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spirv: shlWithOverflow

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This commit is contained in:
Robin Voetter
2024-01-16 23:06:15 +01:00
parent 15cf5f88c1
commit 2f815853dc
3 changed files with 104 additions and 33 deletions
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130
src/codegen/spirv.zig
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@@ -1782,19 +1782,6 @@ const DeclGen = struct {
wip.dg.gpa.free(wip.results);
}
/// Return the scalar type of an input vector. This type is expected to be a vector
/// if `wip.is_vector`, and a scalar otherwise.
fn scalarType(wip: WipElementWise, ty: Type) Type {
const mod = wip.dg.module;
if (wip.is_vector) {
assert(ty.isVector(mod));
return ty.childType(mod);
} else {
assert(!ty.isVector(mod));
return ty;
}
}
/// Utility function to extract the element at a particular index in an
/// input vector. This type is expected to be a vector if `wip.is_vector`, and
/// a scalar otherwise.
@@ -1844,7 +1831,7 @@ const DeclGen = struct {
const results = try self.gpa.alloc(IdRef, num_results);
for (results) |*result| result.* = undefined;
const scalar_ty = if (is_vector) result_ty.childType(mod) else result_ty;
const scalar_ty = result_ty.scalarType(mod);
const scalar_ty_ref = try self.resolveType(scalar_ty, .direct);
return .{
@@ -2198,6 +2185,7 @@ const DeclGen = struct {
.add_with_overflow => try self.airAddSubOverflow(inst, .OpIAdd, .OpULessThan, .OpSLessThan),
.sub_with_overflow => try self.airAddSubOverflow(inst, .OpISub, .OpUGreaterThan, .OpSGreaterThan),
.shl_with_overflow => try self.airShlOverflow(inst),
.shuffle => try self.airShuffle(inst),
@@ -2343,23 +2331,30 @@ const DeclGen = struct {
const bin_op = self.air.instructions.items(.data)[@intFromEnum(inst)].bin_op;
const lhs_id = try self.resolve(bin_op.lhs);
const rhs_id = try self.resolve(bin_op.rhs);
const result_ty = self.typeOfIndex(inst);
// Sometimes Zig doesn't make both of the arguments the same types here. SPIR-V expects that,
// so just manually upcast it if required.
// TODO(robin)
const result_ty = self.typeOfIndex(inst);
const shift_ty = self.typeOf(bin_op.rhs);
const scalar_shift_ty_ref = try self.resolveType(shift_ty.scalarType(mod), .direct);
const info = try self.arithmeticTypeInfo(result_ty);
switch (info.class) {
.composite_integer => return self.todo("shift ops for composite integers", .{}),
.integer, .strange_integer => {},
.float, .bool => unreachable,
}
var wip = try self.elementWise(result_ty);
defer wip.deinit();
const shift_ty = wip.scalarType(self.typeOf(bin_op.rhs));
const shift_ty_ref = try self.resolveType(shift_ty, .direct);
for (0..wip.results.len) |i| {
const lhs_elem_id = try wip.elementAt(result_ty, lhs_id, i);
const rhs_elem_id = try wip.elementAt(result_ty, rhs_id, i);
const rhs_elem_id = try wip.elementAt(shift_ty, rhs_id, i);
const shift_id = if (shift_ty_ref != wip.result_ty_ref) blk: {
// TODO: Can we omit normalizing lhs?
const lhs_norm_id = try self.normalizeInt(wip.scalar_ty_ref, lhs_elem_id, info);
// Sometimes Zig doesn't make both of the arguments the same types here. SPIR-V expects that,
// so just manually upcast it if required.
