Skip to content

R
raspberrypi-kernel

openeuler / raspberrypi-kernel

通知 13
Star 1
Fork 0
R
raspberrypi-kernel
提交 1b35a57b 编写于 作者: D David S. Miller
浏览文件
操作

sparc32: Kill off software 32-bit multiply/divide routines. 

For the explicit calls to .udiv/.umul in assembler, I made a
mechanical (read as: safe) transformation.  I didn't attempt
to make any simplifications.

In particular, __ndelay and __udelay can be simplified significantly.
Some of the %y reads are unnecessary and these routines have no need
any longer for allocating a register window, they can be leaf
functions.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
上级 2119ff6d
隐藏空白更改
内联 并排
Showing with 24 addition and 2129 deletion
arch/sparc/kernel/entry.S
浏览文件 @ 1b35a57b
......@@ -1161,11 +1161,13 @@ fpload:
.globl __ndelay
__ndelay:
save %sp, -STACKFRAME_SZ, %sp
mov %i0, %o0
call .umul ! round multiplier up so large ns ok
mov 0x1ae, %o1 ! 2**32 / (1 000 000 000 / HZ)
call .umul
mov %i1, %o1 ! udelay_val
mov %i0, %o0 ! round multiplier up so large ns ok
mov 0x1ae, %o1 ! 2**32 / (1 000 000 000 / HZ)
umul %o0, %o1, %o0
rd %y, %o1
mov %i1, %o1 ! udelay_val
umul %o0, %o1, %o0
rd %y, %o1
ba delay_continue
mov %o1, %o0 ! >>32 later for better resolution
......@@ -1174,18 +1176,21 @@ __udelay:
save %sp, -STACKFRAME_SZ, %sp
mov %i0, %o0
sethi %hi(0x10c7), %o1 ! round multiplier up so large us ok
call .umul
or %o1, %lo(0x10c7), %o1 ! 2**32 / 1 000 000
call .umul
mov %i1, %o1 ! udelay_val
or %o1, %lo(0x10c7), %o1 ! 2**32 / 1 000 000
umul %o0, %o1, %o0
rd %y, %o1
mov %i1, %o1 ! udelay_val
umul %o0, %o1, %o0
rd %y, %o1
sethi %hi(0x028f4b62), %l0 ! Add in rounding constant * 2**32,
or %g0, %lo(0x028f4b62), %l0
addcc %o0, %l0, %o0 ! 2**32 * 0.009 999
bcs,a 3f
add %o1, 0x01, %o1
3:
call .umul
mov HZ, %o0 ! >>32 earlier for wider range
mov HZ, %o0 ! >>32 earlier for wider range
umul %o0, %o1, %o0
rd %y, %o1
delay_continue:
cmp %o0, 0x0
......
arch/sparc/kernel/head_32.S
浏览文件 @ 1b35a57b
......@@ -746,51 +746,6 @@ sun4d_init:
/* Fall through to sun4m_init */
sun4m_init:
#define PATCH_IT(dst, src) \
set (dst), %g5; \
set (src), %g4; \
ld [%g4], %g3; \
st %g3, [%g5]; \
ld [%g4+0x4], %g3; \
st %g3, [%g5+0x4];
/* Signed multiply. */
PATCH_IT(.mul, .mul_patch)
PATCH_IT(.mul+0x08, .mul_patch+0x08)
/* Signed remainder. */
PATCH_IT(.rem, .rem_patch)
PATCH_IT(.rem+0x08, .rem_patch+0x08)
PATCH_IT(.rem+0x10, .rem_patch+0x10)
PATCH_IT(.rem+0x18, .rem_patch+0x18)
PATCH_IT(.rem+0x20, .rem_patch+0x20)
PATCH_IT(.rem+0x28, .rem_patch+0x28)
/* Signed division. */
PATCH_IT(.div, .div_patch)
PATCH_IT(.div+0x08, .div_patch+0x08)
PATCH_IT(.div+0x10, .div_patch+0x10)
PATCH_IT(.div+0x18, .div_patch+0x18)
PATCH_IT(.div+0x20, .div_patch+0x20)
/* Unsigned multiply. */
PATCH_IT(.umul, .umul_patch)
PATCH_IT(.umul+0x08, .umul_patch+0x08)
/* Unsigned remainder. */
PATCH_IT(.urem, .urem_patch)
PATCH_IT(.urem+0x08, .urem_patch+0x08)
PATCH_IT(.urem+0x10, .urem_patch+0x10)
PATCH_IT(.urem+0x18, .urem_patch+0x18)
/* Unsigned division. */
PATCH_IT(.udiv, .udiv_patch)
PATCH_IT(.udiv+0x08, .udiv_patch+0x08)
PATCH_IT(.udiv+0x10, .udiv_patch+0x10)
#undef PATCH_IT
/* Ok, the PROM could have done funny things and apple cider could still
* be sitting in the fault status/address registers. Read them all to
* clear them so we don't get magic faults later on.
......
arch/sparc/kernel/kernel.h
浏览文件 @ 1b35a57b
......@@ -32,9 +32,6 @@ extern void cpu_probe(void);
/* traps_32.c */
extern void handle_hw_divzero(struct pt_regs *regs, unsigned long pc,
unsigned long npc, unsigned long psr);
/* muldiv.c */
extern int do_user_muldiv (struct pt_regs *, unsigned long);
/* irq_32.c */
extern struct irqaction static_irqaction[];
extern int static_irq_count;
......
arch/sparc/kernel/module.c
浏览文件 @ 1b35a57b
......@@ -32,26 +32,11 @@ static void *module_map(unsigned long size)
GFP_KERNEL, PAGE_KERNEL, -1,
__builtin_return_address(0));
}
static char *dot2underscore(char *name)
{
return name;
}
#else
static void *module_map(unsigned long size)
{
return vmalloc(size);
}
/* Replace references to .func with _Func */
static char *dot2underscore(char *name)
{
if (name[0] == '.') {
name[0] = '_';
name[1] = toupper(name[1]);
}
return name;
}
#endif /* CONFIG_SPARC64 */
void *module_alloc(unsigned long size)
......@@ -93,12 +78,8 @@ int module_frob_arch_sections(Elf_Ehdr *hdr,
for (i = 1; i < sechdrs[symidx].sh_size / sizeof(Elf_Sym); i++) {
if (sym[i].st_shndx == SHN_UNDEF) {
if (ELF_ST_TYPE(sym[i].st_info) == STT_REGISTER) {
if (ELF_ST_TYPE(sym[i].st_info) == STT_REGISTER)
sym[i].st_shndx = SHN_ABS;
} else {
char *name = strtab + sym[i].st_name;
dot2underscore(name);
}
}
}
return 0;
......
