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diff --git a/lib/std/special/compiler_rt/divsf3.zig b/lib/std/special/compiler_rt/divsf3.zig
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+++ b/lib/std/special/compiler_rt/divsf3.zig
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+// Ported from:
+//
+// https://github.com/llvm/llvm-project/commit/d674d96bc56c0f377879d01c9d8dfdaaa7859cdb/compiler-rt/lib/builtins/divsf3.c
+
+const std = @import("std");
+const builtin = @import("builtin");
+
+pub extern fn __divsf3(a: f32, b: f32) f32 {
+    @setRuntimeSafety(builtin.is_test);
+    const Z = @IntType(false, f32.bit_count);
+
+    const typeWidth = f32.bit_count;
+    const significandBits = std.math.floatMantissaBits(f32);
+    const exponentBits = std.math.floatExponentBits(f32);
+
+    const signBit = (Z(1) << (significandBits + exponentBits));
+    const maxExponent = ((1 << exponentBits) - 1);
+    const exponentBias = (maxExponent >> 1);
+
+    const implicitBit = (Z(1) << significandBits);
+    const quietBit = implicitBit >> 1;
+    const significandMask = implicitBit - 1;
+
+    const absMask = signBit - 1;
+    const exponentMask = absMask ^ significandMask;
+    const qnanRep = exponentMask | quietBit;
+    const infRep = @bitCast(Z, std.math.inf(f32));
+
+    const aExponent = @truncate(u32, (@bitCast(Z, a) >> significandBits) & maxExponent);
+    const bExponent = @truncate(u32, (@bitCast(Z, b) >> significandBits) & maxExponent);
+    const quotientSign: Z = (@bitCast(Z, a) ^ @bitCast(Z, b)) & signBit;
+
+    var aSignificand: Z = @bitCast(Z, a) & significandMask;
+    var bSignificand: Z = @bitCast(Z, b) & significandMask;
+    var scale: i32 = 0;
+
+    // Detect if a or b is zero, denormal, infinity, or NaN.
+    if (aExponent -% 1 >= maxExponent -% 1 or bExponent -% 1 >= maxExponent -% 1) {
+        const aAbs: Z = @bitCast(Z, a) & absMask;
+        const bAbs: Z = @bitCast(Z, b) & absMask;
+
+        // NaN / anything = qNaN
+        if (aAbs > infRep) return @bitCast(f32, @bitCast(Z, a) | quietBit);
+        // anything / NaN = qNaN
+        if (bAbs > infRep) return @bitCast(f32, @bitCast(Z, b) | quietBit);
+
+        if (aAbs == infRep) {
+            // infinity / infinity = NaN
+            if (bAbs == infRep) {
+                return @bitCast(f32, qnanRep);
+            }
+            // infinity / anything else = +/- infinity
+            else {
+                return @bitCast(f32, aAbs | quotientSign);
+            }
+        }
+
+        // anything else / infinity = +/- 0
+        if (bAbs == infRep) return @bitCast(f32, quotientSign);
+
+        if (aAbs == 0) {
+            // zero / zero = NaN
+            if (bAbs == 0) {
+                return @bitCast(f32, qnanRep);
+            }
+            // zero / anything else = +/- zero
+            else {
+                return @bitCast(f32, quotientSign);
+            }
+        }
+        // anything else / zero = +/- infinity
+        if (bAbs == 0) return @bitCast(f32, infRep | quotientSign);
+
+        // one or both of a or b is denormal, the other (if applicable) is a
+        // normal number.  Renormalize one or both of a and b, and set scale to
+        // include the necessary exponent adjustment.
+        if (aAbs < implicitBit) scale +%= normalize(f32, &aSignificand);
+        if (bAbs < implicitBit) scale -%= normalize(f32, &bSignificand);
+    }
+
+    // Or in the implicit significand bit.  (If we fell through from the
+    // denormal path it was already set by normalize( ), but setting it twice
+    // won't hurt anything.)
+    aSignificand |= implicitBit;
+    bSignificand |= implicitBit;
+    var quotientExponent: i32 = @bitCast(i32, aExponent -% bExponent) +% scale;
+
+    // Align the significand of b as a Q31 fixed-point number in the range
+    // [1, 2.0) and get a Q32 approximate reciprocal using a small minimax
+    // polynomial approximation: reciprocal = 3/4 + 1/sqrt(2) - b/2.  This
+    // is accurate to about 3.5 binary digits.
+    const q31b = bSignificand << 8;
+    var reciprocal = u32(0x7504f333) -% q31b;
+
+    // Now refine the reciprocal estimate using a Newton-Raphson iteration:
+    //
+    //     x1 = x0 * (2 - x0 * b)
+    //
+    // This doubles the number of correct binary digits in the approximation
+    // with each iteration, so after three iterations, we have about 28 binary
+    // digits of accuracy.
