arc: build libgcc in U-Boot

This way we may have very limited set of functions implemented so we
save some space.

Also it allows us to build U-Boot for any ARC core with the same one
toolchain because we don't rely on pre-built libgcc.

For example:
 * we may use little-endian toolchain but build U-Boot for ether
endianess
 * we may use non-multilibbed uClibc toolchain but build U-Boot for
whatever ARC CPU flavour that current GCC supports

Private libgcc built from generic C implementation contributes only 144
bytes to .text section so we don't see significant degradation of size:
--->8---
$ arc-linux-size u-boot.libgcc-prebuilt
   text	   data	    bss	    dec	    hex	filename
 222217	  24912	 214820	 461949	  70c7d	u-boot.libgcc-prebuilt

$ arc-linux-size u-boot.libgcc-private
   text	   data	    bss	    dec	    hex	filename
 222361	  24912	 214820	 462093	  70d0d	u-boot.libgcc-private
--->8---

Also I don't notice visible performance degradation compared to
pre-built libgcc (where at least "*div*" functions are had-written in
assembly) on typical operations of downloading 10Mb uImage over TFTP and
bootm.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
master
Alexey Brodkin 9 years ago
parent 51f4999bc5
commit a67ef280f4
  1. 1
      arch/Kconfig
  2. 3
      arch/arc/Kconfig
  3. 3
      arch/arc/config.mk
  4. 2
      arch/arc/lib/Makefile
  5. 226
      arch/arc/lib/_millicodethunk.S
  6. 161
      arch/arc/lib/libgcc2.c
  7. 132
      arch/arc/lib/libgcc2.h

@ -4,6 +4,7 @@ choice
config ARC
bool "ARC architecture"
select HAVE_PRIVATE_LIBGCC
config ARM
bool "ARM architecture"

@ -4,6 +4,9 @@ menu "ARC architecture"
config SYS_ARCH
default "arc"
config USE_PRIVATE_LIBGCC
default y
config SYS_CPU
default "arcv1"

@ -12,11 +12,14 @@ endif
ifdef CONFIG_SYS_LITTLE_ENDIAN
ARC_CROSS_COMPILE := arc-buildroot-linux-uclibc-
PLATFORM_LDFLAGS += -EL
PLATFORM_CPPFLAGS += -mlittle-endian
endif
ifdef CONFIG_SYS_BIG_ENDIAN
ARC_CROSS_COMPILE := arceb-buildroot-linux-uclibc-
PLATFORM_LDFLAGS += -EB
PLATFORM_CPPFLAGS += -mbig-endian
endif
ifeq ($(CROSS_COMPILE),)

@ -20,3 +20,5 @@ obj-y += reset.o
obj-y += timer.o
obj-$(CONFIG_CMD_BOOTM) += bootm.o
lib-$(CONFIG_USE_PRIVATE_LIBGCC) += _millicodethunk.o libgcc2.o

