arm: prop up software floating point

Just enough to make mov instructions work,
which in turn is enough to make strconv work
when it avoids any floating point calculations.
That makes a bunch of other packages pass
their tests.

Should suffice until hardware floating point
is available.

Enable package tests that now pass
(some due to earlier fixes).

Looks like there is a new integer math bug
exposed in the fmt and json tests.

R=ken2
CC=golang-dev
https://golang.org/cl/2638041

src/cmd/5g/Makefile

@@ -21,7 +21,8 @@ OFILES=\
 	ggen.$O\
 	gsubr.$O\
 	cgen.$O\
-	cgen64.$O
+	cgen64.$O\
+	cplx.$O\
 
 LIB=\
 	../gc/gc.a\

src/cmd/5g/cgen.c

@@ -28,12 +28,6 @@ cgen(Node *n, Node *res)
 	if(res == N || res->type == T)
 		fatal("cgen: res nil");
 
-	// TODO compile complex
-	if(n != N && n->type != T && iscomplex[n->type->etype])
-		return;
-	if(res != N && res->type != T && iscomplex[res->type->etype])
-		return;
-
 	while(n->op == OCONVNOP)
 		n = n->left;
 
@@ -53,6 +47,7 @@ cgen(Node *n, Node *res)
 		goto ret;
 	}
 
+
 	// update addressability for string, slice
 	// can't do in walk because n->left->addable
 	// changes if n->left is an escaping local variable.
@@ -69,7 +64,9 @@ cgen(Node *n, Node *res)
 
 	// if both are addressable, move
 	if(n->addable && res->addable) {
-		if (is64(n->type) || is64(res->type) || n->op == OREGISTER || res->op == OREGISTER) {
+		if(is64(n->type) || is64(res->type) ||
+		   n->op == OREGISTER || res->op == OREGISTER ||
+		   iscomplex[n->type->etype] || iscomplex[res->type->etype]) {
 			gmove(n, res);
 		} else {
 			regalloc(&n1, n->type, N);
@@ -99,8 +96,13 @@ cgen(Node *n, Node *res)
 		return;
 	}
 
+	if(complexop(n, res)) {
+		complexgen(n, res);
+		return;
+	}
+
 	// if n is sudoaddable generate addr and move
-	if (!is64(n->type) && !is64(res->type)) {
+	if (!is64(n->type) && !is64(res->type) && !iscomplex[n->type->etype] && !iscomplex[res->type->etype]) {
 		a = optoas(OAS, n->type);
 		if(sudoaddable(a, n, &addr, &w)) {
 			if (res->op != OREGISTER) {

src/cmd/5g/gsubr.c

@@ -539,6 +539,11 @@ gmove(Node *f, Node *t)
 	tt = simsimtype(t->type);
 	cvt = t->type;
 
+	if(iscomplex[ft] || iscomplex[tt]) {
+		complexmove(f, t);
+		return;
+	}
+
 	// cannot have two memory operands;
 	// except 64-bit, which always copies via registers anyway.
 	if(!is64(f->type) && !is64(t->type) && ismem(f) && ismem(t))

src/cmd/8g/cgen.c

@@ -175,7 +175,7 @@ cgen(Node *n, Node *res)
 	case OREAL:
 	case OIMAG:
 	case OCMPLX:
-		// TODO compile complex
+		fatal("unexpected complex");
 		return;
 
 	// these call bgen to get a bool value

src/cmd/ld/data.c

@@ -387,13 +387,13 @@ codeblk(int32 addr, int32 size)
 			break;
 
 		if(addr < sym->value) {
-			Bprint(&bso, "%-20s %.8llux|", "_", addr);
+			Bprint(&bso, "%-20s %.8llux|", "_", (vlong)addr);
 			for(; addr < sym->value; addr++)
 				Bprint(&bso, " %.2ux", 0);
 			Bprint(&bso, "\n");
 		}
 		p = sym->text;
-		Bprint(&bso, "%.6llux\t%-20s | %P\n", addr, sym->name, p);
+		Bprint(&bso, "%.6llux\t%-20s | %P\n", (vlong)addr, sym->name, p);
 		for(p = p->link; p != P; p = p->link) {
 			if(p->link != P)
 				epc = p->link->pc;
@@ -408,7 +408,7 @@ codeblk(int32 addr, int32 size)
 	}
 
