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authorElie Tournier <[email protected]>2017-08-08 15:39:58 +0100
committerMatt Turner <[email protected]>2019-01-09 16:42:40 -0800
commitf111d72596c4071ad38a2062699f17702bbd9c6d (patch)
tree8e4802bdc8210b0993d8598588cea694e902ea86 /src/compiler/glsl/float64.glsl
parentc036fc97a21d6bf1f7a6ffec9932fb8a79ac262c (diff)
glsl: Add "built-in" functions to do add(fp64, fp64)
v2: use mix and findMSB to optimise. v3: [Sagar] Fix zFrac0 == 0u case in __normalizeRoundAndPackFloat64 Signed-off-by: Elie Tournier <[email protected]>
Diffstat (limited to 'src/compiler/glsl/float64.glsl')
-rw-r--r--src/compiler/glsl/float64.glsl433
1 files changed, 433 insertions, 0 deletions
diff --git a/src/compiler/glsl/float64.glsl b/src/compiler/glsl/float64.glsl
index a2642e9b34e..858e2f3b87d 100644
--- a/src/compiler/glsl/float64.glsl
+++ b/src/compiler/glsl/float64.glsl
@@ -44,6 +44,7 @@
#extension GL_ARB_gpu_shader_int64 : enable
#extension GL_ARB_shader_bit_encoding : enable
#extension GL_EXT_shader_integer_mix : enable
+#extension GL_MESA_shader_integer_functions : enable
#pragma warning(off)
@@ -216,3 +217,435 @@ __fge64(uint64_t a, uint64_t b)
return !__flt64_nonnan(a, b);
}
+
+/* Adds the 64-bit value formed by concatenating `a0' and `a1' to the 64-bit
+ * value formed by concatenating `b0' and `b1'. Addition is modulo 2^64, so
+ * any carry out is lost. The result is broken into two 32-bit pieces which
+ * are stored at the locations pointed to by `z0Ptr' and `z1Ptr'.
+ */
+void
+__add64(uint a0, uint a1, uint b0, uint b1,
+ out uint z0Ptr,
+ out uint z1Ptr)
+{
+ uint z1 = a1 + b1;
+ z1Ptr = z1;
+ z0Ptr = a0 + b0 + uint(z1 < a1);
+}
+
+
+/* Subtracts the 64-bit value formed by concatenating `b0' and `b1' from the
+ * 64-bit value formed by concatenating `a0' and `a1'. Subtraction is modulo
+ * 2^64, so any borrow out (carry out) is lost. The result is broken into two
+ * 32-bit pieces which are stored at the locations pointed to by `z0Ptr' and
+ * `z1Ptr'.
+ */
+void
+__sub64(uint a0, uint a1, uint b0, uint b1,
+ out uint z0Ptr,
+ out uint z1Ptr)
+{
+ z1Ptr = a1 - b1;
+ z0Ptr = a0 - b0 - uint(a1 < b1);
+}
+
+/* Shifts the 64-bit value formed by concatenating `a0' and `a1' right by the
+ * number of bits given in `count'. If any nonzero bits are shifted off, they
+ * are "jammed" into the least significant bit of the result by setting the
+ * least significant bit to 1. The value of `count' can be arbitrarily large;
+ * in particular, if `count' is greater than 64, the result will be either 0
+ * or 1, depending on whether the concatenation of `a0' and `a1' is zero or
+ * nonzero. The result is broken into two 32-bit pieces which are stored at
+ * the locations pointed to by `z0Ptr' and `z1Ptr'.
+ */
+void
+__shift64RightJamming(uint a0,
+ uint a1,
+ int count,
+ out uint z0Ptr,
+ out uint z1Ptr)
+{
+ uint z0;
+ uint z1;
+ int negCount = (-count) & 31;
+
+ z0 = mix(0u, a0, count == 0);
+ z0 = mix(z0, (a0 >> count), count < 32);
+
+ z1 = uint((a0 | a1) != 0u); /* count >= 64 */
+ uint z1_lt64 = (a0>>(count & 31)) | uint(((a0<<negCount) | a1) != 0u);
+ z1 = mix(z1, z1_lt64, count < 64);
+ z1 = mix(z1, (a0 | uint(a1 != 0u)), count == 32);
+ uint z1_lt32 = (a0<<negCount) | (a1>>count) | uint ((a1<<negCount) != 0u);
+ z1 = mix(z1, z1_lt32, count < 32);
+ z1 = mix(z1, a1, count == 0);
+ z1Ptr = z1;
+ z0Ptr = z0;
+}
+
+/* Shifts the 96-bit value formed by concatenating `a0', `a1', and `a2' right
+ * by 32 _plus_ the number of bits given in `count'. The shifted result is
+ * at most 64 nonzero bits; these are broken into two 32-bit pieces which are
+ * stored at the locations pointed to by `z0Ptr' and `z1Ptr'. The bits shifted
+ * off form a third 32-bit result as follows: The _last_ bit shifted off is
+ * the most-significant bit of the extra result, and the other 31 bits of the
+ * extra result are all zero if and only if _all_but_the_last_ bits shifted off
+ * were all zero. This extra result is stored in the location pointed to by
+ * `z2Ptr'. The value of `count' can be arbitrarily large.
