diff --git a/src/codegen.zig b/src/codegen.zig index 4a02a8ffc0..66aa32b14e 100644 --- a/src/codegen.zig +++ b/src/codegen.zig @@ -658,6 +658,7 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type { const mcv = try self.genFuncInst(inst); if (!inst.isUnused()) { + log.debug("{*} => {}", .{ inst, mcv }); const branch = &self.branch_stack.items[self.branch_stack.items.len - 1]; try branch.inst_table.putNoClobber(self.gpa, inst, mcv); } @@ -2039,27 +2040,13 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type { const condition: Condition = switch (cond) { .compare_flags_signed => |cmp_op| blk: { // Here we map to the opposite condition because the jump is to the false branch. - const condition: Condition = switch (cmp_op) { - .gte => .lt, - .gt => .le, - .neq => .eq, - .lt => .ge, - .lte => .gt, - .eq => .ne, - }; - break :blk condition; + const condition = Condition.fromCompareOperatorSigned(cmp_op); + break :blk condition.negate(); }, .compare_flags_unsigned => |cmp_op| blk: { // Here we map to the opposite condition because the jump is to the false branch. - const condition: Condition = switch (cmp_op) { - .gte => .cc, - .gt => .ls, - .neq => .eq, - .lt => .cs, - .lte => .hi, - .eq => .ne, - }; - break :blk condition; + const condition = Condition.fromCompareOperatorUnsigned(cmp_op); + break :blk condition.negate(); }, .register => |reg| blk: { // cmp reg, 1 @@ -2239,7 +2226,7 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type { } }, .arm, .armeb => { - if (math.cast(i26, @intCast(i32, index) - @intCast(i32, self.code.items.len))) |delta| { + if (math.cast(i26, @intCast(i32, index) - @intCast(i32, self.code.items.len + 8))) |delta| { writeInt(u32, try self.code.addManyAsArray(4), Instruction.b(.al, delta).toU32()); } else |err| { return self.fail(src, "TODO: enable larger branch offset", .{}); @@ -2736,6 +2723,22 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type { // Write the debug undefined value. return self.genSetReg(src, reg, .{ .immediate = 0xaaaaaaaa }); }, + .compare_flags_unsigned, + .compare_flags_signed, + => |op| { + const condition = switch (mcv) { + .compare_flags_unsigned => Condition.fromCompareOperatorUnsigned(op), + .compare_flags_signed => Condition.fromCompareOperatorSigned(op), + else => unreachable, + }; + + // mov reg, 0 + // moveq reg, 1 + const zero = Instruction.Operand.imm(0, 0); + const one = Instruction.Operand.imm(1, 0); + writeInt(u32, try self.code.addManyAsArray(4), Instruction.mov(.al, reg, zero).toU32()); + writeInt(u32, try self.code.addManyAsArray(4), Instruction.mov(condition, reg, one).toU32()); + }, .immediate => |x| { if (x > math.maxInt(u32)) return self.fail(src, "ARM registers are 32-bit wide", .{}); diff --git a/src/codegen/arm.zig b/src/codegen/arm.zig index 33ff789648..978c653cb0 100644 --- a/src/codegen/arm.zig +++ b/src/codegen/arm.zig @@ -35,8 +35,74 @@ pub const Condition = enum(u4) { le, /// always al, + + /// Converts a std.math.CompareOperator into a condition flag, + /// i.e. returns the condition that is true iff the result of the + /// comparison is true. Assumes signed comparison + pub fn fromCompareOperatorSigned(op: std.math.CompareOperator) Condition { + return switch (op) { + .gte => .ge, + .gt => .gt, + .neq => .ne, + .lt => .lt, + .lte => .le, + .eq => .eq, + }; + } + + /// Converts a std.math.CompareOperator into a condition flag, + /// i.e. returns the condition that is true iff the result of the + /// comparison is true. Assumes unsigned comparison + pub fn fromCompareOperatorUnsigned(op: std.math.CompareOperator) Condition { + return switch (op) { + .gte => .cs, + .gt => .hi, + .neq => .ne, + .lt => .cc, + .lte => .ls, + .eq => .eq, + }; + } + + /// Returns the condition which is true iff the given condition is + /// false (if such a condition exists) + pub fn negate(cond: Condition) Condition { + return switch (cond) { + .eq => .ne, + .ne => .eq, + .cs => .cc, + .cc => .cs, + .mi => .pl, + .pl => .mi, + .vs => .vc, + .vc => .vs, + .hi => .ls, + .ls => .hi, + .ge => .lt, + .lt => .ge, + .gt => .le, + .le => .gt, + .al => unreachable, + }; + } }; +test "condition from CompareOperator" { + testing.expectEqual(@as(Condition, .eq), Condition.fromCompareOperatorSigned(.eq)); + testing.expectEqual(@as(Condition, .eq), Condition.fromCompareOperatorUnsigned(.eq)); + + testing.expectEqual(@as(Condition, .gt), Condition.fromCompareOperatorSigned(.gt)); + testing.expectEqual(@as(Condition, .hi), Condition.fromCompareOperatorUnsigned(.gt)); + + testing.expectEqual(@as(Condition, .le), Condition.fromCompareOperatorSigned(.lte)); + testing.expectEqual(@as(Condition, .ls), Condition.fromCompareOperatorUnsigned(.lte)); +} + +test "negate condition" { + testing.expectEqual(@as(Condition, .eq), Condition.ne.negate()); + testing.expectEqual(@as(Condition, .ne), Condition.eq.negate()); +} + /// Represents a register in the ARM instruction set architecture pub const Register = enum(u5) { r0,