arch/sparc/kernel/muldiv.c 已删除 100644 → 0
浏览文件 @ 2119ff6d
/*
* muldiv.c: Hardware multiply/division illegal instruction trap
* for sun4c/sun4 (which do not have those instructions)
*
* Copyright (C) 1996 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
* Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
*
* 2004-12-25 Krzysztof Helt (krzysztof.h1@wp.pl)
* - fixed registers constrains in inline assembly declarations
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <asm/ptrace.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include "kernel.h"
/* #define DEBUG_MULDIV */
static inline int has_imm13(int insn)
{
return (insn & 0x2000);
}
static inline int is_foocc(int insn)
{
return (insn & 0x800000);
}
static inline int sign_extend_imm13(int imm)
{
return imm << 19 >> 19;
}
static inline void advance(struct pt_regs *regs)
{
regs->pc = regs->npc;
regs->npc += 4;
}
static inline void maybe_flush_windows(unsigned int rs1, unsigned int rs2,
unsigned int rd)
{
if(rs2 >= 16 || rs1 >= 16 || rd >= 16) {
/* Wheee... */
__asm__ __volatile__("save %sp, -0x40, %sp\n\t"
"save %sp, -0x40, %sp\n\t"
"save %sp, -0x40, %sp\n\t"
"save %sp, -0x40, %sp\n\t"
"save %sp, -0x40, %sp\n\t"
"save %sp, -0x40, %sp\n\t"
"save %sp, -0x40, %sp\n\t"
"restore; restore; restore; restore;\n\t"
"restore; restore; restore;\n\t");
}
}
#define fetch_reg(reg, regs) ({ \
struct reg_window32 __user *win; \
register unsigned long ret; \
\
if (!(reg)) ret = 0; \
else if ((reg) < 16) { \
ret = regs->u_regs[(reg)]; \
} else { \
/* Ho hum, the slightly complicated case. */ \
win = (struct reg_window32 __user *)regs->u_regs[UREG_FP];\
if (get_user (ret, &win->locals[(reg) - 16])) return -1;\
} \
ret; \
})
static inline int
store_reg(unsigned int result, unsigned int reg, struct pt_regs *regs)
{
struct reg_window32 __user *win;
if (!reg)
return 0;
if (reg < 16) {
regs->u_regs[reg] = result;
return 0;
} else {
/* need to use put_user() in this case: */
win = (struct reg_window32 __user *) regs->u_regs[UREG_FP];
return (put_user(result, &win->locals[reg - 16]));
}
}
/* Should return 0 if mul/div emulation succeeded and SIGILL should
* not be issued.
*/
int do_user_muldiv(struct pt_regs *regs, unsigned long pc)
{
unsigned int insn;
int inst;
unsigned int rs1, rs2, rdv;
if (!pc)
return -1; /* This happens to often, I think */
if (get_user (insn, (unsigned int __user *)pc))
return -1;
if ((insn & 0xc1400000) != 0x80400000)
return -1;
inst = ((insn >> 19) & 0xf);
if ((inst & 0xe) != 10 && (inst & 0xe) != 14)
return -1;
/* Now we know we have to do something with umul, smul, udiv or sdiv */
rs1 = (insn >> 14) & 0x1f;
rs2 = insn & 0x1f;
rdv = (insn >> 25) & 0x1f;
if (has_imm13(insn)) {
maybe_flush_windows(rs1, 0, rdv);
rs2 = sign_extend_imm13(insn);
} else {
maybe_flush_windows(rs1, rs2, rdv);
rs2 = fetch_reg(rs2, regs);
}
rs1 = fetch_reg(rs1, regs);
switch (inst) {
case 10: /* umul */
#ifdef DEBUG_MULDIV
printk ("unsigned muldiv: 0x%x * 0x%x = ", rs1, rs2);
#endif
__asm__ __volatile__ ("\n\t"
"mov %0, %%o0\n\t"
"call .umul\n\t"
" mov %1, %%o1\n\t"
"mov %%o0, %0\n\t"
"mov %%o1, %1\n\t"
: "=r" (rs1), "=r" (rs2)
: "0" (rs1), "1" (rs2)
: "o0", "o1", "o2", "o3", "o4", "o5", "o7", "cc");
#ifdef DEBUG_MULDIV
printk ("0x%x%08x\n", rs2, rs1);
#endif
if (store_reg(rs1, rdv, regs))
return -1;
regs->y = rs2;
break;
case 11: /* smul */
#ifdef DEBUG_MULDIV
printk ("signed muldiv: 0x%x * 0x%x = ", rs1, rs2);
#endif
__asm__ __volatile__ ("\n\t"
"mov %0, %%o0\n\t"
"call .mul\n\t"
" mov %1, %%o1\n\t"
"mov %%o0, %0\n\t"
"mov %%o1, %1\n\t"
: "=r" (rs1), "=r" (rs2)
: "0" (rs1), "1" (rs2)
: "o0", "o1", "o2", "o3", "o4", "o5", "o7", "cc");
#ifdef DEBUG_MULDIV
printk ("0x%x%08x\n", rs2, rs1);
#endif
if (store_reg(rs1, rdv, regs))
return -1;
regs->y = rs2;
break;
case 14: /* udiv */
#ifdef DEBUG_MULDIV
printk ("unsigned muldiv: 0x%x%08x / 0x%x = ", regs->y, rs1, rs2);
#endif
if (!rs2) {
#ifdef DEBUG_MULDIV
printk ("DIVISION BY ZERO\n");
#endif
handle_hw_divzero (regs, pc, regs->npc, regs->psr);
return 0;
}
__asm__ __volatile__ ("\n\t"
"mov %2, %%o0\n\t"
"mov %0, %%o1\n\t"
"mov %%g0, %%o2\n\t"
"call __udivdi3\n\t"
" mov %1, %%o3\n\t"
"mov %%o1, %0\n\t"
"mov %%o0, %1\n\t"
: "=r" (rs1), "=r" (rs2)
: "r" (regs->y), "0" (rs1), "1" (rs2)
: "o0", "o1", "o2", "o3", "o4", "o5", "o7",
"g1", "g2", "g3", "cc");
#ifdef DEBUG_MULDIV
printk ("0x%x\n", rs1);
#endif
if (store_reg(rs1, rdv, regs))
return -1;
break;
case 15: /* sdiv */
#ifdef DEBUG_MULDIV
printk ("signed muldiv: 0x%x%08x / 0x%x = ", regs->y, rs1, rs2);
#endif
if (!rs2) {
#ifdef DEBUG_MULDIV
printk ("DIVISION BY ZERO\n");
#endif
handle_hw_divzero (regs, pc, regs->npc, regs->psr);
return 0;
}
__asm__ __volatile__ ("\n\t"
"mov %2, %%o0\n\t"
"mov %0, %%o1\n\t"
"mov %%g0, %%o2\n\t"
"call __divdi3\n\t"
" mov %1, %%o3\n\t"
"mov %%o1, %0\n\t"
"mov %%o0, %1\n\t"
: "=r" (rs1), "=r" (rs2)
: "r" (regs->y), "0" (rs1), "1" (rs2)
: "o0", "o1", "o2", "o3", "o4", "o5", "o7",
"g1", "g2", "g3", "cc");
#ifdef DEBUG_MULDIV
printk ("0x%x\n", rs1);
#endif
if (store_reg(rs1, rdv, regs))
return -1;
break;
}
if (is_foocc (insn)) {
regs->psr &= ~PSR_ICC;
if ((inst & 0xe) == 14) {
/* ?div */
if (rs2) regs->psr |= PSR_V;
}
if (!rs1) regs->psr |= PSR_Z;
if (((int)rs1) < 0) regs->psr |= PSR_N;
#ifdef DEBUG_MULDIV
printk ("psr muldiv: %08x\n", regs->psr);
#endif
}
advance(regs);
return 0;
}
arch/sparc/kernel/traps_32.c
浏览文件 @ 1b35a57b
......@@ -120,8 +120,6 @@ void do_illegal_instruction(struct pt_regs *regs, unsigned long pc, unsigned lon
printk("Ill instr. at pc=%08lx instruction is %08lx\n",
regs->pc, *(unsigned long *)regs->pc);
#endif
if (!do_user_muldiv (regs, pc))
return;
info.si_signo = SIGILL;
info.si_errno = 0;
......
