handle shift counts greater than 31 properly

This commit is contained in:
Joel Dice 2009-03-05 19:05:39 -07:00
parent 16e81bcc07
commit ec610a5521

View File

@ -426,8 +426,13 @@ void shiftLeftC(Context* con, unsigned size, Const* a, Reg* b, Reg* t)
{ {
int sh = getVal(a); int sh = getVal(a);
if (size == 8) { if (size == 8) {
issue(con, rlwinm(H(t),H(b),sh,0,31-sh)); if (sh < 32) {
issue(con, rlwimi(H(t),R(b),sh,32-sh,31)); issue(con, rlwinm(H(t),H(b),sh,0,31-sh));
issue(con, rlwimi(H(t),R(b),sh,32-sh,31));
} else {
issue(con, rlwinm(H(t),R(b),sh-32,0,63-sh));
issue(con, li(R(t),0));
}
} }
issue(con, slwi(R(t), R(b), sh)); issue(con, slwi(R(t), R(b), sh));
} }
@ -455,9 +460,14 @@ void shiftRightC(Context* con, unsigned size, Const* a, Reg* b, Reg* t)
{ {
int sh = getVal(a); int sh = getVal(a);
if(size == 8) { if(size == 8) {
issue(con, rlwinm(R(t),R(b),32-sh,sh,31)); if (sh < 32) {
issue(con, rlwimi(R(t),H(b),32-sh,0,sh-1)); issue(con, rlwinm(R(t),R(b),32-sh,sh,31));
issue(con, srawi(H(t),H(b),sh)); issue(con, rlwimi(R(t),H(b),32-sh,0,sh-1));
issue(con, srawi(H(t),H(b),sh));
} else {
issue(con, srawi(H(t),H(b),31));
issue(con, srawi(R(t),H(b),sh-32));
}
} else { } else {
issue(con, srawi(R(t), R(b), sh)); issue(con, srawi(R(t), R(b), sh));
} }
@ -482,10 +492,17 @@ void unsignedShiftRightR(Context* con, unsigned size, Reg* a, Reg* b, Reg* t)
void unsignedShiftRightC(Context* con, unsigned size, Const* a, Reg* b, Reg* t) void unsignedShiftRightC(Context* con, unsigned size, Const* a, Reg* b, Reg* t)
{ {
int sh = getVal(a); int sh = getVal(a);
issue(con, srwi(R(t), R(b), sh));
if (size == 8) { if (size == 8) {
issue(con, rlwimi(R(t),H(b),32-sh,0,sh-1)); if (sh < 32) {
issue(con, rlwinm(H(t),H(b),32-sh,sh,31)); issue(con, srwi(R(t), R(b), sh));
issue(con, rlwimi(R(t),H(b),32-sh,0,sh-1));
issue(con, rlwinm(H(t),H(b),32-sh,sh,31));
} else {
issue(con, rlwinm(R(t),H(b),64-sh,sh-32,31));
issue(con, li(H(t),0));
}
} else {
issue(con, srwi(R(t), R(b), sh));
} }
} }