@ -0,0 +1,226 @@
/*
* Copyright (C) 1995, 1997, 2007-2013 Free Software Foundation, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
/* ANSI concatenation macros. */
#define CONCAT1(a, b) CONCAT2(a, b)
#define CONCAT2(a, b) a ## b
/* Use the right prefix for global labels. */
#define SYM(x) CONCAT1 (__USER_LABEL_PREFIX__, x)
#ifndef WORKING_ASSEMBLER
#define abs_l abs
#define asl_l asl
#define mov_l mov
#endif
#define FUNC(X) .type SYM(X),@function
#define HIDDEN_FUNC(X) FUNC(X)` .hidden X
#define ENDFUNC0(X) .Lfe_##X: .size X,.Lfe_##X-X
#define ENDFUNC(X) ENDFUNC0(X)
.section .text
.align 4
.global SYM(__st_r13_to_r15)
.global SYM(__st_r13_to_r16)
.global SYM(__st_r13_to_r17)
.global SYM(__st_r13_to_r18)
.global SYM(__st_r13_to_r19)
.global SYM(__st_r13_to_r20)
.global SYM(__st_r13_to_r21)
.global SYM(__st_r13_to_r22)
.global SYM(__st_r13_to_r23)
.global SYM(__st_r13_to_r24)
.global SYM(__st_r13_to_r25)
HIDDEN_FUNC(__st_r13_to_r15)
HIDDEN_FUNC(__st_r13_to_r16)
HIDDEN_FUNC(__st_r13_to_r17)
HIDDEN_FUNC(__st_r13_to_r18)
HIDDEN_FUNC(__st_r13_to_r19)
HIDDEN_FUNC(__st_r13_to_r20)
HIDDEN_FUNC(__st_r13_to_r21)
HIDDEN_FUNC(__st_r13_to_r22)
HIDDEN_FUNC(__st_r13_to_r23)
HIDDEN_FUNC(__st_r13_to_r24)
HIDDEN_FUNC(__st_r13_to_r25)
.align 4
SYM(__st_r13_to_r25):
st r25, [sp,48]
SYM(__st_r13_to_r24):
st r24, [sp,44]
SYM(__st_r13_to_r23):
st r23, [sp,40]
SYM(__st_r13_to_r22):
st r22, [sp,36]
SYM(__st_r13_to_r21):
st r21, [sp,32]
SYM(__st_r13_to_r20):
st r20, [sp,28]
SYM(__st_r13_to_r19):
st r19, [sp,24]
SYM(__st_r13_to_r18):
st r18, [sp,20]
SYM(__st_r13_to_r17):
st r17, [sp,16]
SYM(__st_r13_to_r16):
st r16, [sp,12]
SYM(__st_r13_to_r15):
#ifdef __ARC700__
st r15, [sp,8] ; minimum function size to avoid stall: 6 bytes.
#else
st_s r15, [sp,8]
#endif
st_s r14, [sp,4]
j_s.d [%blink]
st_s r13, [sp,0]
ENDFUNC(__st_r13_to_r15)
ENDFUNC(__st_r13_to_r16)
ENDFUNC(__st_r13_to_r17)
ENDFUNC(__st_r13_to_r18)
ENDFUNC(__st_r13_to_r19)
ENDFUNC(__st_r13_to_r20)
ENDFUNC(__st_r13_to_r21)
ENDFUNC(__st_r13_to_r22)
ENDFUNC(__st_r13_to_r23)
ENDFUNC(__st_r13_to_r24)
ENDFUNC(__st_r13_to_r25)
.section .text
.align 4
; ==================================
; the loads
.global SYM(__ld_r13_to_r15)
.global SYM(__ld_r13_to_r16)
.global SYM(__ld_r13_to_r17)
.global SYM(__ld_r13_to_r18)
.global SYM(__ld_r13_to_r19)
.global SYM(__ld_r13_to_r20)
.global SYM(__ld_r13_to_r21)
.global SYM(__ld_r13_to_r22)
.global SYM(__ld_r13_to_r23)
.global SYM(__ld_r13_to_r24)
.global SYM(__ld_r13_to_r25)
HIDDEN_FUNC(__ld_r13_to_r15)
HIDDEN_FUNC(__ld_r13_to_r16)
HIDDEN_FUNC(__ld_r13_to_r17)
HIDDEN_FUNC(__ld_r13_to_r18)
HIDDEN_FUNC(__ld_r13_to_r19)
HIDDEN_FUNC(__ld_r13_to_r20)
HIDDEN_FUNC(__ld_r13_to_r21)
