gwj / at91sam9263 · Commits

Commit a87aa10b85dcaf8e1a4cc962edbd562a96f78650

Authored by balrog
1 parent 7997d92f

ARMv6: fix SIMD add/sub carry flags (Vincent Palatin). 

After a quick code review, it seems to be a bad cut-n-paste between
16-bit and 8-bit UADD/USUB, indeed UADD8/USUB8 tries to set GE bits by
pair instead of one at a time.
Besides, the addition operations (UADD8/UADD16) set GE bits to "NOT
carry" instead of "carry" (probably once again due to a copy of the
substraction code which sets flags to "NOT borrow")


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4900 c046a42c-6fe2-441c-8c8c-71466251a162
Inline Side-by-side
Showing 1 changed file with 4 additions and 4 deletions
target-arm/helper.c
  View file @a87aa10
... ... @@ -2059,7 +2059,7 @@ static inline uint8_t sub8_usat(uint8_t a, uint8_t b)
2059 2059 uint32_t sum; \
2060 2060 sum = (uint32_t)(uint16_t)(a) + (uint32_t)(uint16_t)(b); \
2061 2061 RESULT(sum, n, 16); \
2062   - if ((sum >> 16) == 0) \
  2062 + if ((sum >> 16) == 1) \
2063 2063 ge |= 3 << (n * 2); \
2064 2064 } while(0)
2065 2065  
... ... @@ -2067,8 +2067,8 @@ static inline uint8_t sub8_usat(uint8_t a, uint8_t b)
2067 2067 uint32_t sum; \
2068 2068 sum = (uint32_t)(uint8_t)(a) + (uint32_t)(uint8_t)(b); \
2069 2069 RESULT(sum, n, 8); \
2070   - if ((sum >> 8) == 0) \
2071   - ge |= 3 << (n * 2); \
  2070 + if ((sum >> 8) == 1) \
  2071 + ge |= 1 << n; \
2072 2072 } while(0)
2073 2073  
2074 2074 #define SUB16(a, b, n) do { \
... ... @@ -2084,7 +2084,7 @@ static inline uint8_t sub8_usat(uint8_t a, uint8_t b)
2084 2084 sum = (uint32_t)(uint8_t)(a) - (uint32_t)(uint8_t)(b); \
2085 2085 RESULT(sum, n, 8); \
2086 2086 if ((sum >> 8) == 0) \
2087   - ge |= 3 << (n * 2); \
  2087 + ge |= 1 << n; \
2088 2088 } while(0)
2089 2089  
2090 2090 #define PFX u
... ...