Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 213 insertions, 0 deletions

diff --git a/vendor/compiler_builtins/src/float/add.rs b/vendor/compiler_builtins/src/float/add.rs
new file mode 100644
index 000000000..67f6c2c14
--- /dev/null
+++ b/vendor/compiler_builtins/src/float/add.rs
@@ -0,0 +1,213 @@
+use float::Float;
+use int::{CastInto, Int};
+
+/// Returns `a + b`
+fn add<F: Float>(a: F, b: F) -> F
+where
+    u32: CastInto<F::Int>,
+    F::Int: CastInto<u32>,
+    i32: CastInto<F::Int>,
+    F::Int: CastInto<i32>,
+{
+    let one = F::Int::ONE;
+    let zero = F::Int::ZERO;
+
+    let bits = F::BITS.cast();
+    let significand_bits = F::SIGNIFICAND_BITS;
+    let max_exponent = F::EXPONENT_MAX;
+
+    let implicit_bit = F::IMPLICIT_BIT;
+    let significand_mask = F::SIGNIFICAND_MASK;
+    let sign_bit = F::SIGN_MASK as F::Int;
+    let abs_mask = sign_bit - one;
+    let exponent_mask = F::EXPONENT_MASK;
+    let inf_rep = exponent_mask;
+    let quiet_bit = implicit_bit >> 1;
+    let qnan_rep = exponent_mask | quiet_bit;
+
+    let mut a_rep = a.repr();
+    let mut b_rep = b.repr();
+    let a_abs = a_rep & abs_mask;
+    let b_abs = b_rep & abs_mask;
+
+    // Detect if a or b is zero, infinity, or NaN.
+    if a_abs.wrapping_sub(one) >= inf_rep - one || b_abs.wrapping_sub(one) >= inf_rep - one {
+        // NaN + anything = qNaN
+        if a_abs > inf_rep {
+            return F::from_repr(a_abs | quiet_bit);
+        }
+        // anything + NaN = qNaN
+        if b_abs > inf_rep {
+            return F::from_repr(b_abs | quiet_bit);
+        }
+
+        if a_abs == inf_rep {
+            // +/-infinity + -/+infinity = qNaN
+            if (a.repr() ^ b.repr()) == sign_bit {
+                return F::from_repr(qnan_rep);
+            } else {
+                // +/-infinity + anything remaining = +/- infinity
+                return a;
+            }
+        }
+
+        // anything remaining + +/-infinity = +/-infinity
+        if b_abs == inf_rep {
+            return b;
+        }
+
+        // zero + anything = anything
+        if a_abs == Int::ZERO {
+            // but we need to get the sign right for zero + zero
+            if b_abs == Int::ZERO {
+                return F::from_repr(a.repr() & b.repr());
+            } else {
+                return b;
+            }
+        }
+
+        // anything + zero = anything
+        if b_abs == Int::ZERO {
+            return a;
+        }
+    }
+
+    // Swap a and b if necessary so that a has the larger absolute value.
+    if b_abs > a_abs {
+        // Don't use mem::swap because it may generate references to memcpy in unoptimized code.
+        let tmp = a_rep;
+        a_rep = b_rep;
+        b_rep = tmp;
+    }
+
+    // Extract the exponent and significand from the (possibly swapped) a and b.
+    let mut a_exponent: i32 = ((a_rep & exponent_mask) >> significand_bits).cast();
+    let mut b_exponent: i32 = ((b_rep & exponent_mask) >> significand_bits).cast();
+    let mut a_significand = a_rep & significand_mask;
+    let mut b_significand = b_rep & significand_mask;
+
+    // normalize any denormals, and adjust the exponent accordingly.
+    if a_exponent == 0 {
+        let (exponent, significand) = F::normalize(a_significand);
+        a_exponent = exponent;
+        a_significand = significand;
+    }
+    if b_exponent == 0 {
+        let (exponent, significand) = F::normalize(b_significand);
+        b_exponent = exponent;
+        b_significand = significand;
+    }
+
+    // The sign of the result is the sign of the larger operand, a.  If they
+    // have opposite signs, we are performing a subtraction; otherwise addition.