arch/sparc/lib/Makefile
浏览文件 @ 1b35a57b
......@@ -4,7 +4,7 @@
asflags-y := -ansi -DST_DIV0=0x02
ccflags-y := -Werror
lib-$(CONFIG_SPARC32) += mul.o rem.o sdiv.o udiv.o umul.o urem.o ashrdi3.o
lib-$(CONFIG_SPARC32) += ashrdi3.o
lib-$(CONFIG_SPARC32) += memcpy.o memset.o
lib-y += strlen.o
lib-y += checksum_$(BITS).o
......
arch/sparc/lib/divdi3.S
浏览文件 @ 1b35a57b
......@@ -19,7 +19,6 @@ Boston, MA 02111-1307, USA. */
.text
.align 4
.global .udiv
.globl __divdi3
__divdi3:
save %sp,-104,%sp
......@@ -83,8 +82,9 @@ __divdi3:
bne .LL85
mov %i0,%o2
mov 1,%o0
call .udiv,0
mov 0,%o1
wr %g0, 0, %y
udiv %o0, %o1, %o0
mov %o0,%o4
mov %i0,%o2
.LL85:
......
arch/sparc/lib/ksyms.c
浏览文件 @ 1b35a57b
......@@ -61,16 +61,6 @@ extern void ___rw_read_try(void);
extern void ___rw_read_exit(void);
extern void ___rw_write_enter(void);
/* Alias functions whose names begin with "." and export the aliases.
* The module references will be fixed up by module_frob_arch_sections.
*/
extern int _Div(int, int);
extern int _Mul(int, int);
extern int _Rem(int, int);
extern unsigned _Udiv(unsigned, unsigned);
extern unsigned _Umul(unsigned, unsigned);
extern unsigned _Urem(unsigned, unsigned);
/* Networking helper routines. */
EXPORT_SYMBOL(__csum_partial_copy_sparc_generic);
......@@ -95,13 +85,6 @@ EXPORT_SYMBOL(__ashldi3);
EXPORT_SYMBOL(__lshrdi3);
EXPORT_SYMBOL(__muldi3);
EXPORT_SYMBOL(__divdi3);
EXPORT_SYMBOL(_Rem);
EXPORT_SYMBOL(_Urem);
EXPORT_SYMBOL(_Mul);
EXPORT_SYMBOL(_Umul);
EXPORT_SYMBOL(_Div);
EXPORT_SYMBOL(_Udiv);
#endif
/*
......
arch/sparc/lib/mul.S 已删除 100644 → 0
浏览文件 @ 2119ff6d
/*
* mul.S: This routine was taken from glibc-1.09 and is covered
* by the GNU Library General Public License Version 2.
*/
/*
* Signed multiply, from Appendix E of the Sparc Version 8
* Architecture Manual.
*/
/*
* Returns %o0 * %o1 in %o1%o0 (i.e., %o1 holds the upper 32 bits of
* the 64-bit product).
*
* This code optimizes short (less than 13-bit) multiplies.
*/
.globl .mul
.globl _Mul
.mul:
_Mul: /* needed for export */
mov %o0, %y ! multiplier -> Y
andncc %o0, 0xfff, %g0 ! test bits 12..31
be Lmul_shortway ! if zero, can do it the short way
andcc %g0, %g0, %o4 ! zero the partial product and clear N and V
/*
* Long multiply. 32 steps, followed by a final shift step.
*/
mulscc %o4, %o1, %o4 ! 1
mulscc %o4, %o1, %o4 ! 2
mulscc %o4, %o1, %o4 ! 3
mulscc %o4, %o1, %o4 ! 4
mulscc %o4, %o1, %o4 ! 5
mulscc %o4, %o1, %o4 ! 6
mulscc %o4, %o1, %o4 ! 7
mulscc %o4, %o1, %o4 ! 8
mulscc %o4, %o1, %o4 ! 9
mulscc %o4, %o1, %o4 ! 10
mulscc %o4, %o1, %o4 ! 11
mulscc %o4, %o1, %o4 ! 12
mulscc %o4, %o1, %o4 ! 13
mulscc %o4, %o1, %o4 ! 14
mulscc %o4, %o1, %o4 ! 15
mulscc %o4, %o1, %o4 ! 16
mulscc %o4, %o1, %o4 ! 17
mulscc %o4, %o1, %o4 ! 18
mulscc %o4, %o1, %o4 ! 19
mulscc %o4, %o1, %o4 ! 20
mulscc %o4, %o1, %o4 ! 21
mulscc %o4, %o1, %o4 ! 22
mulscc %o4, %o1, %o4 ! 23
mulscc %o4, %o1, %o4 ! 24
mulscc %o4, %o1, %o4 ! 25
mulscc %o4, %o1, %o4 ! 26
mulscc %o4, %o1, %o4 ! 27
mulscc %o4, %o1, %o4 ! 28
mulscc %o4, %o1, %o4 ! 29
mulscc %o4, %o1, %o4 ! 30
mulscc %o4, %o1, %o4 ! 31
mulscc %o4, %o1, %o4 ! 32
mulscc %o4, %g0, %o4 ! final shift
! If %o0 was negative, the result is
! (%o0 * %o1) + (%o1 << 32))
! We fix that here.
#if 0
tst %o0
bge 1f
rd %y, %o0
! %o0 was indeed negative; fix upper 32 bits of result by subtracting
! %o1 (i.e., return %o4 - %o1 in %o1).
retl
sub %o4, %o1, %o1
1:
retl
mov %o4, %o1
#else
/* Faster code adapted from tege@sics.se's code for umul.S. */
sra %o0, 31, %o2 ! make mask from sign bit
and %o1, %o2, %o2 ! %o2 = 0 or %o1, depending on sign of %o0
rd %y, %o0 ! get lower half of product
retl
sub %o4, %o2, %o1 ! subtract compensation
! and put upper half in place
#endif
Lmul_shortway:
/*
* Short multiply. 12 steps, followed by a final shift step.
* The resulting bits are off by 12 and (32-12) = 20 bit positions,
* but there is no problem with %o0 being negative (unlike above).
*/
mulscc %o4, %o1, %o4 ! 1
mulscc %o4, %o1, %o4 ! 2
mulscc %o4, %o1, %o4 ! 3
mulscc %o4, %o1, %o4 ! 4
mulscc %o4, %o1, %o4 ! 5
mulscc %o4, %o1, %o4 ! 6
mulscc %o4, %o1, %o4 ! 7
mulscc %o4, %o1, %o4 ! 8
mulscc %o4, %o1, %o4 ! 9
mulscc %o4, %o1, %o4 ! 10
mulscc %o4, %o1, %o4 ! 11
mulscc %o4, %o1, %o4 ! 12
mulscc %o4, %g0, %o4 ! final shift
/*
* %o4 has 20 of the bits that should be in the low part of the
* result; %y has the bottom 12 (as %y's top 12). That is:
*
* %o4 %y
* +----------------+----------------+
* | -12- | -20- | -12- | -20- |
* +------(---------+------)---------+
* --hi-- ----low-part----
*
* The upper 12 bits of %o4 should be sign-extended to form the
* high part of the product (i.e., highpart = %o4 >> 20).
