Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

rsa: use portable intrinsic for 64x64bit multiplication on Win ARM64 #20244

Closed
wants to merge 1 commit into from
Closed

rsa: use portable intrinsic for 64x64bit multiplication on Win ARM64 #20244

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
24 changes: 23 additions & 1 deletion crypto/bn/rsa_sup_mul.c
View file
Open in desktop
Expand Up @@ -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
Expand Down