+ * (This routine makes more sense if `a0', `a1', and `a2' are considered
+ * to form a fixed-point value with binary point between `a1' and `a2'. This
+ * fixed-point value is shifted right by the number of bits given in `count',
+ * and the integer part of the result is returned at the locations pointed to
+ * by `z0Ptr' and `z1Ptr'. The fractional part of the result may be slightly
+ * corrupted as described above, and is returned at the location pointed to by
+ * `z2Ptr'.)
+ */
+void
+__shift64ExtraRightJamming(uint a0, uint a1, uint a2,
+ int count,
+ out uint z0Ptr,
+ out uint z1Ptr,
+ out uint z2Ptr)
+{
+ uint z0 = 0u;
+ uint z1;
+ uint z2;
+ int negCount = (-count) & 31;
+
+ z2 = mix(uint(a0 != 0u), a0, count == 64);
+ z2 = mix(z2, a0 << negCount, count < 64);
+ z2 = mix(z2, a1 << negCount, count < 32);
+
+ z1 = mix(0u, (a0 >> (count & 31)), count < 64);
+ z1 = mix(z1, (a0<<negCount) | (a1>>count), count < 32);
+
+ a2 = mix(a2 | a1, a2, count < 32);
+ z0 = mix(z0, a0 >> count, count < 32);
+ z2 |= uint(a2 != 0u);
+
+ z0 = mix(z0, 0u, (count == 32));
+ z1 = mix(z1, a0, (count == 32));
+ z2 = mix(z2, a1, (count == 32));
+ z0 = mix(z0, a0, (count == 0));
+ z1 = mix(z1, a1, (count == 0));
+ z2 = mix(z2, a2, (count == 0));
+ z2Ptr = z2;
+ z1Ptr = z1;
+ z0Ptr = z0;
+}
+
+/* Shifts the 64-bit value formed by concatenating `a0' and `a1' left by the
+ * number of bits given in `count'. Any bits shifted off are lost. The value
+ * of `count' must be less than 32. The result is broken into two 32-bit
+ * pieces which are stored at the locations pointed to by `z0Ptr' and `z1Ptr'.
+ */
+void
+__shortShift64Left(uint a0, uint a1,
+ int count,
+ out uint z0Ptr,
+ out uint z1Ptr)
+{
+ z1Ptr = a1<<count;
+ z0Ptr = mix((a0 << count | (a1 >> ((-count) & 31))), a0, count == 0);
+}
+
+/* Packs the sign `zSign', the exponent `zExp', and the significand formed by
+ * the concatenation of `zFrac0' and `zFrac1' into a double-precision floating-
+ * point value, returning the result. After being shifted into the proper
+ * positions, the three fields `zSign', `zExp', and `zFrac0' are simply added
+ * together to form the most significant 32 bits of the result. This means
+ * that any integer portion of `zFrac0' will be added into the exponent. Since
+ * a properly normalized significand will have an integer portion equal to 1,
+ * the `zExp' input should be 1 less than the desired result exponent whenever
+ * `zFrac0' and `zFrac1' concatenated form a complete, normalized significand.
+ */
+uint64_t
+__packFloat64(uint zSign, int zExp, uint zFrac0, uint zFrac1)
+{
+ uvec2 z;
+
+ z.y = (zSign << 31) + (uint(zExp) << 20) + zFrac0;
+ z.x = zFrac1;
+ return packUint2x32(z);
+}
+
+/* Takes an abstract floating-point value having sign `zSign', exponent `zExp',
+ * and extended significand formed by the concatenation of `zFrac0', `zFrac1',
+ * and `zFrac2', and returns the proper double-precision floating-point value
+ * corresponding to the abstract input. Ordinarily, the abstract value is
+ * simply rounded and packed into the double-precision format, with the inexact
+ * exception raised if the abstract input cannot be represented exactly.