*/
rd %y, %o5
sll %o4, 12, %o0 ! shift middle bits left 12
srl %o5, 20, %o5 ! shift low bits right 20, zero fill at left
or %o5, %o0, %o0 ! construct low part of result
retl
sra %o4, 20, %o1 ! ... and extract high part of result
.globl .mul_patch
.mul_patch:
smul %o0, %o1, %o0
retl
rd %y, %o1
nop
arch/sparc/lib/muldi3.S
浏览文件 @ 1b35a57b
......@@ -63,12 +63,12 @@ __muldi3:
rd %y, %o1
mov %o1, %l3
mov %i1, %o0
call .umul
mov %i2, %o1
umul %o0, %o1, %o0
mov %o0, %l0
mov %i0, %o0
call .umul
mov %i3, %o1
umul %o0, %o1, %o0
add %l0, %o0, %l0
mov %l2, %i0
add %l2, %l0, %i0
......
arch/sparc/lib/rem.S 已删除 100644 → 0
浏览文件 @ 2119ff6d
/*
* rem.S: This routine was taken from glibc-1.09 and is covered
* by the GNU Library General Public License Version 2.
*/
/* This file is generated from divrem.m4; DO NOT EDIT! */
/*
* Division and remainder, from Appendix E of the Sparc Version 8
* Architecture Manual, with fixes from Gordon Irlam.
*/
/*
* Input: dividend and divisor in %o0 and %o1 respectively.
*
* m4 parameters:
* .rem name of function to generate
* rem rem=div => %o0 / %o1; rem=rem => %o0 % %o1
* true true=true => signed; true=false => unsigned
*
* Algorithm parameters:
* N how many bits per iteration we try to get (4)
* WORDSIZE total number of bits (32)
*
* Derived constants:
* TOPBITS number of bits in the top decade of a number
*
* Important variables:
* Q the partial quotient under development (initially 0)
* R the remainder so far, initially the dividend
* ITER number of main division loop iterations required;
* equal to ceil(log2(quotient) / N). Note that this
* is the log base (2^N) of the quotient.
* V the current comparand, initially divisor*2^(ITER*N-1)
*
* Cost:
* Current estimate for non-large dividend is
* ceil(log2(quotient) / N) * (10 + 7N/2) + C
* A large dividend is one greater than 2^(31-TOPBITS) and takes a
* different path, as the upper bits of the quotient must be developed
* one bit at a time.
*/
.globl .rem
.globl _Rem
.rem:
_Rem: /* needed for export */
! compute sign of result; if neither is negative, no problem
orcc %o1, %o0, %g0 ! either negative?
bge 2f ! no, go do the divide
mov %o0, %g2 ! compute sign in any case
tst %o1
bge 1f
tst %o0
! %o1 is definitely negative; %o0 might also be negative
bge 2f ! if %o0 not negative...
sub %g0, %o1, %o1 ! in any case, make %o1 nonneg
1: ! %o0 is negative, %o1 is nonnegative
sub %g0, %o0, %o0 ! make %o0 nonnegative
2:
! Ready to divide. Compute size of quotient; scale comparand.
orcc %o1, %g0, %o5
bne 1f
mov %o0, %o3
! Divide by zero trap. If it returns, return 0 (about as
! wrong as possible, but that is what SunOS does...).
ta ST_DIV0
retl
clr %o0
1:
cmp %o3, %o5 ! if %o1 exceeds %o0, done
blu Lgot_result ! (and algorithm fails otherwise)
clr %o2
sethi %hi(1 << (32 - 4 - 1)), %g1
cmp %o3, %g1
blu Lnot_really_big
clr %o4
! Here the dividend is >= 2**(31-N) or so. We must be careful here,
! as our usual N-at-a-shot divide step will cause overflow and havoc.
! The number of bits in the result here is N*ITER+SC, where SC <= N.
! Compute ITER in an unorthodox manner: know we need to shift V into
! the top decade: so do not even bother to compare to R.
1:
cmp %o5, %g1
bgeu 3f
mov 1, %g7
sll %o5, 4, %o5
b 1b
add %o4, 1, %o4
! Now compute %g7.
2:
addcc %o5, %o5, %o5
bcc Lnot_too_big
add %g7, 1, %g7
! We get here if the %o1 overflowed while shifting.
! This means that %o3 has the high-order bit set.
! Restore %o5 and subtract from %o3.
sll %g1, 4, %g1 ! high order bit
srl %o5, 1, %o5 ! rest of %o5
add %o5, %g1, %o5
b Ldo_single_div
sub %g7, 1, %g7
Lnot_too_big:
3:
cmp %o5, %o3
blu 2b
nop
be Ldo_single_div
nop
/* NB: these are commented out in the V8-Sparc manual as well */
/* (I do not understand this) */
! %o5 > %o3: went too far: back up 1 step
! srl %o5, 1, %o5
! dec %g7
! do single-bit divide steps
!
! We have to be careful here. We know that %o3 >= %o5, so we can do the
! first divide step without thinking. BUT, the others are conditional,
! and are only done if %o3 >= 0. Because both %o3 and %o5 may have the high-
! order bit set in the first step, just falling into the regular
! division loop will mess up the first time around.
! So we unroll slightly...
Ldo_single_div:
subcc %g7, 1, %g7
bl Lend_regular_divide
nop
sub %o3, %o5, %o3
mov 1, %o2
b Lend_single_divloop
nop
Lsingle_divloop:
sll %o2, 1, %o2
bl 1f
srl %o5, 1, %o5
! %o3 >= 0
sub %o3, %o5, %o3
b 2f
add %o2, 1, %o2
1: ! %o3 < 0
add %o3, %o5, %o3
sub %o2, 1, %o2
2:
Lend_single_divloop:
subcc %g7, 1, %g7
bge Lsingle_divloop
tst %o3
b,a Lend_regular_divide
Lnot_really_big:
1:
sll %o5, 4, %o5
cmp %o5, %o3
bleu 1b
addcc %o4, 1, %o4
be Lgot_result
sub %o4, 1, %o4
tst %o3 ! set up for initial iteration
Ldivloop:
sll %o2, 4, %o2
! depth 1, accumulated bits 0
bl L.1.16
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 2, accumulated bits 1
bl L.2.17
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 3, accumulated bits 3
bl L.3.19
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits 7
bl L.4.23
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (7*2+1), %o2
L.4.23:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (7*2-1), %o2
L.3.19:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits 5
bl L.4.21
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (5*2+1), %o2
L.4.21:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (5*2-1), %o2
L.2.17:
! remainder is negative
addcc %o3,%o5,%o3
! depth 3, accumulated bits 1
bl L.3.17
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits 3
bl L.4.19
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (3*2+1), %o2
L.4.19:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (3*2-1), %o2
L.3.17:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits 1
bl L.4.17
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (1*2+1), %o2
L.4.17:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (1*2-1), %o2
L.1.16:
! remainder is negative
addcc %o3,%o5,%o3
! depth 2, accumulated bits -1
bl L.2.15
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 3, accumulated bits -1
bl L.3.15
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits -1
bl L.4.15
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-1*2+1), %o2
L.4.15:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-1*2-1), %o2
L.3.15:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits -3
bl L.4.13
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-3*2+1), %o2
L.4.13:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-3*2-1), %o2
L.2.15:
! remainder is negative
addcc %o3,%o5,%o3
! depth 3, accumulated bits -3
bl L.3.13
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits -5
bl L.4.11
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-5*2+1), %o2
L.4.11:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-5*2-1), %o2
L.3.13:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits -7
bl L.4.9
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-7*2+1), %o2
L.4.9:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-7*2-1), %o2
9:
Lend_regular_divide:
subcc %o4, 1, %o4
bge Ldivloop
tst %o3
bl,a Lgot_result
! non-restoring fixup here (one instruction only!)
