From 6dece9913f459f46c86d383e0da2ea544ce73f63 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Fri, 12 Jan 2024 10:10:20 +0100 Subject: [PATCH] libgcc: Use may_alias attribute in bitint handlers As discussed on IRC, the following patch uses may_alias attribute, so that on targets like aarch64 where abi_limb_mode != limb_mode the library accesses the limbs (half limbs of the ABI) in the arrays with conservative alias set. 2024-01-12 Jakub Jelinek * libgcc2.h (UBILtype): New typedef with may_alias attribute. (__mulbitint3, __divmodbitint4): Use UBILtype * instead of UWtype * and const UBILtype * instead of const UWtype *. * libgcc2.c (bitint_reduce_prec, bitint_mul_1, bitint_addmul_1, __mulbitint3, bitint_negate, bitint_submul_1, __divmodbitint4): Likewise. * soft-fp/bitint.h (UBILtype): Change define into a typedef with may_alias attribute. --- libgcc/libgcc2.c | 34 +++++++++++++++++----------------- libgcc/libgcc2.h | 10 ++++++---- libgcc/soft-fp/bitint.h | 8 ++++---- 3 files changed, 27 insertions(+), 25 deletions(-) diff --git a/libgcc/libgcc2.c b/libgcc/libgcc2.c index eee8bce90797..e04d169f888a 100644 --- a/libgcc/libgcc2.c +++ b/libgcc/libgcc2.c @@ -1309,7 +1309,7 @@ __udivdi3 (UDWtype n, UDWtype d) some narrower _BitInt value, reduce precision. */ static inline __attribute__((__always_inline__)) SItype -bitint_reduce_prec (const UWtype **p, SItype prec) +bitint_reduce_prec (const UBILtype **p, SItype prec) { UWtype mslimb; SItype i; @@ -1421,7 +1421,7 @@ bitint_reduce_prec (const UWtype **p, SItype prec) /* D = S * L. */ static UWtype -bitint_mul_1 (UWtype *d, const UWtype *s, UWtype l, SItype n) +bitint_mul_1 (UBILtype *d, const UBILtype *s, UWtype l, SItype n) { UWtype sv, hi, lo, c = 0; do @@ -1440,7 +1440,7 @@ bitint_mul_1 (UWtype *d, const UWtype *s, UWtype l, SItype n) /* D += S * L. */ static UWtype -bitint_addmul_1 (UWtype *d, const UWtype *s, UWtype l, SItype n) +bitint_addmul_1 (UBILtype *d, const UBILtype *s, UWtype l, SItype n) { UWtype sv, hi, lo, c = 0; do @@ -1465,9 +1465,9 @@ bitint_addmul_1 (UWtype *d, const UWtype *s, UWtype l, SItype n) positive. */ void -__mulbitint3 (UWtype *ret, SItype retprec, - const UWtype *u, SItype uprec, - const UWtype *v, SItype vprec) +__mulbitint3 (UBILtype *ret, SItype retprec, + const UBILtype *u, SItype uprec, + const UBILtype *v, SItype vprec) { uprec = bitint_reduce_prec (&u, uprec); vprec = bitint_reduce_prec (&v, vprec); @@ -1480,7 +1480,7 @@ __mulbitint3 (UWtype *ret, SItype retprec, || (avprec > auprec && !(uprec >= 0 && vprec < 0))) { SItype p; - const UWtype *t; + const UBILtype *t; p = uprec; uprec = vprec; vprec = p; p = auprec; auprec = avprec; avprec = p; t = u; u = v; v = t; @@ -1643,7 +1643,7 @@ __mulbitint3 (UWtype *ret, SItype retprec, /* D = -S. */ static void -bitint_negate (UWtype *d, const UWtype *s, SItype n) +bitint_negate (UBILtype *d, const UBILtype *s, SItype n) { UWtype c = 1; do @@ -1660,7 +1660,7 @@ bitint_negate (UWtype *d, const UWtype *s, SItype n) /* D -= S * L. */ static UWtype -bitint_submul_1 (UWtype *d, const UWtype *s, UWtype l, SItype n) +bitint_submul_1 (UBILtype *d, const UBILtype *s, UWtype l, SItype