[llvm] 7086025 - [Dependence Analysis] Enable delinearization of fixed sized arrays
Andy Kaylor via llvm-commits
llvm-commits at lists.llvm.org
Mon May 10 10:30:45 PDT 2021
Author: Andy Kaylor
Date: 2021-05-10T10:30:15-07:00
New Revision: 7086025d6567562d31fadbaccf08b4fd72ec2100
URL: https://github.com/llvm/llvm-project/commit/7086025d6567562d31fadbaccf08b4fd72ec2100
DIFF: https://github.com/llvm/llvm-project/commit/7086025d6567562d31fadbaccf08b4fd72ec2100.diff
LOG: [Dependence Analysis] Enable delinearization of fixed sized arrays
Patch by Artem Radzikhovskyy!
Allow delinearization of fixed sized arrays if we can prove that the GEP indices do not overflow the array dimensions. The checks applied are similar to the ones that are used for delinearization of parametric size arrays. Make sure that the GEP indices are non-negative and that they are smaller than the range of that dimension.
Changes Summary:
- Updated the LIT tests with more exact values, as we are able to delinearize and apply more exact tests
- profitability.ll - now able to delinearize in all cases, no need to use -da-disable-delinearization-checks flag and run the test twice
- loop-interchange-optimization-remarks.ll - in one of the cases we are able to delinearize without using -da-disable-delinearization-checks
- SimpleSIVNoValidityCheckFixedSize.ll - removed unnecessary "-da-disable-delinearization-checks" flag. Now can get the exact answer without it.
- SimpleSIVNoValidityCheckFixedSize.ll and PreliminaryNoValidityCheckFixedSize.ll - made negative tests more explicit, in order to demonstrate the need for "-da-disable-delinearization-checks" flag
Differential Revision: https://reviews.llvm.org/D101486
Added:
Modified:
llvm/lib/Analysis/DependenceAnalysis.cpp
llvm/test/Analysis/DependenceAnalysis/Coupled.ll
llvm/test/Analysis/DependenceAnalysis/Invariant.ll
llvm/test/Analysis/DependenceAnalysis/PreliminaryNoValidityCheckFixedSize.ll
llvm/test/Analysis/DependenceAnalysis/Separability.ll
llvm/test/Analysis/DependenceAnalysis/SimpleSIVNoValidityCheck.ll
llvm/test/Analysis/DependenceAnalysis/SimpleSIVNoValidityCheckFixedSize.ll
llvm/test/Transforms/LoopInterchange/loop-interchange-optimization-remarks.ll
llvm/test/Transforms/LoopInterchange/profitability.ll
Removed:
################################################################################
diff --git a/llvm/lib/Analysis/DependenceAnalysis.cpp b/llvm/lib/Analysis/DependenceAnalysis.cpp
index be6046113d30c..f11cce38406ad 100644
--- a/llvm/lib/Analysis/DependenceAnalysis.cpp
+++ b/llvm/lib/Analysis/DependenceAnalysis.cpp
@@ -3304,16 +3304,6 @@ bool DependenceInfo::tryDelinearizeFixedSize(
const SCEV *DstAccessFn, SmallVectorImpl<const SCEV *> &SrcSubscripts,
SmallVectorImpl<const SCEV *> &DstSubscripts) {
- // In general we cannot safely assume that the subscripts recovered from GEPs
- // are in the range of values defined for their corresponding array
- // dimensions. For example some C language usage/interpretation make it
- // impossible to verify this at compile-time. As such we give up here unless
- // we can assume that the subscripts do not overlap into neighboring
- // dimensions and that the number of dimensions matches the number of
- // subscripts being recovered.
- if (!DisableDelinearizationChecks)
- return false;
-
Value *SrcPtr = getLoadStorePointerOperand(Src);
Value *DstPtr = getLoadStorePointerOperand(Dst);
const SCEVUnknown *SrcBase =
@@ -3352,22 +3342,55 @@ bool DependenceInfo::tryDelinearizeFixedSize(
// Check that for identical base pointers we do not miss index offsets
// that have been added before this GEP is applied.
