Fix long (and long long) to long double, unsigned to long double and unsigned

long (and unsigned long long) to long double conversions.
- Add a parameter that specifies the position of the sign bit to the _QP_TTOQ
  macro, previously it always looked at bit 31.  Pass a negative number to
  disable sign inspection for unsigned types.  This fixes _Qp_xtoq(),
  _Qp_uitoq() and _Qp_uxtoq().
- In the functions __fpu_itof() and __fpu_xtof(), look at the sign bit to
  decide whether we're doing a conversion from an unsigned type.  If so, don't
  negate the mantissa if the integer exceeds the biggest signed number.

PR:		55773
Patch by:	Stephen Paskaluk (based upon)
MFC after:	2 weeks

2 files changed, 24 insertions, 10 deletions

diff --git a/lib/libc/sparc64/fpu/fpu_explode.c b/lib/libc/sparc64/fpu/fpu_explode.c
index 7c1f3eb..09f8908 100644
--- a/lib/libc/sparc64/fpu/fpu_explode.c
+++ b/lib/libc/sparc64/fpu/fpu_explode.c
@@ -101,7 +101,14 @@ __fpu_itof(fp, i)
 	 * fpu_norm()'s handling of `supernormals'; see fpu_subr.c.
 	 */
 	fp->fp_exp = FP_LG;
-	fp->fp_mant[0] = (int)i < 0 ? -i : i;
+	/*
+	 * The sign bit decides whether i should be interpreted as
+	 * a signed or unsigned entity.
+	 */
+	if (fp->fp_sign && (int)i < 0)
+		fp->fp_mant[0] = -i;
+	else
+		fp->fp_mant[0] = i;
 	fp->fp_mant[1] = 0;
 	fp->fp_mant[2] = 0;
 	fp->fp_mant[3] = 0;
@@ -127,7 +134,14 @@ __fpu_xtof(fp, i)
 	 * fpu_norm()'s handling of `supernormals'; see fpu_subr.c.
 	 */
 	fp->fp_exp = FP_LG2;
-	*((int64_t*)fp->fp_mant) = (int64_t)i < 0 ? -i : i;
+	/*
+	 * The sign bit decides whether i should be interpreted as
+	 * a signed or unsigned entity.
+	 */
+	if (fp->fp_sign && (int64_t)i < 0)
+		*((int64_t*)fp->fp_mant) = -i;
+	else
+		*((int64_t*)fp->fp_mant) = i;
 	fp->fp_mant[2] = 0;
 	fp->fp_mant[3] = 0;
 	__fpu_norm(fp);
diff --git a/lib/libc/sparc64/fpu/fpu_qp.c b/lib/libc/sparc64/fpu/fpu_qp.c
index 9e3bedc..e730eba 100644
--- a/lib/libc/sparc64/fpu/fpu_qp.c
+++ b/lib/libc/sparc64/fpu/fpu_qp.c
@@ -51,7 +51,7 @@ _Qp_ ## op(u_int *c, u_int *a, u_int *b) \
 	c[0] = __fpu_ftoq(&fe, r, c); \
 }
 
-#define	_QP_TTOQ(qname, fname, ntype, atype, ...) \
+#define	_QP_TTOQ(qname, fname, ntype, signpos, atype, ...) \
 void _Qp_ ## qname ## toq(u_int *c, ntype n); \
 void \
 _Qp_ ## qname ## toq(u_int *c, ntype n) \
@@ -59,7 +59,7 @@ _Qp_ ## qname ## toq(u_int *c, ntype n) \
 	struct fpemu fe; \
 	union { atype a[2]; ntype n; } u = { .n = n }; \
 	__asm __volatile("stx %%fsr, %0" : "=m" (fe.fe_fsr) :); \
-	fe.fe_f1.fp_sign = u.a[0] >> 31; \
+	fe.fe_f1.fp_sign = (signpos >= 0) ? u.a[0] >> signpos : 0; \
 	fe.fe_f1.fp_sticky = 0; \
 	fe.fe_f1.fp_class = __fpu_ ## fname ## tof(&fe.fe_f1, __VA_ARGS__); \
 	c[0] = __fpu_ftoq(&fe, &fe.fe_f1, c); \
@@ -123,12 +123,12 @@ _QP_OP(div)
 _QP_OP(mul)
 _QP_OP(sub)
 
-_QP_TTOQ(d,	d,	double,	u_int,	u.a[0], u.a[1])
-_QP_TTOQ(i,	i,	int,	u_int,	u.a[0])
-_QP_TTOQ(s,	s,	float,	u_int,	u.a[0])
-_QP_TTOQ(x,	x,	long,	u_long,	u.a[0])
-_QP_TTOQ(ui,	i,	u_int,	u_int,	u.a[0])
-_QP_TTOQ(ux,	x,	u_long,	u_long,	u.a[0])
+_QP_TTOQ(d,	d,	double,	31, u_int,  u.a[0], u.a[1])
+_QP_TTOQ(i,	i,	int,	31, u_int,  u.a[0])
+_QP_TTOQ(s,	s,	float,	31, u_int,  u.a[0])
+_QP_TTOQ(x,	x,	long,	63, u_long, u.a[0])
+_QP_TTOQ(ui,	i,	u_int,	-1, u_int,  u.a[0])
+_QP_TTOQ(ux,	x,	u_long,	-1, u_long, u.a[0])
 
 _QP_QTOT(d,	d,	double,	&u.a)
 _QP_QTOT(i,	i,	int)