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cbe: don't emit unused undefined array literals

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kcbanner 2023-01-28 02:06:14 -05:00 committed by Andrew Kelley
parent 317d57115d
commit fcb05ee2e7
1 changed files with 9 additions and 6 deletions
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15
src/codegen/c.zig
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@ -3726,16 +3726,15 @@ fn airStore(f: *Function, inst: Air.Inst.Index) !CValue {
const ptr_val = try f.resolveInst(bin_op.lhs);
const src_ty = f.air.typeOf(bin_op.rhs);
const src_val = try f.resolveInst(bin_op.rhs);
try reap(f, inst, &.{ bin_op.lhs, bin_op.rhs });
// TODO Sema should emit a different instruction when the store should
// possibly do the safety 0xaa bytes for undefined.
const src_val_is_undefined =
if (f.air.value(bin_op.rhs)) |v| v.isUndefDeep() else false;
if (src_val_is_undefined)
if (src_val_is_undefined) {
try reap(f, inst, &.{ bin_op.lhs, bin_op.rhs });
return try storeUndefined(f, ptr_info.pointee_type, ptr_val);
}
const target = f.object.dg.module.getTarget();
const is_aligned = ptr_info.@"align" == 0 or
@ -3744,6 +3743,9 @@ fn airStore(f: *Function, inst: Air.Inst.Index) !CValue {
const need_memcpy = !is_aligned or is_array;
const writer = f.object.writer();
const src_val = try f.resolveInst(bin_op.rhs);
try reap(f, inst, &.{ bin_op.lhs, bin_op.rhs });
if (need_memcpy) {
// For this memcpy to safely work we need the rhs to have the same
// underlying type as the lhs (i.e. they must both be arrays of the same underlying type).
@ -4344,8 +4346,9 @@ fn airDbgInline(f: *Function, inst: Air.Inst.Index) !CValue {
fn airDbgVar(f: *Function, inst: Air.Inst.Index) !CValue {
const pl_op = f.air.instructions.items(.data)[inst].pl_op;
const name = f.air.nullTerminatedString(pl_op.payload);
const operand = try f.resolveInst(pl_op.operand);
_ = operand;
const operand_is_undef = if (f.air.value(pl_op.operand)) |v| v.isUndefDeep() else false;
if (!operand_is_undef) _ = try f.resolveInst(pl_op.operand);
try reap(f, inst, &.{pl_op.operand});
const writer = f.object.writer();
try writer.print("/* var:{s} */\n", .{name});