From 5140d6be5e71cd5d75697d47ba510d117773e970 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Fri, 6 Nov 2020 10:59:36 -0800 Subject: qemu/host-utils: Use __builtin_bitreverseN MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Clang has added some builtins for these operations; use them if available. Reviewed-by: Alex Bennée Reviewed-by: David Hildenbrand Signed-off-by: Richard Henderson --- include/qemu/host-utils.h | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'include/qemu/host-utils.h') diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h index cdca2991d8..f1e52851e0 100644 --- a/include/qemu/host-utils.h +++ b/include/qemu/host-utils.h @@ -272,6 +272,9 @@ static inline int ctpop64(uint64_t val) */ static inline uint8_t revbit8(uint8_t x) { +#if __has_builtin(__builtin_bitreverse8) + return __builtin_bitreverse8(x); +#else /* Assign the correct nibble position. */ x = ((x & 0xf0) >> 4) | ((x & 0x0f) << 4); @@ -281,6 +284,7 @@ static inline uint8_t revbit8(uint8_t x) | ((x & 0x22) << 1) | ((x & 0x11) << 3); return x; +#endif } /** @@ -289,6 +293,9 @@ static inline uint8_t revbit8(uint8_t x) */ static inline uint16_t revbit16(uint16_t x) { +#if __has_builtin(__builtin_bitreverse16) + return __builtin_bitreverse16(x); +#else /* Assign the correct byte position. */ x = bswap16(x); /* Assign the correct nibble position. */ @@ -300,6 +307,7 @@ static inline uint16_t revbit16(uint16_t x) | ((x & 0x2222) << 1) | ((x & 0x1111) << 3); return x; +#endif } /** @@ -308,6 +316,9 @@ static inline uint16_t revbit16(uint16_t x) */ static inline uint32_t revbit32(uint32_t x) { +#if __has_builtin(__builtin_bitreverse32) + return __builtin_bitreverse32(x); +#else /* Assign the correct byte position. */ x = bswap32(x); /* Assign the correct nibble position. */ @@ -319,6 +330,7 @@ static inline uint32_t revbit32(uint32_t x) | ((x & 0x22222222u) << 1) | ((x & 0x11111111u) << 3); return x; +#endif } /** @@ -327,6 +339,9 @@ static inline uint32_t revbit32(uint32_t x) */ static inline uint64_t revbit64(uint64_t x) { +#if __has_builtin(__builtin_bitreverse64) + return __builtin_bitreverse64(x); +#else /* Assign the correct byte position. */ x = bswap64(x); /* Assign the correct nibble position. */ @@ -338,6 +353,7 @@ static inline uint64_t revbit64(uint64_t x) | ((x & 0x2222222222222222ull) << 1) | ((x & 0x1111111111111111ull) << 3); return x; +#endif } /* Host type specific sizes of these routines. */ -- cgit 1.4.1 From cec07c0b6129757337282287870da2d4c3958f48 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Fri, 6 Nov 2020 17:42:36 -0800 Subject: qemu/host-utils: Add wrappers for overflow builtins MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit These builtins came in with gcc 5 and clang 3.8, which are slightly newer than our supported minimum compiler versions. Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson --- include/qemu/host-utils.h | 225 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 225 insertions(+) (limited to 'include/qemu/host-utils.h') diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h index f1e52851e0..cb95626c7d 100644 --- a/include/qemu/host-utils.h +++ b/include/qemu/host-utils.h @@ -356,6 +356,231 @@ static inline uint64_t revbit64(uint64_t x) #endif } +/** + * sadd32_overflow - addition with overflow indication + * @x, @y: addends + * @ret: Output for sum + * + * Computes *@ret = @x + @y, and returns true if and only if that + * value has been truncated. + */ +static inline bool sadd32_overflow(int32_t x, int32_t y, int32_t *ret) +{ +#if __has_builtin(__builtin_add_overflow) || __GNUC__ >= 5 + return __builtin_add_overflow(x, y, ret); +#else + *ret = x + y; + return ((*ret ^ x) & ~(x ^ y)) < 0; +#endif +} + +/** + * sadd64_overflow - addition with overflow indication + * @x, @y: addends + * @ret: Output for sum + * + * Computes *@ret = @x + @y, and returns true if and only if that + * value has been truncated. + */ +static inline bool sadd64_overflow(int64_t x, int64_t y, int64_t *ret) +{ +#if __has_builtin(__builtin_add_overflow) || __GNUC__ >= 5 + return __builtin_add_overflow(x, y, ret); +#else + *ret = x + y; + return ((*ret ^ x) & ~(x ^ y)) < 0; +#endif +} + +/** + * uadd32_overflow - addition with overflow indication + * @x, @y: addends + * @ret: Output for sum + * + * Computes *@ret = @x + @y, and returns true if and only if that + * value has been truncated. + */ +static inline bool uadd32_overflow(uint32_t x, uint32_t y, uint32_t *ret) +{ +#if __has_builtin(__builtin_add_overflow) || __GNUC__ >= 5 + return __builtin_add_overflow(x, y, ret); +#else + *ret = x + y; + return *ret < x; +#endif +} + +/** + * uadd64_overflow - addition with overflow indication + * @x, @y: addends + * @ret: Output for sum + * + * Computes *@ret = @x + @y, and returns true if and only if that + * value has been truncated. + */ +static inline bool uadd64_overflow(uint64_t x, uint64_t y, uint64_t *ret) +{ +#if __has_builtin(__builtin_add_overflow) || __GNUC__ >= 5 + return __builtin_add_overflow(x, y, ret); +#else + *ret = x + y; + return *ret < x; +#endif +} + +/** + * ssub32_overflow - subtraction with overflow indication + * @x: Minuend + * @y: Subtrahend + * @ret: Output for difference + * + * Computes *@ret = @x - @y, and returns true if and only if that + * value has been truncated. + */ +static inline bool ssub32_overflow(int32_t x, int32_t y, int32_t *ret) +{ +#if __has_builtin(__builtin_sub_overflow) || __GNUC__ >= 5 + return __builtin_sub_overflow(x, y, ret); +#else + *ret = x - y; + return ((*ret ^ x) & (x ^ y)) < 0; +#endif +} + +/** + * ssub64_overflow - subtraction with overflow indication + * @x: Minuend + * @y: Subtrahend + * @ret: Output for sum + * + * Computes *@ret = @x - @y, and returns true if and only if that + * value has been truncated. + */ +static inline bool ssub64_overflow(int64_t x, int64_t y, int64_t *ret) +{ +#if __has_builtin(__builtin_sub_overflow) || __GNUC__ >= 5 + return __builtin_sub_overflow(x, y, ret); +#else + *ret = x - y; + return ((*ret ^ x) & (x ^ y)) < 0; +#endif +} + +/** + * usub32_overflow - subtraction with overflow indication + * @x: Minuend + * @y: Subtrahend + * @ret: Output for sum + * + * Computes *@ret = @x - @y, and returns true if and only if that + * value has been truncated. + */ +static inline bool usub32_overflow(uint32_t x, uint32_t y, uint32_t *ret) +{ +#if __has_builtin(__builtin_sub_overflow) || __GNUC__ >= 5 + return __builtin_sub_overflow(x, y, ret); +#else + *ret = x - y; + return x < y; +#endif +} + +/** + * usub64_overflow - subtraction with overflow indication + * @x: Minuend + * @y: Subtrahend + * @ret: Output for sum + * + * Computes *@ret = @x - @y, and returns true if and only if that + * value has been truncated. + */ +static inline bool usub64_overflow(uint64_t x, uint64_t y, uint64_t *ret) +{ +#if __has_builtin(__builtin_sub_overflow) || __GNUC__ >= 5 + return __builtin_sub_overflow(x, y, ret); +#else + *ret = x - y; + return x < y; +#endif +} + +/** + * smul32_overflow - multiplication with overflow indication + * @x, @y: Input multipliers + * @ret: Output for product + * + * Computes *@ret = @x * @y, and returns true if and only if that + * value has been truncated. + */ +static inline bool smul32_overflow(int32_t x, int32_t y, int32_t *ret) +{ +#if __has_builtin(__builtin_mul_overflow) || __GNUC__ >= 5 + return __builtin_mul_overflow(x, y, ret); +#else + int64_t z = (int64_t)x * y; + *ret = z; + return *ret != z; +#endif +} + +/** + * smul64_overflow - multiplication with overflow indication + * @x, @y: Input multipliers + * @ret: Output for product + * + * Computes *@ret = @x * @y, and returns true if and only if that + * value has been truncated. + */ +static inline bool smul64_overflow(int64_t x, int64_t y, int64_t *ret) +{ +#if __has_builtin(__builtin_mul_overflow) || __GNUC__ >= 5 + return __builtin_mul_overflow(x, y, ret); +#else + uint64_t hi, lo; + muls64(&lo, &hi, x, y); + *ret = lo; + return hi != ((int64_t)lo >> 63); +#endif +} + +/** + * umul32_overflow - multiplication with overflow indication + * @x, @y: Input multipliers + * @ret: Output for product + * + * Computes *@ret = @x * @y, and returns true if and only if that + * value has been truncated. + */ +static inline bool umul32_overflow(uint32_t x, uint32_t y, uint32_t *ret) +{ +#if __has_builtin(__builtin_mul_overflow) || __GNUC__ >= 5 + return __builtin_mul_overflow(x, y, ret); +#else + uint64_t z = (uint64_t)x * y; + *ret = z; + return z > UINT32_MAX; +#endif +} + +/** + * umul64_overflow - multiplication with overflow indication + * @x, @y: Input multipliers + * @ret: Output for product + * + * Computes *@ret = @x * @y, and returns true if and only if that + * value has been truncated. + */ +static inline bool umul64_overflow(uint64_t x, uint64_t y, uint64_t *ret) +{ +#if __has_builtin(__builtin_mul_overflow) || __GNUC__ >= 5 + return __builtin_mul_overflow(x, y, ret); +#else + uint64_t hi; + mulu64(ret, &hi, x, y); + return hi != 0; +#endif +} + /* Host type specific sizes of these routines. */ #if ULONG_MAX == UINT32_MAX -- cgit 1.4.1 From 1ec8070e58a30bd175a1c7186bff797488e8a17b Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Fri, 13 Nov 2020 03:22:23 +0000 Subject: qemu/host-utils: Add wrappers for carry builtins MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit These builtins came in clang 3.8, but are not present in gcc through version 11. Even in clang the optimization is only ideal on x86_64, but never worse than the hand-coding that we currently do. Reviewed-by: Alex Bennée Signed-off-by: Richard Henderson --- include/qemu/host-utils.h | 50 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) (limited to 'include/qemu/host-utils.h') diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h index cb95626c7d..711b221704 100644 --- a/include/qemu/host-utils.h +++ b/include/qemu/host-utils.h @@ -26,6 +26,7 @@ #ifndef HOST_UTILS_H #define HOST_UTILS_H +#include "qemu/compiler.h" #include "qemu/bswap.h" #ifdef CONFIG_INT128 @@ -581,6 +582,55 @@ static inline bool umul64_overflow(uint64_t x, uint64_t y, uint64_t *ret) #endif } +/** + * uadd64_carry - addition with carry-in and carry-out + * @x, @y: addends + * @pcarry: in-out carry value + * + * Computes @x + @y + *@pcarry, placing the carry-out back + * into *@pcarry and returning the 64-bit sum. + */ +static inline uint64_t uadd64_carry(uint64_t x, uint64_t y, bool *pcarry) +{ +#if __has_builtin(__builtin_addcll) + unsigned long long c = *pcarry; + x = __builtin_addcll(x, y, c, &c); + *pcarry = c & 1; + return x; +#else + bool c = *pcarry; + /* This is clang's internal expansion of __builtin_addc. */ + c = uadd64_overflow(x, c, &x); + c |= uadd64_overflow(x, y, &x); + *pcarry = c; + return x; +#endif +} + +/** + * usub64_borrow - subtraction with borrow-in and borrow-out + * @x, @y: addends + * @pborrow: in-out borrow value + * + * Computes @x - @y - *@pborrow, placing the borrow-out back + * into *@pborrow and returning the 64-bit sum. + */ +static inline uint64_t usub64_borrow(uint64_t x, uint64_t y, bool *pborrow) +{ +#if __has_builtin(__builtin_subcll) + unsigned long long b = *pborrow; + x = __builtin_subcll(x, y, b, &b); + *pborrow = b & 1; + return x; +#else + bool b = *pborrow; + b = usub64_overflow(x, b, &x); + b |= usub64_overflow(x, y, &x); + *pborrow = b; + return x; +#endif +} + /* Host type specific sizes of these routines. */ #if ULONG_MAX == UINT32_MAX -- cgit 1.4.1