Skip to content

Commit

Permalink
deps: cherry-pick Windows ARM64 fix for openssl
Browse files Browse the repository at this point in the history
Original commit message:

    rsa: add msvc intrinsic for non x64 platforms

    _umul128() is x86_64 (x64) only, while __umulh() works everywhere, but
    doesn't generate optimal code on x64

PR-URL: #46573
Refs: openssl/openssl#20244
Reviewed-By: Moshe Atlow <moshe@atlow.co.il>
Reviewed-By: Richard Lau <rlau@redhat.com>
richardlau authored and RafaelGSS committed Feb 14, 2023
1 parent d8559aa commit 66a24ce
Showing 1 changed file with 23 additions and 1 deletion.
24 changes: 23 additions & 1 deletion deps/openssl/openssl/crypto/bn/rsa_sup_mul.c
Original file line number Diff line number Diff line change
@@ -110,12 +110,34 @@ static ossl_inline void _mul_limb(limb_t *hi, limb_t *lo, limb_t a, limb_t b)
*lo = (limb_t)t;
}
#elif (BN_BYTES == 8) && (defined _MSC_VER)
/* https://learn.microsoft.com/en-us/cpp/intrinsics/umul128?view=msvc-170 */
# if defined(_M_X64)
/*
* on x86_64 (x64) we can use the _umul128 intrinsic to get one `mul`
* instruction to get both high and low 64 bits of the multiplication.
* https://learn.microsoft.com/en-us/cpp/intrinsics/umul128?view=msvc-140
*/
#include <intrin.h>
#pragma intrinsic(_umul128)
static ossl_inline void _mul_limb(limb_t *hi, limb_t *lo, limb_t a, limb_t b)
{
*lo = _umul128(a, b, hi);
}
# elif defined(_M_ARM64) || defined (_M_IA64)
/*
* We can't use the __umulh() on x86_64 as then msvc generates two `mul`
* instructions; so use this more portable intrinsic on platforms that
* don't support _umul128 (like aarch64 (ARM64) or ia64)
* https://learn.microsoft.com/en-us/cpp/intrinsics/umulh?view=msvc-140
*/
#include <intrin.h>
static ossl_inline void _mul_limb(limb_t *hi, limb_t *lo, limb_t a, limb_t b)
{
*lo = a * b;
*hi = __umulh(a, b);
}
# else
# error Only x64, ARM64 and IA64 supported.
# endif /* defined(_M_X64) */
#else
/*
* if the compiler doesn't have either a 128bit data type nor a "return

0 comments on commit 66a24ce

Please sign in to comment.