+ * However, if the abstract value is too large, the overflow and inexact
+ * exceptions are raised and an infinity or maximal finite value is returned.
+ * If the abstract value is too small, the input value is rounded to a
+ * subnormal number, and the underflow and inexact exceptions are raised if the
+ * abstract input cannot be represented exactly as a subnormal double-precision
+ * floating-point number.
+ * The input significand must be normalized or smaller. If the input
+ * significand is not normalized, `zExp' must be 0; in that case, the result
+ * returned is a subnormal number, and it must not require rounding. In the
+ * usual case that the input significand is normalized, `zExp' must be 1 less
+ * than the "true" floating-point exponent. The handling of underflow and
+ * overflow follows the IEEE Standard for Floating-Point Arithmetic.
+ */
+uint64_t
+__roundAndPackFloat64(uint zSign,
+ int zExp,
+ uint zFrac0,
+ uint zFrac1,
+ uint zFrac2)
+{
+ bool roundNearestEven;
+ bool increment;
+
+ roundNearestEven = FLOAT_ROUNDING_MODE == FLOAT_ROUND_NEAREST_EVEN;
+ increment = int(zFrac2) < 0;
+ if (!roundNearestEven) {
+ if (FLOAT_ROUNDING_MODE == FLOAT_ROUND_TO_ZERO) {
+ increment = false;
+ } else {
+ if (zSign != 0u) {
+ increment = (FLOAT_ROUNDING_MODE == FLOAT_ROUND_DOWN) &&
+ (zFrac2 != 0u);
+ } else {
+ increment = (FLOAT_ROUNDING_MODE == FLOAT_ROUND_UP) &&
+ (zFrac2 != 0u);
+ }
+ }
+ }
+ if (0x7FD <= zExp) {
+ if ((0x7FD < zExp) ||
+ ((zExp == 0x7FD) &&
+ (0x001FFFFFu == zFrac0 && 0xFFFFFFFFu == zFrac1) &&
+ increment)) {
+ if ((FLOAT_ROUNDING_MODE == FLOAT_ROUND_TO_ZERO) ||
+ ((zSign != 0u) && (FLOAT_ROUNDING_MODE == FLOAT_ROUND_UP)) ||
+ ((zSign == 0u) && (FLOAT_ROUNDING_MODE == FLOAT_ROUND_DOWN))) {
+ return __packFloat64(zSign, 0x7FE, 0x000FFFFFu, 0xFFFFFFFFu);
+ }
+ return __packFloat64(zSign, 0x7FF, 0u, 0u);
+ }
+ if (zExp < 0) {
+ __shift64ExtraRightJamming(
+ zFrac0, zFrac1, zFrac2, -zExp, zFrac0, zFrac1, zFrac2);
+ zExp = 0;
+ if (roundNearestEven) {
+ increment = zFrac2 < 0u;
+ } else {
+ if (zSign != 0u) {
+ increment = (FLOAT_ROUNDING_MODE == FLOAT_ROUND_DOWN) &&
+ (zFrac2 != 0u);
+ } else {
+ increment = (FLOAT_ROUNDING_MODE == FLOAT_ROUND_UP) &&
+ (zFrac2 != 0u);
+ }
+ }
+ }
+ }
+ if (increment) {
+ __add64(zFrac0, zFrac1, 0u, 1u, zFrac0, zFrac1);
+ zFrac1 &= ~((zFrac2 + uint(zFrac2 == 0u)) & uint(roundNearestEven));
+ } else {
+ zExp = mix(zExp, 0, (zFrac0 | zFrac1) == 0u);
+ }
+ return __packFloat64(zSign, zExp, zFrac0, zFrac1);
+}
+
+/* Returns the number of leading 0 bits before the most-significant 1 bit of
+ * `a'. If `a' is zero, 32 is returned.
+ */
+int
+__countLeadingZeros32(uint a)
+{
+ int shiftCount;
+ shiftCount = mix(31 - findMSB(a), 32, a == 0u);
+ return shiftCount;
+}
+
+/* Takes an abstract floating-point value having sign `zSign', exponent `zExp',
+ * and significand formed by the concatenation of `zSig0' and `zSig1', and
+ * returns the proper double-precision floating-point value corresponding
+ * to the abstract input. This routine is just like `__roundAndPackFloat64'
+ * except that the input significand has fewer bits and does not have to be
+ * normalized. In all cases, `zExp' must be 1 less than the "true" floating-
+ * point exponent.
