From 15cc83e27ae8a1740d9b7e2ec14044903979a832 Mon Sep 17 00:00:00 2001 From: Veikka Tuominen Date: Wed, 30 Nov 2022 16:11:27 +0200 Subject: cbe: reduce amount of temporary locals --- src/codegen/c.zig | 282 +++++++++++++++++++++++++++++------------------------- 1 file changed, 153 insertions(+), 129 deletions(-) (limited to 'src/codegen') diff --git a/src/codegen/c.zig b/src/codegen/c.zig index 6df3893cbe..9e814df958 100644 --- a/src/codegen/c.zig +++ b/src/codegen/c.zig @@ -50,6 +50,8 @@ pub const CValue = union(enum) { /// Render these bytes literally. /// TODO make this a [*:0]const u8 to save memory bytes: []const u8, + /// Index of an instruction that should later be rendered inline. + inline_index: Air.Inst.Index, }; const BlockData = struct { @@ -79,6 +81,7 @@ const ValueRenderLocation = enum { FunctionArgument, Initializer, Other, + condition, }; const BuiltinInfo = enum { @@ -278,6 +281,19 @@ pub const Function = struct { return result; } + fn resolveInstNoInline(f: *Function, inst: Air.Inst.Ref) !CValue { + const operand = try f.resolveInst(inst); + if (operand != .inline_index) return operand; + + const inst_ty = f.air.typeOf(inst); + const writer = f.object.writer(); + const local = try f.allocLocal(inst_ty, .Const); + try writer.writeAll(" = "); + try f.writeCValueInline(operand.inline_index); + try writer.writeAll(";\n"); + return local; + } + fn wantSafety(f: *Function) bool { return switch (f.object.dg.module.optimizeMode()) { .Debug, .ReleaseSafe => true, @@ -313,10 +329,74 @@ pub const Function = struct { .constant => |inst| { const ty = f.air.typeOf(inst); const val = f.air.value(inst).?; - return f.object.dg.renderValue(w, ty, val, location); + try f.object.dg.renderValue(w, ty, val, location); + }, + .undef => |ty| try f.object.dg.renderValue(w, ty, Value.undef, location), + .inline_index => |node| { + if (location != .condition) try w.writeByte('('); + try f.writeCValueInline(node); + if (location != .condition) try w.writeByte(')'); + }, + else => try f.object.dg.writeCValue(w, c_value), + } + } + + const E = error{ OutOfMemory, AnalysisFail }; + + fn writeCValueInline(f: *Function, inst: Air.Inst.Index) E!void { + switch (f.air.instructions.items(.tag)[inst]) { + // zig fmt: off + // TODO use a different strategy for add, sub, mul, div + // that communicates to the optimizer that wrapping is UB. + .add => try airBinOp(f, inst, "+", "add", .None), + .sub => try airBinOp(f, inst, "-", "sub", .None), + .mul => try airBinOp(f, inst, "*", "mul", .None), + + .div_float => try airBinBuiltinCall(f, inst, "div", .None), + + .div_trunc, .div_exact => try airBinOp(f, inst, "/", "div_trunc", .None), + .rem => { + const bin_op = f.air.instructions.items(.data)[inst].bin_op; + const lhs_ty = f.air.typeOf(bin_op.lhs); + // For binary operations @TypeOf(lhs)==@TypeOf(rhs), + // so we only check one. + if (lhs_ty.isInt()) + try airBinOp(f, inst, "%", "rem", .None) + else + try airBinFloatOp(f, inst, "fmod"); }, - .undef => |ty| return f.object.dg.renderValue(w, ty, Value.undef, location), - else => return f.object.dg.writeCValue(w, c_value), + .div_floor => try airBinBuiltinCall(f, inst, "div_floor", .None), + .mod => try airBinBuiltinCall(f, inst, "mod", .None), + + .addwrap => try airBinBuiltinCall(f, inst, "addw", .Bits), + .subwrap => try airBinBuiltinCall(f, inst, "subw", .Bits), + .mulwrap => try airBinBuiltinCall(f, inst, "mulw", .Bits), + + .add_sat => try airBinBuiltinCall(f, inst, "adds", .Bits), + .sub_sat => try airBinBuiltinCall(f, inst, "subs", .Bits), + .mul_sat => try airBinBuiltinCall(f, inst, "muls", .Bits), + .shl_sat => try airBinBuiltinCall(f, inst, "shls", .Bits), + + .min => try airMinMax(f, inst, '<', "fmin"), + .max => try airMinMax(f, inst, '>', "fmax"), + + .cmp_gt => try airCmpOp(f, inst, ">", "gt"), + .cmp_gte => try airCmpOp(f, inst, ">=", "ge"), + .cmp_lt => try airCmpOp(f, inst, "<", "lt"), + .cmp_lte => try airCmpOp(f, inst, "<=", "le"), + + .cmp_eq => try airEquality(f, inst, "((", "==", "eq"), + .cmp_neq => try airEquality(f, inst, "!((", "!=", "ne"), + + .bool_and, .bit_and => try airBinOp(f, inst, "&", "and", .None), + .bool_or, .bit_or => try airBinOp(f, inst, "|", "or", .None), + .xor => try airBinOp(f, inst, "^", "xor", .None), + .shr, .shr_exact => try airBinBuiltinCall(f, inst, "shr", .None), + .shl, => try airBinBuiltinCall(f, inst, "shlw", .Bits), + .shl_exact => try airBinOp(f, inst, "<<", "shl", .None), + .not => try airNot (f, inst), + else => unreachable, + // zig fmt: on } } @@ -2072,7 +2152,7 @@ pub const DeclGen = struct { fn writeCValue(dg: *DeclGen, w: anytype, c_value: CValue) !void { switch (c_value) { - .none => unreachable, + .none, .inline_index => unreachable, .local => |i| return w.print("t{d}", .{i}), .local_ref => |i| return w.print("&t{d}", .{i}), .constant => unreachable, @@ -2091,7 +2171,7 @@ pub const DeclGen = struct { fn writeCValueDeref(dg: *DeclGen, w: anytype, c_value: CValue) !void { switch (c_value) { - .none => unreachable, + .none, .inline_index => unreachable, .local => |i| return w.print("(*t{d})", .{i}), .local_ref => |i| return w.print("t{d}", .{i}), .constant => unreachable, @@ -2121,7 +2201,7 @@ pub const DeclGen = struct { fn writeCValueDerefMember(dg: *DeclGen, writer: anytype, c_value: CValue, member: CValue) !void { switch (c_value) { - .none, .constant, .field, .undef => unreachable, + .none, .constant, .field, .undef, .inline_index => unreachable, .local, .arg, .decl, .identifier, .bytes => { try dg.writeCValue(writer, c_value); try writer.writeAll("->"); @@ -2437,37 +2517,26 @@ fn genBody(f: *Function, body: []const Air.Inst.Index) error{ AnalysisFail, OutO .ptr_add => try airPtrAddSub(f, inst, '+'), .ptr_sub => try airPtrAddSub(f, inst, '-'), - // TODO use a different strategy for add, sub, mul, div - // that communicates to the optimizer that wrapping is UB. - .add => try airBinOp(f, inst, "+", "add", .None), - .sub => try airBinOp(f, inst, "-", "sub", .None), - .mul => try airBinOp(f, inst, "*", "mul", .None), + .add => CValue{ .inline_index = inst }, + .sub => CValue{ .inline_index = inst }, + .mul => CValue{ .inline_index = inst }, .neg => try airFloatNeg(f, inst), - .div_float => try airBinBuiltinCall(f, inst, "div", .None), + .div_float => CValue{ .inline_index = inst }, - .div_trunc, .div_exact => try airBinOp(f, inst, "/", "div_trunc", .None), - .rem => blk: { - const bin_op = f.air.instructions.items(.data)[inst].bin_op; - const lhs_ty = f.air.typeOf(bin_op.lhs); - // For binary operations @TypeOf(lhs)==@TypeOf(rhs), - // so we only check one. - break :blk if (lhs_ty.isInt()) - try airBinOp(f, inst, "%", "rem", .None) - else - try airBinFloatOp(f, inst, "fmod"); - }, - .div_floor => try airBinBuiltinCall(f, inst, "div_floor", .None), - .mod => try