HIDDEN_FUNC(__ld_r13_to_r22)
HIDDEN_FUNC(__ld_r13_to_r23)
HIDDEN_FUNC(__ld_r13_to_r24)
HIDDEN_FUNC(__ld_r13_to_r25)
SYM(__ld_r13_to_r25):
ld r25, [sp,48]
SYM(__ld_r13_to_r24):
ld r24, [sp,44]
SYM(__ld_r13_to_r23):
ld r23, [sp,40]
SYM(__ld_r13_to_r22):
ld r22, [sp,36]
SYM(__ld_r13_to_r21):
ld r21, [sp,32]
SYM(__ld_r13_to_r20):
ld r20, [sp,28]
SYM(__ld_r13_to_r19):
ld r19, [sp,24]
SYM(__ld_r13_to_r18):
ld r18, [sp,20]
SYM(__ld_r13_to_r17):
ld r17, [sp,16]
SYM(__ld_r13_to_r16):
ld r16, [sp,12]
SYM(__ld_r13_to_r15):
#ifdef __ARC700__
ld r15, [sp,8] ; minimum function size to avoid stall: 6 bytes.
#else
ld_s r15, [sp,8]
#endif
ld_s r14, [sp,4]
j_s.d [%blink]
ld_s r13, [sp,0]
ENDFUNC(__ld_r13_to_r15)
ENDFUNC(__ld_r13_to_r16)
ENDFUNC(__ld_r13_to_r17)
ENDFUNC(__ld_r13_to_r18)
ENDFUNC(__ld_r13_to_r19)
ENDFUNC(__ld_r13_to_r20)
ENDFUNC(__ld_r13_to_r21)
ENDFUNC(__ld_r13_to_r22)
ENDFUNC(__ld_r13_to_r23)
ENDFUNC(__ld_r13_to_r24)
ENDFUNC(__ld_r13_to_r25)
.global SYM(__ld_r13_to_r14_ret)
.global SYM(__ld_r13_to_r15_ret)
.global SYM(__ld_r13_to_r16_ret)
.global SYM(__ld_r13_to_r17_ret)
.global SYM(__ld_r13_to_r18_ret)
.global SYM(__ld_r13_to_r19_ret)
.global SYM(__ld_r13_to_r20_ret)
.global SYM(__ld_r13_to_r21_ret)
.global SYM(__ld_r13_to_r22_ret)
.global SYM(__ld_r13_to_r23_ret)
.global SYM(__ld_r13_to_r24_ret)
.global SYM(__ld_r13_to_r25_ret)
HIDDEN_FUNC(__ld_r13_to_r14_ret)
HIDDEN_FUNC(__ld_r13_to_r15_ret)
HIDDEN_FUNC(__ld_r13_to_r16_ret)
HIDDEN_FUNC(__ld_r13_to_r17_ret)
HIDDEN_FUNC(__ld_r13_to_r18_ret)
HIDDEN_FUNC(__ld_r13_to_r19_ret)
HIDDEN_FUNC(__ld_r13_to_r20_ret)
HIDDEN_FUNC(__ld_r13_to_r21_ret)
HIDDEN_FUNC(__ld_r13_to_r22_ret)
HIDDEN_FUNC(__ld_r13_to_r23_ret)
HIDDEN_FUNC(__ld_r13_to_r24_ret)
HIDDEN_FUNC(__ld_r13_to_r25_ret)
.section .text
.align 4
SYM(__ld_r13_to_r25_ret):
ld r25, [sp,48]
SYM(__ld_r13_to_r24_ret):
ld r24, [sp,44]
SYM(__ld_r13_to_r23_ret):
ld r23, [sp,40]
SYM(__ld_r13_to_r22_ret):
ld r22, [sp,36]
SYM(__ld_r13_to_r21_ret):
ld r21, [sp,32]
SYM(__ld_r13_to_r20_ret):
ld r20, [sp,28]
SYM(__ld_r13_to_r19_ret):
ld r19, [sp,24]
SYM(__ld_r13_to_r18_ret):
ld r18, [sp,20]
SYM(__ld_r13_to_r17_ret):
ld r17, [sp,16]
SYM(__ld_r13_to_r16_ret):
ld r16, [sp,12]
SYM(__ld_r13_to_r15_ret):
ld r15, [sp,8]
SYM(__ld_r13_to_r14_ret):
ld blink,[sp,r12]
ld_s r14, [sp,4]
ld.ab r13, [sp,r12]
j_s.d [%blink]
add_s sp,sp,4
ENDFUNC(__ld_r13_to_r14_ret)
ENDFUNC(__ld_r13_to_r15_ret)
ENDFUNC(__ld_r13_to_r16_ret)
ENDFUNC(__ld_r13_to_r17_ret)
ENDFUNC(__ld_r13_to_r18_ret)
ENDFUNC(__ld_r13_to_r19_ret)
ENDFUNC(__ld_r13_to_r20_ret)
ENDFUNC(__ld_r13_to_r21_ret)
ENDFUNC(__ld_r13_to_r22_ret)
ENDFUNC(__ld_r13_to_r23_ret)
ENDFUNC(__ld_r13_to_r24_ret)
ENDFUNC(__ld_r13_to_r25_ret)