- if (SrcBasePtr == SrcBase->getValue() && DstBasePtr == DstBase->getValue()) {
- assert(SrcSubscripts.size() == DstSubscripts.size() &&
- SrcSubscripts.size() == SrcSizes.size() + 1 &&
- "Expected equal number of entries in the list of sizes and "
- "subscripts.");
- LLVM_DEBUG({
- dbgs() << "Delinearized subscripts of fixed-size array\n"
- << "SrcGEP:" << *SrcGEP << "\n"
- << "DstGEP:" << *DstGEP << "\n";
- });
- return true;
+ if (SrcBasePtr != SrcBase->getValue() || DstBasePtr != DstBase->getValue()) {
+ SrcSubscripts.clear();
+ DstSubscripts.clear();
+ return false;
}
- SrcSubscripts.clear();
- DstSubscripts.clear();
- return false;
+ assert(SrcSubscripts.size() == DstSubscripts.size() &&
+ SrcSubscripts.size() == SrcSizes.size() + 1 &&
+ "Expected equal number of entries in the list of sizes and "
+ "subscripts.");
+
+ // In general we cannot safely assume that the subscripts recovered from GEPs
+ // are in the range of values defined for their corresponding array
+ // dimensions. For example some C language usage/interpretation make it
+ // impossible to verify this at compile-time. As such we can only delinearize
+ // iff the subscripts are positive and are less than the range of the
+ // dimension.
+ if (!DisableDelinearizationChecks) {
+ auto AllIndiciesInRange = [&](SmallVector<int, 4> &DimensionSizes,
+ SmallVectorImpl<const SCEV *> &Subscripts,
+ Value *Ptr) {
+ size_t SSize = Subscripts.size();
+ for (size_t I = 1; I < SSize; ++I) {
+ const SCEV *S = Subscripts[I];
+ if (!isKnownNonNegative(S, Ptr))
+ return false;
+ if (auto *SType = dyn_cast<IntegerType>(S->getType())) {
+ const SCEV *Range = SE->getConstant(
+ ConstantInt::get(SType, DimensionSizes[I - 1], false));
+ if (!isKnownLessThan(S, Range))
+ return false;
+ }
+ }
+ return true;
+ };
+
+ if (!AllIndiciesInRange(SrcSizes, SrcSubscripts, SrcPtr) ||
+ !AllIndiciesInRange(DstSizes, DstSubscripts, DstPtr)) {
+ SrcSubscripts.clear();
+ DstSubscripts.clear();
+ return false;
+ }
+ }
+ LLVM_DEBUG({
+ dbgs() << "Delinearized subscripts of fixed-size array\n"
+ << "SrcGEP:" << *SrcGEP << "\n"
+ << "DstGEP:" << *DstGEP << "\n";
+ });
+ return true;
}
bool DependenceInfo::tryDelinearizeParametricSize(
diff --git a/llvm/test/Analysis/DependenceAnalysis/Coupled.ll b/llvm/test/Analysis/DependenceAnalysis/Coupled.ll
index 4817bc922a1c0..942e5a4350019 100644
--- a/llvm/test/Analysis/DependenceAnalysis/Coupled.ll
+++ b/llvm/test/Analysis/DependenceAnalysis/Coupled.ll
@@ -438,7 +438,8 @@ entry:
; CHECK-LABEL: couple11
; CHECK: da analyze - none!
-; CHECK: da analyze - flow [=|<]!
+; CHECK: da analyze - flow [=|<] splitable!
+; CHECK: da analyze - split level = 1, iteration = 9!
; CHECK: da analyze - confused!
; CHECK: da analyze - none!
; CHECK: da analyze - confused!
@@ -476,7 +477,8 @@ entry:
; CHECK-LABEL: couple12
; CHECK: da analyze - none!
-; CHECK: da analyze - flow [<]!
+; CHECK: da analyze - flow [<] splitable!
