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gc: fix up floating point NaN comparisons

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Fixes #167.

R=ken2
https://golang.org/cl/155062
This commit is contained in:
Russ Cox 2009-11-15 17:24:14 -08:00
parent 391e082ca9
commit ef46a9ddac
7 changed files with 181 additions and 38 deletions
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13
src/cmd/5g/cgen.c
View File

@ -895,8 +895,19 @@ bgen(Node *n, int true, Prog *to)
case OLE:
case OGE:
a = n->op;
if(!true)
if(!true) {
if(isfloat[nl->type->etype]) {
// brcom is not valid on floats when NaN is involved.
p1 = gbranch(AJMP, T);
p2 = gbranch(AJMP, T);
patch(p1, pc);
bgen(n, 1, p2);
patch(gbranch(AJMP, T), to);
patch(p2, pc);
goto ret;
}
a = brcom(a);
}
// make simplest on right
if(nl->op == OLITERAL || nl->ullman < nr->ullman) {

55
src/cmd/6g/cgen.c
View File

@ -668,7 +668,7 @@ void
bgen(Node *n, int true, Prog *to)
{
int et, a;
Node *nl, *nr, *r;
Node *nl, *nr, *l, *r;
Node n1, n2, tmp;
Prog *p1, *p2;
@ -782,8 +782,19 @@ bgen(Node *n, int true, Prog *to)
case OLE:
case OGE:
a = n->op;
if(!true)
if(!true) {
if(isfloat[nr->type->etype]) {
// brcom is not valid on floats when NaN is involved.
p1 = gbranch(AJMP, T);
p2 = gbranch(AJMP, T);
patch(p1, pc);
bgen(n, 1, p2);
patch(gbranch(AJMP, T), to);
patch(p2, pc);
goto ret;
}
a = brcom(a);
}
// make simplest on right
if(nl->op == OLITERAL || nl->ullman < nr->ullman) {
@ -792,7 +803,7 @@ bgen(Node *n, int true, Prog *to)
nl = nr;
nr = r;
}
if(isslice(nl->type)) {
// only valid to cmp darray to literal nil
if((a != OEQ && a != ONE) || nr->op != OLITERAL) {
@ -831,8 +842,6 @@ bgen(Node *n, int true, Prog *to)
break;
}
a = optoas(a, nr->type);
if(nr->ullman >= UINF) {
regalloc(&n1, nr->type, N);
cgen(nr, &n1);
@ -847,12 +856,7 @@ bgen(Node *n, int true, Prog *to)
regalloc(&n2, nr->type, &n2);
cgen(&tmp, &n2);
gins(optoas(OCMP, nr->type), &n1, &n2);
patch(gbranch(a, nr->type), to);
regfree(&n1);
regfree(&n2);
break;
goto cmp;
}
regalloc(&n1, nl->type, N);
@ -860,17 +864,40 @@ bgen(Node *n, int true, Prog *to)
if(smallintconst(nr)) {
gins(optoas(OCMP, nr->type), &n1, nr);
patch(gbranch(a, nr->type), to);
patch(gbranch(optoas(a, nr->type), nr->type), to);
regfree(&n1);
break;
}
regalloc(&n2, nr->type, N);
cgen(nr, &n2);
cmp:
// only < and <= work right with NaN; reverse if needed
l = &n1;
r = &n2;
if(isfloat[nl->type->etype] && (a == OGT || a == OGE)) {
l = &n2;
r = &n1;
a = brrev(a);
}
gins(optoas(OCMP, nr->type), &n1, &n2);
patch(gbranch(a, nr->type), to);
gins(optoas(OCMP, nr->type), l, r);
if(isfloat[nr->type->etype] && (n->op == OEQ || n->op == ONE)) {
if(n->op == OEQ) {
// neither NE nor P
p1 = gbranch(AJNE, T);
p2 = gbranch(AJPS, T);
patch(gbranch(AJMP, T), to);
patch(p1, pc);
patch(p2, pc);
} else {
// either NE or P
patch(gbranch(AJNE, T), to);
patch(gbranch(AJPS, T), to);
}
} else
patch(gbranch(optoas(a, nr->type), nr->type), to);
regfree(&n1);
regfree(&n2);
break;