+ */
+uint64_t
+__normalizeRoundAndPackFloat64(uint zSign,
+ int zExp,
+ uint zFrac0,
+ uint zFrac1)
+{
+ int shiftCount;
+ uint zFrac2;
+
+ if (zFrac0 == 0u) {
+ zExp -= 32;
+ zFrac0 = zFrac1;
+ zFrac1 = 0u;
+ }
+
+ shiftCount = __countLeadingZeros32(zFrac0) - 11;
+ if (0 <= shiftCount) {
+ zFrac2 = 0u;
+ __shortShift64Left(zFrac0, zFrac1, shiftCount, zFrac0, zFrac1);
+ } else {
+ __shift64ExtraRightJamming(
+ zFrac0, zFrac1, 0u, -shiftCount, zFrac0, zFrac1, zFrac2);
+ }
+ zExp -= shiftCount;
+ return __roundAndPackFloat64(zSign, zExp, zFrac0, zFrac1, zFrac2);
+}
+
+/* Takes two double-precision floating-point values `a' and `b', one of which
+ * is a NaN, and returns the appropriate NaN result.
+ */
+uint64_t
+__propagateFloat64NaN(uint64_t __a, uint64_t __b)
+{
+ bool aIsNaN = __is_nan(__a);
+ bool bIsNaN = __is_nan(__b);
+ uvec2 a = unpackUint2x32(__a);
+ uvec2 b = unpackUint2x32(__b);
+ a.y |= 0x00080000u;
+ b.y |= 0x00080000u;
+
+ return packUint2x32(mix(b, mix(a, b, bvec2(bIsNaN, bIsNaN)), bvec2(aIsNaN, aIsNaN)));
+}
+
+/* Returns the result of adding the double-precision floating-point values
+ * `a' and `b'. The operation is performed according to the IEEE Standard for
+ * Floating-Point Arithmetic.
+ */
+uint64_t
+__fadd64(uint64_t a, uint64_t b)
+{
+ uint aSign = __extractFloat64Sign(a);
+ uint bSign = __extractFloat64Sign(b);
+ uint aFracLo = __extractFloat64FracLo(a);
+ uint aFracHi = __extractFloat64FracHi(a);
+ uint bFracLo = __extractFloat64FracLo(b);
+ uint bFracHi = __extractFloat64FracHi(b);
+ int aExp = __extractFloat64Exp(a);
+ int bExp = __extractFloat64Exp(b);
+ uint zFrac0 = 0u;
+ uint zFrac1 = 0u;
+ int expDiff = aExp - bExp;
+ if (aSign == bSign) {
+ uint zFrac2 = 0u;
+ int zExp;
+ bool orig_exp_diff_is_zero = (expDiff == 0);
+
+ if (orig_exp_diff_is_zero) {
+ if (aExp == 0x7FF) {
+ bool propagate = (aFracHi | aFracLo | bFracHi | bFracLo) != 0u;
+ return mix(a, __propagateFloat64NaN(a, b), propagate);
+ }
+ __add64(aFracHi, aFracLo, bFracHi, bFracLo, zFrac0, zFrac1);
+ if (aExp == 0)
+ return __packFloat64(aSign, 0, zFrac0, zFrac1);
+ zFrac2 = 0u;
+ zFrac0 |= 0x00200000u;
+ zExp = aExp;
+ __shift64ExtraRightJamming(
+ zFrac0, zFrac1, zFrac2, 1, zFrac0, zFrac1, zFrac2);
+ } else if (0 < expDiff) {
+ if (aExp == 0x7FF) {
+ bool propagate = (aFracHi | aFracLo) != 0u;
+ return mix(a, __propagateFloat64NaN(a, b), propagate);
+ }
+
+ expDiff = mix(expDiff, expDiff - 1, bExp == 0);
+ bFracHi = mix(bFracHi | 0x00100000u, bFracHi, bExp == 0);
+ __shift64ExtraRightJamming(
+ bFracHi, bFracLo, 0u, expDiff, bFracHi, bFracLo, zFrac2);
+ zExp = aExp;
+ } else if (expDiff < 0) {
+ if (bExp == 0x7FF) {
+ bool propagate = (bFracHi | bFracLo) != 0u;
+ return mix(__packFloat64(aSign, 0x7ff, 0u, 0u), __propagateFloat64NaN(a, b), propagate);
+ }
+ expDiff = mix(expDiff, expDiff + 1, aExp == 0);
