gc: fix up floating point NaN comparisons
Fixes #167.
R=ken2
https://golang.org/cl/155062
diff --git a/src/cmd/5g/cgen.c b/src/cmd/5g/cgen.c
index 9fc5939..019704c 100644
--- a/src/cmd/5g/cgen.c
+++ b/src/cmd/5g/cgen.c
@@ -895,8 +895,19 @@
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) {
diff --git a/src/cmd/6g/cgen.c b/src/cmd/6g/cgen.c
index 2ee7934..041f6c1 100644
--- a/src/cmd/6g/cgen.c
+++ b/src/cmd/6g/cgen.c
@@ -668,7 +668,7 @@
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 @@
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 @@
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 @@
break;
}
- a = optoas(a, nr->type);
-
if(nr->ullman >= UINF) {
regalloc(&n1, nr->type, N);
cgen(nr, &n1);
@@ -847,12 +856,7 @@
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 @@
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;
diff --git a/src/cmd/6g/gsubr.c b/src/cmd/6g/gsubr.c
index 20b79c0..4f3c85a 100644
--- a/src/cmd/6g/gsubr.c
+++ b/src/cmd/6g/gsubr.c
@@ -1146,8 +1146,6 @@
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 @@
case CASE(OLE, TUINT16):
case CASE(OLE, TUINT32):
case CASE(OLE, TUINT64):
- case CASE(OGE, TFLOAT32):
- case CASE(OGE, TFLOAT64):
a = AJLS;
break;
diff --git a/src/cmd/8g/cgen.c b/src/cmd/8g/cgen.c
index bf0b263..ee4df87 100644
--- a/src/cmd/8g/cgen.c
+++ b/src/cmd/8g/cgen.c
@@ -838,8 +838,19 @@
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 @@
}
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 @@
}
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 @@
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 @@
gmove(&tmp, &n2);
tempfree(&tmp);
+cmp:
gins(optoas(OCMP, nr->type), &n1, &n2);
patch(gbranch(a, nr->type), to);
regfree(&n2);
diff --git a/src/cmd/8g/gsubr.c b/src/cmd/8g/gsubr.c
index dea802f4..71a7494 100755
--- a/src/cmd/8g/gsubr.c
+++ b/src/cmd/8g/gsubr.c
@@ -260,8 +260,6 @@
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 @@
case CASE(OLE, TUINT16):
case CASE(OLE, TUINT32):
case CASE(OLE, TUINT64):
- case CASE(OGE, TFLOAT32):
- case CASE(OGE, TFLOAT64):
a = AJLS;
break;
diff --git a/test/float_lit.go b/test/float_lit.go
index a78a6e9..be4460e4 100644
--- a/test/float_lit.go
+++ b/test/float_lit.go
@@ -20,8 +20,8 @@
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 @@
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"); }
diff --git a/test/floatcmp.go b/test/floatcmp.go
new file mode 100644
index 0000000..26fc6ad
--- /dev/null
+++ b/test/floatcmp.go
@@ -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);
+ }
+ }
+}
