On Mon, 2007-03-19 at 22:53 +0000, Julian Seward wrote:
> Thinking about this more, you ask "is this correct", but that
> is only meaningful if you say what the specification is.
> Correct relative to what?
>
> > Yes, it seems to be the correct way, but thinking more about the
> > problem, it appeared to me that the implementation could be even easier
> > than yours. It seems to me that this may be sufficient:
> > uint64_t float64_to_uint64 (float64 a STATUS_PARAM)
> > {
> > int64_t v;
> >
> > v = llrint(a + (float64)INT64_MIN);
> >
> > return v - INT64_MIN;
> > }
>
> If a is NaN then so is the argument to llrint. 'man llrint' says:
>
> If x is infinite or NaN, or if the rounded value is
> outside the range of the return type, the numeric result
> is unspecified.
>
> So then float64_to_uint64 produces an unspecified result.
>
> It seems to me much safer to test and handle NaN, Inf and
> out-of-range values specially. However, even that does not help
> unless you say what the specification is.
Well, you are right, but the function float64_to_int64 acts the same way
in that code.
If we want to follow IEEE compliance, we have to use the softfloat
functions instead, not the softfloat-native ones. Or we should sanitize
the whole softfloat.c code, to be consistent, it seems.
Here's an updated patch, with two more functions. The added functions
are:
float32 uint32_to_float32(unsigned int v STATUS_PARAM)
float64 uint32_to_float64(unsigned int v STATUS_PARAM)
float32 uint64_to_float32( uint64_t v STATUS_PARAM)
float64 uint64_to_float64( uint64_t v STATUS_PARAM)
unsigned int float32_to_uint32( float32 a STATUS_PARAM)
unsigned int float32_to_uint32_round_to_zero( float32 a STATUS_PARAM)
unsigned int float64_to_uint32( float64 a STATUS_PARAM)
unsigned int float64_to_uint32_round_to_zero( float64 a STATUS_PARAM)
uint64_t float64_to_uint64 (float64 a STATUS_PARAM)
uint64_t float64_to_uint64_round_to_zero (float64 a STATUS_PARAM)
Note that some of those functions already exist in softfloat.c but not
in softfloat-native.c.
--
J. Mayer <[EMAIL PROTECTED]>
Never organized
Index: fpu/softfloat-native.c
===================================================================
RCS file: /sources/qemu/qemu/fpu/softfloat-native.c,v
retrieving revision 1.6
diff -u -d -d -p -r1.6 softfloat-native.c
--- fpu/softfloat-native.c 28 Oct 2006 19:27:11 -0000 1.6
+++ fpu/softfloat-native.c 19 Mar 2007 23:05:29 -0000
@@ -59,11 +59,21 @@ float32 int32_to_float32(int v STATUS_PA
return (float32)v;
}
+float32 uint32_to_float32(unsigned int v STATUS_PARAM)
+{
+ return (float32)v;
+}
+
float64 int32_to_float64(int v STATUS_PARAM)
{
return (float64)v;
}
+float64 uint32_to_float64(unsigned int v STATUS_PARAM)
+{
+ return (float64)v;
+}
+
#ifdef FLOATX80
floatx80 int32_to_floatx80(int v STATUS_PARAM)
{
@@ -74,10 +84,18 @@ float32 int64_to_float32( int64_t v STAT
{
return (float32)v;
}
+float32 uint64_to_float32( uint64_t v STATUS_PARAM)
+{
+ return (float32)v;
+}
float64 int64_to_float64( int64_t v STATUS_PARAM)
{
return (float64)v;
}
+float64 uint64_to_float64( uint64_t v STATUS_PARAM)
+{
+ return (float64)v;
+}
#ifdef FLOATX80
floatx80 int64_to_floatx80( int64_t v STATUS_PARAM)
{
@@ -132,6 +150,37 @@ floatx80 float32_to_floatx80( float32 a
}
#endif
+unsigned int float32_to_uint32( float32 a STATUS_PARAM)
+{
+ int64_t v;
+ unsigned int res;
+
+ v = llrintf(a);
+ if (v < 0) {
+ res = 0;
+ } else if (v > 0xffffffff) {
+ res = 0xffffffff;
+ } else {
+ res = v;
+ }
+ return res;
+}
+unsigned int float32_to_uint32_round_to_zero( float32 a STATUS_PARAM)
+{
+ int64_t v;
+ unsigned int res;
+
+ v = (int64_t)a;
+ if (v < 0) {
+ res = 0;
+ } else if (v > 0xffffffff) {
+ res = 0xffffffff;
+ } else {
+ res = v;
+ }
+ return res;
+}
+
/*----------------------------------------------------------------------------
| Software IEC/IEEE single-precision operations.
