[polly] r283233 - [ScopInfo] Add -polly-unprofitable-scalar-accs option.
Michael Kruse via llvm-commits
llvm-commits at lists.llvm.org
Tue Oct 4 10:33:39 PDT 2016
Author: meinersbur
Date: Tue Oct 4 12:33:39 2016
New Revision: 283233
URL: http://llvm.org/viewvc/llvm-project?rev=283233&view=rev
Log:
[ScopInfo] Add -polly-unprofitable-scalar-accs option.
With this option one can disable the heuristic that assumes that statements with
a scalar write access cannot be profitably optimized. Such a statement instances
necessarily have WAW-dependences to itself. With DeLICM scalar accesses can be
changed to array accesses, which can avoid these WAW-dependence.
Added:
polly/trunk/test/ScopInfo/unprofitable_scalar-accs.ll
Modified:
polly/trunk/lib/Analysis/ScopInfo.cpp
Modified: polly/trunk/lib/Analysis/ScopInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/lib/Analysis/ScopInfo.cpp?rev=283233&r1=283232&r2=283233&view=diff
==============================================================================
--- polly/trunk/lib/Analysis/ScopInfo.cpp (original)
+++ polly/trunk/lib/Analysis/ScopInfo.cpp Tue Oct 4 12:33:39 2016
@@ -104,6 +104,11 @@ static cl::opt<bool>
cl::desc("Abort if an isl error is encountered"),
cl::init(true), cl::cat(PollyCategory));
+static cl::opt<bool> UnprofitableScalarAccs(
+ "polly-unprofitable-scalar-accs",
+ cl::desc("Count statements with scalar accesses as not optimizable"),
+ cl::Hidden, cl::init(true), cl::cat(PollyCategory));
+
//===----------------------------------------------------------------------===//
// Create a sequence of two schedules. Either argument may be null and is
@@ -3650,7 +3655,7 @@ bool Scop::isProfitable() const {
ContainsScalarAccs |= MA->isScalarKind();
}
- if (ContainsArrayAccs && !ContainsScalarAccs)
+ if (!UnprofitableScalarAccs || (ContainsArrayAccs && !ContainsScalarAccs))
OptimizableStmtsOrLoops += Stmt.getNumIterators();
}
Added: polly/trunk/test/ScopInfo/unprofitable_scalar-accs.ll
URL: http://llvm.org/viewvc/llvm-project/polly/trunk/test/ScopInfo/unprofitable_scalar-accs.ll?rev=283233&view=auto
==============================================================================
--- polly/trunk/test/ScopInfo/unprofitable_scalar-accs.ll (added)
+++ polly/trunk/test/ScopInfo/unprofitable_scalar-accs.ll Tue Oct 4 12:33:39 2016
@@ -0,0 +1,97 @@
+; RUN: opt %loadPolly -polly-process-unprofitable=false -polly-unprofitable-scalar-accs=false -polly-scops -analyze < %s | FileCheck %s
+; RUN: opt %loadPolly -polly-process-unprofitable=false -polly-unprofitable-scalar-accs=true -polly-scops -analyze < %s | FileCheck %s --check-prefix=HEURISTIC
+
+; Check the effect of -polly-unprofitable-scalar-accs
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+define void @func(i32 %n, i32 %m, double* noalias nonnull %A) {
+entry:
+ br label %outer.for
+
+outer.for:
+ %j = phi i32 [0, %entry], [%j.inc, %outer.inc]
+ %j.cmp = icmp slt i32 %j, %n
+ br i1 %j.cmp, label %inner.for, label %outer.exit
+
+ inner.for:
+ %i = phi i32 [1, %outer.for], [%i.inc, %inner.inc]
+ %b = phi double [0.0, %outer.for], [%a, %inner.inc]
+ %i.cmp = icmp slt i32 %i, %m
+ br i1 %i.cmp, label %body1, label %inner.exit
+
+ body1:
+ %A_idx = getelementptr inbounds double, double* %A, i32 %i
+ %a = load double, double* %A_idx
+ store double %a, double* %A_idx
+ br label %inner.inc
+
+ inner.inc:
+ %i.inc = add nuw nsw i32 %i, 1
+ br label %inner.for
+
+ inner.exit:
+ br label %outer.inc
+
+outer.inc:
+ store double %b, double* %A
+ %j.inc = add nuw nsw i32 %j, 1
+ br label %outer.for
+
+outer.exit:
+ br label %return
+
+return:
+ ret void
+}
+
+
+; CHECK: Statements {
+; CHECK-NEXT: Stmt_outer_for
+; CHECK-NEXT: Domain :=
+; CHECK-NEXT: [n, m] -> { Stmt_outer_for[i0] : 0 <= i0 <= n; Stmt_outer_for[0] : n < 0 };
+; CHECK-NEXT: Schedule :=
+; CHECK-NEXT: [n, m] -> { Stmt_outer_for[i0] -> [i0, 0, 0, 0] : i0 <= n; Stmt_outer_for[0] -> [0, 0, 0, 0] : n < 0 };
+; CHECK-NEXT: MustWriteAccess := [Reduction Type: NONE] [Scalar: 1]
+; CHECK-NEXT: [n, m] -> { Stmt_outer_for[i0] -> MemRef_b__phi[] };
+; CHECK-NEXT: Stmt_inner_for
+; CHECK-NEXT: Domain :=
+; CHECK-NEXT: [n, m] -> { Stmt_inner_for[i0, i1] : 0 <= i0 < n and 0 <= i1 < m; Stmt_inner_for[i0, 0] : m <= 0 and 0 <= i0 < n };
+; CHECK-NEXT: Schedule :=
+; CHECK-NEXT: [n, m] -> { Stmt_inner_for[i0, i1] -> [i0, 1, i1, 0] : i1 < m; Stmt_inner_for[i0, 0] -> [i0, 1, 0, 0] : m <= 0 };
+; CHECK-NEXT: ReadAccess := [Reduction Type: NONE] [Scalar: 1]
+; CHECK-NEXT: [n, m] -> { Stmt_inner_for[i0, i1] -> MemRef_b__phi[] };
+; CHECK-NEXT: MustWriteAccess := [Reduction Type: NONE] [Scalar: 1]
+; CHECK-NEXT: [n, m] -> { Stmt_inner_for[i0, i1] -> MemRef_b[] };
+; CHECK-NEXT: Stmt_body1
+; CHECK-NEXT: Domain :=
+; CHECK-NEXT: [n, m] -> { Stmt_body1[i0, i1] : 0 <= i0 < n and 0 <= i1 <= -2 + m };
+; CHECK-NEXT: Schedule :=
+; CHECK-NEXT: [n, m] -> { Stmt_body1[i0, i1] -> [i0, 1, i1, 1] };
+; CHECK-NEXT: MustWriteAccess := [Reduction Type: NONE] [Scalar: 1]
+; CHECK-NEXT: [n, m] -> { Stmt_body1[i0, i1] -> MemRef_a[] };
+; CHECK-NEXT: ReadAccess := [Reduction Type: NONE] [Scalar: 0]
+; CHECK-NEXT: [n, m] -> { Stmt_body1[i0, i1] -> MemRef_A[1 + i1] };
+; CHECK-NEXT: MustWriteAccess := [Reduction Type: NONE] [Scalar: 0]
+; CHECK-NEXT: [n, m] -> { Stmt_body1[i0, i1] -> MemRef_A[1 + i1] };
+; CHECK-NEXT: Stmt_inner_inc
+; CHECK-NEXT: Domain :=
+; CHECK-NEXT: [n, m] -> { Stmt_inner_inc[i0, i1] : 0 <= i0 < n and 0 <= i1 <= -2 + m };
+; CHECK-NEXT: Schedule :=
+; CHECK-NEXT: [n, m] -> { Stmt_inner_inc[i0, i1] -> [i0, 1, i1, 2] };
+; CHECK-NEXT: ReadAccess := [Reduction Type: NONE] [Scalar: 1]
+; CHECK-NEXT: [n, m] -> { Stmt_inner_inc[i0, i1] -> MemRef_a[] };
+; CHECK-NEXT: MustWriteAccess := [Reduction Type: NONE] [Scalar: 1]
+; CHECK-NEXT: [n, m] -> { Stmt_inner_inc[i0, i1] -> MemRef_b__phi[] };
+; CHECK-NEXT: Stmt_outer_inc
+; CHECK-NEXT: Domain :=
+; CHECK-NEXT: [n, m] -> { Stmt_outer_inc[i0] : 0 <= i0 < n };
+; CHECK-NEXT: Schedule :=
+; CHECK-NEXT: [n, m] -> { Stmt_outer_inc[i0] -> [i0, 2, 0, 0] };
+; CHECK-NEXT: MustWriteAccess := [Reduction Type: NONE] [Scalar: 0]
+; CHECK-NEXT: [n, m] -> { Stmt_outer_inc[i0] -> MemRef_A[0] };
+; CHECK-NEXT: ReadAccess := [Reduction Type: NONE] [Scalar: 1]
+; CHECK-NEXT: [n, m] -> { Stmt_outer_inc[i0] -> MemRef_b[] };
+; CHECK-NEXT: }
+
+; HEURISTIC-NOT: Statements
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