+    var correction: u32 = undefined;
+    correction = @truncate(u32, ~(u64(reciprocal) *% q31b >> 32) +% 1);
+    reciprocal = @truncate(u32, u64(reciprocal) *% correction >> 31);
+    correction = @truncate(u32, ~(u64(reciprocal) *% q31b >> 32) +% 1);
+    reciprocal = @truncate(u32, u64(reciprocal) *% correction >> 31);
+    correction = @truncate(u32, ~(u64(reciprocal) *% q31b >> 32) +% 1);
+    reciprocal = @truncate(u32, u64(reciprocal) *% correction >> 31);
+
+    // Exhaustive testing shows that the error in reciprocal after three steps
+    // is in the interval [-0x1.f58108p-31, 0x1.d0e48cp-29], in line with our
+    // expectations.  We bump the reciprocal by a tiny value to force the error
+    // to be strictly positive (in the range [0x1.4fdfp-37,0x1.287246p-29], to
+    // be specific).  This also causes 1/1 to give a sensible approximation
+    // instead of zero (due to overflow).
+    reciprocal -%= 2;
+
+    // The numerical reciprocal is accurate to within 2^-28, lies in the
+    // interval [0x1.000000eep-1, 0x1.fffffffcp-1], and is strictly smaller
+    // than the true reciprocal of b.  Multiplying a by this reciprocal thus
+    // gives a numerical q = a/b in Q24 with the following properties:
+    //
+    //    1. q < a/b
+    //    2. q is in the interval [0x1.000000eep-1, 0x1.fffffffcp0)
+    //    3. the error in q is at most 2^-24 + 2^-27 -- the 2^24 term comes
+    //       from the fact that we truncate the product, and the 2^27 term
+    //       is the error in the reciprocal of b scaled by the maximum
+    //       possible value of a.  As a consequence of this error bound,
+    //       either q or nextafter(q) is the correctly rounded
+    var quotient: Z = @truncate(u32, u64(reciprocal) *% (aSignificand << 1) >> 32);
+
+    // Two cases: quotient is in [0.5, 1.0) or quotient is in [1.0, 2.0).
+    // In either case, we are going to compute a residual of the form
+    //
+    //     r = a - q*b
+    //
+    // We know from the construction of q that r satisfies:
+    //
+    //     0 <= r < ulp(q)*b
+    //
+    // if r is greater than 1/2 ulp(q)*b, then q rounds up.  Otherwise, we
+    // already have the correct result.  The exact halfway case cannot occur.
+    // We also take this time to right shift quotient if it falls in the [1,2)
+    // range and adjust the exponent accordingly.
+    var residual: Z = undefined;
+    if (quotient < (implicitBit << 1)) {
+        residual = (aSignificand << 24) -% quotient *% bSignificand;
+        quotientExponent -%= 1;
+    } else {
+        quotient >>= 1;
+        residual = (aSignificand << 23) -% quotient *% bSignificand;
+    }
+
+    const writtenExponent = quotientExponent +% exponentBias;
+
+    if (writtenExponent >= maxExponent) {
+        // If we have overflowed the exponent, return infinity.
+        return @bitCast(f32, infRep | quotientSign);
+    } else if (writtenExponent < 1) {
+        if (writtenExponent == 0) {
+            // Check whether the rounded result is normal.
+            const round = @boolToInt((residual << 1) > bSignificand);
+            // Clear the implicit bit.
+            var absResult = quotient & significandMask;
+            // Round.
+            absResult += round;
+            if ((absResult & ~significandMask) > 0) {
+                // The rounded result is normal; return it.
+                return @bitCast(f32, absResult | quotientSign);
+            }
+        }
+        // Flush denormals to zero.  In the future, it would be nice to add
+        // code to round them correctly.
+        return @bitCast(f32, quotientSign);
+    } else {
+        const round = @boolToInt((residual << 1) > bSignificand);
+        // Clear the implicit bit
+        var absResult = quotient & significandMask;
+        // Insert the exponent
+        absResult |= @bitCast(Z, writtenExponent) << significandBits;
+        // Round
+        absResult +%= round;
+        // Insert the sign and return
+        return @bitCast(f32, absResult | quotientSign);
+    }
+}
+
+fn normalize(comptime T: type, significand: *@IntType(false, T.bit_count)) i32 {
+    @setRuntimeSafety(builtin.is_test);
+    const Z = @IntType(false, T.bit_count);
+    const significandBits = std.math.floatMantissaBits(T);
+    const implicitBit = Z(1) << significandBits;
+
+    const shift = @clz(Z, significand.*) - @clz(Z, implicitBit);
+    significand.* <<= @intCast(std.math.Log2Int(Z), shift);
+    return 1 - shift;
+}
+
+test "import divsf3" {
+    _ = @import("divsf3_test.zig");
+}