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Conditionally save volatile regs

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Mid 2025-10-15 14:10:42 +03:00
parent 692ed4d21c
commit f978b66662
2 changed files with 39 additions and 12 deletions
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2
src/ast/usedef.c
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@ -204,6 +204,8 @@ void ast_usedef_reset(AST *chu) {
for(size_t sii = 0; sii < chu->chunk.varCount; sii++) { for(size_t sii = 0; sii < chu->chunk.varCount; sii++) {
ScopeItem *si = chu->chunk.vars[sii]; ScopeItem *si = chu->chunk.vars[sii];
assert(si->data.var.declaration != NULL && "All local vars must have defined declaration location");
if(ast_stmt_is_after(chu, si->data.var.liveRangeEnd, s) == 0 && ast_stmt_is_after(chu, target, si->data.var.liveRangeEnd) == 0 && ast_stmt_is_after(chu, si->data.var.declaration, target) == 0) { if(ast_stmt_is_after(chu, si->data.var.liveRangeEnd, s) == 0 && ast_stmt_is_after(chu, target, si->data.var.liveRangeEnd) == 0 && ast_stmt_is_after(chu, si->data.var.declaration, target) == 0) {
si->data.var.liveRangeEnd = s; si->data.var.liveRangeEnd = s;

49
src/x86/cg.c
View File

@ -260,6 +260,27 @@ static int lr_empty(ScopeItem *a) {
return !a->data.var.liveRangeStart; return !a->data.var.liveRangeStart;
} }
static bool is_resource_in_use_right_now_at_this_current_point_in_time_and_also_not_created_right_now(AST *tlc, AST *statement, size_t resource) {
for(size_t vi = 0; vi < tlc->chunk.varCount; vi++) {
ScopeItem *si = tlc->chunk.vars[vi];
if((REG_CLASSES[si->data.var.registerClass].rs[si->data.var.color] & resource) == 0) {
continue;
}
if(ast_stmt_is_after(tlc, statement, si->data.var.liveRangeEnd) == 1 || statement == si->data.var.liveRangeEnd) {
continue;
}
if(si->data.var.usedefFirst == NULL) {
// Even if the resource is in use, the variable itself isn't so we don't care
continue;
}
if(!lr_empty(si) && (ast_stmt_is_after(tlc, statement, si->data.var.liveRangeStart) == 1
&& ast_stmt_is_after(tlc, si->data.var.liveRangeEnd, statement) == 1)) {
return true;
}
}
return false;
}
void cg_chunk(CGState *cg, AST *a) { void cg_chunk(CGState *cg, AST *a) {
AST *s = a->chunk.statementFirst; AST *s = a->chunk.statementFirst;
@ -390,12 +411,14 @@ void cg_chunk(CGState *cg, AST *a) {
AST *e = s->stmtAssign.to; AST *e = s->stmtAssign.to;
if(x86_ia16()) { if(is_resource_in_use_right_now_at_this_current_point_in_time_and_also_not_created_right_now(a, s, HWR_ECX)) {
puts("push cx"); puts(x86_ia16() ? "push cx" : "push ecx");
puts("push dx"); }
} else { if(is_resource_in_use_right_now_at_this_current_point_in_time_and_also_not_created_right_now(a, s, HWR_EDX)) {
puts("push ecx"); puts(x86_ia16() ? "push dx" : "push edx");
puts("push edx"); }
if(is_resource_in_use_right_now_at_this_current_point_in_time_and_also_not_created_right_now(a, s, HWR_EAX)) {
puts(x86_ia16() ? "push ax" : "push eax");
} }
int argCount = e->exprCall.what->expression.type->pointer.of->function.argCount; int argCount = e->exprCall.what->expression.type->pointer.of->function.argCount;
@ -422,12 +445,14 @@ void cg_chunk(CGState *cg, AST *a) {
} }
} }
if(x86_ia16()) { if(is_resource_in_use_right_now_at_this_current_point_in_time_and_also_not_created_right_now(a, s, HWR_EAX)) {
puts("pop dx"); puts(x86_ia16() ? "pop ax" : "pop eax");
puts("pop cx"); }
} else { if(is_resource_in_use_right_now_at_this_current_point_in_time_and_also_not_created_right_now(a, s, HWR_EDX)) {
puts("pop edx"); puts(x86_ia16() ? "pop dx" : "pop edx");
puts("pop ecx"); }
if(is_resource_in_use_right_now_at_this_current_point_in_time_and_also_not_created_right_now(a, s, HWR_ECX)) {
puts(x86_ia16() ? "pop cx" : "pop ecx");
} }
} else if(s->nodeKind == AST_STMT_ASSIGN) { } else if(s->nodeKind == AST_STMT_ASSIGN) {