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mp: fix mpnot and add mpasr

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This commit is contained in:
aiju 2016-08-28 10:49:41 +02:00
parent 193daffafb
commit cf2f2a8841
2 changed files with 23 additions and 1 deletions
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9
sys/man/2/mp
View file

@ -127,6 +127,9 @@ void mptrunc(mpint *b, int n, mpint *res)
void mpxtend(mpint *b, int n, mpint *res)
.PP
.B
void mpasr(mpint *b, int n, mpint *res)
.PP
.B
void mpmul(mpint *b1, mpint *b2, mpint *prod)
.PP
.B
@ -584,6 +587,12 @@ Logical operations (treating negative numbers using two's complement):
.I mpnot
.BR "res = ~b1" .
.TP
.I mpasr
.BR "res = b>>shift"
(\fImpasr\fR, unlike
.IR mpright ,
uses two's complement).
.TP
.I mptrunc
truncates
.I b

15
sys/src/libmp/port/mplogic.c
View file

@ -85,7 +85,8 @@ void
mpnot(mpint *b, mpint *r)
{
mpadd(b, mpone, r);
r->sign ^= -2;
if(r->top != 0)
r->sign ^= -2;
}
void
@ -193,3 +194,15 @@ mpxtend(mpint *b, int n, mpint *r)
}
mpnorm(r);
}
void
mpasr(mpint *b, int n, mpint *r)
{
if(b->sign > 0 || n <= 0){
mpright(b, n, r);
return;
}
mpadd(b, mpone, r);
mpright(r, n, r);
mpsub(r, mpone, r);
}