airBinBuiltinCall(f, inst, "mod", .None), + .div_trunc, .div_exact => CValue{ .inline_index = inst }, + .rem => CValue{ .inline_index = inst }, + .div_floor => CValue{ .inline_index = inst }, + .mod => CValue{ .inline_index = inst }, - .addwrap => try airBinBuiltinCall(f, inst, "addw", .Bits), - .subwrap => try airBinBuiltinCall(f, inst, "subw", .Bits), - .mulwrap => try airBinBuiltinCall(f, inst, "mulw", .Bits), + .addwrap => CValue{ .inline_index = inst }, + .subwrap => CValue{ .inline_index = inst }, + .mulwrap => CValue{ .inline_index = inst }, - .add_sat => try airBinBuiltinCall(f, inst, "adds", .Bits), - .sub_sat => try airBinBuiltinCall(f, inst, "subs", .Bits), - .mul_sat => try airBinBuiltinCall(f, inst, "muls", .Bits), - .shl_sat => try airBinBuiltinCall(f, inst, "shls", .Bits), + .add_sat => CValue{ .inline_index = inst }, + .sub_sat => CValue{ .inline_index = inst }, + .mul_sat => CValue{ .inline_index = inst }, + .shl_sat => CValue{ .inline_index = inst }, .sqrt, .sin, @@ -2492,30 +2561,30 @@ fn genBody(f: *Function, body: []const Air.Inst.Index) error{ AnalysisFail, OutO .mul_with_overflow => try airOverflow(f, inst, "mul", .Bits), .shl_with_overflow => try airOverflow(f, inst, "shl", .Bits), - .min => try airMinMax(f, inst, '<', "fmin"), - .max => try airMinMax(f, inst, '>', "fmax"), + .min => CValue{ .inline_index = inst }, + .max => CValue{ .inline_index = inst }, .slice => try airSlice(f, inst), - .cmp_gt => try airCmpOp(f, inst, ">", "gt"), - .cmp_gte => try airCmpOp(f, inst, ">=", "ge"), - .cmp_lt => try airCmpOp(f, inst, "<", "lt"), - .cmp_lte => try airCmpOp(f, inst, "<=", "le"), + .cmp_gt => CValue{ .inline_index = inst }, + .cmp_gte => CValue{ .inline_index = inst }, + .cmp_lt => CValue{ .inline_index = inst }, + .cmp_lte => CValue{ .inline_index = inst }, - .cmp_eq => try airEquality(f, inst, "((", "==", "eq"), - .cmp_neq => try airEquality(f, inst, "!((", "!=", "ne"), + .cmp_eq => CValue{ .inline_index = inst }, + .cmp_neq => CValue{ .inline_index = inst }, .cmp_vector => return f.fail("TODO: C backend: implement cmp_vector", .{}), .cmp_lt_errors_len => try airCmpLtErrorsLen(f, inst), // bool_and and bool_or are non-short-circuit operations - .bool_and, .bit_and => try airBinOp(f, inst, "&", "and", .None), - .bool_or, .bit_or => try airBinOp(f, inst, "|", "or", .None), - .xor => try airBinOp(f, inst, "^", "xor", .None), - .shr, .shr_exact => try airBinBuiltinCall(f, inst, "shr", .None), - .shl, => try airBinBuiltinCall(f, inst, "shlw", .Bits), - .shl_exact => try airBinOp(f, inst, "<<", "shl", .None), - .not => try airNot (f, inst), + .bool_and, .bit_and => CValue{ .inline_index = inst }, + .bool_or, .bit_or => CValue{ .inline_index = inst }, + .xor => CValue{ .inline_index = inst }, + .shr, .shr_exact => CValue{ .inline_index = inst }, + .shl, => CValue{ .inline_index = inst }, + .shl_exact => CValue{ .inline_index = inst }, + .not => CValue{ .inline_index = inst }, .optional_payload => try airOptionalPayload(f, inst), .optional_payload_ptr => try airOptionalPayloadPtr(f, inst), @@ -3260,25 +3329,18 @@ fn airOverflow(f: *Function, inst: Air.Inst.Index, operation: []const u8, info: return local; } -fn airNot(f: *Function, inst: Air.Inst.Index) !CValue { - if (f.liveness.isUnused(inst)) return CValue.none; - +fn airNot(f: *Function, inst: Air.Inst.Index) !void { const ty_op = f.air.instructions.items(.data)[inst].ty_op; const op = try