Commit eb1e75b2b8
Changed files (9)
lib/std/special/compiler_rt/bswap.zig
@@ -6,7 +6,6 @@ const builtin = @import("builtin");
// ie for u32
// DE AD BE EF <- little|big endian
// FE BE AD DE <- big|little endian
-// ie for u32
// ff 00 00 00 >> 3*8 (leftmost byte)
// 00 ff 00 00 >> 1*8 (2nd left byte)
// 00 00 ff 00 << 1*8 (2n right byte)
lib/std/special/compiler_rt/mulo.zig
@@ -0,0 +1,69 @@
+const builtin = @import("builtin");
+
+// mulo - multiplication overflow
+// - muloXi4_generic for unoptimized version
+
+// return a*b.
+// return if a*b overflows => 1 else => 0
+// see https://stackoverflow.com/a/26320664 for possible implementations
+
+fn muloXi4_generic(comptime ST: type) fn (a: ST, b: ST, overflow: *c_int) callconv(.C) ST {
+ return struct {
+ fn f(a: ST, b: ST, overflow: *c_int) callconv(.C) ST {
+ @setRuntimeSafety(builtin.is_test);
+ const BSIZE = @bitSizeOf(ST);
+ comptime var UT = switch (ST) {
+ i32 => u32,
+ i64 => u64,
+ i128 => u128,
+ else => unreachable,
+ };
+ const min = @bitCast(ST, @as(UT, 1 << (BSIZE - 1)));
+ const max = ~min;
+ overflow.* = 0;
+ const result = a *% b;
+
+ // edge cases
+ if (a == min) {
+ if (b != 0 and b != 1) overflow.* = 1;
+ return result;
+ }
+ if (b == min) {
+ if (a != 0 and a != 1) overflow.* = 1;
+ return result;
+ }
+
+ // take sign of x sx
+ const sa = a >> (BSIZE - 1);
+ const sb = b >> (BSIZE - 1);
+ // take absolute value of a and b via
+ // abs(x) = (x^sx)) - sx
+ const abs_a = (a ^ sa) -% sa;
+ const abs_b = (b ^ sb) -% sb;
+
+ // unitary magnitude, cannot have overflow
+ if (abs_a < 2 or abs_b < 2) return result;
+
+ // compare the signs of operands
+ if ((a ^ b) >> (BSIZE - 1) != 0) {
+ if (abs_a > @divTrunc(max, abs_b)) overflow.* = 1;
+ } else {
+ if (abs_a > @divTrunc(min, -abs_b)) overflow.* = 1;
+ }
+
+ return result;
+ }
+ }.f;
+}
+
+pub const __mulosi4 = muloXi4_generic(i32);
+
+pub const __mulodi4 = muloXi4_generic(i64);
+
+pub const __muloti4 = muloXi4_generic(i128);
+
+test {
+ _ = @import("mulosi4_test.zig");
+ _ = @import("mulodi4_test.zig");
+ _ = @import("muloti4_test.zig");
+}
lib/std/special/compiler_rt/mulodi4.zig
@@ -1,42 +0,0 @@
-const builtin = @import("builtin");
-const compiler_rt = @import("../compiler_rt.zig");
-
-pub fn __mulodi4(a: i64, b: i64, overflow: *c_int) callconv(.C) i64 {
- @setRuntimeSafety(builtin.is_test);
-
- const min = @bitCast(i64, @as(u64, 1 << (64 - 1)));
- const max = ~min;
-
- overflow.* = 0;
- const result = a *% b;
-
- // Edge cases
- if (a == min) {
- if (b != 0 and b != 1) overflow.* = 1;
- return result;
- }
- if (b == min) {
- if (a != 0 and a != 1) overflow.* = 1;
- return result;
- }
-
- // Take absolute value of a and b via abs(x) = (x^(x >> 63)) - (x >> 63).