+ aFracHi = mix(aFracHi | 0x00100000u, aFracHi, aExp == 0);
+ __shift64ExtraRightJamming(
+ aFracHi, aFracLo, 0u, - expDiff, aFracHi, aFracLo, zFrac2);
+ zExp = bExp;
+ }
+ if (!orig_exp_diff_is_zero) {
+ aFracHi |= 0x00100000u;
+ __add64(aFracHi, aFracLo, bFracHi, bFracLo, zFrac0, zFrac1);
+ --zExp;
+ if (!(zFrac0 < 0x00200000u)) {
+ __shift64ExtraRightJamming(zFrac0, zFrac1, zFrac2, 1, zFrac0, zFrac1, zFrac2);
+ ++zExp;
+ }
+ }
+ return __roundAndPackFloat64(aSign, zExp, zFrac0, zFrac1, zFrac2);
+
+ } else {
+ int zExp;
+
+ __shortShift64Left(aFracHi, aFracLo, 10, aFracHi, aFracLo);
+ __shortShift64Left(bFracHi, bFracLo, 10, bFracHi, bFracLo);
+ if (0 < expDiff) {
+ if (aExp == 0x7FF) {
+ bool propagate = (aFracHi | aFracLo) != 0u;
+ return mix(a, __propagateFloat64NaN(a, b), propagate);
+ }
+ expDiff = mix(expDiff, expDiff - 1, bExp == 0);
+ bFracHi = mix(bFracHi | 0x40000000u, bFracHi, bExp == 0);
+ __shift64RightJamming(bFracHi, bFracLo, expDiff, bFracHi, bFracLo);
+ aFracHi |= 0x40000000u;
+ __sub64(aFracHi, aFracLo, bFracHi, bFracLo, zFrac0, zFrac1);
+ zExp = aExp;
+ --zExp;
+ return __normalizeRoundAndPackFloat64(aSign, zExp - 10, zFrac0, zFrac1);
+ }
+ if (expDiff < 0) {
+ if (bExp == 0x7FF) {
+ bool propagate = (bFracHi | bFracLo) != 0u;
+ return mix(__packFloat64(aSign ^ 1u, 0x7ff, 0u, 0u), __propagateFloat64NaN(a, b), propagate);
+ }
+ expDiff = mix(expDiff, expDiff + 1, aExp == 0);
+ aFracHi = mix(aFracHi | 0x40000000u, aFracHi, aExp == 0);
+ __shift64RightJamming(aFracHi, aFracLo, - expDiff, aFracHi, aFracLo);
+ bFracHi |= 0x40000000u;
+ __sub64(bFracHi, bFracLo, aFracHi, aFracLo, zFrac0, zFrac1);
+ zExp = bExp;
+ aSign ^= 1u;
+ --zExp;
+ return __normalizeRoundAndPackFloat64(aSign, zExp - 10, zFrac0, zFrac1);
+ }
+ if (aExp == 0x7FF) {
+ bool propagate = (aFracHi | aFracLo | bFracHi | bFracLo) != 0u;
+ return mix(0xFFFFFFFFFFFFFFFFUL, __propagateFloat64NaN(a, b), propagate);
+ }
+ bExp = mix(bExp, 1, aExp == 0);
+ aExp = mix(aExp, 1, aExp == 0);
+ bool zexp_normal = false;
+ bool blta = true;
+ if (bFracHi < aFracHi) {
+ __sub64(aFracHi, aFracLo, bFracHi, bFracLo, zFrac0, zFrac1);
+ zexp_normal = true;
+ }
+ else if (aFracHi < bFracHi) {
+ __sub64(bFracHi, bFracLo, aFracHi, aFracLo, zFrac0, zFrac1);
+ blta = false;
+ zexp_normal = true;
+ }
+ else if (bFracLo < aFracLo) {
+ __sub64(aFracHi, aFracLo, bFracHi, bFracLo, zFrac0, zFrac1);
+ zexp_normal = true;
+ }
+ else if (aFracLo < bFracLo) {
+ __sub64(bFracHi, bFracLo, aFracHi, aFracLo, zFrac0, zFrac1);
+ blta = false;
+ zexp_normal = true;
+ }
+ zExp = mix(bExp, aExp, blta);
+ aSign = mix(aSign ^ 1u, aSign, blta);
+ uint64_t retval_0 = __packFloat64(uint(FLOAT_ROUNDING_MODE == FLOAT_ROUND_DOWN), 0, 0u, 0u);
+ uint64_t retval_1 = __normalizeRoundAndPackFloat64(aSign, zExp - 11, zFrac0, zFrac1);
+ return mix(retval_0, retval_1, zexp_normal);
+ }
+}