diff options
Diffstat (limited to 'target-arm/op_helper.c')
-rw-r--r-- | target-arm/op_helper.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/target-arm/op_helper.c b/target-arm/op_helper.c index 6748b0605..79b3f1a45 100644 --- a/target-arm/op_helper.c +++ b/target-arm/op_helper.c @@ -304,3 +304,151 @@ void HELPER(set_user_reg)(uint32_t regno, uint32_t val) } } +/* ??? Flag setting arithmetic is awkward because we need to do comparisons. + The only way to do that in TCG is a conditional branch, which clobbers + all our temporaries. For now implement these as helper functions. */ + +uint32_t HELPER (add_cc)(uint32_t a, uint32_t b) +{ + uint32_t result; + result = T0 + T1; + env->NZF = result; + env->CF = result < a; + env->VF = (a ^ b ^ -1) & (a ^ result); + return result; +} + +uint32_t HELPER(adc_cc)(uint32_t a, uint32_t b) +{ + uint32_t result; + if (!env->CF) { + result = a + b; + env->CF = result < a; + } else { + result = a + b + 1; + env->CF = result <= a; + } + env->VF = (a ^ b ^ -1) & (a ^ result); + env->NZF = result; + return result; +} + +uint32_t HELPER(sub_cc)(uint32_t a, uint32_t b) +{ + uint32_t result; + result = a - b; + env->NZF = result; + env->CF = a >= b; + env->VF = (a ^ b) & (a ^ result); + return result; +} + +uint32_t HELPER(sbc_cc)(uint32_t a, uint32_t b) +{ + uint32_t result; + if (!env->CF) { + result = a - b - 1; + env->CF = a > b; + } else { + result = a - b; + env->CF = a >= b; + } + env->VF = (a ^ b) & (a ^ result); + env->NZF = result; + return result; +} + +/* Similarly for variable shift instructions. */ + +uint32_t HELPER(shl)(uint32_t x, uint32_t i) +{ + int shift = i & 0xff; + if (shift >= 32) + return 0; + return x << shift; +} + +uint32_t HELPER(shr)(uint32_t x, uint32_t i) +{ + int shift = i & 0xff; + if (shift >= 32) + return 0; + return (uint32_t)x >> shift; +} + +uint32_t HELPER(sar)(uint32_t x, uint32_t i) +{ + int shift = i & 0xff; + if (shift >= 32) + shift = 31; + return (int32_t)x >> shift; +} + +uint32_t HELPER(ror)(uint32_t x, uint32_t i) +{ + int shift = i & 0xff; + if (shift == 0) + return x; + return (x >> shift) | (x << (32 - shift)); +} + +uint32_t HELPER(shl_cc)(uint32_t x, uint32_t i) +{ + int shift = i & 0xff; + if (shift >= 32) { + if (shift == 32) + env->CF = x & 1; + else + env->CF = 0; + return 0; + } else if (shift != 0) { + env->CF = (x >> (32 - shift)) & 1; + return x << shift; + } + return x; +} + +uint32_t HELPER(shr_cc)(uint32_t x, uint32_t i) +{ + int shift = i & 0xff; + if (shift >= 32) { + if (shift == 32) + env->CF = (x >> 31) & 1; + else + env->CF = 0; + return 0; + } else if (shift != 0) { + env->CF = (x >> (shift - 1)) & 1; + return x >> shift; + } + return x; +} + +uint32_t HELPER(sar_cc)(uint32_t x, uint32_t i) +{ + int shift = i & 0xff; + if (shift >= 32) { + env->CF = (x >> 31) & 1; + return (int32_t)x >> 31; + } else if (shift != 0) { + env->CF = (x >> (shift - 1)) & 1; + return (int32_t)x >> shift; + } + return x; +} + +uint32_t HELPER(ror_cc)(uint32_t x, uint32_t i) +{ + int shift1, shift; + shift1 = i & 0xff; + shift = shift1 & 0x1f; + if (shift == 0) { + if (shift1 != 0) + env->CF = (x >> 31) & 1; + return x; + } else { + env->CF = (x >> (shift - 1)) & 1; + return ((uint32_t)x >> shift) | (x << (32 - shift)); + } +} + |