- const abs_a = (a ^ (a >> 63)) -% (a >> 63);
- const abs_b = (b ^ (b >> 63)) -% (b >> 63);
-
- // Unitary magnitude, cannot have overflow
- if (abs_a < 2 or abs_b < 2) return result;
-
- // Compare the signs of the operands
- if ((a ^ b) >> 63 != 0) {
- if (abs_a > @divTrunc(max, abs_b)) overflow.* = 1;
- } else {
- if (abs_a > @divTrunc(min, -abs_b)) overflow.* = 1;
- }
-
- return result;
-}
-
-test {
- _ = @import("mulodi4_test.zig");
-}
lib/std/special/compiler_rt/mulodi4_test.zig
@@ -1,9 +1,11 @@
-const __mulodi4 = @import("mulodi4.zig").__mulodi4;
+const mulo = @import("mulo.zig");
const testing = @import("std").testing;
+// ported from https://github.com/llvm-mirror/compiler-rt/tree/release_80/test/builtins/Unit
+
fn test__mulodi4(a: i64, b: i64, expected: i64, expected_overflow: c_int) !void {
var overflow: c_int = undefined;
- const x = __mulodi4(a, b, &overflow);
+ const x = mulo.__mulodi4(a, b, &overflow);
try testing.expect(overflow == expected_overflow and (expected_overflow != 0 or x == expected));
}
lib/std/special/compiler_rt/mulosi4_test.zig
@@ -0,0 +1,72 @@
+const mulo = @import("mulo.zig");
+const testing = @import("std").testing;
+
+// ported from https://github.com/llvm-mirror/compiler-rt/tree/release_80/test/builtins/Unit
+
+fn test__mulosi4(a: i32, b: i32, expected: i32, expected_overflow: c_int) !void {
+ var overflow: c_int = undefined;
+ const x = mulo.__mulosi4(a, b, &overflow);
+ try testing.expect(overflow == expected_overflow and (expected_overflow != 0 or x == expected));
+}
+
+test "mulosi4" {
+ try test__mulosi4(0, 0, 0, 0);
+ try test__mulosi4(0, 1, 0, 0);
+ try test__mulosi4(1, 0, 0, 0);
+ try test__mulosi4(0, 10, 0, 0);
+ try test__mulosi4(10, 0, 0, 0);
+ try test__mulosi4(0, 0x1234567, 0, 0);
+ try test__mulosi4(0x1234567, 0, 0, 0);
+
+ try test__mulosi4(0, -1, 0, 0);
+ try test__mulosi4(-1, 0, 0, 0);
+ try test__mulosi4(0, -10, 0, 0);
+ try test__mulosi4(-10, 0, 0, 0);
+ try test__mulosi4(0, -0x1234567, 0, 0);
+ try test__mulosi4(-0x1234567, 0, 0, 0);
+
+ try test__mulosi4(1, 1, 1, 0);
+ try test__mulosi4(1, 10, 10, 0);
+ try test__mulosi4(10, 1, 10, 0);
+ try test__mulosi4(1, 0x1234567, 0x1234567, 0);
+ try test__mulosi4(0x1234567, 1, 0x1234567, 0);
+
+ try test__mulosi4(1, -1, -1, 0);
+ try test__mulosi4(1, -10, -10, 0);
+ try test__mulosi4(-10, 1, -10, 0);
+ try test__mulosi4(1, -0x1234567, -0x1234567, 0);
+ try test__mulosi4(-0x1234567, 1, -0x1234567, 0);
+
+ try test__mulosi4(0x7FFFFFFF, -2, @bitCast(i32, @as(u32, 0x80000001)), 1);
+ try test__mulosi4(-2, 0x7FFFFFFF, @bitCast(i32, @as(u32, 0x80000001)), 1);
+ try test__mulosi4(0x7FFFFFFF, -1, @bitCast(i32, @as(u32, 0x80000001)), 0);
+ try test__mulosi4(-1, 0x7FFFFFFF, @bitCast(i32, @as(u32, 0x80000001)), 0);
+ try test__mulosi4(0x7FFFFFFF, 0, 0, 0);
+ try test__mulosi4(0, 0x7FFFFFFF, 0, 0);
+ try test__mulosi4(0x7FFFFFFF, 1, 0x7FFFFFFF, 0);
+ try test__mulosi4(1, 0x7FFFFFFF, 0x7FFFFFFF, 0);
