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Commit caef3486 by Jim Stichnoth
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Subzero: Use a "deterministic" random shuffle for register allocation.

To make this work, Subzero provides its own RandomShuffle() as a replacement for std::random_shuffle(), and the Subzero implementation doesn't depend on the stdlib implementation. BUG= https://code.google.com/p/nativeclient/issues/detail?id=4129 R=jvoung@chromium.org Review URL: https://codereview.chromium.org/1072913002
parent 6e293c81
Showing with 35 additions and 23 deletions
src/IceRNG.h
...@@ -53,6 +53,15 @@ private: ...@@ -53,6 +53,15 @@ private:
RandomNumberGenerator &RNG; RandomNumberGenerator &RNG;
}; };
// RandomShuffle is an implementation of std::random_shuffle() that
// doesn't change across stdlib implementations. Adapted from a
// sample implementation at cppreference.com.
template <class RandomIt, class RandomFunc>
void RandomShuffle(RandomIt First, RandomIt Last, RandomFunc &&RNG) {
for (auto i = Last - First - 1; i > 0; --i)
std::swap(First[i], First[RNG(i + 1)]);
}
} // end of namespace Ice } // end of namespace Ice
#endif // SUBZERO_SRC_ICERNG_H #endif // SUBZERO_SRC_ICERNG_H
src/IceTargetLoweringX8632.cpp
...@@ -4621,7 +4621,7 @@ void TargetX8632::makeRandomRegisterPermutation( ...@@ -4621,7 +4621,7 @@ void TargetX8632::makeRandomRegisterPermutation(
for (auto I : EquivalenceClasses) { for (auto I : EquivalenceClasses) {
const RegisterList &List = I.second; const RegisterList &List = I.second;
RegisterList Shuffled(List); RegisterList Shuffled(List);
std::random_shuffle(Shuffled.begin(), Shuffled.end(), RNG); RandomShuffle(Shuffled.begin(), Shuffled.end(), RNG);
for (size_t SI = 0, SE = Shuffled.size(); SI < SE; ++SI) { for (size_t SI = 0, SE = Shuffled.size(); SI < SE; ++SI) {
Permutation[List[SI]] = Shuffled[SI]; Permutation[List[SI]] = Shuffled[SI];
++NumShuffled; ++NumShuffled;
......
tests_lit/llvm2ice_tests/randomize-regalloc.ll
...@@ -26,11 +26,11 @@ entry: ...@@ -26,11 +26,11 @@ entry:
; OPTM1_1-NEXT: movups XMMWORD PTR [esp+0x20],xmm0 ; OPTM1_1-NEXT: movups XMMWORD PTR [esp+0x20],xmm0
; OPTM1_1-NEXT: movups XMMWORD PTR [esp+0x10],xmm1 ; OPTM1_1-NEXT: movups XMMWORD PTR [esp+0x10],xmm1
; OPTM1_1-NEXT: movups xmm0,XMMWORD PTR [esp+0x20] ; OPTM1_1-NEXT: movups xmm0,XMMWORD PTR [esp+0x20]
; OPTM1_1-NEXT: pshufd xmm7,XMMWORD PTR [esp+0x20],0x31 ; OPTM1_1-NEXT: pshufd xmm1,XMMWORD PTR [esp+0x20],0x31
; OPTM1_1-NEXT: pshufd xmm4,XMMWORD PTR [esp+0x10],0x31 ; OPTM1_1-NEXT: pshufd xmm2,XMMWORD PTR [esp+0x10],0x31
; OPTM1_1-NEXT: pmuludq xmm0,XMMWORD PTR [esp+0x10] ; OPTM1_1-NEXT: pmuludq xmm0,XMMWORD PTR [esp+0x10]
; OPTM1_1-NEXT: pmuludq xmm7,xmm4 ; OPTM1_1-NEXT: pmuludq xmm1,xmm2
; OPTM1_1-NEXT: shufps xmm0,xmm7,0x88 ; OPTM1_1-NEXT: shufps xmm0,xmm1,0x88
; OPTM1_1-NEXT: pshufd xmm0,xmm0,0xd8 ; OPTM1_1-NEXT: pshufd xmm0,xmm0,0xd8
; OPTM1_1-NEXT: movups XMMWORD PTR [esp],xmm0 ; OPTM1_1-NEXT: movups XMMWORD PTR [esp],xmm0
; OPTM1_1-NEXT: movups xmm0,XMMWORD PTR [esp] ; OPTM1_1-NEXT: movups xmm0,XMMWORD PTR [esp]
...@@ -38,14 +38,14 @@ entry: ...@@ -38,14 +38,14 @@ entry:
; OPTM1_1-NEXT: ret ; OPTM1_1-NEXT: ret
; CHECK_1-LABEL: mul_v4i32 ; CHECK_1-LABEL: mul_v4i32
; CHECK_1: movups xmm6,xmm0 ; CHECK_1: movups xmm5,xmm0
; CHECK_1-NEXT: pshufd xmm0,xmm0,0x31 ; CHECK_1-NEXT: pshufd xmm0,xmm0,0x31
