}
static nir_ssa_def *
+build_frexp16(nir_builder *b, nir_ssa_def *x, nir_ssa_def **exponent)
+{
+ assert(x->bit_size == 16);
+
+ nir_ssa_def *abs_x = nir_fabs(b, x);
+ nir_ssa_def *zero = nir_imm_floatN_t(b, 0, 16);
+
+ /* Half-precision floating-point values are stored as
+ * 1 sign bit;
+ * 5 exponent bits;
+ * 10 mantissa bits.
+ *
+ * An exponent shift of 10 will shift the mantissa out, leaving only the
+ * exponent and sign bit (which itself may be zero, if the absolute value
+ * was taken before the bitcast and shift).
+ */
+ nir_ssa_def *exponent_shift = nir_imm_int(b, 10);
+ nir_ssa_def *exponent_bias = nir_imm_intN_t(b, -14, 16);
+
+ nir_ssa_def *sign_mantissa_mask = nir_imm_intN_t(b, 0x83ffu, 16);
+
+ /* Exponent of floating-point values in the range [0.5, 1.0). */
+ nir_ssa_def *exponent_value = nir_imm_intN_t(b, 0x3800u, 16);
+
+ nir_ssa_def *is_not_zero = nir_fne(b, abs_x, zero);
+
+ /* Significand return must be of the same type as the input, but the
+ * exponent must be a 32-bit integer.
+ */
+ *exponent =
+ nir_i2i32(b,
+ nir_iadd(b, nir_ushr(b, abs_x, exponent_shift),
+ nir_bcsel(b, is_not_zero, exponent_bias, zero)));
+
+ return nir_ior(b, nir_iand(b, x, sign_mantissa_mask),
+ nir_bcsel(b, is_not_zero, exponent_value, zero));
+}
+
+static nir_ssa_def *
build_frexp32(nir_builder *b, nir_ssa_def *x, nir_ssa_def **exponent)
{
nir_ssa_def *abs_x = nir_fabs(b, x);
nir_ssa_def *exponent;
if (src[0]->bit_size == 64)
val->ssa->def = build_frexp64(nb, src[0], &exponent);
- else
+ else if (src[0]->bit_size == 32)
val->ssa->def = build_frexp32(nb, src[0], &exponent);
+ else
+ val->ssa->def = build_frexp16(nb, src[0], &exponent);
nir_store_deref(nb, vtn_nir_deref(b, w[6]), exponent, 0xf);
return;
}
if (src[0]->bit_size == 64)
val->ssa->elems[0]->def = build_frexp64(nb, src[0],
&val->ssa->elems[1]->def);
- else
+ else if (src[0]->bit_size == 32)
val->ssa->elems[0]->def = build_frexp32(nb, src[0],
&val->ssa->elems[1]->def);
+ else
+ val->ssa->elems[0]->def = build_frexp16(nb, src[0],
+ &val->ssa->elems[1]->def);
return;
}