add %o3, %o1, %o3
Lgot_result:
! check to see if answer should be < 0
tst %g2
bl,a 1f
sub %g0, %o3, %o3
1:
retl
mov %o3, %o0
.globl .rem_patch
.rem_patch:
sra %o0, 0x1f, %o4
wr %o4, 0x0, %y
nop
nop
nop
sdivcc %o0, %o1, %o2
bvs,a 1f
xnor %o2, %g0, %o2
1: smul %o2, %o1, %o2
retl
sub %o0, %o2, %o0
nop
arch/sparc/lib/sdiv.S 已删除 100644 → 0
浏览文件 @ 2119ff6d
/*
* sdiv.S: This routine was taken from glibc-1.09 and is covered
* by the GNU Library General Public License Version 2.
*/
/* This file is generated from divrem.m4; DO NOT EDIT! */
/*
* Division and remainder, from Appendix E of the Sparc Version 8
* Architecture Manual, with fixes from Gordon Irlam.
*/
/*
* Input: dividend and divisor in %o0 and %o1 respectively.
*
* m4 parameters:
* .div name of function to generate
* div div=div => %o0 / %o1; div=rem => %o0 % %o1
* true true=true => signed; true=false => unsigned
*
* Algorithm parameters:
* N how many bits per iteration we try to get (4)
* WORDSIZE total number of bits (32)
*
* Derived constants:
* TOPBITS number of bits in the top decade of a number
*
* Important variables:
* Q the partial quotient under development (initially 0)
* R the remainder so far, initially the dividend
* ITER number of main division loop iterations required;
* equal to ceil(log2(quotient) / N). Note that this
* is the log base (2^N) of the quotient.
* V the current comparand, initially divisor*2^(ITER*N-1)
*
* Cost:
* Current estimate for non-large dividend is
* ceil(log2(quotient) / N) * (10 + 7N/2) + C
* A large dividend is one greater than 2^(31-TOPBITS) and takes a
* different path, as the upper bits of the quotient must be developed
* one bit at a time.
*/
.globl .div
.globl _Div
.div:
_Div: /* needed for export */
! compute sign of result; if neither is negative, no problem
orcc %o1, %o0, %g0 ! either negative?
bge 2f ! no, go do the divide
xor %o1, %o0, %g2 ! compute sign in any case
tst %o1
bge 1f
tst %o0
! %o1 is definitely negative; %o0 might also be negative
bge 2f ! if %o0 not negative...
sub %g0, %o1, %o1 ! in any case, make %o1 nonneg
1: ! %o0 is negative, %o1 is nonnegative
sub %g0, %o0, %o0 ! make %o0 nonnegative
2:
! Ready to divide. Compute size of quotient; scale comparand.
orcc %o1, %g0, %o5
bne 1f
mov %o0, %o3
! Divide by zero trap. If it returns, return 0 (about as
! wrong as possible, but that is what SunOS does...).
ta ST_DIV0
retl
clr %o0
1:
cmp %o3, %o5 ! if %o1 exceeds %o0, done
blu Lgot_result ! (and algorithm fails otherwise)
clr %o2
sethi %hi(1 << (32 - 4 - 1)), %g1
cmp %o3, %g1
blu Lnot_really_big
clr %o4
! Here the dividend is >= 2**(31-N) or so. We must be careful here,
! as our usual N-at-a-shot divide step will cause overflow and havoc.
! The number of bits in the result here is N*ITER+SC, where SC <= N.
! Compute ITER in an unorthodox manner: know we need to shift V into
! the top decade: so do not even bother to compare to R.
1:
cmp %o5, %g1
bgeu 3f
mov 1, %g7
sll %o5, 4, %o5
b 1b
add %o4, 1, %o4
! Now compute %g7.
2:
addcc %o5, %o5, %o5
bcc Lnot_too_big
add %g7, 1, %g7
! We get here if the %o1 overflowed while shifting.
! This means that %o3 has the high-order bit set.
! Restore %o5 and subtract from %o3.
sll %g1, 4, %g1 ! high order bit
srl %o5, 1, %o5 ! rest of %o5
add %o5, %g1, %o5
b Ldo_single_div
sub %g7, 1, %g7
Lnot_too_big:
3:
cmp %o5, %o3
blu 2b
nop
be Ldo_single_div
nop
/* NB: these are commented out in the V8-Sparc manual as well */
/* (I do not understand this) */
! %o5 > %o3: went too far: back up 1 step
! srl %o5, 1, %o5
! dec %g7
! do single-bit divide steps
!
! We have to be careful here. We know that %o3 >= %o5, so we can do the
! first divide step without thinking. BUT, the others are conditional,
! and are only done if %o3 >= 0. Because both %o3 and %o5 may have the high-
! order bit set in the first step, just falling into the regular
! division loop will mess up the first time around.
! So we unroll slightly...
Ldo_single_div:
subcc %g7, 1, %g7
bl Lend_regular_divide
nop
sub %o3, %o5, %o3
mov 1, %o2
b Lend_single_divloop
nop
Lsingle_divloop:
sll %o2, 1, %o2
bl 1f
srl %o5, 1, %o5
! %o3 >= 0
sub %o3, %o5, %o3
b 2f
add %o2, 1, %o2
1: ! %o3 < 0
add %o3, %o5, %o3
sub %o2, 1, %o2
2:
Lend_single_divloop:
subcc %g7, 1, %g7
bge Lsingle_divloop
tst %o3
b,a Lend_regular_divide
Lnot_really_big:
1:
sll %o5, 4, %o5
cmp %o5, %o3
bleu 1b
addcc %o4, 1, %o4
be Lgot_result
sub %o4, 1, %o4
tst %o3 ! set up for initial iteration
Ldivloop:
sll %o2, 4, %o2
! depth 1, accumulated bits 0
bl L.1.16
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 2, accumulated bits 1
bl L.2.17
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 3, accumulated bits 3
bl L.3.19
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits 7
bl L.4.23
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (7*2+1), %o2
L.4.23:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (7*2-1), %o2
L.3.19:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits 5
bl L.4.21
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (5*2+1), %o2
L.4.21:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (5*2-1), %o2
L.2.17:
! remainder is negative
addcc %o3,%o5,%o3
! depth 3, accumulated bits 1
bl L.3.17
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits 3
bl L.4.19
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (3*2+1), %o2
L.4.19:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (3*2-1), %o2
L.3.17:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits 1
bl L.4.17
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (1*2+1), %o2
L.4.17:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (1*2-1), %o2
L.1.16:
! remainder is negative
addcc %o3,%o5,%o3
! depth 2, accumulated bits -1
bl L.2.15
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 3, accumulated bits -1
bl L.3.15
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits -1
bl L.4.15
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-1*2+1), %o2
L.4.15:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-1*2-1), %o2
L.3.15:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits -3
bl L.4.13
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-3*2+1), %o2
L.4.13:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-3*2-1), %o2
L.2.15:
! remainder is negative
addcc %o3,%o5,%o3
! depth 3, accumulated bits -3
bl L.3.13
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits -5
bl L.4.11
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-5*2+1), %o2
L.4.11:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-5*2-1), %o2
L.3.13:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits -7
bl L.4.9
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-7*2+1), %o2
L.4.9:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-7*2-1), %o2
9:
Lend_regular_divide:
subcc %o4, 1, %o4
bge Ldivloop
tst %o3
bl,a Lgot_result
! non-restoring fixup here (one instruction only!)
