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Faster /mod and /i primitives

db4
Slava Pestov 2008-11-21 01:54:45 -06:00
parent 1addde1567
commit 27503bf67f
1 changed files with 28 additions and 15 deletions
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43
vm/math.c
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@ -33,18 +33,18 @@ void primitive_float_to_fixnum(void)
#define POP_FIXNUMS(x,y) \
F_FIXNUM y = untag_fixnum_fast(dpop()); \
F_FIXNUM x = untag_fixnum_fast(dpop());
F_FIXNUM x = untag_fixnum_fast(dpeek());
void primitive_fixnum_add(void)
{
POP_FIXNUMS(x,y)
box_signed_cell(x + y);
drepl(allot_integer(x + y));
}
void primitive_fixnum_subtract(void)
{
POP_FIXNUMS(x,y)
box_signed_cell(x - y);
drepl(allot_integer(x - y));
}
/* Multiply two integers, and trap overflow.
@ -54,20 +54,20 @@ void primitive_fixnum_multiply(void)
POP_FIXNUMS(x,y)
if(x == 0 || y == 0)
dpush(tag_fixnum(0));
drepl(tag_fixnum(0));
else
{
F_FIXNUM prod = x * y;
/* if this is not equal, we have overflow */
if(prod / x == y)
box_signed_cell(prod);
drepl(allot_integer(prod));
else
{
F_ARRAY *bx = fixnum_to_bignum(x);
REGISTER_BIGNUM(bx);
F_ARRAY *by = fixnum_to_bignum(y);
UNREGISTER_BIGNUM(bx);
dpush(tag_bignum(bignum_multiply(bx,by)));
drepl(tag_bignum(bignum_multiply(bx,by)));
}
}
}
@ -75,14 +75,27 @@ void primitive_fixnum_multiply(void)
void primitive_fixnum_divint(void)
{
POP_FIXNUMS(x,y)
box_signed_cell(x / y);
F_FIXNUM result = x / y;
if(result == -FIXNUM_MIN)
drepl(allot_integer(-FIXNUM_MIN));
else
drepl(tag_fixnum(result));
}
void primitive_fixnum_divmod(void)
{
POP_FIXNUMS(x,y)
box_signed_cell(x / y);
dpush(tag_fixnum(x % y));
F_FIXNUM y = get(ds);
F_FIXNUM x = get(ds - CELLS);
if(y == -1 && x == tag_fixnum(FIXNUM_MIN))
{
put(ds - CELLS,allot_integer(-FIXNUM_MIN));
put(ds,tag_fixnum(0));
}
else
{
put(ds - CELLS,tag_fixnum(x / y));
put(ds,x % y);
}
}
/*
@ -96,15 +109,15 @@ void primitive_fixnum_shift(void)
if(x == 0 || y == 0)
{
dpush(tag_fixnum(x));
drepl(tag_fixnum(x));
return;
}
else if(y < 0)
{
if(y <= -WORD_SIZE)
dpush(x < 0 ? tag_fixnum(-1) : tag_fixnum(0));
drepl(x < 0 ? tag_fixnum(-1) : tag_fixnum(0));
else
dpush(tag_fixnum(x >> -y));
drepl(tag_fixnum(x >> -y));
return;
}
else if(y < WORD_SIZE - TAG_BITS)
@ -112,12 +125,12 @@ void primitive_fixnum_shift(void)
F_FIXNUM mask = -((F_FIXNUM)1 << (WORD_SIZE - 1 - TAG_BITS - y));
if((x > 0 && (x & mask) == 0) || (x & mask) == mask)
{
dpush(tag_fixnum(x << y));
drepl(tag_fixnum(x << y));
return;
}
}
dpush(tag_bignum(bignum_arithmetic_shift(
drepl(tag_bignum(bignum_arithmetic_shift(
fixnum_to_bignum(x),y)));
}