This is an archive of the discontinued LLVM Phabricator instance.

Differential D49872

[Polly][ScopDetect] Add option -polly-allow-nonaffine-read and enable by default.
AcceptedPublic

Authored by Meinersbur on Jul 26 2018, 1:32 PM.

Details

Reviewers
grosser
philip.pfaffe
proton
bollu
Summary

Read-only non-affine memory reads are not as destructive to the schedulability of a SCoP as writes are. Typical use cases such as table lookups have no influence on how statements can be arranged relative to other statements in the SCoP. This patch allows non-affine read accesses by default, but non-affine writes will still be rejected unless the -polly-allow-nonaffine flag is passed.

Table lookups are common in codes that @proton is working on adding to LLVM's test-suite.

Diff Detail

Event Timeline

Meinersbur created this revision.Jul 26 2018, 1:32 PM
philip.pfaffe added a comment.Jul 27 2018, 1:59 AM

Does this still allow disproving data dependences?

Meinersbur added a comment.Jul 27 2018, 9:02 AM
In D49872#1177957, @philip.pfaffe wrote:

Does this still allow disproving data dependences?

Just like -polly-allow-nonaffine acesses will be are overestimated to any element in an array. It does not affect dependence checks for other arrays. If the array is not written to at all in the SCoP, there are not even additional dependences.

grosser accepted this revision.Jul 28 2018, 10:43 PM

Hi Michael,

this changes works for me. Thanks Michael.

Best,
Tobias

This revision is now accepted and ready to land.Jul 28 2018, 10:43 PM
Meinersbur added a comment.Jul 30 2018, 7:57 PM

Cannot commit this as it miscompiles a few test-suite tests (as does -polly-allow-nonaffine):

FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pabsw_239.test (64 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_packssdw_217.test (67 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_packusdw_296.test (73 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_paddsw_102.test (97 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_paddusw_104.test (104 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_paddw_92.test (110 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pavgw_127.test (119 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pavgw_128.test (120 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pcmpeqw_113.test (146 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pcmpgtw_114.test (160 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pmaxsw_129.test (174 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pmaxuw_283.test (186 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pminsw_130.test (194 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pminuw_284.test (206 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pmulhuw_110.test (210 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pmulhuw_134.test (212 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pmulhuw_133.test (213 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pmulhuw_135.test (214 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pmulhw_106.test (227 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pmulhw_107.test (228 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pmulhw_109.test (230 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pmulhw_108.test (231 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_pmullw_94.test (248 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_psubsw_103.test (265 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_psubusw_105.test (273 of 1340)
FAIL: test-suite :: Bitcode/simd_ops/simd_ops_test_op_psubw_93.test (281 of 1340)
NOEXE: test-suite :: External/SPEC/CFP2017rate/526.blender_r/526.blender_r.test (532 of 1340)
FAIL: test-suite :: External/SPEC/CINT2006/401.bzip2/401.bzip2.test (554 of 1340)
FAIL: test-suite :: External/SPEC/CINT2006/458.sjeng/458.sjeng.test (563 of 1340)
FAIL: test-suite :: External/SPEC/CINT2017rate/502.gcc_r/502.gcc_r.test (569 of 1340)
FAIL: test-suite :: External/SPEC/CINT2017speed/602.gcc_s/602.gcc_s.test (578 of 1340)
FAIL: test-suite :: MultiSource/Benchmarks/TSVC/ControlLoops-flt/ControlLoops-flt.test (741 of 1340)
FAIL: test-suite :: MultiSource/Benchmarks/TSVC/ControlLoops-dbl/ControlLoops-dbl.test (742 of 1340)
FAIL: test-suite :: Polybench/Polybench-boost/linear-algebra/kernels/3mm/Pboost_3mm.test (1021 of 1340)
grosser added a comment.Jul 31 2018, 2:35 AM

Interesting. Any idea what is going wrong here?

