ShuriZma
/
xenia-canary
mirror of https://github.com/xenia-canary/xenia-canary.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Prevent context promotion across instructions marked volatile.

This commit is contained in:
Ben Vanik 2014-08-06 11:40:10 -07:00
parent 9efd372d92
commit 646b32ad4f
1 changed files with 12 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
src/alloy/compiler/passes/context_promotion_pass.cc
View File

@ -98,7 +98,10 @@ void ContextPromotionPass::PromoteBlock(Block* block) {
Instr* i = block->instr_head;
while (i) {
if (i->opcode == &OPCODE_LOAD_CONTEXT_info) {
if (i->opcode->flags & OPCODE_FLAG_VOLATILE) {
// Volatile instruction - requires all context values be flushed.
xe_zero_struct(context_values_, context_values_size_);
} else if (i->opcode == &OPCODE_LOAD_CONTEXT_info) {
size_t offset = i->src1.offset;
Value* previous_value = context_values_[offset];
if (previous_value) {
@ -123,18 +126,22 @@ void ContextPromotionPass::PromoteBlock(Block* block) {
void ContextPromotionPass::RemoveDeadStoresBlock(Block* block) {
// TODO(benvanik): use a bitvector.
// To avoid clearing the structure, we use a token.
auto token = (Value*)block;
// Upper bits are block address, lower bits increment each reset.
uint64_t token = reinterpret_cast<uint64_t>(block) << 16;
// Walk backwards and mark offsets that are written to.
// If the offset was written to earlier, ignore the store.
Instr* i = block->instr_tail;
while (i) {
Instr* prev = i->prev;
if (i->opcode == &OPCODE_STORE_CONTEXT_info) {
if (i->opcode->flags & OPCODE_FLAG_VOLATILE) {
// Volatile instruction - requires all context values be flushed.
++token;
} else if (i->opcode == &OPCODE_STORE_CONTEXT_info) {
size_t offset = i->src1.offset;
if (context_values_[offset] != token) {
if (context_values_[offset] != reinterpret_cast<Value*>(token)) {
// Mark offset as written to.
context_values_[offset] = token;
context_values_[offset] = reinterpret_cast<Value*>(token);
} else {
// Already written to. Remove this store.
i->Remove();