diff options
Diffstat (limited to 'target-arm/helper.c')
| -rw-r--r-- | target-arm/helper.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/target-arm/helper.c b/target-arm/helper.c index c61c610919..ee6cd598fd 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -1922,3 +1922,248 @@ void cpu_arm_set_cp_io(CPUARMState *env, int cpnum, } #endif + +/* Note that signed overflow is undefined in C. The following routines are + careful to use unsigned types where modulo arithmetic is required. + Failure to do so _will_ break on newer gcc. */ + +/* Signed saturating arithmetic. */ + +/* Perform 16-bit signed satruating addition. */ +static inline uint16_t add16_sat(uint16_t a, uint16_t b) +{ + uint16_t res; + + res = a + b; + if (((res ^ a) & 0x8000) && !((a ^ b) & 0x8000)) { + if (a & 0x8000) + res = 0x8000; + else + res = 0x7fff; + } + return res; +} + +/* Perform 8-bit signed satruating addition. */ +static inline uint8_t add8_sat(uint8_t a, uint8_t b) +{ + uint8_t res; + + res = a + b; + if (((res ^ a) & 0x80) && !((a ^ b) & 0x80)) { + if (a & 0x80) + res = 0x80; + else + res = 0x7f; + } + return res; +} + +/* Perform 16-bit signed satruating subtraction. */ +static inline uint16_t sub16_sat(uint16_t a, uint16_t b) +{ + uint16_t res; + + res = a - b; + if (((res ^ a) & 0x8000) && ((a ^ b) & 0x8000)) { + if (a & 0x8000) + res = 0x8000; + else + res = 0x7fff; + } + return res; +} + +/* Perform 8-bit signed satruating subtraction. */ +static inline uint8_t sub8_sat(uint8_t a, uint8_t b) +{ + uint8_t res; + + res = a - b; + if (((res ^ a) & 0x80) && ((a ^ b) & 0x80)) { + if (a & 0x80) + res = 0x80; + else + res = 0x7f; + } + return res; +} + +#define ADD16(a, b, n) RESULT(add16_sat(a, b), n, 16); +#define SUB16(a, b, n) RESULT(sub16_sat(a, b), n, 16); +#define ADD8(a, b, n) RESULT(add8_sat(a, b), n, 8); +#define SUB8(a, b, n) RESULT(sub8_sat(a, b), n, 8); +#define PFX q + +#include "op_addsub.h" + +/* Unsigned saturating arithmetic. */ +static inline uint16_t add16_usat(uint16_t a, uint8_t b) +{ + uint16_t res; + res = a + b; + if (res < a) + res = 0xffff; + return res; +} + +static inline uint16_t sub16_usat(uint16_t a, uint8_t b) +{ + if (a < b) + return a - b; + else + return 0; +} + +static inline uint8_t add8_usat(uint8_t a, uint8_t b) +{ + uint8_t res; + res = a + b; + if (res < a) + res = 0xff; + return res; +} + +static inline uint8_t sub8_usat(uint8_t a, uint8_t b) +{ + if (a < b) + return a - b; + else + return 0; +} + +#define ADD16(a, b, n) RESULT(add16_usat(a, b), n, 16); +#define SUB16(a, b, n) RESULT(sub16_usat(a, b), n, 16); +#define ADD8(a, b, n) RESULT(add8_usat(a, b), n, 8); +#define SUB8(a, b, n) RESULT(sub8_usat(a, b), n, 8); +#define PFX uq + +#include "op_addsub.h" + +/* Signed modulo arithmetic. */ +#define SARITH16(a, b, n, op) do { \ + int32_t sum; \ + sum = (int16_t)((uint16_t)(a) op (uint16_t)(b)); \ + RESULT(sum, n, 16); \ + if (sum >= 0) \ + ge |= 3 << (n * 