4
src/cmd/6g/gsubr.c
View File

@ -1146,8 +1146,6 @@ optoas(int op, Type *t)
case CASE(OLT, TUINT16):
case CASE(OLT, TUINT32):
case CASE(OLT, TUINT64):
case CASE(OGT, TFLOAT32):
case CASE(OGT, TFLOAT64):
a = AJCS;
break;
@ -1162,8 +1160,6 @@ optoas(int op, Type *t)
case CASE(OLE, TUINT16):
case CASE(OLE, TUINT32):
case CASE(OLE, TUINT64):
case CASE(OGE, TFLOAT32):
case CASE(OGE, TFLOAT64):
a = AJLS;
break;

47
src/cmd/8g/cgen.c
View File

@ -838,8 +838,19 @@ bgen(Node *n, int true, Prog *to)
case OLE:
case OGE:
a = n->op;
if(!true)
if(!true) {
if(isfloat[nl->type->etype]) {
// brcom is not valid on floats when NaN is involved.
p1 = gbranch(AJMP, T);
p2 = gbranch(AJMP, T);
patch(p1, pc);
bgen(n, 1, p2);
patch(gbranch(AJMP, T), to);
patch(p2, pc);
break;
}
a = brcom(a);
}
// make simplest on right
if(nl->op == OLITERAL || nl->ullman < nr->ullman) {
@ -888,6 +899,14 @@ bgen(Node *n, int true, Prog *to)
}
if(isfloat[nr->type->etype]) {
a = brrev(a); // because the args are stacked
if(a == OGE || a == OGT) {
// only < and <= work right with NaN; reverse if needed
r = nr;
nr = nl;
nl = r;
a = brrev(a);
}
nodreg(&tmp, nr->type, D_F0);
nodreg(&n2, nr->type, D_F0 + 1);
nodreg(&ax, types[TUINT16], D_AX);
@ -915,7 +934,19 @@ bgen(Node *n, int true, Prog *to)
}
gins(AFSTSW, N, &ax);
gins(ASAHF, N, N);
patch(gbranch(optoas(brrev(a), nr->type), T), to);
if(a == OEQ) {
// neither NE nor P
p1 = gbranch(AJNE, T);
p2 = gbranch(AJPS, T);
patch(gbranch(AJMP, T), to);
patch(p1, pc);
patch(p2, pc);
} else if(a == ONE) {
// either NE or P
patch(gbranch(AJNE, T), to);
patch(gbranch(AJPS, T), to);
} else
patch(gbranch(optoas(a, nr->type), T), to);
break;
}
@ -941,21 +972,14 @@ bgen(Node *n, int true, Prog *to)
a = optoas(a, nr->type);
if(nr->ullman >= UINF) {
tempalloc(&n1, nl->type);
tempalloc(&tmp, nr->type);
cgen(nr, &tmp);
tempalloc(&n1, nl->type);
cgen(nl, &n1);
regalloc(&n2, nr->type, N);
cgen(&tmp, &n2);
gins(optoas(OCMP, nr->type), &n1, &n2);
patch(gbranch(a, nr->type), to);
tempfree(&n1);
tempfree(&tmp);
regfree(&n2);
break;
goto cmp;
}
tempalloc(&n1, nl->type);
@ -974,6 +998,7 @@ bgen(Node *n, int true, Prog *to)
gmove(&tmp, &n2);
tempfree(&tmp);
cmp:
gins(optoas(OCMP, nr->type), &n1, &n2);
patch(gbranch(a, nr->type), to);
regfree(&n2);

4
src/cmd/8g/gsubr.c
View File

@ -260,8 +260,6 @@ optoas(int op, Type *t)
case CASE(OLT, TUINT16):
case CASE(OLT, TUINT32):
case CASE(OLT, TUINT64):
case CASE(OGT, TFLOAT32):
case CASE(OGT, TFLOAT64):
a = AJCS;
break;
@ -276,8 +274,6 @@ optoas(int op, Type *t)
case CASE(OLE, TUINT16):
case CASE(OLE, TUINT32):
case CASE(OLE, TUINT64):
case CASE(OGE, TFLOAT32):
case CASE(OGE, TFLOAT64):
a = AJLS;
break;

