motiejus/zig
1
Fork 0
Code Releases Activity

stage2 AArch64: generate less no-op branches

Browse Source 
mirroring d486a7b811 for aarch64
This commit is contained in:
joachimschmidt557
2022-03-05 08:54:15 +01:00
parent 691ec964ef
commit ed7e2938ff
1 changed files with 22 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
src/arch/aarch64/CodeGen.zig
View File

@@ -443,14 +443,17 @@ fn gen(self: *Self) !void {
});
// exitlude jumps
if (self.exitlude_jump_relocs.items.len == 1) {
// There is only one relocation. Hence,
// this relocation must be at the end of
// the code. Therefore, we can just delete
// the space initially reserved for the
// jump
self.mir_instructions.orderedRemove(self.exitlude_jump_relocs.items[0]);
} else for (self.exitlude_jump_relocs.items) |jmp_reloc| {
if (self.exitlude_jump_relocs.items.len > 0 and
self.exitlude_jump_relocs.items[self.exitlude_jump_relocs.items.len - 1] == self.mir_instructions.len - 2)
{
// If the last Mir instruction (apart from the
// dbg_epilogue_begin) is the last exitlude jump
// relocation (which would just jump one instruction
// further), it can be safely removed
self.mir_instructions.orderedRemove(self.exitlude_jump_relocs.pop());
}
for (self.exitlude_jump_relocs.items) |jmp_reloc| {
self.mir_instructions.set(jmp_reloc, .{
.tag = .b,
.data = .{ .inst = @intCast(u32, self.mir_instructions.len) },
@@ -2958,7 +2961,17 @@ fn airBlock(self: *Self, inst: Air.Inst.Index) !void {
const body = self.air.extra[extra.end..][0..extra.data.body_len];
try self.genBody(body);
for (self.blocks.getPtr(inst).?.relocs.items) |reloc| try self.performReloc(reloc);
// relocations for `br` instructions
const relocs = &self.blocks.getPtr(inst).?.relocs;
if (relocs.items.len > 0 and relocs.items[relocs.items.len - 1] == self.mir_instructions.len - 1) {
// If the last Mir instruction is the last relocation (which
// would just jump one instruction further), it can be safely
// removed
self.mir_instructions.orderedRemove(relocs.pop());
}
for (relocs.items) |reloc| {
try self.performReloc(reloc);
}
const result = self.blocks.getPtr(inst).?.mcv;
return self.finishAir(inst, result, .{ .none, .none, .none });