; CHECK_1-NEXT: pshufd xmm5,xmm1,0x31 ; CHECK_1-NEXT: pshufd xmm3,xmm1,0x31
; CHECK_1-NEXT: pmuludq xmm6,xmm1 ; CHECK_1-NEXT: pmuludq xmm5,xmm1
; CHECK_1-NEXT: pmuludq xmm0,xmm5 ; CHECK_1-NEXT: pmuludq xmm0,xmm3
; CHECK_1-NEXT: shufps xmm6,xmm0,0x88 ; CHECK_1-NEXT: shufps xmm5,xmm0,0x88
; CHECK_1-NEXT: pshufd xmm6,xmm6,0xd8 ; CHECK_1-NEXT: pshufd xmm5,xmm5,0xd8
; CHECK_1-NEXT: movups xmm0,xmm6 ; CHECK_1-NEXT: movups xmm0,xmm5
; CHECK_1-NEXT: ret ; CHECK_1-NEXT: ret
; OPTM1_123-LABEL: mul_v4i32 ; OPTM1_123-LABEL: mul_v4i32
...@@ -53,11 +53,11 @@ entry: ...@@ -53,11 +53,11 @@ entry:
; OPTM1_123-NEXT: movups XMMWORD PTR [esp+0x20],xmm0 ; OPTM1_123-NEXT: movups XMMWORD PTR [esp+0x20],xmm0
; OPTM1_123-NEXT: movups XMMWORD PTR [esp+0x10],xmm1 ; OPTM1_123-NEXT: movups XMMWORD PTR [esp+0x10],xmm1
; OPTM1_123-NEXT: movups xmm0,XMMWORD PTR [esp+0x20] ; OPTM1_123-NEXT: movups xmm0,XMMWORD PTR [esp+0x20]
; OPTM1_123-NEXT: pshufd xmm2,XMMWORD PTR [esp+0x20],0x31 ; OPTM1_123-NEXT: pshufd xmm1,XMMWORD PTR [esp+0x20],0x31
; OPTM1_123-NEXT: pshufd xmm6,XMMWORD PTR [esp+0x10],0x31 ; OPTM1_123-NEXT: pshufd xmm6,XMMWORD PTR [esp+0x10],0x31
; OPTM1_123-NEXT: pmuludq xmm0,XMMWORD PTR [esp+0x10] ; OPTM1_123-NEXT: pmuludq xmm0,XMMWORD PTR [esp+0x10]
; OPTM1_123-NEXT: pmuludq xmm2,xmm6 ; OPTM1_123-NEXT: pmuludq xmm1,xmm6
; OPTM1_123-NEXT: shufps xmm0,xmm2,0x88 ; OPTM1_123-NEXT: shufps xmm0,xmm1,0x88
; OPTM1_123-NEXT: pshufd xmm0,xmm0,0xd8 ; OPTM1_123-NEXT: pshufd xmm0,xmm0,0xd8
; OPTM1_123-NEXT: movups XMMWORD PTR [esp],xmm0 ; OPTM1_123-NEXT: movups XMMWORD PTR [esp],xmm0
; OPTM1_123-NEXT: movups xmm0,XMMWORD PTR [esp] ; OPTM1_123-NEXT: movups xmm0,XMMWORD PTR [esp]
...@@ -65,14 +65,14 @@ entry: ...@@ -65,14 +65,14 @@ entry:
; OPTM1_123-NEXT: ret ; OPTM1_123-NEXT: ret
; CHECK_123-LABEL: mul_v4i32 ; CHECK_123-LABEL: mul_v4i32
; CHECK_123: movups xmm3,xmm0 ; CHECK_123: movups xmm4,xmm0
; CHECK_123-NEXT: pshufd xmm0,xmm0,0x31 ; CHECK_123-NEXT: pshufd xmm0,xmm0,0x31
; CHECK_123-NEXT: pshufd xmm7,xmm1,0x31 ; CHECK_123-NEXT: pshufd xmm2,xmm1,0x31
; CHECK_123-NEXT: pmuludq xmm3,xmm1 ; CHECK_123-NEXT: pmuludq xmm4,xmm1
; CHECK_123-NEXT: pmuludq xmm0,xmm7 ; CHECK_123-NEXT: pmuludq xmm0,xmm2
; CHECK_123-NEXT: shufps xmm3,xmm0,0x88 ; CHECK_123-NEXT: shufps xmm4,xmm0,0x88
; CHECK_123-NEXT: pshufd xmm3,xmm3,0xd8 ; CHECK_123-NEXT: pshufd xmm4,xmm4,0xd8
; CHECK_123-NEXT: movups xmm0,xmm3 ; CHECK_123-NEXT: movups xmm0,xmm4
; CHECK_123-NEXT: ret ; CHECK_123-NEXT: ret
} }
......
unittest/IceELFSectionTest.cpp
...@@ -90,8 +90,11 @@ TEST(IceELFSectionTest, StringTableBuilderPermSeveral) { ...@@ -90,8 +90,11 @@ TEST(IceELFSectionTest, StringTableBuilderPermSeveral) {
Strings.push_back(".shstrtab"); Strings.push_back(".shstrtab");
Strings.push_back("_start"); Strings.push_back("_start");
const SizeT NumTests = 128; const SizeT NumTests = 128;
const uint64_t RandomSeed = 12345; // arbitrary value for now
RandomNumberGenerator R(RandomSeed);
RandomNumberGeneratorWrapper RNG(R);
for (SizeT i = 0; i < NumTests; ++i) { for (SizeT i = 0; i < NumTests; ++i) {
std::random_shuffle(Strings.begin(), Strings.end()); RandomShuffle(Strings.begin(), Strings.end(), RNG);
ELFStringTableSection Strtab(".strtab", SHT_STRTAB, 0, 1, 0); ELFStringTableSection Strtab(".strtab", SHT_STRTAB, 0, 1, 0);
for (auto &S : Strings) { for (auto &S : Strings) {
Strtab.add(S); Strtab.add(S);
......
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