8
test/float_lit.go
View File

@ -20,8 +20,8 @@ close(da float64, ia, ib int64, pow int) bool
db := float64(ia) / float64(ib);
db *= pow10(pow);
if da == 0 {
if db == 0 {
if da == 0 || db == 0 {
if da == 0 && db == 0 {
return true;
}
return false;
@ -59,8 +59,8 @@ main()
if !close(-210e3, -210, 1, 3) { print("-210e3 is ", -210e3, "\n"); }
if !close(0E-1, 0, 1, 0) { print("0E-1 is ", 0E-1, "\n"); }
if !close(+0e23, 0, 1, 23) { print("+0e23 is ", +0e23, "\n"); }
if !close(-0e345, 0, 1, 345) { print("-0e345 is ", -0e345, "\n"); }
if !close(+0e23, 0, 1, 1) { print("+0e23 is ", +0e23, "\n"); }
if !close(-0e345, 0, 1, 1) { print("-0e345 is ", -0e345, "\n"); }
if !close(0E1, 0, 1, 1) { print("0E1 is ", 0E1, "\n"); }
if !close(+10e23, 10, 1, 23) { print("+10e23 is ", +10e23, "\n"); }

88
test/floatcmp.go Normal file
View File

@ -0,0 +1,88 @@
// $G $F.go && $L $F.$A && ./$A.out
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
import "math"
type floatTest struct {
name string;
expr bool;
want bool;
}
var nan float64 = math.NaN();
var f float64 = 1;
var tests = []floatTest{
floatTest{"nan == nan", nan == nan, false},
floatTest{"nan != nan", nan != nan, true},
floatTest{"nan < nan", nan < nan, false},
floatTest{"nan > nan", nan > nan, false},
floatTest{"nan <= nan", nan <= nan, false},
floatTest{"nan >= nan", nan >= nan, false},
floatTest{"f == nan", f == nan, false},
floatTest{"f != nan", f != nan, true},
floatTest{"f < nan", f < nan, false},
floatTest{"f > nan", f > nan, false},
floatTest{"f <= nan", f <= nan, false},
floatTest{"f >= nan", f >= nan, false},
floatTest{"nan == f", nan == f, false},
floatTest{"nan != f", nan != f, true},
floatTest{"nan < f", nan < f, false},
floatTest{"nan > f", nan > f, false},
floatTest{"nan <= f", nan <= f, false},
floatTest{"nan >= f", nan >= f, false},
floatTest{"!(nan == nan)", !(nan == nan), true},
floatTest{"!(nan != nan)", !(nan != nan), false},
floatTest{"!(nan < nan)", !(nan < nan), true},
floatTest{"!(nan > nan)", !(nan > nan), true},
floatTest{"!(nan <= nan)", !(nan <= nan), true},
floatTest{"!(nan >= nan)", !(nan >= nan), true},
floatTest{"!(f == nan)", !(f == nan), true},
floatTest{"!(f != nan)", !(f != nan), false},
floatTest{"!(f < nan)", !(f < nan), true},
floatTest{"!(f > nan)", !(f > nan), true},
floatTest{"!(f <= nan)", !(f <= nan), true},
floatTest{"!(f >= nan)", !(f >= nan), true},
floatTest{"!(nan == f)", !(nan == f), true},
floatTest{"!(nan != f)", !(nan != f), false},
floatTest{"!(nan < f)", !(nan < f), true},
floatTest{"!(nan > f)", !(nan > f), true},
floatTest{"!(nan <= f)", !(nan <= f), true},
floatTest{"!(nan >= f)", !(nan >= f), true},
floatTest{"!!(nan == nan)", !!(nan == nan), false},
floatTest{"!!(nan != nan)", !!(nan != nan), true},
floatTest{"!!(nan < nan)", !!(nan < nan), false},
floatTest{"!!(nan > nan)", !!(nan > nan), false},
floatTest{"!!(nan <= nan)", !!(nan <= nan), false},
floatTest{"!!(nan >= nan)", !!(nan >= nan), false},
floatTest{"!!(f == nan)", !!(f == nan), false},
floatTest{"!!(f != nan)", !!(f != nan), true},
floatTest{"!!(f < nan)", !!(f < nan), false},
floatTest{"!!(f > nan)", !!(f > nan), false},
floatTest{"!!(f <= nan)", !!(f <= nan), false},
floatTest{"!!(f >= nan)", !!(f >= nan), false},
floatTest{"!!(nan == f)", !!(nan == f), false},
floatTest{"!!(nan != f)", !!(nan != f), true},
floatTest{"!!(nan < f)", !!(nan < f), false},
floatTest{"!!(nan > f)", !!(nan > f), false},
floatTest{"!!(nan <= f)", !!(nan <= f), false},
floatTest{"!!(nan >= f)", !!(nan >= f), false},
}
func main() {
bad := false;
for _, t := range tests {
if t.expr != t.want {
if !bad {
bad = true;
println("BUG: floatcmp");
}
println(t.name, "=", t.expr, "want", t.want);
}
}
}