Revision Contents

PathSize
lib/
Analysis/
19 lines
test/
Isl/
CodeGen/
2 lines
ScopDetect/
40 lines
2 lines
2 lines
2 lines
ScopDetectionDiagnostics/
12 lines

Diff 157561

lib/Analysis/ScopDetection.cpp

Show First 20 Lines • Show All 187 Lines • ▼ Show 20 Lines
static cl::opt<bool> static cl::opt<bool>
AllowNonAffine("polly-allow-nonaffine", AllowNonAffine("polly-allow-nonaffine",
cl::desc("Allow non affine access functions in arrays"), cl::desc("Allow non affine access functions in arrays"),
cl::Hidden, cl::init(false), cl::ZeroOrMore, cl::Hidden, cl::init(false), cl::ZeroOrMore,
cl::cat(PollyCategory)); cl::cat(PollyCategory));
static cl::opt<bool> static cl::opt<bool>
AllowNonAffineRead("polly-allow-nonaffine-read",
cl::desc("Allow non-affine read functions in arrays"),
cl::Hidden, cl::init(true), cl::ZeroOrMore,
cl::cat(PollyCategory));
static cl::opt<bool>
AllowModrefCall("polly-allow-modref-calls", AllowModrefCall("polly-allow-modref-calls",
cl::desc("Allow functions with known modref behavior"), cl::desc("Allow functions with known modref behavior"),
cl::Hidden, cl::init(false), cl::ZeroOrMore, cl::Hidden, cl::init(false), cl::ZeroOrMore,
cl::cat(PollyCategory)); cl::cat(PollyCategory));
static cl::opt<bool> AllowNonAffineSubRegions( static cl::opt<bool> AllowNonAffineSubRegions(
"polly-allow-nonaffine-branches", "polly-allow-nonaffine-branches",
cl::desc("Allow non affine conditions for branches"), cl::Hidden, cl::desc("Allow non affine conditions for branches"), cl::Hidden,
▲ Show 20 Lines • Show All 749 Lines • ▼ Show 20 Linesbool ScopDetection::hasValidArraySizes(DetectionContext &Context,
if (Sizes.empty()) { if (Sizes.empty()) {
if (AllowNonAffine) if (AllowNonAffine)
return true; return true;
for (const auto &Pair : Context.Accesses[BasePointer]) { for (const auto &Pair : Context.Accesses[BasePointer]) {
const Instruction *Insn = Pair.first; const Instruction *Insn = Pair.first;
const SCEV *AF = Pair.second; const SCEV *AF = Pair.second;
if (!isAffine(AF, Scope, Context)) { if (!isAffine(AF, Scope, Context) &&
(Insn->mayWriteToMemory() || !AllowNonAffineRead)) {
invalid<ReportNonAffineAccess>(Context, /*Assert=*/true, AF, Insn, invalid<ReportNonAffineAccess>(Context, /*Assert=*/true, AF, Insn,
BaseValue); BaseValue);
if (!KeepGoing) if (!KeepGoing)
return false; return false;
} }
} }
return false; return false;
} }
Show All 38 Lines if (!AF) {
for (const SCEV *S : Acc->DelinearizedSubscripts) for (const SCEV *S : Acc->DelinearizedSubscripts)
if (!isAffine(S, Scope, Context)) if (!isAffine(S, Scope, Context))
IsNonAffine = true; IsNonAffine = true;
} }
// (Possibly) report non affine access // (Possibly) report non affine access
if (IsNonAffine) { if (IsNonAffine) {
BasePtrHasNonAffine = true; BasePtrHasNonAffine = true;
if (!AllowNonAffine) bool AllowThisNonAffine =
AllowNonAffine || (!Insn->mayWriteToMemory() && AllowNonAffineRead);
if (!AllowThisNonAffine)
invalid<ReportNonAffineAccess>(Context, /*Assert=*/true, Pair.second, invalid<ReportNonAffineAccess>(Context, /*Assert=*/true, Pair.second,
Insn, BaseValue); Insn, BaseValue);
if (!KeepGoing && !AllowNonAffine) if (!KeepGoing && !AllowThisNonAffine)
return false; return false;
} }
} }
if (!BasePtrHasNonAffine) if (!BasePtrHasNonAffine)
Context.InsnToMemAcc.insert(TempMemoryAccesses.begin(), Context.InsnToMemAcc.insert(TempMemoryAccesses.begin(),
TempMemoryAccesses.end()); TempMemoryAccesses.end());
▲ Show 20 Lines • Show All 91 Lines • ▼ Show 20 Lines if (isa<MemIntrinsic>(Inst) && !IsAffine) {
return invalid<ReportNonAffineAccess>(Context, /*Assert=*/true, AF, Inst, return invalid<ReportNonAffineAccess>(Context, /*Assert=*/true, AF, Inst,
BV); BV);
} else if (PollyDelinearize && !IsVariantInNonAffineLoop) { } else if (PollyDelinearize && !IsVariantInNonAffineLoop) {
Context.Accesses[BP].push_back({Inst, AF}); Context.Accesses[BP].push_back({Inst, AF});
if (!IsAffine || hasIVParams(AF)) if (!IsAffine || hasIVParams(AF))
Context.NonAffineAccesses.insert( Context.NonAffineAccesses.insert(
std::make_pair(BP, LI.getLoopFor(Inst->getParent()))); std::make_pair(BP, LI.getLoopFor(Inst->getParent())));
} else if (!AllowNonAffine && !IsAffine) { } else if (!IsAffine && !AllowNonAffine &&
(Inst->mayWriteToMemory() || !AllowNonAffineRead)) {
return invalid<ReportNonAffineAccess>(Context, /*Assert=*/true, AF, Inst, return invalid<ReportNonAffineAccess>(Context, /*Assert=*/true, AF, Inst,
BV); BV);
} }
if (IgnoreAliasing) if (IgnoreAliasing)
return true; return true;
// Check if the base pointer of the memory access does alias with // Check if the base pointer of the memory access does alias with
▲ Show 20 Lines • Show All 810 Lines • Show Last 20 Lines

