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-rw-r--r--newlib/ChangeLog15
-rw-r--r--newlib/libc/stdlib/mprec.h49
-rw-r--r--newlib/libc/stdlib/strtod.c41
3 files changed, 47 insertions, 58 deletions
diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index c3e5a15d6..bc11fe183 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,18 @@
+2008-06-25 Hans-Peter Nilsson <hp@axis.com>
+
+ Fix strict-aliasing issues with _strtod_r and Storeinc.
+ * libc/stdlib/strtod.c (_strtod_r): Change local variables aadj,
+ rv, rv0 from double to type U. Use accessor macros dval, dword0
+ and dword1 for all accesses except for the ULtod call, where rv.i
+ replaces the pointer cast.
+ * libc/stdlib/mprec.h (U): Rename member L to i for easier re-use
+ of access macros. Tweak comment.
+ Remove #ifdef'd YES_ALIAS code.
+ (dword0, dword1, dval): Define in terms of uncast union member
+ access. Ditto for _DOUBLE_IS_32BITS variants.
+ (Storeinc): Replace aliasing-flawed microoptimized definition with
+ alternative suggested in comment. Remove now stale comment.
+
2008-06-21 Corinna Vinschen <corinna@vinschen.de>
* libc/include/machine/setjmp.h (_longjmp): Define as function on
diff --git a/newlib/libc/stdlib/mprec.h b/newlib/libc/stdlib/mprec.h
index 498de5b74..dea89bf11 100644
--- a/newlib/libc/stdlib/mprec.h
+++ b/newlib/libc/stdlib/mprec.h
@@ -78,31 +78,18 @@ union double_union
#define word1(x) (x.i[1])
#endif
-
-/* The following is taken from gdtoaimp.h for use with new strtod. */
+/* The following is taken from gdtoaimp.h for use with new strtod, but
+ adjusted to avoid invalid type-punning. */
typedef __int32_t Long;
-typedef union { double d; __ULong L[2]; } U;
-#ifdef YES_ALIAS
-#define dval(x) x
-#ifdef IEEE_8087
-#define dword0(x) ((__ULong *)&x)[1]
-#define dword1(x) ((__ULong *)&x)[0]
-#else
-#define dword0(x) ((__ULong *)&x)[0]
-#define dword1(x) ((__ULong *)&x)[1]
-#endif
-#else /* !YES_ALIAS */
-#ifdef IEEE_8087
-#define dword0(x) ((U*)&x)->L[1]
-#define dword1(x) ((U*)&x)->L[0]
-#else
-#define dword0(x) ((U*)&x)->L[0]
-#define dword1(x) ((U*)&x)->L[1]
-#endif
-#define dval(x) ((U*)&x)->d
-#endif /* YES_ALIAS */
+/* Unfortunately, because __ULong might be a different type than
+ __uint32_t, we can't re-use union double_union as-is without
+ further edits in strtod.c. */
+typedef union { double d; __ULong i[2]; } U;
+#define dword0(x) word0(x)
+#define dword1(x) word1(x)
+#define dval(x) (x.d)
#undef SI
#ifdef Sudden_Underflow
@@ -111,17 +98,7 @@ typedef union { double d; __ULong L[2]; } U;
#define SI 0
#endif
-/* The following definition of Storeinc is appropriate for MIPS processors.
- * An alternative that might be better on some machines is
- * #define Storeinc(a,b,c) (*a++ = b << 16 | c & 0xffff)
- */
-#if defined (__IEEE_BYTES_LITTLE_ENDIAN) + defined (IEEE_8087) + defined (VAX)
-#define Storeinc(a,b,c) (((unsigned short *)a)[1] = (unsigned short)b, \
-((unsigned short *)a)[0] = (unsigned short)c, a++)
-#else
-#define Storeinc(a,b,c) (((unsigned short *)a)[0] = (unsigned short)b, \
-((unsigned short *)a)[1] = (unsigned short)c, a++)
-#endif
+#define Storeinc(a,b,c) (*(a)++ = (b) << 16 | (c) & 0xffff)
/* #define P DBL_MANT_DIG */
/* Ten_pmax = floor(P*log(2)/log(5)) */
@@ -167,11 +144,7 @@ typedef union { double d; __ULong L[2]; } U;
#define word0(x) (x.i[0])
#define word1(x) 0
-#ifdef YES_ALIAS
-#define dword0(x) ((__ULong *)&x)[0]
-#else
-#define dword0(x) ((U*)&x)->L[0]
-#endif
+#define dword0(x) word0(x)
#define dword1(x) 0
#else
diff --git a/newlib/libc/stdlib/strtod.c b/newlib/libc/stdlib/strtod.c
index 80e5aacef..703fbce1d 100644