n) { UWtype sv, hi, lo, c = 0; do @@ -1687,10 +1687,10 @@ bitint_submul_1 (UWtype *d, const UWtype *s, UWtype l, SItype n) should be 0. */ void -__divmodbitint4 (UWtype *q, SItype qprec, - UWtype *r, SItype rprec, - const UWtype *u, SItype uprec, - const UWtype *v, SItype vprec) +__divmodbitint4 (UBILtype *q, SItype qprec, + UBILtype *r, SItype rprec, + const UBILtype *u, SItype uprec, + const UBILtype *v, SItype vprec) { uprec = bitint_reduce_prec (&u, uprec); vprec = bitint_reduce_prec (&v, vprec); @@ -1747,7 +1747,7 @@ __divmodbitint4 (UWtype *q, SItype qprec, if (qn >= qn2) qn2 = 0; USItype sz = un + 1 + vn + qn2; - UWtype *buf = __builtin_alloca (sz * sizeof (UWtype)); + UBILtype *buf = __builtin_alloca (sz * sizeof (UWtype)); USItype uidx, vidx; #if __LIBGCC_BITINT_ORDER__ == __ORDER_BIG_ENDIAN__ uidx = un - 1; @@ -1768,9 +1768,9 @@ __divmodbitint4 (UWtype *q, SItype qprec, __builtin_memcpy (buf + un + 1, v, vn * sizeof (UWtype)); if (vp) buf[un + 1 + BITINT_END (0, vn - 1)] &= (((UWtype) 1 << vp) - 1); - UWtype *u2 = buf; - UWtype *v2 = u2 + un + 1; - UWtype *q2 = v2 + vn; + UBILtype *u2 = buf; + UBILtype *v2 = u2 + un + 1; + UBILtype *q2 = v2 + vn; if (!qn2) q2 = q + BITINT_END (qn - (un - vn + 1), 0); diff --git a/libgcc/libgcc2.h b/libgcc/libgcc2.h index c4ee96518e34..5050456eada3 100644 --- a/libgcc/libgcc2.h +++ b/libgcc/libgcc2.h @@ -402,10 +402,12 @@ extern UDWtype __udivmoddi4 (UDWtype, UDWtype, UDWtype *); #if (defined(__BITINT_MAXWIDTH__) \ && (defined(L_mulbitint3) || defined(L_divmodbitint4))) /* _BitInt support. */ -extern void __mulbitint3 (UWtype *, SItype, const UWtype *, SItype, - const UWtype *, SItype); -extern void __divmodbitint4 (UWtype *, SItype, UWtype *, SItype, - const UWtype *, SItype, const UWtype *, SItype); +typedef UWtype __attribute__((__may_alias__)) UBILtype; +extern void __mulbitint3 (UBILtype *, SItype, const UBILtype *, SItype, + const UBILtype *, SItype); +extern void __divmodbitint4 (UBILtype *, SItype, UBILtype *, SItype, + const UBILtype *, SItype, const UBILtype *, + SItype); #endif /* __negdi2 is static inline when building other libgcc2 portions. */ diff --git a/libgcc/soft-fp/bitint.h b/libgcc/soft-fp/bitint.h index 20cd41ba1156..cb4d822cb49b 100644 --- a/libgcc/soft-fp/bitint.h +++ b/libgcc/soft-fp/bitint.h @@ -33,19 +33,19 @@ see the files COPYING3 and COPYING.RUNTIME respectively. If not, see #if BIL_UNITS_PER_WORD == 8 #define BIL_TYPE_SIZE (8 * __CHAR_BIT__) #define BILtype DItype -#define UBILtype UDItype +typedef UDItype __attribute__ ((__may_alias__)) UBILtype; #elif BIL_UNITS_PER_WORD == 4 #define BIL_TYPE_SIZE (4 * __CHAR_BIT__) #define BILtype SItype -#define UBILtype USItype +typedef USItype __attribute__ ((__may_alias__)) UBILtype; #elif BIL_UNITS_PER_WORD == 2 #define BIL_TYPE_SIZE (2 * __CHAR_BIT__) #define BILtype HItype -#define UBILtype UHItype +typedef UHItype __attribute__ ((__may_alias__)) UBILtype; #else #define BIL_TYPE_SIZE __CHAR_BIT__ #define BILtype QItype -#define UBILtype UQItype +typedef UQItype __attribute__ ((__may_alias__)) UBILtype; #endif /* If *P is zero or sign extended (the latter only for PREC < 0) from -- 2.43.5