2); \ + } while(0) + +#define SARITH8(a, b, n, op) do { \ + int32_t sum; \ + sum = (int8_t)((uint8_t)(a) op (uint8_t)(b)); \ + RESULT(sum, n, 8); \ + if (sum >= 0) \ + ge |= 1 << n; \ + } while(0) + + +#define ADD16(a, b, n) SARITH16(a, b, n, +) +#define SUB16(a, b, n) SARITH16(a, b, n, -) +#define ADD8(a, b, n) SARITH8(a, b, n, +) +#define SUB8(a, b, n) SARITH8(a, b, n, -) +#define PFX s +#define ARITH_GE + +#include "op_addsub.h" + +/* Unsigned modulo arithmetic. */ +#define ADD16(a, b, n) do { \ + uint32_t sum; \ + sum = (uint32_t)(uint16_t)(a) + (uint32_t)(uint16_t)(b); \ + RESULT(sum, n, 16); \ + if ((sum >> 16) == 0) \ + ge |= 3 << (n * 2); \ + } while(0) + +#define ADD8(a, b, n) do { \ + uint32_t sum; \ + sum = (uint32_t)(uint8_t)(a) + (uint32_t)(uint8_t)(b); \ + RESULT(sum, n, 8); \ + if ((sum >> 8) == 0) \ + ge |= 3 << (n * 2); \ + } while(0) + +#define SUB16(a, b, n) do { \ + uint32_t sum; \ + sum = (uint32_t)(uint16_t)(a) - (uint32_t)(uint16_t)(b); \ + RESULT(sum, n, 16); \ + if ((sum >> 16) == 0) \ + ge |= 3 << (n * 2); \ + } while(0) + +#define SUB8(a, b, n) do { \ + uint32_t sum; \ + sum = (uint32_t)(uint8_t)(a) - (uint32_t)(uint8_t)(b); \ + RESULT(sum, n, 8); \ + if ((sum >> 8) == 0) \ + ge |= 3 << (n * 2); \ + } while(0) + +#define PFX u +#define ARITH_GE + +#include "op_addsub.h" + +/* Halved signed arithmetic. */ +#define ADD16(a, b, n) \ + RESULT(((int32_t)(int16_t)(a) + (int32_t)(int16_t)(b)) >> 1, n, 16) +#define SUB16(a, b, n) \ + RESULT(((int32_t)(int16_t)(a) - (int32_t)(int16_t)(b)) >> 1, n, 16) +#define ADD8(a, b, n) \ + RESULT(((int32_t)(int8_t)(a) + (int32_t)(int8_t)(b)) >> 1, n, 8) +#define SUB8(a, b, n) \ + RESULT(((int32_t)(int8_t)(a) - (int32_t)(int8_t)(b)) >> 1, n, 8) +#define PFX sh + +#include "op_addsub.h" + +/* Halved unsigned arithmetic. */ +#define ADD16(a, b, n) \ + RESULT(((uint32_t)(uint16_t)(a) + (uint32_t)(uint16_t)(b)) >> 1, n, 16) +#define SUB16(a, b, n) \ + RESULT(((uint32_t)(uint16_t)(a) - (uint32_t)(uint16_t)(b)) >> 1, n, 16) +#define ADD8(a, b, n) \ + RESULT(((uint32_t)(uint8_t)(a) + (uint32_t)(uint8_t)(b)) >> 1, n, 8) +#define SUB8(a, b, n) \ + RESULT(((uint32_t)(uint8_t)(a) - (uint32_t)(uint8_t)(b)) >> 1, n, 8) +#define PFX uh + +#include "op_addsub.h" + +static inline uint8_t do_usad(uint8_t a, uint8_t b) +{ + if (a > b) + return a - b; + else + return b - a; +} + +/* Unsigned sum of absolute byte differences. */ +uint32_t HELPER(usad8)(uint32_t a, uint32_t b) +{ + uint32_t sum; + sum = do_usad(a, b); + sum += do_usad(a >> 8, b >> 8); + sum += do_usad(a >> 16, b >>16); + sum += do_usad(a >> 24, b >> 24); + return sum; +} + +/* For ARMv6 SEL instruction. */ +uint32_t HELPER(sel_flags)(uint32_t flags, uint32_t a, uint32_t b) +{ + uint32_t mask; + + mask = 0; + if (flags & 1) + mask |= 0xff; + if (flags & 2) + mask |= 0xff00; + if (flags & 4) + mask |= 0xff0000; + if (flags & 8) + mask |= 0xff000000; + return (a & mask) | (b & ~mask); +} + |