+; CHECK: da analyze - split level = 1, iteration = 11!
; CHECK: da analyze - confused!
; CHECK: da analyze - none!
; CHECK: da analyze - confused!
diff --git a/llvm/test/Analysis/DependenceAnalysis/Invariant.ll b/llvm/test/Analysis/DependenceAnalysis/Invariant.ll
index 20358768bc827..94fddcca72128 100644
--- a/llvm/test/Analysis/DependenceAnalysis/Invariant.ll
+++ b/llvm/test/Analysis/DependenceAnalysis/Invariant.ll
@@ -5,9 +5,20 @@
; Test for a bug, which caused an assert when an invalid
; SCEVAddRecExpr is created in addToCoefficient.
+; float foo (float g, float* rr[40]) {
+; float res= 0.0f;
+; for (int i = 0; i < 40; i += 5) {
+; for (int j = 0; j < 40; j += 5) {
+; float add = rr[j][j] + rr[i][j];
+; res = add > g? add : res;
+; }
+; }
+; return res;
+; }
+
; CHECK-LABEL: foo
; CHECK: da analyze - consistent input [S 0]!
-; CHECK: da analyze - input [* *|<]!
+; CHECK: da analyze - input [* 0|<]!
; CHECK: da analyze - none!
define float @foo(float %g, [40 x float]* %rr) nounwind {
diff --git a/llvm/test/Analysis/DependenceAnalysis/PreliminaryNoValidityCheckFixedSize.ll b/llvm/test/Analysis/DependenceAnalysis/PreliminaryNoValidityCheckFixedSize.ll
index 21bc37d17047d..d91d3a5d384fd 100644
--- a/llvm/test/Analysis/DependenceAnalysis/PreliminaryNoValidityCheckFixedSize.ll
+++ b/llvm/test/Analysis/DependenceAnalysis/PreliminaryNoValidityCheckFixedSize.ll
@@ -1,5 +1,7 @@
; RUN: opt < %s -disable-output "-passes=print<da>" -aa-pipeline=basic-aa 2>&1 \
; RUN: -da-disable-delinearization-checks | FileCheck %s
+; RUN: opt < %s -disable-output "-passes=print<da>" -aa-pipeline=basic-aa 2>&1 \
+; RUN: | FileCheck --check-prefix=LIN %s
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.6.0"
@@ -25,6 +27,14 @@ entry:
; CHECK: da analyze - confused!
; CHECK: da analyze - output [* * *]!
+; LIN-LABEL: p2
+; LIN: da analyze - output [* * *]!
+; LIN: da analyze - flow [* *|<]!
+; LIN: da analyze - confused!
+; LIN: da analyze - input [* * *]!
+; LIN: da analyze - confused!
+; LIN: da analyze - output [* * *]!
+
for.cond1.preheader.preheader: ; preds = %entry
br label %for.cond1.preheader
diff --git a/llvm/test/Analysis/DependenceAnalysis/Separability.ll b/llvm/test/Analysis/DependenceAnalysis/Separability.ll
index 93803cf5c0694..6ced53ec4ffa2 100644
--- a/llvm/test/Analysis/DependenceAnalysis/Separability.ll
+++ b/llvm/test/Analysis/DependenceAnalysis/Separability.ll
@@ -17,7 +17,7 @@ define void @sep0([100 x [100 x i32]]* %A, i32* %B, i32 %n) nounwind uwtable ssp
entry:
br label %for.cond1.preheader
-; CHECK: da analyze - output [= * * S]!
+; CHECK: da analyze - output [0 * * S]!
; CHECK: da analyze - flow [* * * *|<]!
; CHECK: da analyze - confused!
; CHECK: da analyze - input [* * S *]!
@@ -92,7 +92,7 @@ define void @sep1([100 x [100 x i32]]* %A, i32* %B, i32 %n) nounwind uwtable ssp
entry:
br label %for.cond1.preheader
-; CHECK: da analyze - output [= * * S]!
+; CHECK: da analyze - output [0 * * S]!
