mirror/zig
1
0
Fork 0
mirror of https://github.com/ziglang/zig.git synced 2026-01-06 13:33:21 +00:00
Code Issues Packages Projects Releases Wiki Activity

CBE and LLVM: handle unused try instructions

Browse Source 
In both backends they did not observe the Liveness information for try
instructions. Now they do. For the C backend this is necessary for
correctness; for the LLVM backend, it improves code generation.
This commit is contained in:
Andrew Kelley 2022-12-03 19:30:08 -07:00
parent f2e59e41c1
commit 4aae0b09cf
2 changed files with 14 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
src/codegen/c.zig
View File

@ -4092,9 +4092,14 @@ fn lowerTry(
}
}
try reap(f, inst, &.{operand});
if (f.liveness.isUnused(inst)) {
return CValue.none;
}
const target = f.object.dg.module.getTarget();
const is_array = lowersToArray(payload_ty, target);
try reap(f, inst, &.{operand});
const local = try f.allocLocal(inst, result_ty);
if (is_array) {
try writer.writeAll("memcpy(");

10
src/codegen/llvm.zig
View File

@ -5346,7 +5346,8 @@ pub const FuncGen = struct {
const err_union_ty = self.air.typeOf(pl_op.operand);
const payload_ty = self.air.typeOfIndex(inst);
const can_elide_load = if (isByRef(payload_ty)) self.canElideLoad(body_tail) else false;
return lowerTry(self, err_union, body, err_union_ty, false, can_elide_load, payload_ty);
const is_unused = self.liveness.isUnused(inst);
return lowerTry(self, err_union, body, err_union_ty, false, can_elide_load, is_unused, payload_ty);
}
fn airTryPtr(self: *FuncGen, inst: Air.Inst.Index) !?*llvm.Value {
@ -5356,7 +5357,8 @@ pub const FuncGen = struct {
const body = self.air.extra[extra.end..][0..extra.data.body_len];
const err_union_ty = self.air.typeOf(extra.data.ptr).childType();
const payload_ty = self.air.typeOfIndex(inst);
return lowerTry(self, err_union_ptr, body, err_union_ty, true, true, payload_ty);
const is_unused = self.liveness.isUnused(inst);
return lowerTry(self, err_union_ptr, body, err_union_ty, true, true, is_unused, payload_ty);
}
fn lowerTry(
@ -5366,6 +5368,7 @@ pub const FuncGen = struct {
err_union_ty: Type,
operand_is_ptr: bool,
can_elide_load: bool,
is_unused: bool,
result_ty: Type,
) !?*llvm.Value {
const payload_ty = err_union_ty.errorUnionPayload();
@ -5405,6 +5408,9 @@ pub const FuncGen = struct {
fg.builder.positionBuilderAtEnd(continue_block);
}
if (is_unused) {
return null;
}
if (!payload_has_bits) {
if (!operand_is_ptr) return null;