test/Isl/CodeGen/two-loops-right-after-each-other-2.ll

; RUN: opt %loadPolly -polly-codegen -S < %s | FileCheck %s ; RUN: opt %loadPolly -polly-codegen -polly-allow-nonaffine-read=0 -S < %s | FileCheck %s
; CHECK: polly.merge_new_and_old: ; CHECK: polly.merge_new_and_old:
; CHECK-NEXT: merge = phi ; CHECK-NEXT: merge = phi
%struct.ImageParameters = type { i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, float, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i8**, i8**, i32, i32***, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [9 x [16 x [16 x i16]]], [5 x [16 x [16 x i16]]], [9 x [8 x [8 x i16]]], [2 x [4 x [16 x [16 x i16]]]], [16 x [16 x i16]], [16 x [16 x i32]], i32****, i32***, i32***, i32***, i32****, i32****, %struct.Picture*, %struct.Slice*, %struct.macroblock*, i32*, i32*, i32, i32, i32, i32, [4 x [4 x i32]], i32, i32, i32, i32, i32, double, i32, i32, i32, i32, i16******, i16******, i16******, i16******, [15 x i16], i32, i32, i32, i32, i32, i32, i32, i32, [6 x [32 x i32]], i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [1 x i32], i32, i32, [2 x i32], i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, %struct.DecRefPicMarking*, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, double**, double***, i32***, double**, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [3 x [2 x i32]], [2 x i32], i32, i32, i16, i32, i32, i32, i32, i32 } %struct.ImageParameters = type { i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, float, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i8**, i8**, i32, i32***, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [9 x [16 x [16 x i16]]], [5 x [16 x [16 x i16]]], [9 x [8 x [8 x i16]]], [2 x [4 x [16 x [16 x i16]]]], [16 x [16 x i16]], [16 x [16 x i32]], i32****, i32***, i32***, i32***, i32****, i32****, %struct.Picture*, %struct.Slice*, %struct.macroblock*, i32*, i32*, i32, i32, i32, i32, [4 x [4 x i32]], i32, i32, i32, i32, i32, double, i32, i32, i32, i32, i16******, i16******, i16******, i16******, [15 x i16], i32, i32, i32, i32, i32, i32, i32, i32, [6 x [32 x i32]], i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [1 x i32], i32, i32, [2 x i32], i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, %struct.DecRefPicMarking*, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, double**, double***, i32***, double**, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [3 x [2 x i32]], [2 x i32], i32, i32, i16, i32, i32, i32, i32, i32 }
%struct.Picture = type { i32, i32, [100 x %struct.Slice*], i32, float, float, float } %struct.Picture = type { i32, i32, [100 x %struct.Slice*], i32, float, float, float }
%struct.Slice = type { i32, i32, i32, i32, i32, i32, %struct.datapartition*, %struct.MotionInfoContexts*, %struct.TextureInfoContexts*, i32, i32*, i32*, i32*, i32, i32*, i32*, i32*, i32 (i32)*, [3 x [2 x i32]] } %struct.Slice = type { i32, i32, i32, i32, i32, i32, %struct.datapartition*, %struct.MotionInfoContexts*, %struct.TextureInfoContexts*, i32, i32*, i32*, i32*, i32, i32*, i32*, i32*, i32 (i32)*, [3 x [2 x i32]] }
%struct.datapartition = type { %struct.Bitstream*, %struct.EncodingEnvironment, %struct.EncodingEnvironment } %struct.datapartition = type { %struct.Bitstream*, %struct.EncodingEnvironment, %struct.EncodingEnvironment }
▲ Show 20 Lines • Show All 50 Lines • Show Last 20 Lines