; CHECK: da analyze - flow [* * * *|<]!
; CHECK: da analyze - confused!
; CHECK: da analyze - input [* * S *]!
@@ -166,10 +166,10 @@ define void @sep2([100 x [100 x [100 x i32]]]* %A, i32* %B, i32 %n) nounwind uwt
entry:
br label %for.cond1.preheader
-; CHECK: da analyze - output [= S = =]!
-; CHECK: da analyze - flow [* * * <>]!
+; CHECK: da analyze - consistent output [0 S 0 0]!
+; CHECK: da analyze - flow [> * * -10]!
; CHECK: da analyze - confused!
-; CHECK: da analyze - input [= * * *]!
+; CHECK: da analyze - input [0 * * 0]!
; CHECK: da analyze - confused!
; CHECK: da analyze - none!
@@ -240,10 +240,10 @@ define void @sep3([100 x [100 x [100 x i32]]]* %A, i32* %B, i32 %n) nounwind uwt
entry:
br label %for.cond1.preheader
-; CHECK: da analyze - output [= S = =]!
-; CHECK: da analyze - flow [* * * *|<]!
+; CHECK: da analyze - consistent output [0 S 0 0]!
+; CHECK: da analyze - flow [> * * *]!
; CHECK: da analyze - confused!
-; CHECK: da analyze - input [= * * *]!
+; CHECK: da analyze - input [0 * * 0]!
; CHECK: da analyze - confused!
; CHECK: da analyze - none!
diff --git a/llvm/test/Analysis/DependenceAnalysis/SimpleSIVNoValidityCheck.ll b/llvm/test/Analysis/DependenceAnalysis/SimpleSIVNoValidityCheck.ll
index e6ddafdad96dd..45717bc537999 100644
--- a/llvm/test/Analysis/DependenceAnalysis/SimpleSIVNoValidityCheck.ll
+++ b/llvm/test/Analysis/DependenceAnalysis/SimpleSIVNoValidityCheck.ll
@@ -1,12 +1,18 @@
; RUN: opt < %s -disable-output -passes="print<da>" \
; RUN: -da-disable-delinearization-checks 2>&1 | FileCheck %s
-; RUN: opt < %s -da -analyze -enable-new-pm=0 -da-disable-delinearization-checks | FileCheck %s
+; RUN: opt < %s -disable-output -passes="print<da>" \
+; RUN: 2>&1 | FileCheck --check-prefix=LIN %s
; CHECK-LABEL: t1
; CHECK: da analyze - none!
; CHECK: da analyze - consistent anti [1 -2]!
; CHECK: da analyze - none!
+; LIN-LABEL: t1
+; LIN: da analyze - input [* *]!
+; LIN: da analyze - anti [* *|<]!
+; LIN: da analyze - output [* *]!
+
;; void t1(int n, int m, int a[][m]) {
;; for (int i = 0; i < n-1; ++i)
;; for (int j = 2; j < m; ++j)
@@ -58,6 +64,11 @@ for.end14: ; preds = %entry, %for.inc12
; CHECK: da analyze - consistent anti [1 -2 0 -3 2]!
; CHECK: da analyze - none!
+; LIN-LABEL: t2
+; LIN: da analyze - input [* * * * *]!
+; LIN: da analyze - anti [* * * * *|<]!
+; LIN: da analyze - output [* * * * *]!
+
;; void t2(int n, int m, int a[][n][n][n][m]) {
;; for (int i1 = 0; i1 < n-1; ++i1)
;; for (int i2 = 2; i2 < n; ++i2)
@@ -179,6 +190,11 @@ for.end50: ; preds = %entry, %for.inc48
; CHECK: da analyze - consistent anti [1 -2]!
; CHECK: da analyze - none!
+; LIN-LABEL: t3
+; LIN: da analyze - input [* *]!
+; LIN: da analyze - anti [* *|<]!
+; LIN: da analyze - output [* *]!
+
;; // No sign or zero extension, but with compile-time unknown loop lower bound.
