fixup! address more comments

Created using spr 1.3.8-beta.1

Author: melver

llvm/include/llvm/Support/SipHash.h

@@ -33,6 +33,13 @@ LLVM_ABI void getSipHash_2_4_64(ArrayRef<uint8_t> In, const uint8_t (&K)[16],
 LLVM_ABI void getSipHash_2_4_128(ArrayRef<uint8_t> In, const uint8_t (&K)[16],
                                  uint8_t (&Out)[16]);
 
+/// Compute a stable 64-bit hash of the given string.
+///
+/// The exact algorithm is the little-endian interpretation of the
+/// non-doubled (i.e. 64-bit) result of applying a SipHash-2-4 using
+/// a specific seed value which can be found in the source.
+LLVM_ABI uint64_t getStableSipHash(StringRef Str);
+
 /// Compute a stable non-zero 16-bit hash of the given string.
 ///
 /// The exact algorithm is the little-endian interpretation of the

llvm/lib/Support/SipHash.cpp

@@ -35,14 +35,19 @@ void llvm::getSipHash_2_4_128(ArrayRef<uint8_t> In, const uint8_t (&K)[16],
   siphash<2, 4>(In.data(), In.size(), K, Out);
 }
 
-/// Compute an ABI-stable 16-bit hash of the given string.
-uint16_t llvm::getPointerAuthStableSipHash(StringRef Str) {
+/// Compute an ABI-stable 64-bit hash of the given string.
+uint64_t llvm::getStableSipHash(StringRef Str) {
   static const uint8_t K[16] = {0xb5, 0xd4, 0xc9, 0xeb, 0x79, 0x10, 0x4a, 0x79,
                                 0x6f, 0xec, 0x8b, 0x1b, 0x42, 0x87, 0x81, 0xd4};
 
   uint8_t RawHashBytes[8];
   getSipHash_2_4_64(arrayRefFromStringRef(Str), K, RawHashBytes);
-  uint64_t RawHash = endian::read64le(RawHashBytes);
+  return endian::read64le(RawHashBytes);
+}
+
+/// Compute an ABI-stable 16-bit hash of the given string.
+uint16_t llvm::getPointerAuthStableSipHash(StringRef Str) {
+  uint64_t RawHash = getStableSipHash(Str);
 
   // Produce a non-zero 16-bit discriminator.
   uint16_t Discriminator = (RawHash % 0xFFFF) + 1;

llvm/lib/Transforms/Instrumentation/AllocToken.cpp

@@ -40,8 +40,8 @@
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/RandomNumberGenerator.h"
+#include "llvm/Support/SipHash.h"
 #include "llvm/Support/raw_ostream.h"
-#include "llvm/Support/xxhash.h"
 #include <cassert>
 #include <cstddef>
 #include <cstdint>
@@ -176,7 +176,7 @@ class RandomMode : public ModeBase {
 };
 
 /// Implementation for TokenMode::TypeHash. The implementation ensures
-/// hashes are stable across different compiler invocations. Uses xxHash as the
+/// hashes are stable across different compiler invocations. Uses SipHash as the
 /// hash function.
 class TypeHashMode : public ModeBase {
 public:
@@ -185,7 +185,7 @@ class TypeHashMode : public ModeBase {
   uint64_t operator()(const CallBase &CB, OptimizationRemarkEmitter &ORE) {
     if (MDNode *N = getAllocTokenMetadata(CB)) {
       MDString *S = cast<MDString>(N->getOperand(0));
-      return boundedToken(xxHash64(S->getString()));
+      return boundedToken(getStableSipHash(S->getString()));
     }
     remarkNoMetadata(CB, ORE);
     return ClFallbackToken;

llvm/test/Instrumentation/AllocToken/extralibfuncs.ll

@@ -11,7 +11,7 @@ define ptr @test_extra_libfuncs() sanitize_alloc_token {
 ; CHECK-LABEL: define ptr @test_extra_libfuncs(
 ; CHECK-SAME: ) #[[ATTR1:[0-9]+]] {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
-; CHECK-NEXT:    [[TMP0:%.*]] = call { ptr, i64 } @__alloc_token___size_returning_new(i64 10, i64 6985720287680550851), !alloc_token [[META0:![0-9]+]]
+; CHECK-NEXT:    [[TMP0:%.*]] = call { ptr, i64 } @__alloc_token___size_returning_new(i64 10, i64 2689373973731826898), !alloc_token [[META0:![0-9]+]]
 ; CHECK-NEXT:    [[PTR1:%.*]] = extractvalue { ptr, i64 } [[TMP0]], 0
 ; CHECK-NEXT:    ret ptr [[PTR1]]
 ;
@@ -28,8 +28,8 @@ define ptr @test_replaceable_new() sanitize_alloc_token {
 ; CHECK-LABEL: define ptr @test_replaceable_new(
 ; CHECK-SAME: ) #[[ATTR1]] {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
-; CHECK-NEXT:    [[TMP0:%.*]] = call ptr @__alloc_token__Znwm(i64 32, i64 6985720287680550851), !alloc_token [[META0]]
-; CHECK-NEXT:    [[TMP1:%.*]] = call ptr @__alloc_token__Znam(i64 64, i64 6985720287680550851), !alloc_token [[META0]]
+; CHECK-NEXT:    [[TMP0:%.*]] = call ptr @__alloc_token__Znwm(i64 32, i64 2689373973731826898), !alloc_token [[META0]]
+; CHECK-NEXT:    [[TMP1:%.*]] = call ptr @__alloc_token__Znam(i64 64, i64 2689373973731826898), !alloc_token [[META0]]
 ; CHECK-NEXT:    ret ptr [[TMP0]]
 ;
 entry:

llvm/test/Instrumentation/AllocToken/remark.ll

@@ -12,7 +12,7 @@ define ptr @test_has_metadata() sanitize_alloc_token {
 ; CHECK-LABEL: define ptr @test_has_metadata(
 ; CHECK-SAME: ) #[[ATTR1:[0-9]+]] {
 ; CHECK-NEXT:  [[ENTRY:.*:]]
-; CHECK-NEXT:    [[TMP0:%.*]] = call ptr @__alloc_token_malloc(i64 64, i64 6985720287680550851), !alloc_token [[META0:![0-9]+]]
+; CHECK-NEXT:    [[TMP0:%.*]] = call ptr @__alloc_token_malloc(i64 64, i64 2689373973731826898), !alloc_token [[META0:![0-9]+]]
 ; CHECK-NEXT:    ret ptr [[TMP0]]
 ;
 entry:

llvm/unittests/Support/SipHashTest.cpp

@@ -50,6 +50,13 @@ TEST(SipHashTest, SipHash_2_4_128) {
   }
 }
 
+// Tests for the 64-bit stable SipHash wrapper.
+TEST(SipHashTest, StableSipHash) {
+  EXPECT_EQ(0xB2BB69BB0A2AC0F1UL, getStableSipHash(""));
+  EXPECT_EQ(0x9304ABFF427B72E8UL, getStableSipHash("strlen"));
+  EXPECT_EQ(0x55F45179A08AE51BUL, getStableSipHash("_ZN1 ind; f"));
+}
+
 // Tests for the ptrauth-specific SipHash wrapper.
 TEST(SipHashTest, PointerAuthSipHash) {
   // Test some basic cases.