sub %o2, 1, %o2
Lgot_result:
! check to see if answer should be < 0
tst %g2
bl,a 1f
sub %g0, %o2, %o2
1:
retl
mov %o2, %o0
.globl .div_patch
.div_patch:
sra %o0, 0x1f, %o2
wr %o2, 0x0, %y
nop
nop
nop
sdivcc %o0, %o1, %o0
bvs,a 1f
xnor %o0, %g0, %o0
1: retl
nop
arch/sparc/lib/udiv.S 已删除 100644 → 0
浏览文件 @ 2119ff6d
/*
* udiv.S: This routine was taken from glibc-1.09 and is covered
* by the GNU Library General Public License Version 2.
*/
/* This file is generated from divrem.m4; DO NOT EDIT! */
/*
* Division and remainder, from Appendix E of the Sparc Version 8
* Architecture Manual, with fixes from Gordon Irlam.
*/
/*
* Input: dividend and divisor in %o0 and %o1 respectively.
*
* m4 parameters:
* .udiv name of function to generate
* div div=div => %o0 / %o1; div=rem => %o0 % %o1
* false false=true => signed; false=false => unsigned
*
* Algorithm parameters:
* N how many bits per iteration we try to get (4)
* WORDSIZE total number of bits (32)
*
* Derived constants:
* TOPBITS number of bits in the top decade of a number
*
* Important variables:
* Q the partial quotient under development (initially 0)
* R the remainder so far, initially the dividend
* ITER number of main division loop iterations required;
* equal to ceil(log2(quotient) / N). Note that this
* is the log base (2^N) of the quotient.
* V the current comparand, initially divisor*2^(ITER*N-1)
*
* Cost:
* Current estimate for non-large dividend is
* ceil(log2(quotient) / N) * (10 + 7N/2) + C
* A large dividend is one greater than 2^(31-TOPBITS) and takes a
* different path, as the upper bits of the quotient must be developed
* one bit at a time.
*/
.globl .udiv
.globl _Udiv
.udiv:
_Udiv: /* needed for export */
! Ready to divide. Compute size of quotient; scale comparand.
orcc %o1, %g0, %o5
bne 1f
mov %o0, %o3
! Divide by zero trap. If it returns, return 0 (about as
! wrong as possible, but that is what SunOS does...).
ta ST_DIV0
retl
clr %o0
1:
cmp %o3, %o5 ! if %o1 exceeds %o0, done
blu Lgot_result ! (and algorithm fails otherwise)
clr %o2
sethi %hi(1 << (32 - 4 - 1)), %g1
cmp %o3, %g1
blu Lnot_really_big
clr %o4
! Here the dividend is >= 2**(31-N) or so. We must be careful here,
! as our usual N-at-a-shot divide step will cause overflow and havoc.
! The number of bits in the result here is N*ITER+SC, where SC <= N.
! Compute ITER in an unorthodox manner: know we need to shift V into
! the top decade: so do not even bother to compare to R.
1:
cmp %o5, %g1
bgeu 3f
mov 1, %g7
sll %o5, 4, %o5
b 1b
add %o4, 1, %o4
! Now compute %g7.
2:
addcc %o5, %o5, %o5
bcc Lnot_too_big
add %g7, 1, %g7
! We get here if the %o1 overflowed while shifting.
! This means that %o3 has the high-order bit set.
! Restore %o5 and subtract from %o3.
sll %g1, 4, %g1 ! high order bit
srl %o5, 1, %o5 ! rest of %o5
add %o5, %g1, %o5
b Ldo_single_div
sub %g7, 1, %g7
Lnot_too_big:
3:
cmp %o5, %o3
blu 2b
nop
be Ldo_single_div
nop
/* NB: these are commented out in the V8-Sparc manual as well */
/* (I do not understand this) */
! %o5 > %o3: went too far: back up 1 step
! srl %o5, 1, %o5
! dec %g7
! do single-bit divide steps
!
! We have to be careful here. We know that %o3 >= %o5, so we can do the
! first divide step without thinking. BUT, the others are conditional,
! and are only done if %o3 >= 0. Because both %o3 and %o5 may have the high-
! order bit set in the first step, just falling into the regular
! division loop will mess up the first time around.
! So we unroll slightly...
Ldo_single_div:
subcc %g7, 1, %g7
bl Lend_regular_divide
nop
sub %o3, %o5, %o3
mov 1, %o2
b Lend_single_divloop
nop
Lsingle_divloop:
sll %o2, 1, %o2
bl 1f
srl %o5, 1, %o5
! %o3 >= 0
sub %o3, %o5, %o3
b 2f
add %o2, 1, %o2
1: ! %o3 < 0
add %o3, %o5, %o3
sub %o2, 1, %o2
2:
Lend_single_divloop:
subcc %g7, 1, %g7
bge Lsingle_divloop
tst %o3
b,a Lend_regular_divide
Lnot_really_big:
1:
sll %o5, 4, %o5
cmp %o5, %o3
bleu 1b
addcc %o4, 1, %o4
be Lgot_result
sub %o4, 1, %o4
tst %o3 ! set up for initial iteration
Ldivloop:
sll %o2, 4, %o2
! depth 1, accumulated bits 0
bl L.1.16
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 2, accumulated bits 1
bl L.2.17
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 3, accumulated bits 3
bl L.3.19
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits 7
bl L.4.23
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (7*2+1), %o2
L.4.23:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (7*2-1), %o2
L.3.19:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits 5
bl L.4.21
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (5*2+1), %o2
L.4.21:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (5*2-1), %o2
L.2.17:
! remainder is negative
addcc %o3,%o5,%o3
! depth 3, accumulated bits 1
bl L.3.17
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits 3
bl L.4.19
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (3*2+1), %o2
L.4.19:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (3*2-1), %o2
L.3.17:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits 1
bl L.4.17
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (1*2+1), %o2
L.4.17:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (1*2-1), %o2
L.1.16:
! remainder is negative
addcc %o3,%o5,%o3
! depth 2, accumulated bits -1
bl L.2.15
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 3, accumulated bits -1
bl L.3.15
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits -1
bl L.4.15
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-1*2+1), %o2
L.4.15:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-1*2-1), %o2
L.3.15:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits -3
bl L.4.13
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-3*2+1), %o2
L.4.13:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-3*2-1), %o2
L.2.15:
! remainder is negative
addcc %o3,%o5,%o3
! depth 3, accumulated bits -3
bl L.3.13
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits -5
bl L.4.11
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-5*2+1), %o2
L.4.11:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-5*2-1), %o2
L.3.13:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits -7
bl L.4.9
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-7*2+1), %o2
L.4.9:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-7*2-1), %o2
9:
Lend_regular_divide:
subcc %o4, 1, %o4
bge Ldivloop
tst %o3
bl,a Lgot_result
! non-restoring fixup here (one instruction only!)
