mirror/psxrecomp
1
0
Fork 0
mirror of https://github.com/RetroPortingToolKit/psxrecomp synced 2026-10-27 18:52:11 -04:00
Code Issues Packages Projects Releases Wiki Activity

Merge pull request #162 from Unchiga/lwlr-load-delay

Browse Source 
Forward a pending load into an LWL/LWR merge
This commit is contained in:
Matt Stanley
2026-08-20 15:16:58 -07:00
committed by GitHub
parent 43fb799c3f c77f8adcc0
commit 4673db2056
5 changed files with 240 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files
recompiler/src/code_generator.cpp
+22 -3
View File
@@ -432,7 +432,7 @@ std::string CodeGenerator::translate_lwl(uint32_t instr) {
return fmt::format("(void)psx_lwl(cpu, {}, {}, 0, 0x{:X}u);", addr, reg_name(rt), mask);
}
return fmt::format("{} = psx_lwl(cpu, {}, {}, {}, 0x{:X}u);",
reg_name(rt), addr, reg_name(rt), rt, mask);
reg_name(rt), addr, lwlr_merge_operand(rt), rt, mask);
}
std::string CodeGenerator::translate_lwr(uint32_t instr) {
@@ -452,7 +452,7 @@ std::string CodeGenerator::translate_lwr(uint32_t instr) {
return fmt::format("(void)psx_lwr(cpu, {}, {}, 0, 0x{:X}u);", addr, reg_name(rt), mask);
}
return fmt::format("{} = psx_lwr(cpu, {}, {}, {}, 0x{:X}u);",
reg_name(rt), addr, reg_name(rt), rt, mask);
reg_name(rt), addr, lwlr_merge_operand(rt), rt, mask);
}
std::string CodeGenerator::translate_swl(uint32_t instr) {
@@ -1894,7 +1894,22 @@ std::string CodeGenerator::translate_basic_block(
if (!is_cf) {
if (cycle_per_insn) emit_pre_icache(addr, config_.indent);
if (cycle_per_insn) emit_pre_timing(instr, config_.indent);
// If this is the successor half of a deferred load pair AND it is an
// LWL/LWR merging into that same register, hardware forwards the
// pending load into the merge (see set_lwlr_merge_forward). Point
// the merge operand at the deferred temporary before translating.
const uint32_t succ_op = instr >> 26;
const bool succ_is_lwlr = (succ_op == 0x22u || succ_op == 0x26u);
const bool forward_to_lwlr =
delayed_load_active && addr == delayed_load_addr + 4u &&
succ_is_lwlr && get_rt(instr) == delayed_load_dest;
if (forward_to_lwlr) {
set_lwlr_merge_forward(
delayed_load_dest,
fmt::format("psx_ldd_{:08X}", delayed_load_addr));
}
std::string emitted = translate_instruction(addr, instr);
if (forward_to_lwlr) clear_lwlr_merge_forward();
int load_dest = simple_load_dest(instr);
bool defer_load = false;
if (!delayed_load_active && load_dest > 0 && addr + 4u <= block.end_addr &&
@@ -1933,7 +1948,11 @@ std::string CodeGenerator::translate_basic_block(
}
ss << emitted << "\n";
if (delayed_load_active && addr == delayed_load_addr + 4u) {
if (writes_gpr(instr, delayed_load_dest)) {
if (forward_to_lwlr) {
ss << config_.indent << fmt::format(
"/* psx_ldd_{:08X} forwarded into the LWL/LWR merge above */\n",
delayed_load_addr);
} else if (writes_gpr(instr, delayed_load_dest)) {
ss << config_.indent << fmt::format(
"(void)psx_ldd_{:08X}; /* successor write wins */\n",
delayed_load_addr);