This patch allows developer to tell gcc which nios2 cpu features he enabled in his design. This way gcc will generate more efficient code for a specific platform.
Signed-off-by: Kirill Smirnov kirill.k.smirnov@gmail.com --- arch/nios2/Kconfig | 31 +++++++++++++++++++++++++++++++ arch/nios2/config.mk | 22 ++++++++++++++++++++++ 2 files changed, 53 insertions(+)
diff --git a/arch/nios2/Kconfig b/arch/nios2/Kconfig index bb4fb2ac3a..12be43343c 100644 --- a/arch/nios2/Kconfig +++ b/arch/nios2/Kconfig @@ -11,4 +11,35 @@ config SYS_CONFIG_NAME The header file include/configs/<CONFIG_SYS_CONFIG_NAME>.h should be included from include/config.h.
+config SYS_TUNE_CPU_FEATURES + bool "Tune cpu features" + default n + help + Tune gcc flags to reflect nios2 cpu features. + If a specific feature is enabled the corresponding + -mhw-<feature> flag is passed to gcc. Otherwise, + -mno-hw-<features> flag is passed. + +if SYS_TUNE_CPU_FEATURES + +config SYS_HW_DIV + bool "Enable div family of instructions" + default n + help + This options passes -mhw-div flag to gcc. + +config SYS_HW_MUL + bool "Enable mul family of instructions" + default y + help + This options passes -mhw-mul flag to gcc. + +config SYS_HW_MULX + bool "Enable mulx family of instructions" + default n + help + This options passes -mhw-mulx flag to gcc. + +endif + endmenu diff --git a/arch/nios2/config.mk b/arch/nios2/config.mk index 82bd887961..bbb5d7f853 100644 --- a/arch/nios2/config.mk +++ b/arch/nios2/config.mk @@ -15,5 +15,27 @@ CONFIG_STANDALONE_LOAD_ADDR ?= 0x02000000 PLATFORM_CPPFLAGS += -D__NIOS2__ PLATFORM_CPPFLAGS += -G0
+ifeq ($(CONFIG_SYS_TUNE_CPU_FEATURES),y) + +ifeq ($(CONFIG_SYS_HW_DIV),y) +PLATFORM_CPPFLAGS += -mhw-div +else +PLATFORM_CPPFLAGS += -mno-hw-div +endif + +ifeq ($(CONFIG_SYS_HW_MUL),y) +PLATFORM_CPPFLAGS += -mhw-mul +else +PLATFORM_CPPFLAGS += -mno-hw-mul +endif + +ifeq ($(CONFIG_SYS_HW_MULX),y) +PLATFORM_CPPFLAGS += -mhw-mulx +else +PLATFORM_CPPFLAGS += -mno-hw-mulx +endif + +endif + LDFLAGS_FINAL += --gc-sections PLATFORM_RELFLAGS += -ffunction-sections -fdata-sections