1# $FreeBSD$ 2 3# 4# Warning flags for compiling the kernel and components of the kernel. 5# 6# Note that the newly added -Wcast-qual is responsible for generating 7# most of the remaining warnings. Warnings introduced with -Wall will 8# also pop up, but are easier to fix. 9CWARNFLAGS?= -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes \ 10 -Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual \ 11 -fformat-extensions -std=c99 12# 13# The following flags are next up for working on: 14# -W 15 16# 17# On the i386, do not align the stack to 16-byte boundaries. Otherwise GCC 18# 2.95 adds code to the entry and exit point of every function to align the 19# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack 20# per function call. While the 16-byte alignment may benefit micro benchmarks, 21# it is probably an overall loss as it makes the code bigger (less efficient 22# use of code cache tag lines) and uses more stack (less efficient use of data 23# cache tag lines) 24# 25.if ${MACHINE_ARCH} == "i386" 26CFLAGS+= -mno-align-long-strings -mpreferred-stack-boundary=2 27INLINE_LIMIT?= 15000 28.endif 29 30# 31# On the alpha, make sure that we don't use floating-point registers and 32# allow the use of BWX etc instructions (only needed for low-level i/o). 33# Also, reserve register t7 to point at per-cpu global variables. 34# 35.if ${MACHINE_ARCH} == "alpha" 36CFLAGS+= -mno-fp-regs -ffixed-8 -Wa,-mev6 37INLINE_LIMIT?= 15000 38.endif 39 40# 41# For IA-64, we use r13 for the kernel globals pointer and we only use 42# a very small subset of float registers for integer divides. 43# 44.if ${MACHINE_ARCH} == "ia64" 45CFLAGS+= -ffixed-r13 -mfixed-range=f32-f127 -mno-sdata 46INLINE_LIMIT?= 15000 47.endif 48 49# 50# For sparc64 we want medlow code model, and we tell gcc to use floating 51# point emulation. This avoids using floating point registers for integer 52# operations which it has a tendency to do. 53# 54.if ${MACHINE_ARCH} == "sparc64" 55CFLAGS+= -mcmodel=medlow -msoft-float 56INLINE_LIMIT?= 15000 57.endif 58 59# 60# For AMD64, use a medium model for now. We'll switch to "kernel" 61# once pmap is ready. Be excessively careful to not generate FPU code. 62# 63.if ${MACHINE_ARCH} == "amd64" 64CFLAGS+= -mcmodel=kernel -mno-red-zone \ 65 -mfpmath=387 -mno-sse -mno-sse2 -mno-mmx -mno-3dnow \ 66 -msoft-float -fno-asynchronous-unwind-tables 67INLINE_LIMIT?= 20000 68.endif 69 70# 71# GCC 3.0 and above like to do certain optimizations based on the 72# assumption that the program is linked against libc. Stop this. 73# 74CFLAGS+= -ffreestanding 75