@ -0,0 +1,161 @@
/*
* Copyright (C) 1989-2013 Free Software Foundation, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include "libgcc2.h"
DWtype
__ashldi3(DWtype u, shift_count_type b)
{
if (b == 0)
return u;
const DWunion uu = {.ll = u};
const shift_count_type bm = W_TYPE_SIZE - b;
DWunion w;
if (bm <= 0) {
w.s.low = 0;
w.s.high = (UWtype)uu.s.low << -bm;
} else {
const UWtype carries = (UWtype) uu.s.low >> bm;
w.s.low = (UWtype)uu.s.low << b;
w.s.high = ((UWtype)uu.s.high << b) | carries;
}
return w.ll;
}
DWtype
__ashrdi3(DWtype u, shift_count_type b)
{
if (b == 0)
return u;
const DWunion uu = {.ll = u};
const shift_count_type bm = W_TYPE_SIZE - b;
DWunion w;
if (bm <= 0) {
/* w.s.high = 1..1 or 0..0 */
w.s.high = uu.s.high >> (W_TYPE_SIZE - 1);
w.s.low = uu.s.high >> -bm;
} else {
const UWtype carries = (UWtype) uu.s.high << bm;
w.s.high = uu.s.high >> b;
w.s.low = ((UWtype)uu.s.low >> b) | carries;
}
return w.ll;
}
DWtype
__lshrdi3(DWtype u, shift_count_type b)
{
if (b == 0)
return u;
const DWunion uu = {.ll = u};
const shift_count_type bm = W_TYPE_SIZE - b;
DWunion w;
if (bm <= 0) {
w.s.high = 0;
w.s.low = (UWtype)uu.s.high >> -bm;
} else {
const UWtype carries = (UWtype)uu.s.high << bm;
w.s.high = (UWtype)uu.s.high >> b;
w.s.low = ((UWtype)uu.s.low >> b) | carries;
}
return w.ll;
}
unsigned long
udivmodsi4(unsigned long num, unsigned long den, int modwanted)
{
unsigned long bit = 1;
unsigned long res = 0;
while (den < num && bit && !(den & (1L<<31))) {
den <<= 1;
bit <<= 1;
}
while (bit) {
if (num >= den) {
num -= den;
res |= bit;
}
bit >>= 1;
den >>= 1;
}
if (modwanted)
return num;
return res;
}
long
__divsi3(long a, long b)
{
int neg = 0;
long res;
if (a < 0) {
a = -a;
neg = !neg;
}
if (b < 0) {
b = -b;
neg = !neg;
}
res = udivmodsi4(a, b, 0);
if (neg)
res = -res;
return res;
}
long
__modsi3(long a, long b)
{
int neg = 0;
long res;
if (a < 0) {
a = -a;
neg = 1;
}
if (b < 0)
b = -b;
res = udivmodsi4(a, b, 1);
if (neg)
res = -res;
return res;
}
long
__udivsi3(long a, long b)
{
return udivmodsi4(a, b, 0);
}
long
__umodsi3(long a, long b)
{
return udivmodsi4(a, b, 1);
}