f.resolveInst(ty_op.operand); const writer = f.object.writer(); const inst_ty = f.air.typeOfIndex(inst); - const local = try f.allocLocal(inst_ty, .Const); const target = f.object.dg.module.getTarget(); if (inst_ty.bitSize(target) > 64) {} - try writer.writeAll(" = "); try writer.writeByte(if (inst_ty.tag() == .bool) '!' else '~'); try f.writeCValue(writer, op, .Other); - try writer.writeAll(";\n"); - - return local; } fn airBinOp( @@ -3287,62 +3349,49 @@ fn airBinOp( operator: []const u8, operation: []const u8, info: BuiltinInfo, -) !CValue { - if (f.liveness.isUnused(inst)) return CValue.none; - +) !void { const bin_op = f.air.instructions.items(.data)[inst].bin_op; const operand_ty = f.air.typeOf(bin_op.lhs); const target = f.object.dg.module.getTarget(); if ((operand_ty.isInt() and operand_ty.bitSize(target) > 64) or operand_ty.isRuntimeFloat()) - return try airBinBuiltinCall(f, inst, operation, info); + return airBinBuiltinCall(f, inst, operation, info); - const inst_ty = f.air.typeOfIndex(inst); const lhs = try f.resolveInst(bin_op.lhs); const rhs = try f.resolveInst(bin_op.rhs); const writer = f.object.writer(); - const local = try f.allocLocal(inst_ty, .Const); - - try writer.writeAll(" = "); try f.writeCValue(writer, lhs, .Other); try writer.writeByte(' '); try writer.writeAll(operator); try writer.writeByte(' '); try f.writeCValue(writer, rhs, .Other); - try writer.writeAll(";\n"); - - return local; } -fn airCmpOp(f: *Function, inst: Air.Inst.Index, operator: []const u8, operation: []const u8) !CValue { - if (f.liveness.isUnused(inst)) return CValue.none; - +fn airCmpOp( + f: *Function, + inst: Air.Inst.Index, + operator: []const u8, + operation: []const u8, +) !void { const bin_op = f.air.instructions.items(.data)[inst].bin_op; const operand_ty = f.air.typeOf(bin_op.lhs); const target = f.object.dg.module.getTarget(); if (operand_ty.isInt() and operand_ty.bitSize(target) > 64) - return try airCmpBuiltinCall(f, inst, operator, "cmp"); + return airCmpBuiltinCall(f, inst, operator, "cmp"); if (operand_ty.isRuntimeFloat()) - return try airCmpBuiltinCall(f, inst, operator, operation); + return airCmpBuiltinCall(f, inst, operator, operation); - const inst_ty = f.air.typeOfIndex(inst); const lhs = try f.resolveInst(bin_op.lhs); const rhs = try f.resolveInst(bin_op.rhs); const writer = f.object.writer(); - const local = try f.allocLocal(inst_ty, .Const); - - try writer.writeAll(" = "); try f.writeCValue(writer, lhs, .Other); try writer.writeByte(' '); try writer.writeAll(operator); try writer.writeByte(' '); try f.writeCValue(writer, rhs, .Other); - try writer.writeAll(";\n"); - - return local; } fn airEquality( @@ -3351,27 +3400,20 @@ fn airEquality( negate_prefix: []const u8, operator: []const u8, operation: []const u8, -) !CValue { - if (f.liveness.isUnused(inst)) return CValue.none; - +) !void { const bin_op = f.air.instructions.items(.data)[inst].bin_op; const operand_ty = f.air.typeOf(bin_op.lhs); const target = f.object.dg.module.getTarget(); if (operand_ty.isInt() and operand_ty.bitSize(target) > 64) - return try airCmpBuiltinCall(f, inst, operator, "cmp"); + return airCmpBuiltinCall(f, inst, operator, "cmp"); if (operand_ty.isRuntimeFloat()) - return try airCmpBuiltinCall(f, inst, operator, operation); + return airCmpBuiltinCall(f, inst, operator, operation); const lhs = try f.resolveInst(bin_op.lhs); const rhs = try f.resolveInst(bin_op.rhs); const