sub %o2, 1, %o2
Lgot_result:
retl
mov %o2, %o0
.globl .udiv_patch
.udiv_patch:
wr %g0, 0x0, %y
nop
nop
retl
udiv %o0, %o1, %o0
nop
arch/sparc/lib/udivdi3.S
浏览文件 @ 1b35a57b
......@@ -60,8 +60,9 @@ __udivdi3:
bne .LL77
mov %i0,%o2
mov 1,%o0
call .udiv,0
mov 0,%o1
wr %g0, 0, %y
udiv %o0, %o1, %o0
mov %o0,%o3
mov %i0,%o2
.LL77:
......
arch/sparc/lib/umul.S 已删除 100644 → 0
浏览文件 @ 2119ff6d
/*
* umul.S: This routine was taken from glibc-1.09 and is covered
* by the GNU Library General Public License Version 2.
*/
/*
* Unsigned multiply. Returns %o0 * %o1 in %o1%o0 (i.e., %o1 holds the
* upper 32 bits of the 64-bit product).
*
* This code optimizes short (less than 13-bit) multiplies. Short
* multiplies require 25 instruction cycles, and long ones require
* 45 instruction cycles.
*
* On return, overflow has occurred (%o1 is not zero) if and only if
* the Z condition code is clear, allowing, e.g., the following:
*
* call .umul
* nop
* bnz overflow (or tnz)
*/
.globl .umul
.globl _Umul
.umul:
_Umul: /* needed for export */
or %o0, %o1, %o4
mov %o0, %y ! multiplier -> Y
andncc %o4, 0xfff, %g0 ! test bits 12..31 of *both* args
be Lmul_shortway ! if zero, can do it the short way
andcc %g0, %g0, %o4 ! zero the partial product and clear N and V
/*
* Long multiply. 32 steps, followed by a final shift step.
*/
mulscc %o4, %o1, %o4 ! 1
mulscc %o4, %o1, %o4 ! 2
mulscc %o4, %o1, %o4 ! 3
mulscc %o4, %o1, %o4 ! 4
mulscc %o4, %o1, %o4 ! 5
mulscc %o4, %o1, %o4 ! 6
mulscc %o4, %o1, %o4 ! 7
mulscc %o4, %o1, %o4 ! 8
mulscc %o4, %o1, %o4 ! 9
mulscc %o4, %o1, %o4 ! 10
mulscc %o4, %o1, %o4 ! 11
mulscc %o4, %o1, %o4 ! 12
mulscc %o4, %o1, %o4 ! 13
mulscc %o4, %o1, %o4 ! 14
mulscc %o4, %o1, %o4 ! 15
mulscc %o4, %o1, %o4 ! 16
mulscc %o4, %o1, %o4 ! 17
mulscc %o4, %o1, %o4 ! 18
mulscc %o4, %o1, %o4 ! 19
mulscc %o4, %o1, %o4 ! 20
mulscc %o4, %o1, %o4 ! 21
mulscc %o4, %o1, %o4 ! 22
mulscc %o4, %o1, %o4 ! 23
mulscc %o4, %o1, %o4 ! 24
mulscc %o4, %o1, %o4 ! 25
mulscc %o4, %o1, %o4 ! 26
mulscc %o4, %o1, %o4 ! 27
mulscc %o4, %o1, %o4 ! 28
mulscc %o4, %o1, %o4 ! 29
mulscc %o4, %o1, %o4 ! 30
mulscc %o4, %o1, %o4 ! 31
mulscc %o4, %o1, %o4 ! 32
mulscc %o4, %g0, %o4 ! final shift
/*
* Normally, with the shift-and-add approach, if both numbers are
* positive you get the correct result. With 32-bit two's-complement
* numbers, -x is represented as
*
* x 32
* ( 2 - ------ ) mod 2 * 2
* 32
* 2
*
* (the `mod 2' subtracts 1 from 1.bbbb). To avoid lots of 2^32s,
* we can treat this as if the radix point were just to the left
* of the sign bit (multiply by 2^32), and get
*
* -x = (2 - x) mod 2
*
* Then, ignoring the `mod 2's for convenience:
*
* x * y = xy
* -x * y = 2y - xy
* x * -y = 2x - xy
* -x * -y = 4 - 2x - 2y + xy
*
* For signed multiplies, we subtract (x << 32) from the partial
* product to fix this problem for negative multipliers (see mul.s).
* Because of the way the shift into the partial product is calculated
* (N xor V), this term is automatically removed for the multiplicand,
* so we don't have to adjust.
*
* But for unsigned multiplies, the high order bit wasn't a sign bit,
* and the correction is wrong. So for unsigned multiplies where the
* high order bit is one, we end up with xy - (y << 32). To fix it
* we add y << 32.
*/
#if 0
tst %o1
bl,a 1f ! if %o1 < 0 (high order bit = 1),
add %o4, %o0, %o4 ! %o4 += %o0 (add y to upper half)
1:
rd %y, %o0 ! get lower half of product
retl
addcc %o4, %g0, %o1 ! put upper half in place and set Z for %o1==0
#else
/* Faster code from tege@sics.se. */
sra %o1, 31, %o2 ! make mask from sign bit
and %o0, %o2, %o2 ! %o2 = 0 or %o0, depending on sign of %o1
rd %y, %o0 ! get lower half of product
retl
addcc %o4, %o2, %o1 ! add compensation and put upper half in place
#endif
Lmul_shortway:
/*
* Short multiply. 12 steps, followed by a final shift step.
* The resulting bits are off by 12 and (32-12) = 20 bit positions,
* but there is no problem with %o0 being negative (unlike above),
* and overflow is impossible (the answer is at most 24 bits long).
*/
mulscc %o4, %o1, %o4 ! 1
mulscc %o4, %o1, %o4 ! 2
mulscc %o4, %o1, %o4 ! 3
mulscc %o4, %o1, %o4 ! 4
mulscc %o4, %o1, %o4 ! 5
mulscc %o4, %o1, %o4 ! 6
mulscc %o4, %o1, %o4 ! 7
mulscc %o4, %o1, %o4 ! 8
mulscc %o4, %o1, %o4 ! 9
mulscc %o4, %o1, %o4 ! 10
mulscc %o4, %o1, %o4 ! 11
mulscc %o4, %o1, %o4 ! 12
mulscc %o4, %g0, %o4 ! final shift
/*
* %o4 has 20 of the bits that should be in the result; %y has
* the bottom 12 (as %y's top 12). That is:
*
* %o4 %y
* +----------------+----------------+
* | -12- | -20- | -12- | -20- |
* +------(---------+------)---------+
* -----result-----
*
* The 12 bits of %o4 left of the `result' area are all zero;
* in fact, all top 20 bits of %o4 are zero.