+    let result_sign = a_rep & sign_bit;
+    let subtraction = ((a_rep ^ b_rep) & sign_bit) != zero;
+
+    // Shift the significands to give us round, guard and sticky, and 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.)
+    a_significand = (a_significand | implicit_bit) << 3;
+    b_significand = (b_significand | implicit_bit) << 3;
+
+    // Shift the significand of b by the difference in exponents, with a sticky
+    // bottom bit to get rounding correct.
+    let align = a_exponent.wrapping_sub(b_exponent).cast();
+    if align != Int::ZERO {
+        if align < bits {
+            let sticky =
+                F::Int::from_bool(b_significand << bits.wrapping_sub(align).cast() != Int::ZERO);
+            b_significand = (b_significand >> align.cast()) | sticky;
+        } else {
+            b_significand = one; // sticky; b is known to be non-zero.
+        }
+    }
+    if subtraction {
+        a_significand = a_significand.wrapping_sub(b_significand);
+        // If a == -b, return +zero.
+        if a_significand == Int::ZERO {
+            return F::from_repr(Int::ZERO);
+        }
+
+        // If partial cancellation occured, we need to left-shift the result
+        // and adjust the exponent:
+        if a_significand < implicit_bit << 3 {
+            let shift =
+                a_significand.leading_zeros() as i32 - (implicit_bit << 3).leading_zeros() as i32;
+            a_significand <<= shift;
+            a_exponent -= shift;
+        }
+    } else {
+        // addition
+        a_significand += b_significand;
+
+        // If the addition carried up, we need to right-shift the result and
+        // adjust the exponent:
+        if a_significand & implicit_bit << 4 != Int::ZERO {
+            let sticky = F::Int::from_bool(a_significand & one != Int::ZERO);
+            a_significand = a_significand >> 1 | sticky;
+            a_exponent += 1;
+        }
+    }
+
+    // If we have overflowed the type, return +/- infinity:
+    if a_exponent >= max_exponent as i32 {
+        return F::from_repr(inf_rep | result_sign);
+    }
+
+    if a_exponent <= 0 {
+        // Result is denormal before rounding; the exponent is zero and we
+        // need to shift the significand.
+        let shift = (1 - a_exponent).cast();
+        let sticky =
+            F::Int::from_bool((a_significand << bits.wrapping_sub(shift).cast()) != Int::ZERO);
+        a_significand = a_significand >> shift.cast() | sticky;
+        a_exponent = 0;
+    }
+
+    // Low three bits are round, guard, and sticky.
+    let a_significand_i32: i32 = a_significand.cast();
+    let round_guard_sticky: i32 = a_significand_i32 & 0x7;
+
+    // Shift the significand into place, and mask off the implicit bit.
+    let mut result = a_significand >> 3 & significand_mask;
+
+    // Insert the exponent and sign.
+    result |= a_exponent.cast() << significand_bits;
+    result |= result_sign;
+
+    // Final rounding.  The result may overflow to infinity, but that is the
+    // correct result in that case.
+    if round_guard_sticky > 0x4 {
+        result += one;
+    }
+    if round_guard_sticky == 0x4 {
+        result += result & one;
+    }
+
+    F::from_repr(result)
+}
+
+intrinsics! {
+    #[aapcs_on_arm]
+    #[arm_aeabi_alias = __aeabi_fadd]
+    pub extern "C" fn __addsf3(a: f32, b: f32) -> f32 {
+        add(a, b)
+    }
+
+    #[aapcs_on_arm]
+    #[arm_aeabi_alias = __aeabi_dadd]
+    pub extern "C" fn __adddf3(a: f64, b: f64) -> f64 {
+        add(a, b)
+    }
+
+    #[cfg(target_arch = "arm")]
+    pub extern "C" fn __addsf3vfp(a: f32, b: f32) -> f32 {
+        a + b
+    }
+
+    #[cfg(target_arch = "arm")]
+    pub extern "C" fn __adddf3vfp(a: f64, b: f64) -> f64 {
+        a + b
+    }
+}