[llvm-branch-commits] Extract SipHash implementation into a header. (PR #134197)
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llvm-branch-commits at lists.llvm.org
Wed Apr 2 21:34:46 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-llvm-support
Author: Peter Collingbourne (pcc)
<details>
<summary>Changes</summary>
This is so that we'll be able to use it in compiler-rt as well.
Dependencies on LLVM Support were removed from the header by restoring
code from the original SipHash implementation.
---
Full diff: https://github.com/llvm/llvm-project/pull/134197.diff
4 Files Affected:
- (modified) llvm/lib/Support/CMakeLists.txt (+5)
- (modified) llvm/lib/Support/SipHash.cpp (+1-130)
- (modified) llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn (+1)
- (added) third-party/siphash/include/siphash/SipHash.h (+161)
``````````diff
diff --git a/llvm/lib/Support/CMakeLists.txt b/llvm/lib/Support/CMakeLists.txt
index 2754c97fce6c1..1b18eb7c6346b 100644
--- a/llvm/lib/Support/CMakeLists.txt
+++ b/llvm/lib/Support/CMakeLists.txt
@@ -368,3 +368,8 @@ if(LLVM_WITH_Z3)
${Z3_INCLUDE_DIR}
)
endif()
+
+target_include_directories(LLVMSupport SYSTEM
+ PRIVATE
+ ${LLVM_THIRD_PARTY_DIR}/siphash/include
+ )
diff --git a/llvm/lib/Support/SipHash.cpp b/llvm/lib/Support/SipHash.cpp
index 68545913a4f59..682e9231c776f 100644
--- a/llvm/lib/Support/SipHash.cpp
+++ b/llvm/lib/Support/SipHash.cpp
@@ -15,9 +15,9 @@
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringRef.h"
-#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/Endian.h"
+#include "siphash/SipHash.h"
#include <cstdint>
using namespace llvm;
@@ -25,135 +25,6 @@ using namespace support;
#define DEBUG_TYPE "llvm-siphash"
-// Lightly adapted from the SipHash reference C implementation:
-// https://github.com/veorq/SipHash
-// by Jean-Philippe Aumasson and Daniel J. Bernstein
-
-#define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))
-
-#define SIPROUND \
- do { \
- v0 += v1; \
- v1 = ROTL(v1, 13); \
- v1 ^= v0; \
- v0 = ROTL(v0, 32); \
- v2 += v3; \
- v3 = ROTL(v3, 16); \
- v3 ^= v2; \
- v0 += v3; \
- v3 = ROTL(v3, 21); \
- v3 ^= v0; \
- v2 += v1; \
- v1 = ROTL(v1, 17); \
- v1 ^= v2; \
- v2 = ROTL(v2, 32); \
- } while (0)
-
-namespace {
-
-/// Computes a SipHash value
-///
-/// \param in: pointer to input data (read-only)
-/// \param inlen: input data length in bytes (any size_t value)
-/// \param k: reference to the key data 16-byte array (read-only)
-/// \returns output data, must be 8 or 16 bytes
-///
-template <int cROUNDS, int dROUNDS, size_t outlen>
-void siphash(const unsigned char *in, uint64_t inlen,
- const unsigned char (&k)[16], unsigned char (&out)[outlen]) {
-
- const unsigned char *ni = (const unsigned char *)in;
- const unsigned char *kk = (const unsigned char *)k;
-
- static_assert(outlen == 8 || outlen == 16, "result should be 8 or 16 bytes");
-
- uint64_t v0 = UINT64_C(0x736f6d6570736575);
- uint64_t v1 = UINT64_C(0x646f72616e646f6d);