test/ScopDetect/allow-nonaffine-read.ll

  • This file was added.
; RUN: opt %loadPolly -polly-detect -polly-allow-nonaffine-read=1 -analyze < %s | FileCheck %s -match-full-lines
;
; The non-affine lookup in the loop body must be allowed.
;
; for (int j = 0; j < n; j += 1) {
; int idx = A[j];
; double val = B[idx];
; C[0] = val;
; }
;
define void @func(i32 %n, i32* noalias nonnull %A, double* noalias nonnull %B, double* noalias nonnull %C) {
entry:
br label %for
for:
%j = phi i32 [0, %entry], [%j.inc, %inc]
%j.cmp = icmp slt i32 %j, %n
br i1 %j.cmp, label %body, label %exit
body:
%idxidx = getelementptr inbounds i32, i32* %A, i32 %j
%idx = load i32, i32* %idxidx
%validx = getelementptr inbounds double, double* %B, i32 %idx
%val = load double, double* %validx
store double %val, double* %C
br label %inc
inc:
%j.inc = add nuw nsw i32 %j, 1
br label %for
exit:
br label %return
return:
ret void
}
; CHECK: Valid Region for Scop: for => return

test/ScopDetect/multidim.ll

; RUN: opt %loadPolly -polly-detect -analyze < %s | FileCheck %s ; RUN: opt %loadPolly -polly-detect -polly-allow-nonaffine-read=0 -analyze < %s | FileCheck %s
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
; CHECK: Valid Region for Scop: bb19 => bb20 ; CHECK: Valid Region for Scop: bb19 => bb20
; Make sure we do not crash in this test case. ; Make sure we do not crash in this test case.
define void @hoge(i8* %arg) { define void @hoge(i8* %arg) {
bb: bb:
Show All 27 Lines

test/ScopDetect/non-affine-loop.ll

; RUN: opt %loadPolly -polly-detect -polly-allow-nonaffine-branches \ ; RUN: opt %loadPolly -polly-detect -polly-allow-nonaffine-branches \
; RUN: -polly-allow-nonaffine-loops=false \ ; RUN: -polly-allow-nonaffine-loops=false \
; RUN: -analyze < %s | FileCheck %s --check-prefix=REJECTNONAFFINELOOPS ; RUN: -analyze < %s | FileCheck %s --check-prefix=REJECTNONAFFINELOOPS
; RUN: opt %loadPolly -polly-detect -polly-allow-nonaffine-branches \ ; RUN: opt %loadPolly -polly-detect -polly-allow-nonaffine-branches \
; RUN: -polly-allow-nonaffine-loops=true \ ; RUN: -polly-allow-nonaffine-loops=true -polly-allow-nonaffine-read=0 \
; RUN: -analyze < %s | FileCheck %s --check-prefix=ALLOWNONAFFINELOOPS ; RUN: -analyze < %s | FileCheck %s --check-prefix=ALLOWNONAFFINELOOPS
; RUN: opt %loadPolly -polly-detect -polly-allow-nonaffine-branches \ ; RUN: opt %loadPolly -polly-detect -polly-allow-nonaffine-branches \
; RUN: -polly-allow-nonaffine-loops=false -polly-allow-nonaffine \ ; RUN: -polly-allow-nonaffine-loops=false -polly-allow-nonaffine \
; RUN: -analyze < %s | FileCheck %s \ ; RUN: -analyze < %s | FileCheck %s \
; RUN: --check-prefix=ALLOWNONAFFINEREGIONSANDACCESSES ; RUN: --check-prefix=ALLOWNONAFFINEREGIONSANDACCESSES
; RUN: opt %loadPolly -polly-detect -polly-allow-nonaffine-branches \ ; RUN: opt %loadPolly -polly-detect -polly-allow-nonaffine-branches \
; RUN: -polly-allow-nonaffine-loops=true -polly-allow-nonaffine \ ; RUN: -polly-allow-nonaffine-loops=true -polly-allow-nonaffine \
; RUN: -analyze < %s | FileCheck %s \ ; RUN: -analyze < %s | FileCheck %s \
▲ Show 20 Lines • Show All 51 Lines • Show Last 20 Lines

