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| author | Bastian Koppelmann <kbastian@mail.uni-paderborn.de> | 2015-03-23 18:24:42 +0100 |
|---|---|---|
| committer | Bastian Koppelmann <kbastian@mail.uni-paderborn.de> | 2015-03-24 09:45:28 +0100 |
| commit | f69c24e4584f2161f90ee7caba38728aa77f937f (patch) | |
| tree | 7bdda3681d43ea7d3b5c832c1d15c5b38eb61307 /target-tricore | |
| parent | 00e1754ff1f6294a29e08398a120663eac723216 (diff) | |
| download | qemu-f69c24e4584f2161f90ee7caba38728aa77f937f.zip | |
target-tricore: properly fix dvinit_b/h_13
The TriCore documentation was wrong on how to calculate ovf bits for those two
instructions, which I confirmed with real hardware (TC1796 chip). An ovf
actually happens, if the result (without remainder) does not fit into 8/16 bits.
Signed-off-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Diffstat (limited to 'target-tricore')
| -rw-r--r-- | target-tricore/op_helper.c | 40 |
1 files changed, 10 insertions, 30 deletions
diff --git a/target-tricore/op_helper.c b/target-tricore/op_helper.c index 2cfa95d696..220ec4a3c1 100644 --- a/target-tricore/op_helper.c +++ b/target-tricore/op_helper.c @@ -1942,29 +1942,19 @@ uint64_t helper_unpack(target_ulong arg1) uint64_t helper_dvinit_b_13(CPUTriCoreState *env, uint32_t r1, uint32_t r2) { uint64_t ret; - int32_t abs_sig_dividend, abs_base_dividend, abs_divisor; - int32_t quotient_sign; + int32_t abs_sig_dividend, abs_divisor; ret = sextract32(r1, 0, 32); ret = ret << 24; - quotient_sign = 0; if (!((r1 & 0x80000000) == (r2 & 0x80000000))) { ret |= 0xffffff; - quotient_sign = 1; } - abs_sig_dividend = abs((int32_t)r1) >> 7; - abs_base_dividend = abs((int32_t)r1) & 0x7f; + abs_sig_dividend = abs((int32_t)r1) >> 8; abs_divisor = abs((int32_t)r2); - /* calc overflow */ - env->PSW_USB_V = 0; - if ((quotient_sign) && (abs_divisor)) { - env->PSW_USB_V = (((abs_sig_dividend == abs_divisor) && - (abs_base_dividend >= abs_divisor)) || - (abs_sig_dividend > abs_divisor)); - } else { - env->PSW_USB_V = (abs_sig_dividend >= abs_divisor); - } + /* calc overflow + ofv if (a/b >= 255) <=> (a/255 >= b) */ + env->PSW_USB_V = (abs_sig_dividend >= abs_divisor) << 31; env->PSW_USB_V = env->PSW_USB_V << 31; env->PSW_USB_SV |= env->PSW_USB_V; env->PSW_USB_AV = 0; @@ -1992,29 +1982,19 @@ uint64_t helper_dvinit_b_131(CPUTriCoreState *env, uint32_t r1, uint32_t r2) uint64_t helper_dvinit_h_13(CPUTriCoreState *env, uint32_t r1, uint32_t r2) { uint64_t ret; - int32_t abs_sig_dividend, abs_base_dividend, abs_divisor; - int32_t quotient_sign; + int32_t abs_sig_dividend, abs_divisor; ret = sextract32(r1, 0, 32); ret = ret << 16; - quotient_sign = 0; if (!((r1 & 0x80000000) == (r2 & 0x80000000))) { ret |= 0xffff; - quotient_sign = 1; } - abs_sig_dividend = abs((int32_t)r1) >> 7; - abs_base_dividend = abs((int32_t)r1) & 0x7f; + abs_sig_dividend = abs((int32_t)r1) >> 16; abs_divisor = abs((int32_t)r2); - /* calc overflow */ - env->PSW_USB_V = 0; - if ((quotient_sign) && (abs_divisor)) { - env->PSW_USB_V = (((abs_sig_dividend == abs_divisor) && - (abs_base_dividend >= abs_divisor)) || - (abs_sig_dividend > abs_divisor)); - } else { - env->PSW_USB_V = (abs_sig_dividend >= abs_divisor); - } + /* calc overflow + ofv if (a/b >= 0xffff) <=> (a/0xffff >= b) */ + env->PSW_USB_V = (abs_sig_dividend >= abs_divisor) << 31; env->PSW_USB_V = env->PSW_USB_V << 31; env->PSW_USB_SV |= env->PSW_USB_V; env->PSW_USB_AV = 0; |