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math: implement absInt for integer vectors

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This commit adds support to absInt for integer vectors.
This commit is contained in:
Jordan Lewis 2022-12-28 14:27:18 -05:00 committed by Veikka Tuominen
parent fc07e1a267
commit 1ec74f1b70
1 changed files with 29 additions and 9 deletions
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38
lib/std/math.zig
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@ -784,15 +784,31 @@ fn testOverflow() !void {
/// See also: `absCast`
pub fn absInt(x: anytype) !@TypeOf(x) {
const T = @TypeOf(x);
comptime assert(@typeInfo(T) == .Int); // must pass an integer to absInt
comptime assert(@typeInfo(T).Int.signedness == .signed); // must pass a signed integer to absInt
if (x == minInt(T)) {
return error.Overflow;
} else {
@setRuntimeSafety(false);
return if (x < 0) -x else x;
}
return switch (@typeInfo(T)) {
.Int => |info| {
comptime assert(info.signedness == .signed); // must pass a signed integer to absInt
if (x == minInt(T)) {
return error.Overflow;
} else {
@setRuntimeSafety(false);
return if (x < 0) -x else x;
}
},
.Vector => |vinfo| blk: {
switch (@typeInfo(vinfo.child)) {
.Int => |info| {
comptime assert(info.signedness == .signed); // must pass a signed integer to absInt
if (@reduce(.Or, x == @splat(vinfo.len, @as(vinfo.child, minInt(vinfo.child))))) {
return error.Overflow;
}
const zero = @splat(vinfo.len, @as(vinfo.child, 0));
break :blk @select(vinfo.child, x > zero, x, -x);
},
else => @compileError("Expected vector of ints, found " ++ @typeName(T)),
}
},
else => @compileError("Expected an int or vector, found " ++ @typeName(T)),
};
}
test "absInt" {
@ -802,6 +818,10 @@ test "absInt" {
fn testAbsInt() !void {
try testing.expect((absInt(@as(i32, -10)) catch unreachable) == 10);
try testing.expect((absInt(@as(i32, 10)) catch unreachable) == 10);
try testing.expectEqual(@Vector(3, i32){ 10, 10, 0 }, (absInt(@Vector(3, i32){ -10, 10, 0 }) catch unreachable));
try testing.expectError(error.Overflow, absInt(@as(i32, minInt(i32))));
try testing.expectError(error.Overflow, absInt(@Vector(3, i32){ 10, -10, minInt(i32) }));
}
/// Divide numerator by denominator, rounding toward zero. Returns an