diff options
| -rw-r--r-- | polly/lib/Transform/Simplify.cpp | 42 | ||||
| -rw-r--r-- | polly/test/Simplify/emptyaccessdomain.ll | 38 | ||||
| -rw-r--r-- | polly/test/Simplify/emptyaccessdomain___%for---%return.jscop | 24 | ||||
| -rw-r--r-- | polly/test/Simplify/emptyaccessdomain___%for---%return.jscop.transformed | 24 |
4 files changed, 126 insertions, 2 deletions
diff --git a/polly/lib/Transform/Simplify.cpp b/polly/lib/Transform/Simplify.cpp index a97fcef98fc..008503bdbb3 100644 --- a/polly/lib/Transform/Simplify.cpp +++ b/polly/lib/Transform/Simplify.cpp @@ -36,6 +36,8 @@ STATISTIC(InBetweenStore, "Number of Load-Store pairs NOT removed because " STATISTIC(TotalOverwritesRemoved, "Number of removed overwritten writes"); STATISTIC(TotalRedundantWritesRemoved, "Number of writes of same value removed in any SCoP"); +STATISTIC(TotalEmptyPartialAccessesRemoved, + "Number of empty partial accesses removed"); STATISTIC(TotalDeadAccessesRemoved, "Number of dead accesses removed"); STATISTIC(TotalDeadInstructionsRemoved, "Number of unused instructions removed"); @@ -97,6 +99,9 @@ private: /// Number of redundant writes removed from this SCoP. int RedundantWritesRemoved = 0; + /// Number of writes with empty access domain removed. + int EmptyPartialAccessesRemoved = 0; + /// Number of unused accesses removed from this SCoP. int DeadAccessesRemoved = 0; @@ -109,8 +114,8 @@ private: /// Return whether at least one simplification has been applied. bool isModified() const { return OverwritesRemoved > 0 || RedundantWritesRemoved > 0 || - DeadAccessesRemoved > 0 || DeadInstructionsRemoved > 0 || - StmtsRemoved > 0; + EmptyPartialAccessesRemoved > 0 || DeadAccessesRemoved > 0 || + DeadInstructionsRemoved > 0 || StmtsRemoved > 0; } MemoryAccess *getReadAccessForValue(ScopStmt *Stmt, llvm::Value *Val) { @@ -319,6 +324,33 @@ private: TotalStmtsRemoved += StmtsRemoved; } + /// Remove accesses that have an empty domain. + void removeEmptyPartialAccesses() { + for (ScopStmt &Stmt : *S) { + // Defer the actual removal to not invalidate iterators. + SmallVector<MemoryAccess *, 8> DeferredRemove; + + for (MemoryAccess *MA : Stmt) { + if (!MA->isWrite()) + continue; + + isl::map AccRel = give(MA->getAccessRelation()); + if (!AccRel.is_empty().is_true()) + continue; + + DEBUG(dbgs() << "Removing " << MA + << " because it's a partial access that never occurs\n"); + DeferredRemove.push_back(MA); + } + + for (MemoryAccess *MA : DeferredRemove) { + Stmt.removeSingleMemoryAccess(MA); + EmptyPartialAccessesRemoved++; + TotalEmptyPartialAccessesRemoved++; + } + } + } + /// Mark all reachable instructions and access, and sweep those that are not /// reachable. void markAndSweep(LoopInfo *LI) { @@ -380,6 +412,8 @@ private: << '\n'; OS.indent(Indent + 4) << "Redundant writes removed: " << RedundantWritesRemoved << "\n"; + OS.indent(Indent + 4) << "Access with empty domains removed: " + << EmptyPartialAccessesRemoved << "\n"; OS.indent(Indent + 4) << "Dead accesses removed: " << DeadAccessesRemoved << '\n'; OS.indent(Indent + 4) << "Dead instructions removed: " @@ -424,6 +458,9 @@ public: DEBUG(dbgs() << "Removing redundant writes...\n"); removeRedundantWrites(); + DEBUG(dbgs() << "Removing partial writes that never happen...\n"); + removeEmptyPartialAccesses(); + DEBUG(dbgs() << "Cleanup unused accesses...\n"); LoopInfo *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo(); markAndSweep(LI); @@ -456,6 +493,7 @@ public: OverwritesRemoved = 0; RedundantWritesRemoved = 0; + EmptyPartialAccessesRemoved = 0; DeadAccessesRemoved = 0; DeadInstructionsRemoved = 0; StmtsRemoved = 0; diff --git a/polly/test/Simplify/emptyaccessdomain.ll b/polly/test/Simplify/emptyaccessdomain.ll new file mode 100644 index 00000000000..641d34e9ecc --- /dev/null +++ b/polly/test/Simplify/emptyaccessdomain.ll @@ -0,0 +1,38 @@ +; RUN: opt %loadPolly -polly-import-jscop -polly-import-jscop-postfix=transformed -polly-simplify -analyze < %s | FileCheck %s -match-full-lines +; +; for (int j = 0; j < n; j += 1) { +; A[0] = 42.0; +; } +; +define void @emptyaccessdomain(i32 %n, double* noalias nonnull %A) { +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: + store double 42.0, double* %A + br label %inc + +inc: + %j.inc = add nuw nsw i32 %j, 1 + br label %for + +exit: + br label %return + +return: + ret void +} + + +; CHECK: Statistics { +; CHECK: Overwrites removed: 1 +; CHECK: Stmts removed: 1 +; CHECK: } + +; CHECK: After accesses { +; CHECK-NEXT: } diff --git a/polly/test/Simplify/emptyaccessdomain___%for---%return.jscop b/polly/test/Simplify/emptyaccessdomain___%for---%return.jscop new file mode 100644 index 00000000000..a0472bc116b --- /dev/null +++ b/polly/test/Simplify/emptyaccessdomain___%for---%return.jscop @@ -0,0 +1,24 @@ +{ + "arrays" : [ + { + "name" : "MemRef_A", + "sizes" : [ "*" ], + "type" : "double" + } + ], + "context" : "[n] -> { : -2147483648 <= n <= 2147483647 }", + "name" : "%for---%return", + "statements" : [ + { + "accesses" : [ + { + "kind" : "write", + "relation" : "[n] -> { Stmt_body[i0] -> MemRef_A[0] }" + } + ], + "domain" : "[n] -> { Stmt_body[i0] : 0 <= i0 < n }", + "name" : "Stmt_body", + "schedule" : "[n] -> { Stmt_body[i0] -> [i0] }" + } + ] +} diff --git a/polly/test/Simplify/emptyaccessdomain___%for---%return.jscop.transformed b/polly/test/Simplify/emptyaccessdomain___%for---%return.jscop.transformed new file mode 100644 index 00000000000..e881f7e1232 --- /dev/null +++ b/polly/test/Simplify/emptyaccessdomain___%for---%return.jscop.transformed @@ -0,0 +1,24 @@ +{ + "arrays" : [ + { + "name" : "MemRef_A", + "sizes" : [ "*" ], + "type" : "double" + } + ], + "context" : "[n] -> { : -2147483648 <= n <= 2147483647 }", + "name" : "%for---%return", + "statements" : [ + { + "accesses" : [ + { + "kind" : "write", + "relation" : "[n] -> { Stmt_body[i0] -> MemRef_A[0] : 1 = 0 }" + } + ], + "domain" : "[n] -> { Stmt_body[i0] : 0 <= i0 < n }", + "name" : "Stmt_body", + "schedule" : "[n] -> { Stmt_body[i0] -> [i0] }" + } + ] +} |
