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 -ansi 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 27.endif 28 29# 30# On the alpha, make sure that we don't use floating-point registers and 31# allow the use of BWX etc instructions (only needed for low-level i/o). 32# Also, reserve register t7 to point at per-cpu global variables. 33# 34.if ${MACHINE_ARCH} == "alpha" 35CFLAGS+= -mno-fp-regs -ffixed-8 -Wa,-mev6 36.endif 37 38# 39# For IA-64, we use r13 for the kernel globals pointer and we only use 40# a very small subset of float registers for integer divides. 41# 42.if ${MACHINE_ARCH} == "ia64" 43CFLAGS+= -ffixed-r13 -mfixed-range=f32-f127 -mno-sdata 44.endif 45 46# 47# For sparc64 we want medlow code model, and we tell gcc to use floating 48# point emulation. This avoids using floating point registers for integer 49# operations which it has a tendency to do. 50# 51.if ${MACHINE_ARCH} == "sparc64" 52CFLAGS+= -mcmodel=medlow -msoft-float 53.endif 54 55# 56# GCC 3.0 and above like to do certain optimizations based on the 57# assumption that the program is linked against libc. Stop this. 58# 59CFLAGS+= -ffreestanding 60