writer = f.object.writer(); - const inst_ty = f.air.typeOfIndex(inst); - const local = try f.allocLocal(inst_ty, .Const); - - try writer.writeAll(" = "); - if (operand_ty.zigTypeTag() == .Optional and !operand_ty.isPtrLikeOptional()) { // (A && B) || (C && (A == B)) // A = lhs.is_null ; B = rhs.is_null ; C = rhs.payload == lhs.payload @@ -3388,9 +3430,8 @@ fn airEquality( try f.writeCValue(writer, lhs, .Other); try writer.writeAll(".is_null == "); try f.writeCValue(writer, rhs, .Other); - try writer.writeAll(".is_null));\n"); - - return local; + try writer.writeAll(".is_null))"); + return; } try f.writeCValue(writer, lhs, .Other); @@ -3398,9 +3439,6 @@ fn airEquality( try writer.writeAll(operator); try writer.writeByte(' '); try f.writeCValue(writer, rhs, .Other); - try writer.writeAll(";\n"); - - return local; } fn airCmpLtErrorsLen(f: *Function, inst: Air.Inst.Index) !CValue { @@ -3454,26 +3492,23 @@ fn airPtrAddSub(f: *Function, inst: Air.Inst.Index, operator: u8) !CValue { return local; } -fn airMinMax(f: *Function, inst: Air.Inst.Index, operator: u8, operation: []const u8) !CValue { - if (f.liveness.isUnused(inst)) return CValue.none; - +fn airMinMax(f: *Function, inst: Air.Inst.Index, operator: u8, operation: []const u8) !void { const bin_op = f.air.instructions.items(.data)[inst].bin_op; const inst_ty = f.air.typeOfIndex(inst); const target = f.object.dg.module.getTarget(); if (inst_ty.isInt() and inst_ty.bitSize(target) > 64) - return try airBinBuiltinCall(f, inst, operation[1..], .None); + return airBinBuiltinCall(f, inst, operation[1..], .None); if (inst_ty.isRuntimeFloat()) - return try airBinFloatOp(f, inst, operation); + return airBinFloatOp(f, inst, operation); const lhs = try f.resolveInst(bin_op.lhs); const rhs = try f.resolveInst(bin_op.rhs); const writer = f.object.writer(); - const local = try f.allocLocal(inst_ty, .Const); // (lhs <> rhs) ? lhs : rhs - try writer.writeAll(" = ("); + try writer.writeAll("("); try f.writeCValue(writer, lhs, .Other); try writer.writeByte(' '); try writer.writeByte(operator); @@ -3483,9 +3518,6 @@ fn airMinMax(f: *Function, inst: Air.Inst.Index, operator: u8, operation: []cons try f.writeCValue(writer, lhs, .Other); try writer.writeAll(" : "); try f.writeCValue(writer, rhs, .Other); - try writer.writeAll(";\n"); - - return local; } fn airSlice(f: *Function, inst: Air.Inst.Index) !CValue { @@ -3801,7 +3833,7 @@ fn airBitcast(f: *Function, inst: Air.Inst.Index) !CValue { if (f.liveness.isUnused(inst) or !inst_ty.hasRuntimeBits()) return CValue.none; const ty_op = f.air.instructions.items(.data)[inst].ty_op; - const operand = try f.resolveInst(ty_op.operand); + const operand = try f.resolveInstNoInline(ty_op.operand); const writer = f.object.writer(); if (inst_ty.isPtrAtRuntime() and @@ -3899,7 +3931,7 @@ fn airLoop(f: *Function, inst: Air.Inst.Index) !CValue { const body = f.air.extra[loop.end..][0..loop.data.body_len]; const writer = f.object.writer(); try writer.writeAll("while ("); - try f.object.dg.renderValue(writer, Type.bool, Value.true, .Other); + try f.object.dg.renderValue(writer, Type.bool, Value.true, .condition); try writer.writeAll(") "); try genBody(f, body); try writer.writeByte('\n'); @@ -3915,7 +3947,7 @@ fn airCondBr(f: *Function, inst: Air.Inst.Index) !CValue { const writer = f.object.writer(); try writer.writeAll("if ("); - try f.writeCValue(writer, cond, .Other); + try