- uint64_t v2 = UINT64_C(0x6c7967656e657261);
- uint64_t v3 = UINT64_C(0x7465646279746573);
- uint64_t k0 = endian::read64le(kk);
- uint64_t k1 = endian::read64le(kk + 8);
- uint64_t m;
- int i;
- const unsigned char *end = ni + inlen - (inlen % sizeof(uint64_t));
- const int left = inlen & 7;
- uint64_t b = ((uint64_t)inlen) << 56;
- v3 ^= k1;
- v2 ^= k0;
- v1 ^= k1;
- v0 ^= k0;
-
- if (outlen == 16)
- v1 ^= 0xee;
-
- for (; ni != end; ni += 8) {
- m = endian::read64le(ni);
- v3 ^= m;
-
- for (i = 0; i < cROUNDS; ++i)
- SIPROUND;
-
- v0 ^= m;
- }
-
- switch (left) {
- case 7:
- b |= ((uint64_t)ni[6]) << 48;
- LLVM_FALLTHROUGH;
- case 6:
- b |= ((uint64_t)ni[5]) << 40;
- LLVM_FALLTHROUGH;
- case 5:
- b |= ((uint64_t)ni[4]) << 32;
- LLVM_FALLTHROUGH;
- case 4:
- b |= ((uint64_t)ni[3]) << 24;
- LLVM_FALLTHROUGH;
- case 3:
- b |= ((uint64_t)ni[2]) << 16;
- LLVM_FALLTHROUGH;
- case 2:
- b |= ((uint64_t)ni[1]) << 8;
- LLVM_FALLTHROUGH;
- case 1:
- b |= ((uint64_t)ni[0]);
- break;
- case 0:
- break;
- }
-
- v3 ^= b;
-
- for (i = 0; i < cROUNDS; ++i)
- SIPROUND;
-
- v0 ^= b;
-
- if (outlen == 16)
- v2 ^= 0xee;
- else
- v2 ^= 0xff;
-
- for (i = 0; i < dROUNDS; ++i)
- SIPROUND;
-
- b = v0 ^ v1 ^ v2 ^ v3;
- endian::write64le(out, b);
-
- if (outlen == 8)
- return;
-
- v1 ^= 0xdd;
-
- for (i = 0; i < dROUNDS; ++i)
- SIPROUND;
-
- b = v0 ^ v1 ^ v2 ^ v3;
- endian::write64le(out + 8, b);
-}
-
-} // end anonymous namespace
-
void llvm::getSipHash_2_4_64(ArrayRef<uint8_t> In, const uint8_t (&K)[16],
uint8_t (&Out)[8]) {
siphash<2, 4>(In.data(), In.size(), K, Out);
diff --git a/llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn b/llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn
index fe7ff6ef68f99..5461ed5246b85 100644
--- a/llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn
+++ b/llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn
@@ -31,6 +31,7 @@ static_library("Support") {
include_dirs = [
"Unix",
"Windows",
+ "//third-party/siphash/include",
]
sources = [
"AArch64AttributeParser.cpp",
diff --git a/third-party/siphash/include/siphash/SipHash.h b/third-party/siphash/include/siphash/SipHash.h
new file mode 100644
index 0000000000000..9653e9428b123
--- /dev/null
+++ b/third-party/siphash/include/siphash/SipHash.h
@@ -0,0 +1,161 @@
+//===--- SipHash.h - An implementation of SipHash -------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This is a header-only implementation of SipHash. It lacks library
+// dependencies so it can be used from LLVM and compiler-rt.
+//
+//===----------------------------------------------------------------------===//
+
+#include <stddef.h>
+#include <stdint.h>
+
+// Lightly adapted from the SipHash reference C implementation:
+// https://github.com/veorq/SipHash
+// by Jean-Philippe Aumasson and Daniel J. Bernstein
+
+#define ROTL(x, b) (uint64_t)(((x) << (b)) | ((x) >> (64 - (b))))
+
+#define U32TO8_LE(p, v) \
+ (p)[0] = (uint8_t)((v)); \
+ (p)[1] = (uint8_t)((v) >> 8); \
+ (p)[2] = (uint8_t)((v) >> 16); \
