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compiler-rt: Add __moddi3, __divdi3

master
LemonBoy 2019-05-03 09:41:46 +02:00 committed by Andrew Kelley
parent 584dd2863a
commit 1be4e87f0b
1 changed files with 81 additions and 0 deletions
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81
std/special/compiler_rt.zig
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@ -103,8 +103,10 @@ comptime {
@export("__popcountdi2", @import("compiler_rt/popcountdi2.zig").__popcountdi2, linkage);
@export("__divsi3", __divsi3, linkage);
@export("__divdi3", __divdi3, linkage);
@export("__udivsi3", __udivsi3, linkage);
@export("__udivdi3", __udivdi3, linkage);
@export("__moddi3", __moddi3, linkage);
@export("__umoddi3", __umoddi3, linkage);
@export("__divmodsi4", __divmodsi4, linkage);
@export("__udivmodsi4", __udivmodsi4, linkage);
@ -241,6 +243,33 @@ pub fn panic(msg: []const u8, error_return_trace: ?*builtin.StackTrace) noreturn
}
}
extern fn __divdi3(a: i64, b: i64) i64 {
@setRuntimeSafety(is_test);
// Set aside the sign of the quotient.
const sign = @bitCast(u64, (a ^ b) >> 63);
// 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);
// Unsigned division
const res = __udivmoddi4(@bitCast(u64, abs_a), @bitCast(u64, abs_b), null);
// Apply sign of quotient to result and return.
return @bitCast(i64, (res ^ sign) -% sign);
}
extern fn __moddi3(a: i64, b: i64) i64 {
@setRuntimeSafety(is_test);
// 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);
// Unsigned division
var r: u64 = undefined;
_ = __udivmoddi4(@bitCast(u64, abs_a), @bitCast(u64, abs_b), &r);
// Apply the sign of the dividend and return.
return (@bitCast(i64, r) ^ (a >> 63)) -% (a >> 63);
}
extern fn __udivdi3(a: u64, b: u64) u64 {
@setRuntimeSafety(is_test);
return __udivmoddi4(a, b, null);
@ -1374,3 +1403,55 @@ fn test_one_divmodsi4(a: i32, b: i32, expected_q: i32, expected_r: i32) void {
const q: i32 = __divmodsi4(a, b, &r);
testing.expect(q == expected_q and r == expected_r);
}
test "test_divdi3" {
const cases = [][3]i64{
[]i64{ 0, 1, 0},
[]i64{ 0, -1, 0},
[]i64{ 2, 1, 2},
[]i64{ 2, -1, -2},
[]i64{-2, 1, -2},
[]i64{-2, -1, 2},
[]i64{@bitCast(i64, u64(0x8000000000000000)), 1, @bitCast(i64, u64(0x8000000000000000))},
[]i64{@bitCast(i64, u64(0x8000000000000000)), -1, @bitCast(i64, u64(0x8000000000000000))},
[]i64{@bitCast(i64, u64(0x8000000000000000)), -2, 0x4000000000000000},
[]i64{@bitCast(i64, u64(0x8000000000000000)), 2, @bitCast(i64, u64(0xC000000000000000))},
};
for (cases) |case| {
test_one_divdi3(case[0], case[1], case[2]);
}
}
fn test_one_divdi3(a: i64, b: i64, expected_q: i64) void {
const q: i64 = __divdi3(a, b);
testing.expect(q == expected_q);
}
test "test_moddi3" {
const cases = [][3]i64{
[]i64{0, 1, 0},
[]i64{0, -1, 0},
[]i64{5, 3, 2},
[]i64{5, -3, 2},
[]i64{-5, 3, -2},
[]i64{-5, -3, -2},
[]i64{@bitCast(i64, @intCast(u64, 0x8000000000000000)), 1, 0},
[]i64{@bitCast(i64, @intCast(u64, 0x8000000000000000)), -1, 0},
[]i64{@bitCast(i64, @intCast(u64, 0x8000000000000000)), 2, 0},
[]i64{@bitCast(i64, @intCast(u64, 0x8000000000000000)), -2, 0},
[]i64{@bitCast(i64, @intCast(u64, 0x8000000000000000)), 3, -2},
[]i64{@bitCast(i64, @intCast(u64, 0x8000000000000000)), -3, -2},
};
for (cases) |case| {
test_one_moddi3(case[0], case[1], case[2]);
}
}
fn test_one_moddi3(a: i64, b: i64, expected_r: i64) void {
const r: i64 = __moddi3(a, b);
testing.expect(r == expected_r);
}