 	if(addr < eaddr) {
-		Bprint(&bso, "%-20s %.8llux|", "_", addr);
+		Bprint(&bso, "%-20s %.8llux|", "_", (vlong)addr);
 		for(; addr < eaddr; addr++)
 			Bprint(&bso, " %.2ux", 0);
 	}

src/pkg/Makefile

@@ -204,22 +204,14 @@ endif
 ifeq ($(GOARCH),arm)
 # Tests that fail, probably 5g bugs.
 # Disable so that dashboard all.bash can catch regressions.
-NOTEST+=cmath  # floating point
-NOTEST+=crypto/block  # weird bit error
-NOTEST+=encoding/binary  # floating point?
-NOTEST+=exp/datafmt  # crash
-NOTEST+=exp/eval  # crash
-NOTEST+=flag  # floating point
-NOTEST+=fmt  # floating point
-NOTEST+=go/printer  # crash
-NOTEST+=gob  # floating point
-NOTEST+=image/png  # bit errors
-NOTEST+=json  # floating point
-NOTEST+=math  # floating point
-NOTEST+=os/signal  # crash
-NOTEST+=strconv  # floating point
-NOTEST+=syslog  # unix syslog
-NOTEST+=xml  # floating point
+NOTEST+=cmath        # software floating point (lack of) accuracy
+NOTEST+=math         # software floating point (lack of) accuracy
+NOTEST+=strconv      # software floating point (lack of) accuracy
+
+NOTEST+=fmt          # spurious uint overflow
+NOTEST+=gob          # something involving complex
+NOTEST+=json         # spurious uint overflow
+NOTEST+=os/signal    # crash
 endif
 
 TEST=\

src/pkg/runtime/arm/softfloat.c

@@ -169,7 +169,7 @@ s2d(uint32 s)
 		return DNINF;
 	if ((s & ~(1ul << 31)) == FNAN)
 		return DNAN;
-	return (uint64)(s & 0x80000000) << 63 |	// sign
+	return (uint64)(s & 0x80000000) << 32 |	// sign
 		(uint64)((s >> 23 &0xff) + (DOUBLE_EXPBIAS - SINGLE_EXPBIAS)) << 52  |	// exponent
 		(uint64)(s & 0x7fffff) << 29;	// mantissa
 }
@@ -211,7 +211,10 @@ dataprocess(uint32* pc)
 	if (unary) {
 		switch (opcode) {
 		case 0: // mvf
-			m->freg[dest] = frhs(rhs);
+			fd = frhs(rhs);
+			if(prec == 0)
+				fd = s2d(d2s(fd));
+			m->freg[dest] = fd;
 			goto ret;
 		default:
 			goto undef;

src/pkg/strconv/atof.go

@@ -15,9 +15,11 @@ package strconv
 import (
 	"math"
 	"os"
+	"runtime"
 )
 
-var optimize = true // can change for testing
+// TODO(rsc): remove "arm" check
+var optimize = runtime.GOARCH != "arm" // can change for testing
 
 // TODO(rsc): Better truncation handling.
 func stringToDecimal(s string) (neg bool, d *decimal, trunc bool, ok bool) {

src/pkg/strconv/ftoa.go

@@ -11,6 +11,7 @@
 package strconv
 
 import "math"
+import "runtime"
 
 // TODO: move elsewhere?
 type floatInfo struct {
@@ -23,6 +24,9 @@ var float32info = floatInfo{23, 8, -127}
 var float64info = floatInfo{52, 11, -1023}
 
 func floatsize() int {
+	if runtime.GOARCH == "arm" { // TODO(rsc): remove
+		return 32
+	}
 	// Figure out whether float is float32 or float64.
 	// 1e-35 is representable in both, but 1e-70
 	// is too small for a float32.

src/pkg/strconv/internal_test.go

@@ -6,9 +6,17 @@
 
 package strconv
 
+import "runtime"
+
 func NewDecimal(i uint64) *decimal { return newDecimal(i) }
 
 func SetOptimize(b bool) bool {
+	if runtime.GOARCH == "arm" {
+		// optimize is always false on arm,
+		// because the software floating point
+		// has such terrible multiplication.
+		return false
+	}
 	old := optimize
 	optimize = b
 	return old