f.writeCValue(writer, cond, .condition); try writer.writeAll(") "); try genBody(f, then_body); try writer.writeAll(" else "); @@ -4945,16 +4977,12 @@ fn airBinBuiltinCall( inst: Air.Inst.Index, operation: []const u8, info: BuiltinInfo, -) !CValue { - if (f.liveness.isUnused(inst)) return CValue.none; - - const inst_ty = f.air.typeOfIndex(inst); +) !void { const bin_op = f.air.instructions.items(.data)[inst].bin_op; const operand_ty = f.air.typeOf(bin_op.lhs); - const local = try f.allocLocal(inst_ty, .Const); const writer = f.object.writer(); - try writer.writeAll(" = zig_"); + try writer.writeAll("zig_"); try writer.writeAll(operation); try writer.writeByte('_'); try f.object.dg.renderTypeForBuiltinFnName(writer, operand_ty); @@ -4963,8 +4991,7 @@ fn airBinBuiltinCall( try writer.writeAll(", "); try f.writeCValue(writer, try f.resolveInst(bin_op.rhs), .FunctionArgument); try f.object.dg.renderBuiltinInfo(writer, operand_ty, info); - try writer.writeAll(");\n"); - return local; + try writer.writeAll(")"); } fn airCmpBuiltinCall( @@ -4972,16 +4999,12 @@ fn airCmpBuiltinCall( inst: Air.Inst.Index, operator: []const u8, operation: []const u8, -) !CValue { - if (f.liveness.isUnused(inst)) return CValue.none; - - const inst_ty = f.air.typeOfIndex(inst); +) !void { const bin_op = f.air.instructions.items(.data)[inst].bin_op; const operand_ty = f.air.typeOf(bin_op.lhs); - const local = try f.allocLocal(inst_ty, .Const); const writer = f.object.writer(); - try writer.writeAll(" = zig_"); + try writer.writeAll("zig_"); try writer.writeAll(operation); try writer.writeByte('_'); try f.object.dg.renderTypeForBuiltinFnName(writer, operand_ty); @@ -4989,8 +5012,7 @@ fn airCmpBuiltinCall( try f.writeCValue(writer, try f.resolveInst(bin_op.lhs), .FunctionArgument); try writer.writeAll(", "); try f.writeCValue(writer, try f.resolveInst(bin_op.rhs), .FunctionArgument); - try writer.print(") {s} {};\n", .{ operator, try f.fmtIntLiteral(Type.initTag(.i32), Value.zero) }); - return local; + try writer.print(") {s} {}", .{ operator, try f.fmtIntLiteral(Type.initTag(.i32), Value.zero) }); } fn airCmpxchg(f: *Function, inst: Air.Inst.Index, flavor: [*:0]const u8) !CValue { @@ -5727,15 +5749,18 @@ fn airUnFloatOp(f: *Function, inst: Air.Inst.Index, operation: []const u8) !CVal return local; } -fn airBinFloatOp(f: *Function, inst: Air.Inst.Index, operation: []const u8) !CValue { - if (f.liveness.isUnused(inst)) return CValue.none; +fn airBinFloatOp( + f: *Function, + inst: Air.Inst.Index, + operation: []const u8, +) !void { const bin_op = f.air.instructions.items(.data)[inst].bin_op; const writer = f.object.writer(); const inst_ty = f.air.typeOfIndex(inst); const lhs = try f.resolveInst(bin_op.lhs); const rhs = try f.resolveInst(bin_op.rhs); - const local = try f.allocLocal(inst_ty, .Const); - try writer.writeAll(" = zig_libc_name_"); + + try writer.writeAll("zig_libc_name_"); try f.object.dg.renderTypeForBuiltinFnName(writer, inst_ty); try writer.writeByte('('); try writer.writeAll(operation); @@ -5743,8 +5768,7 @@ fn airBinFloatOp(f: *Function, inst: Air.Inst.Index, operation: []const u8) !CVa try f.writeCValue(writer, lhs, .FunctionArgument); try writer.writeAll(", "); try f.writeCValue(writer, rhs, .FunctionArgument); - try writer.writeAll(");\n"); - return local; + try writer.writeAll(")"); } fn airMulAdd(f: *Function, inst: Air.Inst.Index) !CValue { -- cgit v1.2.3