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author | bellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162> | 2005-07-23 20:21:38 +0000 |
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committer | bellard <bellard@c046a42c-6fe2-441c-8c8c-71466251a162> | 2005-07-23 20:21:38 +0000 |
commit | 45bbbb466cf4a6280076ea5a51f67ef5bedee345 (patch) | |
tree | ffa07d8676ab65b3c52370ca3c80c320b72aa96f /target-i386 | |
parent | d592d3033d7bc41db6159e9387591a216e3c46e0 (diff) | |
download | hqemu-45bbbb466cf4a6280076ea5a51f67ef5bedee345.zip hqemu-45bbbb466cf4a6280076ea5a51f67ef5bedee345.tar.gz |
added overflow exceptions in divisions
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1521 c046a42c-6fe2-441c-8c8c-71466251a162
Diffstat (limited to 'target-i386')
-rw-r--r-- | target-i386/helper.c | 44 | ||||
-rw-r--r-- | target-i386/op.c | 21 |
2 files changed, 47 insertions, 18 deletions
diff --git a/target-i386/helper.c b/target-i386/helper.c index 2d241a1..c83dbf2 100644 --- a/target-i386/helper.c +++ b/target-i386/helper.c @@ -1209,13 +1209,13 @@ void raise_exception(int exception_index) #ifdef BUGGY_GCC_DIV64 /* gcc 2.95.4 on PowerPC does not seem to like using __udivdi3, so we call it from another function */ -uint32_t div32(uint32_t *q_ptr, uint64_t num, uint32_t den) +uint32_t div32(uint64_t *q_ptr, uint64_t num, uint32_t den) { *q_ptr = num / den; return num % den; } -int32_t idiv32(int32_t *q_ptr, int64_t num, int32_t den) +int32_t idiv32(int64_t *q_ptr, int64_t num, int32_t den) { *q_ptr = num / den; return num % den; @@ -1224,8 +1224,8 @@ int32_t idiv32(int32_t *q_ptr, int64_t num, int32_t den) void helper_divl_EAX_T0(void) { - unsigned int den, q, r; - uint64_t num; + unsigned int den, r; + uint64_t num, q; num = ((uint32_t)EAX) | ((uint64_t)((uint32_t)EDX) << 32); den = T0; @@ -1238,14 +1238,16 @@ void helper_divl_EAX_T0(void) q = (num / den); r = (num % den); #endif + if (q > 0xffffffff) + raise_exception(EXCP00_DIVZ); EAX = (uint32_t)q; EDX = (uint32_t)r; } void helper_idivl_EAX_T0(void) { - int den, q, r; - int64_t num; + int den, r; + int64_t num, q; num = ((uint32_t)EAX) | ((uint64_t)((uint32_t)EDX) << 32); den = T0; @@ -1258,6 +1260,8 @@ void helper_idivl_EAX_T0(void) q = (num / den); r = (num % den); #endif + if (q != (int32_t)q) + raise_exception(EXCP00_DIVZ); EAX = (uint32_t)q; EDX = (uint32_t)r; } @@ -3254,8 +3258,8 @@ static void imul64(uint64_t *plow, uint64_t *phigh, int64_t a, int64_t b) } } -/* XXX: overflow support */ -static void div64(uint64_t *plow, uint64_t *phigh, uint64_t b) +/* return TRUE if overflow */ +static int div64(uint64_t *plow, uint64_t *phigh, uint64_t b) { uint64_t q, r, a1, a0; int i, qb; @@ -3268,6 +3272,8 @@ static void div64(uint64_t *plow, uint64_t *phigh, uint64_t b) *plow = q; *phigh = r; } else { + if (a1 >= b) + return 1; /* XXX: use a better algorithm */ for(i = 0; i < 64; i++) { a1 = (a1 << 1) | (a0 >> 63); @@ -3286,9 +3292,11 @@ static void div64(uint64_t *plow, uint64_t *phigh, uint64_t b) *plow = a0; *phigh = a1; } + return 0; } -static void idiv64(uint64_t *plow, uint64_t *phigh, int64_t b) +/* return TRUE if overflow */ +static int idiv64(uint64_t *plow, uint64_t *phigh, int64_t b) { int sa, sb; sa = ((int64_t)*phigh < 0); @@ -3297,11 +3305,19 @@ static void idiv64(uint64_t *plow, uint64_t *phigh, int64_t b) sb = (b < 0); if (sb) b = -b; - div64(plow, phigh, b); - if (sa ^ sb) + if (div64(plow, phigh, b) != 0) + return 1; + if (sa ^ sb) { + if (*plow > (1ULL << 63)) + return 1; *plow = - *plow; + } else { + if (*plow >= (1ULL << 63)) + return 1; + } if (sa) *phigh = - *phigh; + return 0; } void helper_mulq_EAX_T0(void) @@ -3344,7 +3360,8 @@ void helper_divq_EAX_T0(void) } r0 = EAX; r1 = EDX; - div64(&r0, &r1, T0); + if (div64(&r0, &r1, T0)) + raise_exception(EXCP00_DIVZ); EAX = r0; EDX = r1; } @@ -3357,7 +3374,8 @@ void helper_idivq_EAX_T0(void) } r0 = EAX; r1 = EDX; - idiv64(&r0, &r1, T0); + if (idiv64(&r0, &r1, T0)) + raise_exception(EXCP00_DIVZ); EAX = r0; EDX = r1; } diff --git a/target-i386/op.c b/target-i386/op.c index 3574576..142b662 100644 --- a/target-i386/op.c +++ b/target-i386/op.c @@ -328,7 +328,6 @@ void OPPROTO op_imulq_T0_T1(void) #endif /* division, flags are undefined */ -/* XXX: add exceptions for overflow */ void OPPROTO op_divb_AL_T0(void) { @@ -339,7 +338,10 @@ void OPPROTO op_divb_AL_T0(void) if (den == 0) { raise_exception(EXCP00_DIVZ); } - q = (num / den) & 0xff; + q = (num / den); + if (q > 0xff) + raise_exception(EXCP00_DIVZ); + q &= 0xff; r = (num % den) & 0xff; EAX = (EAX & ~0xffff) | (r << 8) | q; } @@ -353,7 +355,10 @@ void OPPROTO op_idivb_AL_T0(void) if (den == 0) { raise_exception(EXCP00_DIVZ); } - q = (num / den) & 0xff; + q = (num / den); + if (q != (int8_t)q) + raise_exception(EXCP00_DIVZ); + q &= 0xff; r = (num % den) & 0xff; EAX = (EAX & ~0xffff) | (r << 8) | q; } @@ -367,7 +372,10 @@ void OPPROTO op_divw_AX_T0(void) if (den == 0) { raise_exception(EXCP00_DIVZ); } - q = (num / den) & 0xffff; + q = (num / den); + if (q > 0xffff) + raise_exception(EXCP00_DIVZ); + q &= 0xffff; r = (num % den) & 0xffff; EAX = (EAX & ~0xffff) | q; EDX = (EDX & ~0xffff) | r; @@ -382,7 +390,10 @@ void OPPROTO op_idivw_AX_T0(void) if (den == 0) { raise_exception(EXCP00_DIVZ); } - q = (num / den) & 0xffff; + q = (num / den); + if (q != (int16_t)q) + raise_exception(EXCP00_DIVZ); + q &= 0xffff; r = (num % den) & 0xffff; EAX = (EAX & ~0xffff) | q; EDX = (EDX & ~0xffff) | r; |