test/ScopDetect/parametric-multiply-in-scev-2.ll

; RUN: opt %loadPolly -polly-detect -analyze < %s | FileCheck %s ; RUN: opt %loadPolly -polly-detect -polly-allow-nonaffine-read=0 -analyze < %s | FileCheck %s
; CHECK-NOT: Valid Region ; CHECK-NOT: Valid Region
target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
define void @blam(float* %A, float* %B) { define void @blam(float* %A, float* %B) {
bb: bb:
%tmp1 = alloca i64 %tmp1 = alloca i64
Show All 19 Lines

test/ScopDetectionDiagnostics/ReportMultipleNonAffineAccesses.ll

; RUN: opt %loadPolly -basicaa -pass-remarks-missed="polly-detect" -polly-detect-track-failures -polly-detect -analyze < %s 2>&1| FileCheck %s ; RUN: opt %loadPolly -basicaa -pass-remarks-missed="polly-detect" -polly-allow-nonaffine-read=0 -polly-detect-track-failures -polly-detect -analyze < %s 2>&1| FileCheck %s
; RUN: opt %loadPolly -basicaa -pass-remarks-missed="polly-detect" -polly-detect-track-failures -polly-detect -polly-delinearize=false -polly-detect-keep-going -analyze < %s 2>&1| FileCheck %s -check-prefix=ALL ; RUN: opt %loadPolly -basicaa -pass-remarks-missed="polly-detect" -polly-allow-nonaffine-read=0 -polly-detect-track-failures -polly-detect -polly-delinearize=false -polly-detect-keep-going -analyze < %s 2>&1| FileCheck %s -check-prefix=ALL
; RUN: opt %loadPolly -basicaa -pass-remarks-missed="polly-detect" -polly-detect-track-failures -polly-detect -analyze < %s 2>&1| FileCheck %s -check-prefix=DELIN ; RUN: opt %loadPolly -basicaa -pass-remarks-missed="polly-detect" -polly-allow-nonaffine-read=0 -polly-detect-track-failures -polly-detect -analyze < %s 2>&1| FileCheck %s -check-prefix=DELIN
; RUN: opt %loadPolly -basicaa -pass-remarks-missed="polly-detect" -polly-detect-track-failures -polly-detect -polly-detect-keep-going -analyze < %s 2>&1| FileCheck %s -check-prefix=DELIN-ALL ; RUN: opt %loadPolly -basicaa -pass-remarks-missed="polly-detect" -polly-allow-nonaffine-read=0 -polly-detect-track-failures -polly-detect -polly-detect-keep-going -analyze < %s 2>&1| FileCheck %s -check-prefix=DELIN-ALL
; RUN: opt %loadPolly -basicaa -pass-remarks-missed="polly-detect" -polly-detect-track-failures -polly-detect -polly-allow-nonaffine -analyze < %s 2>&1| FileCheck %s -check-prefix=NONAFFINE ; RUN: opt %loadPolly -basicaa -pass-remarks-missed="polly-detect" -polly-allow-nonaffine-read=0 -polly-detect-track-failures -polly-detect -polly-allow-nonaffine -analyze < %s 2>&1| FileCheck %s -check-prefix=NONAFFINE
; RUN: opt %loadPolly -basicaa -pass-remarks-missed="polly-detect" -polly-detect-track-failures -polly-detect -polly-allow-nonaffine -analyze < %s 2>&1| FileCheck %s -check-prefix=NONAFFINE ; RUN: opt %loadPolly -basicaa -pass-remarks-missed="polly-detect" -polly-allow-nonaffine-read=0 -polly-detect-track-failures -polly-detect -polly-allow-nonaffine -analyze < %s 2>&1| FileCheck %s -check-prefix=NONAFFINE
; 1 void manyaccesses(float A[restrict], long n, float B[restrict][n]) ; 1 void manyaccesses(float A[restrict], long n, float B[restrict][n])
; 2 { ; 2 {
; 3 for (long i = 0; i < 1024; ++i) { ; 3 for (long i = 0; i < 1024; ++i) {
; 4 float a1 = A[2 * i * i]; ; 4 float a1 = A[2 * i * i];
; 5 float a2 = A[2 * i * i + 1]; ; 5 float a2 = A[2 * i * i + 1];
; 6 float b1 = B[0][0]; ; 6 float b1 = B[0][0];
; 7 float b2 = B[i][i]; ; 7 float b2 = B[i][i];
▲ Show 20 Lines • Show All 139 Lines • Show Last 20 Lines