[llvm] r304058 - [SCEVExpander] Try harder to avoid introducing inttoptr
Keno Fischer via llvm-commits
llvm-commits at lists.llvm.org
Fri May 26 20:22:56 PDT 2017
Author: kfischer
Date: Fri May 26 22:22:55 2017
New Revision: 304058
URL: http://llvm.org/viewvc/llvm-project?rev=304058&view=rev
Log:
[SCEVExpander] Try harder to avoid introducing inttoptr
Summary:
This fixes introduction of an incorrect inttoptr/ptrtoint pair in
the included test case which makes use of non-integral pointers. I
suspect there are more cases like this left, but this takes care of
the one I was seeing at the moment.
Reviewers: sanjoy
Subscribers: mzolotukhin, llvm-commits
Differential Revision: https://reviews.llvm.org/D33129
Added:
llvm/trunk/test/Transforms/LoopStrengthReduce/nonintegral.ll
Modified:
llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
llvm/trunk/unittests/Analysis/ScalarEvolutionTest.cpp
Modified: llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp?rev=304058&r1=304057&r2=304058&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp (original)
+++ llvm/trunk/lib/Analysis/ScalarEvolutionExpander.cpp Fri May 26 22:22:55 2017
@@ -1305,12 +1305,17 @@ Value *SCEVExpander::expandAddRecExprLit
// Expand the core addrec. If we need post-loop scaling, force it to
// expand to an integer type to avoid the need for additional casting.
Type *ExpandTy = PostLoopScale ? IntTy : STy;
+ // We can't use a pointer type for the addrec if the pointer type is
+ // non-integral.
+ Type *AddRecPHIExpandTy =
+ DL.isNonIntegralPointerType(STy) ? Normalized->getType() : ExpandTy;
+
// In some cases, we decide to reuse an existing phi node but need to truncate
// it and/or invert the step.
Type *TruncTy = nullptr;
bool InvertStep = false;
- PHINode *PN = getAddRecExprPHILiterally(Normalized, L, ExpandTy, IntTy,
- TruncTy, InvertStep);
+ PHINode *PN = getAddRecExprPHILiterally(Normalized, L, AddRecPHIExpandTy,
+ IntTy, TruncTy, InvertStep);
// Accommodate post-inc mode, if necessary.
Value *Result;
@@ -1383,8 +1388,15 @@ Value *SCEVExpander::expandAddRecExprLit
// Re-apply any non-loop-dominating offset.
if (PostLoopOffset) {
if (PointerType *PTy = dyn_cast<PointerType>(ExpandTy)) {
- const SCEV *const OffsetArray[1] = { PostLoopOffset };
- Result = expandAddToGEP(OffsetArray, OffsetArray+1, PTy, IntTy, Result);
+ if (Result->getType()->isIntegerTy()) {
+ Value *Base = expandCodeFor(PostLoopOffset, ExpandTy);
+ const SCEV *const OffsetArray[1] = {SE.getUnknown(Result)};
+ Result = expandAddToGEP(OffsetArray, OffsetArray + 1, PTy, IntTy, Base);
+ } else {
+ const SCEV *const OffsetArray[1] = {PostLoopOffset};
+ Result =
+ expandAddToGEP(OffsetArray, OffsetArray + 1, PTy, IntTy, Result);
+ }
} else {
Result = InsertNoopCastOfTo(Result, IntTy);
Result = Builder.CreateAdd(Result,
Added: llvm/trunk/test/Transforms/LoopStrengthReduce/nonintegral.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LoopStrengthReduce/nonintegral.ll?rev=304058&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/LoopStrengthReduce/nonintegral.ll (added)
+++ llvm/trunk/test/Transforms/LoopStrengthReduce/nonintegral.ll Fri May 26 22:22:55 2017
@@ -0,0 +1,45 @@
+; RUN: opt -S -loop-reduce < %s | FileCheck %s
+
+; Address Space 10 is non-integral. The optimizer is not allowed to use
+; ptrtoint/inttoptr instructions. Make sure that this doesn't happen
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128-ni:10:11:12"
+target triple = "x86_64-unknown-linux-gnu"
+
+define void @japi1__unsafe_getindex_65028(i64 addrspace(10)* %arg) {
+; CHECK-NOT: inttoptr
+; CHECK-NOT: ptrtoint
+; How exactly SCEV chooses to materialize isn't all that important, as
+; long as it doesn't try to round-trip through integers. As of this writing,
+; it emits a byte-wise gep, which is fine.