--- a/newlib/libc/stdlib/strtod.c
+++ b/newlib/libc/stdlib/strtod.c
@@ -218,7 +218,8 @@ _DEFUN (_strtod_r, (ptr, s00, se),
int bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, decpt, dsign,
e, e1, esign, i, j, k, nd, nd0, nf, nz, nz0, sign;
_CONST char *s, *s0, *s1;
- double aadj, aadj1, adj, rv, rv0;
+ double aadj, adj;
+ U aadj1, rv, rv0;
Long L;
__ULong y, z;
_Bigint *bb, *bb1, *bd, *bd0, *bs, *delta;
@@ -286,7 +287,7 @@ _DEFUN (_strtod_r, (ptr, s00, se),
copybits(bits, fpi.nbits, bb);
Bfree(ptr,bb);
}
- ULtod(((U*)&rv)->L, bits, exp, i);
+ ULtod(rv.i, bits, exp, i);
}}
goto ret;
}
@@ -469,7 +470,7 @@ _DEFUN (_strtod_r, (ptr, s00, se),
#ifdef Honor_FLT_ROUNDS
/* round correctly FLT_ROUNDS = 2 or 3 */
if (sign) {
- rv = -rv;
+ dval(rv) = -dval(rv);
sign = 0;
}
#endif
@@ -485,7 +486,7 @@ _DEFUN (_strtod_r, (ptr, s00, se),
#ifdef Honor_FLT_ROUNDS
/* round correctly FLT_ROUNDS = 2 or 3 */
if (sign) {
- rv = -rv;
+ dval(rv) = -dval(rv);
sign = 0;
}
#endif
@@ -513,7 +514,7 @@ _DEFUN (_strtod_r, (ptr, s00, se),
#ifdef Honor_FLT_ROUNDS
/* round correctly FLT_ROUNDS = 2 or 3 */
if (sign) {
- rv = -rv;
+ dval(rv) = -dval(rv);
sign = 0;
}
#endif
@@ -976,14 +977,14 @@ _DEFUN (_strtod_r, (ptr, s00, se),
}
if ((aadj = ratio(delta, bs)) <= 2.) {
if (dsign)
- aadj = aadj1 = 1.;
+ aadj = dval(aadj1) = 1.;
else if (dword1(rv) || dword0(rv) & Bndry_mask) {
#ifndef Sudden_Underflow
if (dword1(rv) == Tiny1 && !dword0(rv))
goto undfl;
#endif
aadj = 1.;
- aadj1 = -1.;
+ dval(aadj1) = -1.;
}
else {
/* special case -- power of FLT_RADIX to be */
@@ -993,24 +994,24 @@ _DEFUN (_strtod_r, (ptr, s00, se),
aadj = 1./FLT_RADIX;
else
aadj *= 0.5;
- aadj1 = -aadj;
+ dval(aadj1) = -aadj;
}
}
else {
aadj *= 0.5;
- aadj1 = dsign ? aadj : -aadj;
+ dval(aadj1) = dsign ? aadj : -aadj;
#ifdef Check_FLT_ROUNDS
switch(Rounding) {
case 2: /* towards +infinity */
- aadj1 -= 0.5;
+ dval(aadj1) -= 0.5;
break;
case 0: /* towards 0 */
case 3: /* towards -infinity */
- aadj1 += 0.5;
+ dval(aadj1) += 0.5;
}
#else
if (Flt_Rounds == 0)
- aadj1 += 0.5;
+ dval(aadj1) += 0.5;
#endif /*Check_FLT_ROUNDS*/
}
y = dword0(rv) & Exp_mask;
@@ -1020,7 +1021,7 @@ _DEFUN (_strtod_r, (ptr, s00, se),
if (y == Exp_msk1*(DBL_MAX_EXP+Bias-1)) {
dval(rv0) = dval(rv);
dword0(rv) -= P*Exp_msk1;
- adj = aadj1 * ulp(dval(rv));
+ adj = dval(aadj1) * ulp(dval(rv));
dval(rv) += adj;
if ((dword0(rv) & Exp_mask) >=
Exp_msk1*(DBL_MAX_EXP+Bias-P)) {
@@ -1042,18 +1043,18 @@ _DEFUN (_strtod_r, (ptr, s00, se),
if ((z = aadj) <= 0)
z = 1;
aadj = z;
- aadj1 = dsign ? aadj : -aadj;
+ dval(aadj1) = dsign ? aadj : -aadj;
}
dword0(aadj1) += (2*P+1)*Exp_msk1 - y;
}
- adj = aadj1 * ulp(dval(rv));
+ adj = dval(aadj1) * ulp(dval(rv));
dval(rv) += adj;
#else
#ifdef Sudden_Underflow
if ((dword0(rv) & Exp_mask) <= P*Exp_msk1) {
dval(rv0) = dval(rv);
dword0(rv) += P*Exp_msk1;
- adj = aadj1 * ulp(dval(rv));
+ adj = dval(aadj1) * ulp(dval(rv));
dval(rv) += adj;
#ifdef IBM
if ((dword0(rv) & Exp_mask) < P*Exp_msk1)
@@ -1076,7 +1077,7 @@ _DEFUN (_strtod_r, (ptr, s00, se),
dword0(rv) -= P*Exp_msk1;
}
else {
- adj = aadj1 * ulp(dval(rv));
+ adj = dval(aadj1) * ulp(dval(rv));
dval(rv) += adj;
}
#else /*Sudden_Underflow*/
@@ -1088,11 +1089,11 @@ _DEFUN (_strtod_r, (ptr, s00, se),
* example: 1.2e-307 .
*/
if (y <= (P-1)*Exp_msk1 && aadj > 1.) {
- aadj1 = (double)(int)(aadj + 0.5);
+ dval(aadj1) = (double)(int)(aadj + 0.5);
if (!dsign)
- aadj1 = -aadj1;
+ dval(aadj1) = -dval(aadj1);
}
- adj = aadj1 * ulp(dval(rv));
+ adj = dval(aadj1) * ulp(dval(rv));
dval(rv) += adj;
#endif /*Sudden_Underflow*/
#endif /*Avoid_Underflow*/
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