;; void t3(unsigned long long n, unsigned long long m, unsigned long long lb, float a[][m]) {
;; for (unsigned long long i = 0; i < n-1; ++i)
diff --git a/llvm/test/Analysis/DependenceAnalysis/SimpleSIVNoValidityCheckFixedSize.ll b/llvm/test/Analysis/DependenceAnalysis/SimpleSIVNoValidityCheckFixedSize.ll
index 5dcba2252e303..082e692790360 100644
--- a/llvm/test/Analysis/DependenceAnalysis/SimpleSIVNoValidityCheckFixedSize.ll
+++ b/llvm/test/Analysis/DependenceAnalysis/SimpleSIVNoValidityCheckFixedSize.ll
@@ -1,6 +1,8 @@
-; RUN: opt < %s -disable-output -passes="print<da>" \
-; RUN: -da-disable-delinearization-checks 2>&1 | FileCheck %s
-; RUN: opt < %s -da -analyze -enable-new-pm=0 -da-disable-delinearization-checks | FileCheck %s
+; RUN: opt < %s -disable-output -passes="print<da>" 2>&1 | FileCheck %s
+; RUN: opt < %s -da -analyze -enable-new-pm=0 | FileCheck %s
+
+; Note: exact results can be achived even if
+; "-da-disable-delinearization-checks" is not used
; CHECK-LABEL: t1
; CHECK: da analyze - none!
diff --git a/llvm/test/Transforms/LoopInterchange/loop-interchange-optimization-remarks.ll b/llvm/test/Transforms/LoopInterchange/loop-interchange-optimization-remarks.ll
index fb66c86a34741..f40a2897a290a 100644
--- a/llvm/test/Transforms/LoopInterchange/loop-interchange-optimization-remarks.ll
+++ b/llvm/test/Transforms/LoopInterchange/loop-interchange-optimization-remarks.ll
@@ -178,12 +178,12 @@ for.body4: ; preds = %for.body4, %for.con
br i1 %exitcond, label %for.body4, label %for.cond.loopexit
}
-; CHECK: --- !Missed
+; CHECK: --- !Passed
; CHECK-NEXT: Pass: loop-interchange
-; CHECK-NEXT: Name: Dependence
+; CHECK-NEXT: Name: Interchanged
; CHECK-NEXT: Function: test03
; CHECK-NEXT: Args:
-; CHECK-NEXT: - String: Cannot interchange loops due to dependences.
+; CHECK-NEXT: - String: Loop interchanged with enclosing loop.
; CHECK-NEXT: ...
; DELIN: --- !Passed
diff --git a/llvm/test/Transforms/LoopInterchange/profitability.ll b/llvm/test/Transforms/LoopInterchange/profitability.ll
index 996ae61284ff4..79706d8afe6a0 100644
--- a/llvm/test/Transforms/LoopInterchange/profitability.ll
+++ b/llvm/test/Transforms/LoopInterchange/profitability.ll
@@ -2,11 +2,6 @@
; RUN: -pass-remarks=loop-interchange -pass-remarks-missed=loop-interchange
; RUN: FileCheck -input-file %t %s
-; RUN: opt < %s -loop-interchange -pass-remarks-output=%t -verify-dom-info -verify-loop-info \
-; RUN: -pass-remarks=loop-interchange -pass-remarks-missed=loop-interchange \
-; RUN: -da-disable-delinearization-checks
-; RUN: FileCheck --check-prefix=DELIN -input-file %t %s
-
;; We test profitability model in these test cases.
target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
@@ -21,12 +16,9 @@ target triple = "x86_64-unknown-linux-gnu"
;; for(int j=1;j<100;j++)
;; A[j][i] = A[j - 1][i] + B[j][i];
-; CHECK: Name: Dependence
+; CHECK: Name: Interchanged
; CHECK-NEXT: Function: interchange_01
-; DELIN: Name: Interchanged
-; DELIN-NEXT: Function: interchange_01
-
define void @interchange_01() {
entry:
br label %for2.preheader
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