+ (p)[3] = (uint8_t)((v) >> 24);
+
+#define U64TO8_LE(p, v) \
+ U32TO8_LE((p), (uint32_t)((v))); \
+ U32TO8_LE((p) + 4, (uint32_t)((v) >> 32));
+
+#define U8TO64_LE(p) \
+ (((uint64_t)((p)[0])) | ((uint64_t)((p)[1]) << 8) | \
+ ((uint64_t)((p)[2]) << 16) | ((uint64_t)((p)[3]) << 24) | \
+ ((uint64_t)((p)[4]) << 32) | ((uint64_t)((p)[5]) << 40) | \
+ ((uint64_t)((p)[6]) << 48) | ((uint64_t)((p)[7]) << 56))
+
+#define SIPROUND \
+ do { \
+ v0 += v1; \
+ v1 = ROTL(v1, 13); \
+ v1 ^= v0; \
+ v0 = ROTL(v0, 32); \
+ v2 += v3; \
+ v3 = ROTL(v3, 16); \
+ v3 ^= v2; \
+ v0 += v3; \
+ v3 = ROTL(v3, 21); \
+ v3 ^= v0; \
+ v2 += v1; \
+ v1 = ROTL(v1, 17); \
+ v1 ^= v2; \
+ v2 = ROTL(v2, 32); \
+ } while (0)
+
+namespace {
+
+/// Computes a SipHash value
+///
+/// \param in: pointer to input data (read-only)
+/// \param inlen: input data length in bytes (any size_t value)
+/// \param k: reference to the key data 16-byte array (read-only)
+/// \returns output data, must be 8 or 16 bytes
+///
+template <int cROUNDS, int dROUNDS, size_t outlen>
+void siphash(const unsigned char *in, uint64_t inlen,
+ const unsigned char (&k)[16], unsigned char (&out)[outlen]) {
+
+ const unsigned char *ni = (const unsigned char *)in;
+ const unsigned char *kk = (const unsigned char *)k;
+
+ static_assert(outlen == 8 || outlen == 16, "result should be 8 or 16 bytes");
+
+ uint64_t v0 = UINT64_C(0x736f6d6570736575);
+ uint64_t v1 = UINT64_C(0x646f72616e646f6d);
+ uint64_t v2 = UINT64_C(0x6c7967656e657261);
+ uint64_t v3 = UINT64_C(0x7465646279746573);
+ uint64_t k0 = U8TO64_LE(kk);
+ uint64_t k1 = U8TO64_LE(kk + 8);
+ uint64_t m;
+ int i;
+ const unsigned char *end = ni + inlen - (inlen % sizeof(uint64_t));
+ const int left = inlen & 7;
+ uint64_t b = ((uint64_t)inlen) << 56;
+ v3 ^= k1;
+ v2 ^= k0;
+ v1 ^= k1;
+ v0 ^= k0;
+
+ if (outlen == 16)
+ v1 ^= 0xee;
+
+ for (; ni != end; ni += 8) {
+ m = U8TO64_LE(ni);
+ v3 ^= m;
+
+ for (i = 0; i < cROUNDS; ++i)
+ SIPROUND;
+
+ v0 ^= m;
+ }
+
+ switch (left) {
+ case 7:
+ b |= ((uint64_t)ni[6]) << 48;
+ /* FALLTHRU */
+ case 6:
+ b |= ((uint64_t)ni[5]) << 40;
+ /* FALLTHRU */
+ case 5:
+ b |= ((uint64_t)ni[4]) << 32;
+ /* FALLTHRU */
+ case 4:
+ b |= ((uint64_t)ni[3]) << 24;
+ /* FALLTHRU */
+ case 3:
+ b |= ((uint64_t)ni[2]) << 16;
+ /* FALLTHRU */
+ case 2:
+ b |= ((uint64_t)ni[1]) << 8;
+ /* FALLTHRU */
+ case 1:
+ b |= ((uint64_t)ni[0]);
+ /* FALLTHRU */
+ break;
+ case 0:
+ break;
+ }
+
+ v3 ^= b;
+
+ for (i = 0; i < cROUNDS; ++i)
+ SIPROUND;
+
+ v0 ^= b;
+
+ if (outlen == 16)
+ v2 ^= 0xee;
+ else
+ v2 ^= 0xff;
+
+ for (i = 0; i < dROUNDS; ++i)
+ SIPROUND;
+
+ b = v0 ^ v1 ^ v2 ^ v3;
+ U64TO8_LE(out, b);
+
+ if (outlen == 8)
+ return;
+
+ v1 ^= 0xdd;
+
+ for (i = 0; i < dROUNDS; ++i)
+ SIPROUND;
+
+ b = v0 ^ v1 ^ v2 ^ v3;
+ U64TO8_LE(out + 8, b);
+}
+
+} // end anonymous namespace
``````````
</details>
https://github.com/llvm/llvm-project/pull/134197
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