*/
rd %y, %o5
sll %o4, 12, %o0 ! shift middle bits left 12
srl %o5, 20, %o5 ! shift low bits right 20
or %o5, %o0, %o0
retl
addcc %g0, %g0, %o1 ! %o1 = zero, and set Z
.globl .umul_patch
.umul_patch:
umul %o0, %o1, %o0
retl
rd %y, %o1
nop
arch/sparc/lib/urem.S 已删除 100644 → 0
浏览文件 @ 2119ff6d
/*
* urem.S: This routine was taken from glibc-1.09 and is covered
* by the GNU Library General Public License Version 2.
*/
/* This file is generated from divrem.m4; DO NOT EDIT! */
/*
* Division and remainder, from Appendix E of the Sparc Version 8
* Architecture Manual, with fixes from Gordon Irlam.
*/
/*
* Input: dividend and divisor in %o0 and %o1 respectively.
*
* m4 parameters:
* .urem name of function to generate
* rem rem=div => %o0 / %o1; rem=rem => %o0 % %o1
* false false=true => signed; false=false => unsigned
*
* Algorithm parameters:
* N how many bits per iteration we try to get (4)
* WORDSIZE total number of bits (32)
*
* Derived constants:
* TOPBITS number of bits in the top decade of a number
*
* Important variables:
* Q the partial quotient under development (initially 0)
* R the remainder so far, initially the dividend
* ITER number of main division loop iterations required;
* equal to ceil(log2(quotient) / N). Note that this
* is the log base (2^N) of the quotient.
* V the current comparand, initially divisor*2^(ITER*N-1)
*
* Cost:
* Current estimate for non-large dividend is
* ceil(log2(quotient) / N) * (10 + 7N/2) + C
* A large dividend is one greater than 2^(31-TOPBITS) and takes a
* different path, as the upper bits of the quotient must be developed
* one bit at a time.
*/
.globl .urem
.globl _Urem
.urem:
_Urem: /* needed for export */
! Ready to divide. Compute size of quotient; scale comparand.
orcc %o1, %g0, %o5
bne 1f
mov %o0, %o3
! Divide by zero trap. If it returns, return 0 (about as
! wrong as possible, but that is what SunOS does...).
ta ST_DIV0
retl
clr %o0
1:
cmp %o3, %o5 ! if %o1 exceeds %o0, done
blu Lgot_result ! (and algorithm fails otherwise)
clr %o2
sethi %hi(1 << (32 - 4 - 1)), %g1
cmp %o3, %g1
blu Lnot_really_big
clr %o4
! Here the dividend is >= 2**(31-N) or so. We must be careful here,
! as our usual N-at-a-shot divide step will cause overflow and havoc.
! The number of bits in the result here is N*ITER+SC, where SC <= N.
! Compute ITER in an unorthodox manner: know we need to shift V into
! the top decade: so do not even bother to compare to R.
1:
cmp %o5, %g1
bgeu 3f
mov 1, %g7
sll %o5, 4, %o5
b 1b
add %o4, 1, %o4
! Now compute %g7.
2:
addcc %o5, %o5, %o5
bcc Lnot_too_big
add %g7, 1, %g7
! We get here if the %o1 overflowed while shifting.
! This means that %o3 has the high-order bit set.
! Restore %o5 and subtract from %o3.
sll %g1, 4, %g1 ! high order bit
srl %o5, 1, %o5 ! rest of %o5
add %o5, %g1, %o5
b Ldo_single_div
sub %g7, 1, %g7
Lnot_too_big:
3:
cmp %o5, %o3
blu 2b
nop
be Ldo_single_div
nop
/* NB: these are commented out in the V8-Sparc manual as well */
/* (I do not understand this) */
! %o5 > %o3: went too far: back up 1 step
! srl %o5, 1, %o5
! dec %g7
! do single-bit divide steps
!
! We have to be careful here. We know that %o3 >= %o5, so we can do the
! first divide step without thinking. BUT, the others are conditional,
! and are only done if %o3 >= 0. Because both %o3 and %o5 may have the high-
! order bit set in the first step, just falling into the regular
! division loop will mess up the first time around.
! So we unroll slightly...
Ldo_single_div:
subcc %g7, 1, %g7
bl Lend_regular_divide
nop
sub %o3, %o5, %o3
mov 1, %o2
b Lend_single_divloop
nop
Lsingle_divloop:
sll %o2, 1, %o2
bl 1f
srl %o5, 1, %o5
! %o3 >= 0
sub %o3, %o5, %o3
b 2f
add %o2, 1, %o2
1: ! %o3 < 0
add %o3, %o5, %o3
sub %o2, 1, %o2
2:
Lend_single_divloop:
subcc %g7, 1, %g7
bge Lsingle_divloop
tst %o3
b,a Lend_regular_divide
Lnot_really_big:
1:
sll %o5, 4, %o5
cmp %o5, %o3
bleu 1b
addcc %o4, 1, %o4
be Lgot_result
sub %o4, 1, %o4
tst %o3 ! set up for initial iteration
Ldivloop:
sll %o2, 4, %o2
! depth 1, accumulated bits 0
bl L.1.16
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 2, accumulated bits 1
bl L.2.17
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 3, accumulated bits 3
bl L.3.19
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits 7
bl L.4.23
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (7*2+1), %o2
L.4.23:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (7*2-1), %o2
L.3.19:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits 5
bl L.4.21
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (5*2+1), %o2
L.4.21:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (5*2-1), %o2
L.2.17:
! remainder is negative
addcc %o3,%o5,%o3
! depth 3, accumulated bits 1
bl L.3.17
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits 3
bl L.4.19
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (3*2+1), %o2
L.4.19:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (3*2-1), %o2
L.3.17:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits 1
bl L.4.17
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (1*2+1), %o2
L.4.17:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (1*2-1), %o2
L.1.16:
! remainder is negative
addcc %o3,%o5,%o3
! depth 2, accumulated bits -1
bl L.2.15
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 3, accumulated bits -1
bl L.3.15
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits -1
bl L.4.15
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-1*2+1), %o2
L.4.15:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-1*2-1), %o2
L.3.15:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits -3
bl L.4.13
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-3*2+1), %o2
L.4.13:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-3*2-1), %o2
L.2.15:
! remainder is negative
addcc %o3,%o5,%o3
! depth 3, accumulated bits -3
bl L.3.13
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
! depth 4, accumulated bits -5
bl L.4.11
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-5*2+1), %o2
L.4.11:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-5*2-1), %o2
L.3.13:
! remainder is negative
addcc %o3,%o5,%o3
! depth 4, accumulated bits -7
bl L.4.9
srl %o5,1,%o5
! remainder is positive
subcc %o3,%o5,%o3
b 9f
add %o2, (-7*2+1), %o2
L.4.9:
! remainder is negative
addcc %o3,%o5,%o3
b 9f
add %o2, (-7*2-1), %o2
9:
Lend_regular_divide:
subcc %o4, 1, %o4
bge Ldivloop
tst %o3
bl,a Lgot_result
! non-restoring fixup here (one instruction only!)
add %o3, %o1, %o3
Lgot_result:
retl
mov %o3, %o0
.globl .urem_patch
.urem_patch:
wr %g0, 0x0, %y
nop
nop
nop
udiv %o0, %o1, %o2
umul %o2, %o1, %o2
retl
sub %o0, %o2, %o0
Markdown is supported
0% 或 .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑！
想要评论请 注册 或