mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-18 10:35:55 +00:00
edd1f930aa
section to stop gcc generating the dwarf2 .eh_frame unwind tables. It is dead weight for the time being. Maybe it can be used to perform stack traces and/or get the location of function arguments in ddb, but that requires a dwarf2 runtime interpreter, which we do not have. Approved by: re (amd64 "safe" bits)
70 lines
2.3 KiB
Makefile
70 lines
2.3 KiB
Makefile
# $FreeBSD$
|
|
|
|
#
|
|
# Warning flags for compiling the kernel and components of the kernel.
|
|
#
|
|
# Note that the newly added -Wcast-qual is responsible for generating
|
|
# most of the remaining warnings. Warnings introduced with -Wall will
|
|
# also pop up, but are easier to fix.
|
|
CWARNFLAGS?= -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes \
|
|
-Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual \
|
|
-fformat-extensions -std=c99
|
|
#
|
|
# The following flags are next up for working on:
|
|
# -W
|
|
|
|
#
|
|
# On the i386, do not align the stack to 16-byte boundaries. Otherwise GCC
|
|
# 2.95 adds code to the entry and exit point of every function to align the
|
|
# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack
|
|
# per function call. While the 16-byte alignment may benefit micro benchmarks,
|
|
# it is probably an overall loss as it makes the code bigger (less efficient
|
|
# use of code cache tag lines) and uses more stack (less efficient use of data
|
|
# cache tag lines)
|
|
#
|
|
.if ${MACHINE_ARCH} == "i386"
|
|
CFLAGS+= -mno-align-long-strings -mpreferred-stack-boundary=2
|
|
.endif
|
|
|
|
#
|
|
# On the alpha, make sure that we don't use floating-point registers and
|
|
# allow the use of BWX etc instructions (only needed for low-level i/o).
|
|
# Also, reserve register t7 to point at per-cpu global variables.
|
|
#
|
|
.if ${MACHINE_ARCH} == "alpha"
|
|
CFLAGS+= -mno-fp-regs -ffixed-8 -Wa,-mev6
|
|
.endif
|
|
|
|
#
|
|
# For IA-64, we use r13 for the kernel globals pointer and we only use
|
|
# a very small subset of float registers for integer divides.
|
|
#
|
|
.if ${MACHINE_ARCH} == "ia64"
|
|
CFLAGS+= -ffixed-r13 -mfixed-range=f32-f127 -mno-sdata
|
|
.endif
|
|
|
|
#
|
|
# For sparc64 we want medlow code model, and we tell gcc to use floating
|
|
# point emulation. This avoids using floating point registers for integer
|
|
# operations which it has a tendency to do.
|
|
#
|
|
.if ${MACHINE_ARCH} == "sparc64"
|
|
CFLAGS+= -mcmodel=medlow -msoft-float
|
|
.endif
|
|
|
|
#
|
|
# For AMD64, use a medium model for now. We'll switch to "kernel"
|
|
# once pmap is ready. Be excessively careful to not generate FPU code.
|
|
#
|
|
.if ${MACHINE_ARCH} == "amd64"
|
|
CFLAGS+= -mcmodel=kernel -mno-red-zone \
|
|
-mfpmath=387 -mno-sse -mno-sse2 -mno-mmx -mno-3dnow \
|
|
-msoft-float -fno-asynchronous-unwind-tables
|
|
.endif
|
|
|
|
#
|
|
# GCC 3.0 and above like to do certain optimizations based on the
|
|
# assumption that the program is linked against libc. Stop this.
|
|
#
|
|
CFLAGS+= -ffreestanding
|