From 63ff064d2f7e67bb8ce3431ca5d7f8f056ba6bbd Mon Sep 17 00:00:00 2001 From: Tim Ruffing Date: Mon, 14 Nov 2022 17:24:12 -0500 Subject: [PATCH] int128: Add test override for testing __(u)mulh on MSVC X64 Also add a corresponding CI job --- .cirrus.yml | 4 ++++ src/int128_struct_impl.h | 17 +++++++++++------ 2 files changed, 15 insertions(+), 6 deletions(-) diff --git a/.cirrus.yml b/.cirrus.yml index e32f8eb8ca84b..1e18e01c8f949 100644 --- a/.cirrus.yml +++ b/.cirrus.yml @@ -288,6 +288,10 @@ task: - name: "x86_64 (MSVC): Windows (Debian stable, Wine, int128_struct)" env: WIDEMUL: int128_struct + - name: "x86_64 (MSVC): Windows (Debian stable, Wine, int128_struct with __(u)mulh)" + env: + WIDEMUL: int128_struct + CPPFLAGS: -DSECP256K1_MSVC_MULH_TEST_OVERRIDE - name: "i686 (MSVC): Windows (Debian stable, Wine)" env: HOST: i686-w64-mingw32 diff --git a/src/int128_struct_impl.h b/src/int128_struct_impl.h index 6684bfd5dfe9e..5e64ac41987a6 100644 --- a/src/int128_struct_impl.h +++ b/src/int128_struct_impl.h @@ -5,12 +5,13 @@ #if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_ARM64)) /* MSVC */ # include -# if defined(_M_X64) -/* On x84_64 MSVC, use native _(u)mul128 for 64x64->128 multiplications. */ -# define secp256k1_umul128 _umul128 -# define secp256k1_mul128 _mul128 -# else -/* On ARM64 MSVC, use __(u)mulh for the upper half of 64x64 multiplications. */ +# if defined(_M_ARM64) || defined(SECP256K1_MSVC_MULH_TEST_OVERRIDE) +/* On ARM64 MSVC, use __(u)mulh for the upper half of 64x64 multiplications. + (Define SECP256K1_MSVC_MULH_TEST_OVERRIDE to test this code path on X64, + which supports both __(u)mulh and _umul128.) */ +# if defined(SECP256K1_MSVC_MULH_TEST_OVERRIDE) +# pragma message(__FILE__ ": SECP256K1_MSVC_MULH_TEST_OVERRIDE is defined, forcing use of __(u)mulh.") +# endif static SECP256K1_INLINE uint64_t secp256k1_umul128(uint64_t a, uint64_t b, uint64_t* hi) { *hi = __umulh(a, b); return a * b; @@ -20,6 +21,10 @@ static SECP256K1_INLINE int64_t secp256k1_mul128(int64_t a, int64_t b, int64_t* *hi = __mulh(a, b); return a * b; } +# else +/* On x84_64 MSVC, use native _(u)mul128 for 64x64->128 multiplications. */ +# define secp256k1_umul128 _umul128 +# define secp256k1_mul128 _mul128 # endif #else /* On other systems, emulate 64x64->128 multiplications using 32x32->64 multiplications. */