const shift_id = if (scalar_shift_ty_ref != wip.scalar_ty_ref) blk: {
const shift_id = self.spv.allocId();
try self.func.body.emit(self.spv.gpa, .OpUConvert, .{
.id_result_type = wip.scalar_ty_id,
@@ -2368,12 +2363,13 @@ const DeclGen = struct {
});
break :blk shift_id;
} else rhs_elem_id;
const shift_norm_id = try self.normalizeInt(wip.scalar_ty_ref, shift_id, info);
const args = .{
.id_result_type = wip.scalar_ty_id,
.id_result = wip.allocId(i),
.base = lhs_elem_id,
.shift = shift_id,
.base = lhs_norm_id,
.shift = shift_norm_id,
};
if (result_ty.isSignedInt(mod)) {
@@ -2680,6 +2676,88 @@ const DeclGen = struct {
);
}
fn airShlOverflow(self: *DeclGen, inst: Air.Inst.Index) !?IdRef {
if (self.liveness.isUnused(inst)) return null;
const mod = self.module;
const ty_pl = self.air.instructions.items(.data)[@intFromEnum(inst)].ty_pl;
const extra = self.air.extraData(Air.Bin, ty_pl.payload).data;
const lhs = try self.resolve(extra.lhs);
const rhs = try self.resolve(extra.rhs);
const result_ty = self.typeOfIndex(inst);
const operand_ty = self.typeOf(extra.lhs);
const shift_ty = self.typeOf(extra.rhs);
const scalar_shift_ty_ref = try self.resolveType(shift_ty.scalarType(mod), .direct);
const ov_ty = result_ty.structFieldType(1, self.module);
const bool_ty_ref = try self.resolveType(Type.bool, .direct);
const info = try self.arithmeticTypeInfo(operand_ty);
switch (info.class) {
.composite_integer => return self.todo("overflow shift for composite integers", .{}),
.integer, .strange_integer => {},
.float, .bool => unreachable,
}
var wip_result = try self.elementWise(operand_ty);
defer wip_result.deinit();
var wip_ov = try self.elementWise(ov_ty);
defer wip_ov.deinit();
for (0..wip_result.results.len, wip_ov.results) |i, *ov_id| {
const lhs_elem_id = try wip_result.elementAt(operand_ty, lhs, i);
const rhs_elem_id = try wip_result.elementAt(shift_ty, rhs, i);
// Normalize both so that we can shift back and check if the result is the same.
const lhs_norm_id = try self.normalizeInt(wip_result.scalar_ty_ref, lhs_elem_id, info);
// Sometimes Zig doesn't make both of the arguments the same types here. SPIR-V expects that,
// so just manually upcast it if required.
const shift_id = if (scalar_shift_ty_ref != wip_result.scalar_ty_ref) blk: {
const shift_id = self.spv.allocId();
try self.func.body.emit(self.spv.gpa, .OpUConvert, .{
.id_result_type = wip_result.scalar_ty_id,
.id_result = shift_id,
.unsigned_value = rhs_elem_id,
});
break :blk shift_id;
} else rhs_elem_id;
const shift_norm_id = try self.normalizeInt(wip_result.scalar_ty_ref, shift_id, info);
try self.func.body.emit(self.spv.gpa, .OpShiftLeftLogical, .{
.id_result_type = wip_result.scalar_ty_id,
.id_result = wip_result.allocId(i),
.base = lhs_norm_id,
.shift = shift_norm_id,
});
// To check if overflow happened, just check if the right-shifted result is the same value.
const right_shift_id = self.spv.allocId();
try self.func.body.emit(self.spv.gpa, .OpShiftRightLogical, .{
.id_result_type = wip_result.scalar_ty_id,
.id_result = right_shift_id,
.base = try self.normalizeInt(wip_result.scalar_ty_ref, wip_result.results[i], info),
.shift = shift_norm_id,
});
const overflowed_id = self.spv.allocId();
try self.func.body.emit(self.spv.gpa, .OpINotEqual, .{
.id_result_type = self.typeId(bool_ty_ref),
.id_result = overflowed_id,
.operand_1 = lhs_norm_id,
.operand_2 = right_shift_id,
});
ov_id.* = try self.intFromBool(wip_ov.scalar_ty_ref, overflowed_id);
}
return try self.constructStruct(
result_ty,
&.{ operand_ty, ov_ty },
&.{ try wip_result.finalize(), try wip_ov.finalize() },
);
}
fn airShuffle(self: *DeclGen, inst: Air.Inst.Index) !?IdRef {
const mod = self.module;
if (self.liveness.isUnused(inst)) return null;