+ try test__mulosi4(0x7FFFFFFF, 2, @bitCast(i32, @as(u32, 0x80000001)), 1);
+ try test__mulosi4(2, 0x7FFFFFFF, @bitCast(i32, @as(u32, 0x80000001)), 1);
+
+ try test__mulosi4(@bitCast(i32, @as(u32, 0x80000000)), -2, @bitCast(i32, @as(u32, 0x80000000)), 1);
+ try test__mulosi4(-2, @bitCast(i32, @as(u32, 0x80000000)), @bitCast(i32, @as(u32, 0x80000000)), 1);
+ try test__mulosi4(@bitCast(i32, @as(u32, 0x80000000)), -1, @bitCast(i32, @as(u32, 0x80000000)), 1);
+ try test__mulosi4(-1, @bitCast(i32, @as(u32, 0x80000000)), @bitCast(i32, @as(u32, 0x80000000)), 1);
+ try test__mulosi4(@bitCast(i32, @as(u32, 0x80000000)), 0, 0, 0);
+ try test__mulosi4(0, @bitCast(i32, @as(u32, 0x80000000)), 0, 0);
+ try test__mulosi4(@bitCast(i32, @as(u32, 0x80000000)), 1, @bitCast(i32, @as(u32, 0x80000000)), 0);
+ try test__mulosi4(1, @bitCast(i32, @as(u32, 0x80000000)), @bitCast(i32, @as(u32, 0x80000000)), 0);
+ try test__mulosi4(@bitCast(i32, @as(u32, 0x80000000)), 2, @bitCast(i32, @as(u32, 0x80000000)), 1);
+ try test__mulosi4(2, @bitCast(i32, @as(u32, 0x80000000)), @bitCast(i32, @as(u32, 0x80000000)), 1);
+
+ try test__mulosi4(@bitCast(i32, @as(u32, 0x80000001)), -2, @bitCast(i32, @as(u32, 0x80000001)), 1);
+ try test__mulosi4(-2, @bitCast(i32, @as(u32, 0x80000001)), @bitCast(i32, @as(u32, 0x80000001)), 1);
+ try test__mulosi4(@bitCast(i32, @as(u32, 0x80000001)), -1, 0x7FFFFFFF, 0);
+ try test__mulosi4(-1, @bitCast(i32, @as(u32, 0x80000001)), 0x7FFFFFFF, 0);
+ try test__mulosi4(@bitCast(i32, @as(u32, 0x80000001)), 0, 0, 0);
+ try test__mulosi4(0, @bitCast(i32, @as(u32, 0x80000001)), 0, 0);
+ try test__mulosi4(@bitCast(i32, @as(u32, 0x80000001)), 1, @bitCast(i32, @as(u32, 0x80000001)), 0);
+ try test__mulosi4(1, @bitCast(i32, @as(u32, 0x80000001)), @bitCast(i32, @as(u32, 0x80000001)), 0);
+ try test__mulosi4(@bitCast(i32, @as(u32, 0x80000001)), 2, @bitCast(i32, @as(u32, 0x80000000)), 1);
+ try test__mulosi4(2, @bitCast(i32, @as(u32, 0x80000001)), @bitCast(i32, @as(u32, 0x80000000)), 1);
+}
lib/std/special/compiler_rt/muloti4.zig
@@ -1,49 +0,0 @@
-const builtin = @import("builtin");
-const compiler_rt = @import("../compiler_rt.zig");
-
-pub fn __muloti4(a: i128, b: i128, overflow: *c_int) callconv(.C) i128 {
- @setRuntimeSafety(builtin.is_test);
-
- const min = @bitCast(i128, @as(u128, 1 << (128 - 1)));
- const max = ~min;
- overflow.* = 0;
-
- const r = a *% b;
- if (a == min) {
- if (b != 0 and b != 1) {
- overflow.* = 1;
- }
- return r;
- }
- if (b == min) {
- if (a != 0 and a != 1) {
- overflow.* = 1;
- }
- return r;
- }
-
- const sa = a >> (128 - 1);
- const abs_a = (a ^ sa) -% sa;
- const sb = b >> (128 - 1);
- const abs_b = (b ^ sb) -% sb;
-
- if (abs_a < 2 or abs_b < 2) {
- return r;
- }
-
- if (sa == sb) {
- if (abs_a > @divTrunc(max, abs_b)) {
- overflow.* = 1;
- }
- } else {
- if (abs_a > @divTrunc(min, -abs_b)) {
- overflow.* = 1;
- }
- }
-
- return r;
-}
-
-test {
- _ = @import("muloti4_test.zig");
-}
lib/std/special/compiler_rt/muloti4_test.zig