*----------------------------------------------------------------------------*/
@@ -218,6 +267,53 @@ float128 float64_to_float128( float64 a
}
#endif
+unsigned int float64_to_uint32( float64 a STATUS_PARAM)
+{
+ int64_t v;
+ unsigned int res;
+
+ v = llrint(a);
+ if (v < 0) {
+ res = 0;
+ } else if (v > 0xffffffff) {
+ res = 0xffffffff;
+ } else {
+ res = v;
+ }
+ return res;
+}
+unsigned int float64_to_uint32_round_to_zero( float64 a STATUS_PARAM)
+{
+ int64_t v;
+ unsigned int res;
+
+ v = (int64_t)a;
+ if (v < 0) {
+ res = 0;
+ } else if (v > 0xffffffff) {
+ res = 0xffffffff;
+ } else {
+ res = v;
+ }
+ return res;
+}
+uint64_t float64_to_uint64 (float64 a STATUS_PARAM)
+{
+ int64_t v;
+
+ v = llrint(a + (float64)INT64_MIN);
+
+ return v - INT64_MIN;
+}
+uint64_t float64_to_uint64_round_to_zero (float64 a STATUS_PARAM)
+{
+ int64_t v;
+
+ v = (int64_t)(a + (float64)INT64_MIN);
+
+ return v - INT64_MIN;
+}
+
/*----------------------------------------------------------------------------
| Software IEC/IEEE double-precision operations.
*----------------------------------------------------------------------------*/
Index: fpu/softfloat-native.h
===================================================================
RCS file: /sources/qemu/qemu/fpu/softfloat-native.h,v
retrieving revision 1.8
diff -u -d -d -p -r1.8 softfloat-native.h
--- fpu/softfloat-native.h 28 Oct 2006 19:27:11 -0000 1.8
+++ fpu/softfloat-native.h 19 Mar 2007 23:05:29 -0000
@@ -99,7 +99,9 @@ void set_floatx80_rounding_precision(int
| Software IEC/IEEE integer-to-floating-point conversion routines.
*----------------------------------------------------------------------------*/
float32 int32_to_float32( int STATUS_PARAM);
+float32 uint32_to_float32( unsigned int STATUS_PARAM);
float64 int32_to_float64( int STATUS_PARAM);
+float64 uint32_to_float64( unsigned int STATUS_PARAM);
#ifdef FLOATX80
floatx80 int32_to_floatx80( int STATUS_PARAM);
#endif
@@ -107,7 +109,9 @@ floatx80 int32_to_floatx80( int STATUS_P
float128 int32_to_float128( int STATUS_PARAM);
#endif
float32 int64_to_float32( int64_t STATUS_PARAM);
+float32 uint64_to_float32( uint64_t STATUS_PARAM);
float64 int64_to_float64( int64_t STATUS_PARAM);
+float64 uint64_to_float64( uint64_t v STATUS_PARAM);
#ifdef FLOATX80
floatx80 int64_to_floatx80( int64_t STATUS_PARAM);
#endif
@@ -120,6 +124,8 @@ float128 int64_to_float128( int64_t STAT
*----------------------------------------------------------------------------*/
int float32_to_int32( float32 STATUS_PARAM);
int float32_to_int32_round_to_zero( float32 STATUS_PARAM);
+unsigned int float32_to_uint32( float32 a STATUS_PARAM);
+unsigned int float32_to_uint32_round_to_zero( float32 a STATUS_PARAM);
int64_t float32_to_int64( float32 STATUS_PARAM);
int64_t float32_to_int64_round_to_zero( float32 STATUS_PARAM);
float64 float32_to_float64( float32 STATUS_PARAM);
@@ -200,8 +206,12 @@ INLINE float32 float32_chs(float32 a)
*----------------------------------------------------------------------------*/
int float64_to_int32( float64 STATUS_PARAM );
int float64_to_int32_round_to_zero( float64 STATUS_PARAM );
+unsigned int float64_to_uint32( float64 STATUS_PARAM );
+unsigned int float64_to_uint32_round_to_zero( float64 STATUS_PARAM );
int64_t float64_to_int64( float64 STATUS_PARAM );
int64_t float64_to_int64_round_to_zero( float64 STATUS_PARAM );
+uint64_t float64_to_uint64( float64 STATUS_PARAM );
