld-elf/i386/Makefile.inc b/libexec/rtld-elf/i386/Makefile.inc index 7528dbe..a09db6f 100644 --- a/libexec/rtld-elf/i386/Makefile.inc +++ b/libexec/rtld-elf/i386/Makefile.inc @@ -1,6 +1,6 @@ # $FreeBSD$ -CFLAGS+= -mno-mmx -mno-3dnow -mno-sse -mno-sse2 -mno-sse3 -msoft-float +CFLAGS+= ${CFLAGS_NO_SIMD} -msoft-float # Uncomment this to build the dynamic linker as an executable instead # of a shared library: #LDSCRIPT= ${.CURDIR}/${MACHINE_CPUARCH}/elf_rtld.x diff --git a/share/mk/bsd.cpu.mk b/share/mk/bsd.cpu.mk index 5453bd4..f0da4ae 100644 --- a/share/mk/bsd.cpu.mk +++ b/share/mk/bsd.cpu.mk @@ -267,6 +267,27 @@ _CPUCFLAGS += -mfloat-abi=softfp CFLAGS += ${_CPUCFLAGS} .endif +# +# Prohibit the compiler from emitting SIMD instructions. +# These flags are added to CFLAGS in areas where the extra context-switch +# cost outweighs the advantages of SIMD instructions. +# +# gcc: +# Setting -mno-mmx implies -mno-3dnow +# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3 and -mfpmath=387 +# +# clang: +# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa +# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and +# -mno-sse42 +# (-mfpmath= is not supported) +# +.if ${MACHINE_CPUARCH} == "i386" || ${MACHINE_CPUARCH} == "amd64" +CFLAGS_NO_SIMD.clang= -mno-avx +CFLAGS_NO_SIMD= -mno-mmx -mno-sse +.endif +CFLAGS_NO_SIMD += ${CFLAGS_NO_SIMD.${COMPILER_TYPE}} + # Add in any architecture-specific CFLAGS. # These come from make.conf or the command line or the environment. CFLAGS += ${CFLAGS.${MACHINE_ARCH}} |
