compiler-rt: math functions reorg

 * unify the logic for exporting math functions from compiler-rt,
   with the appropriate suffixes and prefixes.
   - add all missing f128 and f80 exports. Functions with missing
     implementations call other functions and have TODO comments.
   - also add f16 functions
 * move math functions from freestanding libc to compiler-rt (#7265)
 * enable all the f128 and f80 code in the stage2 compiler and behavior
   tests (#11161).
 * update std lib to use builtins rather than `std.math`.

1 files changed, 0 insertions, 108 deletions

diff --git a/lib/std/special/compiler_rt/fmodx.zig b/lib/std/special/compiler_rt/fmodx.zig
deleted file mode 100644
index efe16f9f16..0000000000
--- a/lib/std/special/compiler_rt/fmodx.zig
+++ /dev/null
@@ -1,108 +0,0 @@
-const builtin = @import("builtin");
-const std = @import("std");
-const math = std.math;
-const normalize = @import("divdf3.zig").normalize;
-
-// fmodx - floating modulo large, returns the remainder of division for f80 types
-// Logic and flow heavily inspired by MUSL fmodl for 113 mantissa digits
-pub fn fmodx(a: f80, b: f80) callconv(.C) f80 {
-    @setRuntimeSafety(builtin.is_test);
-
-    const T = f80;
-    const Z = std.meta.Int(.unsigned, @bitSizeOf(T));
-
-    const significandBits = math.floatMantissaBits(T);
-    const fractionalBits = math.floatFractionalBits(T);
-    const exponentBits = math.floatExponentBits(T);
-
-    const signBit = (@as(Z, 1) << (significandBits + exponentBits));
-    const maxExponent = ((1 << exponentBits) - 1);
-
-    var aRep = @bitCast(Z, a);
-    var bRep = @bitCast(Z, b);
-
-    const signA = aRep & signBit;
-    var expA = @intCast(i32, (@bitCast(Z, a) >> significandBits) & maxExponent);
-    var expB = @intCast(i32, (@bitCast(Z, b) >> significandBits) & maxExponent);
-
-    // There are 3 cases where the answer is undefined, check for:
-    //   - fmodx(val, 0)
-    //   - fmodx(val, NaN)
-    //   - fmodx(inf, val)
-    // The sign on checked values does not matter.
-    // Doing (a * b) / (a * b) procudes undefined results
-    // because the three cases always produce undefined calculations:
-    //   - 0 / 0
-    //   - val * NaN
-    //   - inf / inf
-    if (b == 0 or math.isNan(b) or expA == maxExponent) {
-        return (a * b) / (a * b);
-    }
-
-    // Remove the sign from both
-    aRep &= ~signBit;
-    bRep &= ~signBit;
-    if (aRep <= bRep) {
-        if (aRep == bRep) {
-            return 0 * a;
-        }
-        return a;
-    }
-
-    if (expA == 0) expA = normalize(f80, &aRep);
-    if (expB == 0) expB = normalize(f80, &bRep);
-
-    var highA: u64 = 0;
-    var highB: u64 = 0;
-    var lowA: u64 = @truncate(u64, aRep);
-    var lowB: u64 = @truncate(u64, bRep);
-
-    while (expA > expB) : (expA -= 1) {
-        var high = highA -% highB;
-        var low = lowA -% lowB;
-        if (lowA < lowB) {
-            high -%= 1;
-        }
-        if (high >> 63 == 0) {
-            if ((high | low) == 0) {
-                return 0 * a;
-            }
-            highA = 2 *% high + (low >> 63);
-            lowA = 2 *% low;
-        } else {
-            highA = 2 *% highA + (lowA >> 63);
-            lowA = 2 *% lowA;
-        }
-    }
-
-    var high = highA -% highB;
-    var low = lowA -% lowB;
-    if (lowA < lowB) {
-        high -%= 1;
-    }
-    if (high >> 63 == 0) {
-        if ((high | low) == 0) {
-            return 0 * a;
-        }
-        highA = high;
-        lowA = low;
-    }
-
-    while ((lowA >> fractionalBits) == 0) {
-        lowA = 2 *% lowA;
-        expA = expA - 1;
-    }
-
-    // Combine the exponent with the sign and significand, normalize if happened to be denormalized
-    if (expA < -fractionalBits) {
-        return @bitCast(T, signA);
-    } else if (expA <= 0) {
-        return @bitCast(T, (lowA >> @intCast(math.Log2Int(u64), 1 - expA)) | signA);
-    } else {
-        return @bitCast(T, lowA | (@as(Z, @intCast(u16, expA)) << significandBits) | signA);
-    }
-}
-
-test {
-    _ = @import("fmodx_test.zig");
-}