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Add __aeabi_{f,d}{add,sub} and __{add,sub}{s,d}f3 to compiler-rt

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vegecode 2019-03-22 22:47:38 -05:00
parent 310f91fb4f
commit 38c2093500
2 changed files with 35 additions and 6 deletions
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9
std/special/compiler_rt.zig
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@ -21,7 +21,11 @@ comptime {
@export("__unordtf2", @import("compiler_rt/comparetf2.zig").__unordtf2, linkage);
@export("__addsf3", @import("compiler_rt/addXf3.zig").__addsf3, linkage);
@export("__adddf3", @import("compiler_rt/addXf3.zig").__adddf3, linkage);
@export("__addtf3", @import("compiler_rt/addXf3.zig").__addtf3, linkage);
@export("__subsf3", @import("compiler_rt/addXf3.zig").__subsf3, linkage);
@export("__subdf3", @import("compiler_rt/addXf3.zig").__subdf3, linkage);
@export("__subtf3", @import("compiler_rt/addXf3.zig").__subtf3, linkage);
@export("__mulsf3", @import("compiler_rt/mulXf3.zig").__mulsf3, linkage);
@ -102,6 +106,11 @@ comptime {
@export("__aeabi_memcmp", __aeabi_memcmp, linkage);
@export("__aeabi_memcmp4", __aeabi_memcmp, linkage);
@export("__aeabi_memcmp8", __aeabi_memcmp, linkage);
@export("__aeabi_fadd", @import("compiler_rt/addXf3.zig").__addsf3, linkage);
@export("__aeabi_dadd", @import("compiler_rt/addXf3.zig").__adddf3, linkage);
@export("__aeabi_fsub", @import("compiler_rt/addXf3.zig").__subsf3, linkage);
@export("__aeabi_dsub", @import("compiler_rt/addXf3.zig").__subdf3, linkage);
}
if (builtin.os == builtin.Os.windows) {
switch (builtin.arch) {

32
std/special/compiler_rt/addXf3.zig
View File

@ -6,10 +6,28 @@ const std = @import("std");
const builtin = @import("builtin");
const compiler_rt = @import("../compiler_rt.zig");
pub extern fn __addsf3(a: f32, b: f32) f32 {
return addXf3(f32, a, b);
}
pub extern fn __adddf3(a: f64, b: f64) f64 {
return addXf3(f64, a, b);
}
pub extern fn __addtf3(a: f128, b: f128) f128 {
return addXf3(f128, a, b);
}
pub extern fn __subsf3(a: f32, b: f32) f32 {
const neg_b = @bitCast(f32, @bitCast(u32, b) ^ (u32(1) << 31));
return addXf3(f32, a, neg_b);
}
pub extern fn __subdf3(a: f64, b: f64) f64 {
const neg_b = @bitCast(f64, @bitCast(u64, b) ^ (u64(1) << 63));
return addXf3(f64, a, neg_b);
}
pub extern fn __subtf3(a: f128, b: f128) f128 {
const neg_b = @bitCast(f128, @bitCast(u128, b) ^ (u128(1) << 127));
return addXf3(f128, a, neg_b);
@ -17,16 +35,18 @@ pub extern fn __subtf3(a: f128, b: f128) f128 {
inline fn normalize(comptime T: type, significand: *@IntType(false, T.bit_count)) i32 {
const Z = @IntType(false, T.bit_count);
const S = @IntType(false, T.bit_count - @clz(Z(T.bit_count) - 1));
const significandBits = std.math.floatMantissaBits(T);
const implicitBit = Z(1) << significandBits;
const shift = @clz(significand.*) - @clz(implicitBit);
significand.* <<= @intCast(u7, shift);
significand.* <<= @intCast(S, shift);
return 1 - shift;
}
inline fn addXf3(comptime T: type, a: T, b: T) T {
const Z = @IntType(false, T.bit_count);
const S = @IntType(false, T.bit_count - @clz(Z(T.bit_count) - 1));
const typeWidth = T.bit_count;
const significandBits = std.math.floatMantissaBits(T);
@ -126,8 +146,8 @@ inline fn addXf3(comptime T: type, a: T, b: T) T {
const @"align" = @intCast(Z, aExponent - bExponent);
if (@"align" != 0) {
if (@"align" < typeWidth) {
const sticky = if (bSignificand << @intCast(u7, typeWidth - @"align") != 0) Z(1) else 0;
bSignificand = (bSignificand >> @truncate(u7, @"align")) | sticky;
const sticky = if (bSignificand << @intCast(S, typeWidth - @"align") != 0) Z(1) else 0;
bSignificand = (bSignificand >> @truncate(S, @"align")) | sticky;
} else {
bSignificand = 1; // sticky; b is known to be non-zero.
}
@ -141,7 +161,7 @@ inline fn addXf3(comptime T: type, a: T, b: T) T {
// and adjust the exponent:
if (aSignificand < implicitBit << 3) {
const shift = @intCast(i32, @clz(aSignificand)) - @intCast(i32, @clz(implicitBit << 3));
aSignificand <<= @intCast(u7, shift);
aSignificand <<= @intCast(S, shift);
aExponent -= shift;
}
} else { // addition
@ -163,8 +183,8 @@ inline fn addXf3(comptime T: type, a: T, b: T) T {
// Result is denormal before rounding; the exponent is zero and we
// need to shift the significand.
const shift = @intCast(Z, 1 - aExponent);
const sticky = if (aSignificand << @intCast(u7, typeWidth - shift) != 0) Z(1) else 0;
aSignificand = aSignificand >> @intCast(u7, shift | sticky);
const sticky = if (aSignificand << @intCast(S, typeWidth - shift) != 0) Z(1) else 0;
aSignificand = aSignificand >> @intCast(S, shift | sticky);
aExponent = 0;
}