+uint64_t float64_to_uint64_round_to_zero( float64 STATUS_PARAM );
float32 float64_to_float32( float64 STATUS_PARAM );
#ifdef FLOATX80
floatx80 float64_to_floatx80( float64 STATUS_PARAM );
Index: fpu/softfloat.c
===================================================================
RCS file: /sources/qemu/qemu/fpu/softfloat.c,v
retrieving revision 1.4
diff -u -d -d -p -r1.4 softfloat.c
--- fpu/softfloat.c 28 Oct 2006 19:27:11 -0000 1.4
+++ fpu/softfloat.c 19 Mar 2007 23:05:29 -0000
@@ -1164,6 +1164,27 @@ float32 int64_to_float32( int64 a STATUS
}
+float64 uint64_to_float32( uint64 a STATUS_PARAM )
+{
+ int8 shiftCount;
+
+ if ( a == 0 ) return 0;
+ shiftCount = countLeadingZeros64( a ) - 40;
+ if ( 0 <= shiftCount ) {
+ return packFloat32( 1 > 0, 0x95 - shiftCount, a<<shiftCount );
+ }
+ else {
+ shiftCount += 7;
+ if ( shiftCount < 0 ) {
+ shift64RightJamming( a, - shiftCount, &a );
+ }
+ else {
+ a <<= shiftCount;
+ }
+ return roundAndPackFloat32( 1 > 0, 0x9C - shiftCount, a STATUS_VAR );
+ }
+}
+
/*----------------------------------------------------------------------------
| Returns the result of converting the 64-bit two's complement integer `a'
| to the double-precision floating-point format. The conversion is performed
@@ -1183,6 +1204,13 @@ float64 int64_to_float64( int64 a STATUS
}
+float64 uint64_to_float64( uint64 a STATUS_PARAM )
+{
+ if ( a == 0 ) return 0;
+ return normalizeRoundAndPackFloat64( 0, 0x43C, a STATUS_VAR );
+
+}
+
#ifdef FLOATX80
/*----------------------------------------------------------------------------
@@ -5282,6 +5310,26 @@ unsigned int float64_to_uint32_round_to_
return res;
}
+uint64_t float64_to_uint64 (float64 a STATUS_PARAM)
+{
+ int64_t v;
+
+ v = int64_to_float64(INT64_MIN STATUS_VAR);
+ v = float64_to_int64((a + v) STATUS_VAR);
+
+ return v - INT64_MIN;
+}
+
+uint64_t float64_to_uint64_round_to_zero (float64 a STATUS_PARAM)
+{
+ int64_t v;
+
+ v = int64_to_float64(INT64_MIN STATUS_VAR);
+ v = float64_to_int64_round_to_zero((a + v) STATUS_VAR);
+
+ return v - INT64_MIN;
+}
+
#define COMPARE(s, nan_exp) \
INLINE int float ## s ## _compare_internal( float ## s a, float ## s b, \
int is_quiet STATUS_PARAM ) \
Index: fpu/softfloat.h
===================================================================
RCS file: /sources/qemu/qemu/fpu/softfloat.h,v
retrieving revision 1.5
diff -u -d -d -p -r1.5 softfloat.h
--- fpu/softfloat.h 28 Oct 2006 19:27:11 -0000 1.5
+++ fpu/softfloat.h 19 Mar 2007 23:05:29 -0000
@@ -193,7 +193,9 @@ floatx80 int32_to_floatx80( int STATUS_P
float128 int32_to_float128( int STATUS_PARAM );
#endif
float32 int64_to_float32( int64_t STATUS_PARAM );
+float32 uint64_to_float32( uint64_t STATUS_PARAM );
float64 int64_to_float64( int64_t STATUS_PARAM );
+float64 uint64_to_float64( uint64_t STATUS_PARAM );
#ifdef FLOATX80
floatx80 int64_to_floatx80( int64_t STATUS_PARAM );
#endif
@@ -258,6 +260,8 @@ unsigned int float64_to_uint32( float64
unsigned int float64_to_uint32_round_to_zero( float64 STATUS_PARAM );
int64_t float64_to_int64( float64 STATUS_PARAM );
int64_t float64_to_int64_round_to_zero( float64 STATUS_PARAM );
+uint64_t float64_to_uint64 (float64 a STATUS_PARAM);
+uint64_t float64_to_uint64_round_to_zero (float64 a STATUS_PARAM);
float32 float64_to_float32( float64 STATUS_PARAM );
#ifdef FLOATX80
floatx80 float64_to_floatx80( float64 STATUS_PARAM );
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