@@ -1,9 +1,11 @@
-const __muloti4 = @import("muloti4.zig").__muloti4;
+const mulo = @import("mulo.zig");
const testing = @import("std").testing;
+// ported from https://github.com/llvm-mirror/compiler-rt/tree/release_80/test/builtins/Unit
+
fn test__muloti4(a: i128, b: i128, expected: i128, expected_overflow: c_int) !void {
var overflow: c_int = undefined;
- const x = __muloti4(a, b, &overflow);
+ const x = mulo.__muloti4(a, b, &overflow);
try testing.expect(overflow == expected_overflow and (expected_overflow != 0 or x == expected));
}
@@ -13,7 +15,6 @@ test "muloti4" {
try test__muloti4(1, 0, 0, 0);
try test__muloti4(0, 10, 0, 0);
try test__muloti4(10, 0, 0, 0);
-
try test__muloti4(0, 81985529216486895, 0, 0);
try test__muloti4(81985529216486895, 0, 0, 0);
@@ -24,6 +25,18 @@ test "muloti4" {
try test__muloti4(0, -81985529216486895, 0, 0);
try test__muloti4(-81985529216486895, 0, 0, 0);
+ try test__muloti4(1, 1, 1, 0);
+ try test__muloti4(1, 10, 10, 0);
+ try test__muloti4(10, 1, 10, 0);
+ try test__muloti4(1, 81985529216486895, 81985529216486895, 0);
+ try test__muloti4(81985529216486895, 1, 81985529216486895, 0);
+
+ try test__muloti4(1, -1, -1, 0);
+ try test__muloti4(1, -10, -10, 0);
+ try test__muloti4(-10, 1, -10, 0);
+ try test__muloti4(1, -81985529216486895, -81985529216486895, 0);
+ try test__muloti4(-81985529216486895, 1, -81985529216486895, 0);
+
try test__muloti4(3037000499, 3037000499, 9223372030926249001, 0);
try test__muloti4(-3037000499, 3037000499, -9223372030926249001, 0);
try test__muloti4(3037000499, -3037000499, -9223372030926249001, 0);
lib/std/special/compiler_rt.zig
@@ -77,9 +77,11 @@ comptime {
@export(__extendhfsf2, .{ .name = "__gnu_h2f_ieee", .linkage = linkage });
// Integral arithmetic which returns if overflow
- const __mulodi4 = @import("compiler_rt/mulodi4.zig").__mulodi4;
+ const __mulosi4 = @import("compiler_rt/mulo.zig").__mulosi4;
+ @export(__mulosi4, .{ .name = "__mulosi4", .linkage = linkage });
+ const __mulodi4 = @import("compiler_rt/mulo.zig").__mulodi4;
@export(__mulodi4, .{ .name = "__mulodi4", .linkage = linkage });
- const __muloti4 = @import("compiler_rt/muloti4.zig").__muloti4;
+ const __muloti4 = @import("compiler_rt/mulo.zig").__muloti4;
@export(__muloti4, .{ .name = "__muloti4", .linkage = linkage });
}
CMakeLists.txt
@@ -494,8 +494,7 @@ set(ZIG_STAGE2_SOURCES
"${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/modti3.zig"
"${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/mulXf3.zig"
"${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/muldi3.zig"
- "${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/mulodi4.zig"
- "${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/muloti4.zig"
+ "${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/mulo.zig"
"${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/multi3.zig"
"${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/negXf2.zig"
"${CMAKE_SOURCE_DIR}/lib/std/special/compiler_rt/negXi2.zig"