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ppcfpopcodes: fix mtfsf emulation.

This commit is contained in:
Maxim Poliakovski 2024-01-02 16:44:21 +01:00
parent 8595dd7d99
commit c25b027de4
1 changed files with 22 additions and 12 deletions
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34
cpu/ppc/ppcfpopcodes.cpp
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@ -873,19 +873,29 @@ void dppc_interpreter::ppc_mffs() {
}
void dppc_interpreter::ppc_mtfsf() {
int reg_b = (ppc_cur_instruction >> 11) & 0x1F;
uint8_t fm = (ppc_cur_instruction >> 17) & 0xFF;
uint32_t cr_mask = 0;
reg_b = (ppc_cur_instruction >> 11) & 31;
crm = (ppc_cur_instruction >> 17) & 255;
cr_mask = ((crm & 1) == 1) ? 0xF0000000 : 0x00000000;
cr_mask += (((crm >> 1) & 1) == 1) ? 0x0F000000 : 0x00000000;
cr_mask += (((crm >> 2) & 1) == 1) ? 0x00F00000 : 0x00000000;
cr_mask += (((crm >> 3) & 1) == 1) ? 0x000F0000 : 0x00000000;
cr_mask += (((crm >> 4) & 1) == 1) ? 0x0000F000 : 0x00000000;
cr_mask += (((crm >> 5) & 1) == 1) ? 0x00000F00 : 0x00000000;
cr_mask += (((crm >> 6) & 1) == 1) ? 0x000000F0 : 0x00000000;
cr_mask += (((crm >> 7) & 1) == 1) ? 0x0000000F : 0x00000000;
uint32_t quickfprval = (uint32_t)(ppc_state.fpr[reg_b].int64_r & 0xFFFFFFFF);
ppc_state.fpscr = (ppc_state.fpscr & ~cr_mask) | (quickfprval & cr_mask);
if (fm == 0xFFU) // the fast case
cr_mask = 0xFFFFFFFFUL;
else { // the slow case
if (fm & 0x80) cr_mask |= 0xF0000000UL;
if (fm & 0x40) cr_mask |= 0x0F000000UL;
if (fm & 0x20) cr_mask |= 0x00F00000UL;
if (fm & 0x10) cr_mask |= 0x000F0000UL;
if (fm & 0x08) cr_mask |= 0x0000F000UL;
if (fm & 0x04) cr_mask |= 0x00000F00UL;
if (fm & 0x02) cr_mask |= 0x000000F0UL;
if (fm & 0x01) cr_mask |= 0x0000000FUL;
}
// ensure neither FEX nor VX will be changed
cr_mask &= ~(FPSCR::FEX | FPSCR::VX);
// copy FPR[reg_b] to FPSCR under control of cr_mask
ppc_state.fpscr = (ppc_state.fpscr & ~cr_mask) | (ppc_state.fpr[reg_b].int64_r & cr_mask);
if (rc_flag)
ppc_update_cr1();