Adding upstream version 16.2.upstream/16.2

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

1 files changed, 202 insertions, 0 deletions

diff --git a/src/common/d2s_intrinsics.h b/src/common/d2s_intrinsics.h
new file mode 100644
index 0000000..ae0f28d
--- /dev/null
+++ b/src/common/d2s_intrinsics.h
@@ -0,0 +1,202 @@
+/*---------------------------------------------------------------------------
+ *
+ * Ryu floating-point output for double precision.
+ *
+ * Portions Copyright (c) 2018-2023, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ *	  src/common/d2s_intrinsics.h
+ *
+ * This is a modification of code taken from github.com/ulfjack/ryu under the
+ * terms of the Boost license (not the Apache license). The original copyright
+ * notice follows:
+ *
+ * Copyright 2018 Ulf Adams
+ *
+ * The contents of this file may be used under the terms of the Apache
+ * License, Version 2.0.
+ *
+ *     (See accompanying file LICENSE-Apache or copy at
+ *      http://www.apache.org/licenses/LICENSE-2.0)
+ *
+ * Alternatively, the contents of this file may be used under the terms of the
+ * Boost Software License, Version 1.0.
+ *
+ *     (See accompanying file LICENSE-Boost or copy at
+ *      https://www.boost.org/LICENSE_1_0.txt)
+ *
+ * Unless required by applicable law or agreed to in writing, this software is
+ * distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.
+ *
+ *---------------------------------------------------------------------------
+ */
+#ifndef RYU_D2S_INTRINSICS_H
+#define RYU_D2S_INTRINSICS_H
+
+#if defined(HAS_64_BIT_INTRINSICS)
+
+#include <intrin.h>
+
+static inline uint64
+umul128(const uint64 a, const uint64 b, uint64 *const productHi)
+{
+	return _umul128(a, b, productHi);
+}
+
+static inline uint64
+shiftright128(const uint64 lo, const uint64 hi, const uint32 dist)
+{
+	/*
+	 * For the __shiftright128 intrinsic, the shift value is always modulo 64.
+	 * In the current implementation of the double-precision version of Ryu,
+	 * the shift value is always < 64. (In the case RYU_OPTIMIZE_SIZE == 0,
+	 * the shift value is in the range [49, 58]. Otherwise in the range [2,
+	 * 59].) Check this here in case a future change requires larger shift
+	 * values. In this case this function needs to be adjusted.
+	 */
+	Assert(dist < 64);
+	return __shiftright128(lo, hi, (unsigned char) dist);
+}
+
+#else							/* defined(HAS_64_BIT_INTRINSICS) */
+
+static inline uint64
+umul128(const uint64 a, const uint64 b, uint64 *const productHi)
+{
+	/*
+	 * The casts here help MSVC to avoid calls to the __allmul library
+	 * function.
+	 */
+	const uint32 aLo = (uint32) a;
+	const uint32 aHi = (uint32) (a >> 32);
+	const uint32 bLo = (uint32) b;
+	const uint32 bHi = (uint32) (b >> 32);
+
+	const uint64 b00 = (uint64) aLo * bLo;
+	const uint64 b01 = (uint64) aLo * bHi;
+	const uint64 b10 = (uint64) aHi * bLo;
+	const uint64 b11 = (uint64) aHi * bHi;
+
+	const uint32 b00Lo = (uint32) b00;
+	const uint32 b00Hi = (uint32) (b00 >> 32);
+
+	const uint64 mid1 = b10 + b00Hi;
+	const uint32 mid1Lo = (uint32) (mid1);
+	const uint32 mid1Hi = (uint32) (mid1 >> 32);
+
+	const uint64 mid2 = b01 + mid1Lo;
+	const uint32 mid2Lo = (uint32) (mid2);
+	const uint32 mid2Hi = (uint32) (mid2 >> 32);
+
+	const uint64 pHi = b11 + mid1Hi + mid2Hi;
+	const uint64 pLo = ((uint64) mid2Lo << 32) + b00Lo;
+
+	*productHi = pHi;
+	return pLo;
+}
+
+static inline uint64
+shiftright128(const uint64 lo, const uint64 hi, const uint32 dist)
+{
+	/* We don't need to handle the case dist >= 64 here (see above). */
+	Assert(dist < 64);
+#if !defined(RYU_32_BIT_PLATFORM)
+	Assert(dist > 0);
+	return (hi << (64 - dist)) | (lo >> dist);
+#else
+	/* Avoid a 64-bit shift by taking advantage of the range of shift values. */
+	Assert(dist >= 32);
+	return (hi << (64 - dist)) | ((uint32) (lo >> 32) >> (dist - 32));
+#endif
+}
+
+#endif							/* // defined(HAS_64_BIT_INTRINSICS) */
+
+#ifdef RYU_32_BIT_PLATFORM
+
+/*  Returns the high 64 bits of the 128-bit product of a and b. */
+static inline uint64
+umulh(const uint64 a, const uint64 b)
+{
+	/*
+	 * Reuse the umul128 implementation. Optimizers will likely eliminate the
+	 * instructions used to compute the low part of the product.
+	 */
+	uint64		hi;
+
+	umul128(a, b, &hi);
+	return hi;
+}
+
+/*----
+ *  On 32-bit platforms, compilers typically generate calls to library
+ *  functions for 64-bit divisions, even if the divisor is a constant.
+ *
+ *  E.g.:
+ *  https://bugs.llvm.org/show_bug.cgi?id=37932
+ *  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=17958
+ *  https://gcc.gnu.org/bugzilla/show_bug.cgi?id=37443
+ *
+ *  The functions here perform division-by-constant using multiplications
+ *  in the same way as 64-bit compilers would do.
+ *
+ *  NB:
+ *  The multipliers and shift values are the ones generated by clang x64
+ *  for expressions like x/5, x/10, etc.
+ *----
+ */
+
+static inline uint64
+div5(const uint64 x)
+{
+	return umulh(x, UINT64CONST(0xCCCCCCCCCCCCCCCD)) >> 2;
+}
+
+static inline uint64
+div10(const uint64 x)
+{
+	return umulh(x, UINT64CONST(0xCCCCCCCCCCCCCCCD)) >> 3;
+}
+
+static inline uint64
+div100(const uint64 x)
+{
+	return umulh(x >> 2, UINT64CONST(0x28F5C28F5C28F5C3)) >> 2;
+}
+
+static inline uint64
+div1e8(const uint64 x)
+{
+	return umulh(x, UINT64CONST(0xABCC77118461CEFD)) >> 26;
+}
+
+#else							/* RYU_32_BIT_PLATFORM */
+
+static inline uint64
+div5(const uint64 x)
+{
+	return x / 5;
+}
+
+static inline uint64
+div10(const uint64 x)
+{
+	return x / 10;
+}
+
+static inline uint64
+div100(const uint64 x)
+{
+	return x / 100;
+}
+
+static inline uint64
+div1e8(const uint64 x)
+{
+	return x / 100000000;
+}
+
+#endif							/* RYU_32_BIT_PLATFORM */
+
+#endif							/* RYU_D2S_INTRINSICS_H */