@ -0,0 +1,132 @@
/*
* Copyright (C) 1989-2013 Free Software Foundation, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef __ASM_LIBGCC_H
#define __ASM_LIBGCC_H
#define UNITS_PER_WORD 4 /* for ARC */
#define BITS_PER_UNIT 8 /* for ARC */
#define W_TYPE_SIZE (4 * BITS_PER_UNIT)
#define MIN_UNITS_PER_WORD UNITS_PER_WORD
/* Work out the largest "word" size that we can deal with on this target. */
#if MIN_UNITS_PER_WORD > 4
# define LIBGCC2_MAX_UNITS_PER_WORD 8
#elif (MIN_UNITS_PER_WORD > 2 \
|| (MIN_UNITS_PER_WORD > 1 && __SIZEOF_LONG_LONG__ > 4))
# define LIBGCC2_MAX_UNITS_PER_WORD 4
#else
# define LIBGCC2_MAX_UNITS_PER_WORD MIN_UNITS_PER_WORD
#endif
/* Work out what word size we are using for this compilation.
The value can be set on the command line. */
#ifndef LIBGCC2_UNITS_PER_WORD
#define LIBGCC2_UNITS_PER_WORD LIBGCC2_MAX_UNITS_PER_WORD
#endif
typedef int QItype __attribute__ ((mode (QI)));
typedef unsigned int UQItype __attribute__ ((mode (QI)));
typedef int HItype __attribute__ ((mode (HI)));
typedef unsigned int UHItype __attribute__ ((mode (HI)));
#if MIN_UNITS_PER_WORD > 1
/* These typedefs are usually forbidden on dsp's with UNITS_PER_WORD 1. */
typedef int SItype __attribute__ ((mode (SI)));
typedef unsigned int USItype __attribute__ ((mode (SI)));
#if __SIZEOF_LONG_LONG__ > 4
/* These typedefs are usually forbidden on archs with UNITS_PER_WORD 2. */
typedef int DItype __attribute__ ((mode (DI)));
typedef unsigned int UDItype __attribute__ ((mode (DI)));
#if MIN_UNITS_PER_WORD > 4
/* These typedefs are usually forbidden on archs with UNITS_PER_WORD 4. */
typedef int TItype __attribute__ ((mode (TI)));
typedef unsigned int UTItype __attribute__ ((mode (TI)));
#endif
#endif
#endif
#if LIBGCC2_UNITS_PER_WORD == 8
#define W_TYPE_SIZE (8 * BITS_PER_UNIT)
#define Wtype DItype
#define UWtype UDItype
#define HWtype DItype
#define UHWtype UDItype
#define DWtype TItype
#define UDWtype UTItype
#ifdef LIBGCC2_GNU_PREFIX
#define __NW(a,b) __gnu_ ## a ## di ## b
#define __NDW(a,b) __gnu_ ## a ## ti ## b
#else
#define __NW(a,b) __ ## a ## di ## b
#define __NDW(a,b) __ ## a ## ti ## b
#endif
#elif LIBGCC2_UNITS_PER_WORD == 4
#define W_TYPE_SIZE (4 * BITS_PER_UNIT)
#define Wtype SItype
#define UWtype USItype
#define HWtype SItype
#define UHWtype USItype
#define DWtype DItype
#define UDWtype UDItype
#ifdef LIBGCC2_GNU_PREFIX
#define __NW(a,b) __gnu_ ## a ## si ## b
#define __NDW(a,b) __gnu_ ## a ## di ## b
#else
#define __NW(a,b) __ ## a ## si ## b
#define __NDW(a,b) __ ## a ## di ## b
#endif
#elif LIBGCC2_UNITS_PER_WORD == 2
#define W_TYPE_SIZE (2 * BITS_PER_UNIT)
#define Wtype HItype
#define UWtype UHItype
#define HWtype HItype
#define UHWtype UHItype
#define DWtype SItype
#define UDWtype USItype
#ifdef LIBGCC2_GNU_PREFIX
#define __NW(a,b) __gnu_ ## a ## hi ## b
#define __NDW(a,b) __gnu_ ## a ## si ## b
#else
#define __NW(a,b) __ ## a ## hi ## b
#define __NDW(a,b) __ ## a ## si ## b
#endif
#else
#define W_TYPE_SIZE BITS_PER_UNIT
#define Wtype QItype
#define UWtype UQItype
#define HWtype QItype
#define UHWtype UQItype
#define DWtype HItype
#define UDWtype UHItype
#ifdef LIBGCC2_GNU_PREFIX
#define __NW(a,b) __gnu_ ## a ## qi ## b
#define __NDW(a,b) __gnu_ ## a ## hi ## b
#else
#define __NW(a,b) __ ## a ## qi ## b
#define __NDW(a,b) __ ## a ## hi ## b
#endif
#endif
typedef int shift_count_type __attribute__((mode (__libgcc_shift_count__)));
#if __BYTE_ORDER__ != __ORDER_LITTLE_ENDIAN__
struct DWstruct {Wtype high, low;};
#else
struct DWstruct {Wtype low, high;};
#endif
/* We need this union to unpack/pack DImode values, since we don't have
any arithmetic yet. Incoming DImode parameters are stored into the
`ll' field, and the unpacked result is read from the struct `s'. */
typedef union {
struct DWstruct s;
DWtype ll;
} DWunion;
#endif /* __ASM_LIBGCC_H */
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