+; CHECK: getelementptr i64, i64 addrspace(10)* {{.*}}, i64 {{.*}}
+top:
+ br label %L86
+
+L86: ; preds = %L86, %top
+ %i.0 = phi i64 [ 0, %top ], [ %tmp, %L86 ]
+ %tmp = add i64 %i.0, 1
+ br i1 undef, label %L86, label %if29
+
+if29: ; preds = %L86
+ %tmp1 = shl i64 %tmp, 1
+ %tmp2 = add i64 %tmp1, -2
+ br label %if31
+
+if31: ; preds = %if38, %if29
+ %"#temp#1.sroa.0.022" = phi i64 [ 0, %if29 ], [ %tmp3, %if38 ]
+ br label %L119
+
+L119: ; preds = %L119, %if31
+ %i5.0 = phi i64 [ %"#temp#1.sroa.0.022", %if31 ], [ %tmp3, %L119 ]
+ %tmp3 = add i64 %i5.0, 1
+ br i1 undef, label %L119, label %if38
+
+if38: ; preds = %L119
+ %tmp4 = add i64 %tmp2, %i5.0
+ %tmp5 = getelementptr i64, i64 addrspace(10)* %arg, i64 %tmp4
+ %tmp6 = load i64, i64 addrspace(10)* %tmp5
+ br i1 undef, label %done, label %if31
+
+done: ; preds = %if38
+ ret void
+}
Modified: llvm/trunk/unittests/Analysis/ScalarEvolutionTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/Analysis/ScalarEvolutionTest.cpp?rev=304058&r1=304057&r2=304058&view=diff
==============================================================================
--- llvm/trunk/unittests/Analysis/ScalarEvolutionTest.cpp (original)
+++ llvm/trunk/unittests/Analysis/ScalarEvolutionTest.cpp Fri May 26 22:22:55 2017
@@ -7,21 +7,22 @@
//
//===----------------------------------------------------------------------===//
-#include "llvm/Analysis/ScalarEvolutionExpander.h"
-#include "llvm/Analysis/ScalarEvolutionExpressions.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/LoopInfo.h"
-#include "llvm/Analysis/TargetLibraryInfo.h"
-#include "llvm/ADT/SmallVector.h"
#include "llvm/Analysis/LoopInfo.h"
+#include "llvm/Analysis/ScalarEvolutionExpander.h"
+#include "llvm/Analysis/ScalarEvolutionExpressions.h"
+#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/AsmParser/Parser.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/Dominators.h"
#include "llvm/IR/GlobalVariable.h"
+#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/LLVMContext.h"
-#include "llvm/IR/Module.h"
#include "llvm/IR/LegacyPassManager.h"
+#include "llvm/IR/Module.h"
#include "llvm/IR/Verifier.h"
#include "llvm/Support/SourceMgr.h"
#include "gtest/gtest.h"
@@ -853,5 +854,82 @@ TEST_F(ScalarEvolutionsTest, SCEVZeroExt
Type *I128Ty = Type::getInt128Ty(Context);
SE.getZeroExtendExpr(S, I128Ty);
}
+
+// Make sure that SCEV doesn't introduce illegal ptrtoint/inttoptr instructions
+TEST_F(ScalarEvolutionsTest, SCEVZeroExtendExprNonIntegral) {
+ /*
+ * Create the following code:
+ * func(i64 addrspace(10)* %arg)
+ * top:
+ * br label %L.ph
+ * L.ph:
+ * br label %L
+ * L:
+ * %phi = phi i64 [i64 0, %L.ph], [ %add, %L2 ]
+ * %add = add i64 %phi2, 1
+ * br i1 undef, label %post, label %L2
+ * post:
+ * %gepbase = getelementptr i64 addrspace(10)* %arg, i64 1
+ * #= %gep = getelementptr i64 addrspace(10)* %gepbase, i64 %add =#
+ * ret void
+ *
+ * We will create the appropriate SCEV expression for %gep and expand it,
+ * then check that no inttoptr/ptrtoint instructions got inserted.
+ */
+
+ // Create a module with non-integral pointers in it's datalayout
+ Module NIM("nonintegral", Context);
+ std::string DataLayout = M.getDataLayoutStr();
+ if (!DataLayout.empty())
+ DataLayout += "-";
+ DataLayout += "ni:10";
+ NIM.setDataLayout(DataLayout);
+
+ Type *T_int1 = Type::getInt1Ty(Context);
+ Type *T_int64 = Type::getInt64Ty(Context);
+ Type *T_pint64 = T_int64->getPointerTo(10);
+
+ FunctionType *FTy =
+ FunctionType::get(Type::getVoidTy(Context), {T_pint64}, false);
+ Function *F = cast<Function>(NIM.getOrInsertFunction("foo", FTy));
+
+ Argument *Arg = &*F->arg_begin();
+
+ BasicBlock *Top = BasicBlock::Create(Context, "top", F);
+ BasicBlock *LPh = BasicBlock::Create(Context, "L.ph", F);
+ BasicBlock *L = BasicBlock::Create(Context, "L", F);
+ BasicBlock *Post = BasicBlock::Create(Context, "post", F);
+
+ IRBuilder<> Builder(Top);
+ Builder.CreateBr(LPh);
+
+ Builder.SetInsertPoint(LPh);
+ Builder.CreateBr(L);
+
+ Builder.SetInsertPoint(L);
+ PHINode *Phi = Builder.CreatePHI(T_int64, 2);
+ Value *Add = Builder.CreateAdd(Phi, ConstantInt::get(T_int64, 1), "add");
+ Builder.CreateCondBr(UndefValue::get(T_int1), L, Post);
+ Phi->addIncoming(ConstantInt::get(T_int64, 0), LPh);
+ Phi->addIncoming(Add, L);
+
+ Builder.SetInsertPoint(Post);
+ Value *GepBase = Builder.CreateGEP(Arg, {ConstantInt::get(T_int64, 1)});
+ Instruction *Ret = Builder.CreateRetVoid();
+
+ ScalarEvolution SE = buildSE(*F);
+ auto *AddRec =
+ SE.getAddRecExpr(SE.getUnknown(GepBase), SE.getConstant(T_int64, 1),
+ LI->getLoopFor(L), SCEV::FlagNUW);
+
+ SCEVExpander Exp(SE, NIM.getDataLayout(), "expander");
+ Exp.disableCanonicalMode();
+ Exp.expandCodeFor(AddRec, T_pint64, Ret);
+
+ // Make sure none of the instructions inserted were inttoptr/ptrtoint.
+ // The verifier will check this.
+ EXPECT_FALSE(verifyFunction(*F, &errs()));
+}
+
} // end anonymous namespace
} // end namespace llvm
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