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X86: Fault on divide by zero instead of panicing.

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This commit is contained in:
Gabe Black 2010-10-29 02:20:47 -07:00
parent 7378424b14
commit 373154a25a
1 changed files with 13 additions and 8 deletions
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21
src/arch/x86/isa/microops/regop.isa
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@ -178,8 +178,7 @@ output decoder {{
uint64_t &quotient, uint64_t &remainder)
{
//Check for divide by zero.
if (divisor == 0)
panic("Divide by zero!\\n");
assert(divisor != 0);
//If the divisor is bigger than the dividend, don't do anything.
if (divisor <= dividend) {
//Shift the divisor so it's msb lines up with the dividend.
@ -518,11 +517,15 @@ let {{
//This is a temporary just for consistency and clarity.
uint64_t dividend = remainder;
//Do the division.
divide(dividend, divisor, quotient, remainder);
//Record the final results.
Remainder = remainder;
Quotient = quotient;
Divisor = divisor;
if (divisor == 0) {
fault = new DivideByZero;
} else {
divide(dividend, divisor, quotient, remainder);
//Record the final results.
Remainder = remainder;
Quotient = quotient;
Divisor = divisor;
}
'''
# Step divide
@ -535,7 +538,9 @@ let {{
int remaining = op2;
//If we overshot, do nothing. This lets us unrool division loops a
//little.
if (remaining) {
if (divisor == 0) {
fault = new DivideByZero;
} else if (remaining) {
if (divisor & (ULL(1) << 63)) {
while (remaining && !(dividend & (ULL(1) << 63))) {
dividend = (dividend << 1) |