[llvm-commits] [llvm] r171281 - in /llvm/trunk: lib/Transforms/Scalar/LICM.cpp test/Transforms/LICM/scalar_promote.ll
Chris Lattner
sabre at nondot.org
Mon Dec 31 00:37:17 PST 2012
Author: lattner
Date: Mon Dec 31 02:37:17 2012
New Revision: 171281
URL: http://llvm.org/viewvc/llvm-project?rev=171281&view=rev
Log:
Fix LICM's memory promotion optimization to preserve TBAA tags when
promoting a store in a loop. This was noticed when working on PR14753,
but isn't directly related.
Modified:
llvm/trunk/lib/Transforms/Scalar/LICM.cpp
llvm/trunk/test/Transforms/LICM/scalar_promote.ll
Modified: llvm/trunk/lib/Transforms/Scalar/LICM.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LICM.cpp?rev=171281&r1=171280&r2=171281&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/LICM.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/LICM.cpp Mon Dec 31 02:37:17 2012
@@ -665,16 +665,18 @@
AliasSetTracker *
DebugLoc DL;
int Alignment;
+ MDNode *TBAATag;
public:
LoopPromoter(Value *SP,
const SmallVectorImpl<Instruction*> &Insts, SSAUpdater &S,
SmallPtrSet<Value*, 4> &PMA,
SmallVectorImpl<BasicBlock*> &LEB,
SmallVectorImpl<Instruction*> &LIP,
- AliasSetTracker &ast, DebugLoc dl, int alignment)
+ AliasSetTracker &ast, DebugLoc dl, int alignment,
+ MDNode *TBAATag)
: LoadAndStorePromoter(Insts, S), SomePtr(SP),
PointerMustAliases(PMA), LoopExitBlocks(LEB), LoopInsertPts(LIP),
- AST(ast), DL(dl), Alignment(alignment) {}
+ AST(ast), DL(dl), Alignment(alignment), TBAATag(TBAATag) {}
virtual bool isInstInList(Instruction *I,
const SmallVectorImpl<Instruction*> &) const {
@@ -698,6 +700,7 @@
StoreInst *NewSI = new StoreInst(LiveInValue, SomePtr, InsertPos);
NewSI->setAlignment(Alignment);
NewSI->setDebugLoc(DL);
+ if (TBAATag) NewSI->setMetadata(LLVMContext::MD_tbaa, TBAATag);
}
}
@@ -751,10 +754,11 @@
// We start with an alignment of one and try to find instructions that allow
// us to prove better alignment.
unsigned Alignment = 1;
+ MDNode *TBAATag = 0;
// Check that all of the pointers in the alias set have the same type. We
// cannot (yet) promote a memory location that is loaded and stored in
- // different sizes.
+ // different sizes. While we are at it, collect alignment and TBAA info.
for (AliasSet::iterator ASI = AS.begin(), E = AS.end(); ASI != E; ++ASI) {
Value *ASIV = ASI->getValue();
PointerMustAliases.insert(ASIV);
@@ -796,8 +800,7 @@
// instruction will be executed, update the alignment.
// Larger is better, with the exception of 0 being the best alignment.
unsigned InstAlignment = store->getAlignment();
- if ((InstAlignment > Alignment || InstAlignment == 0)
- && (Alignment != 0))
+ if ((InstAlignment > Alignment || InstAlignment == 0) && Alignment != 0)
if (isGuaranteedToExecute(*Use)) {
GuaranteedToExecute = true;
Alignment = InstAlignment;
@@ -809,6 +812,14 @@
} else
return; // Not a load or store.
+ // Merge the TBAA tags.
+ if (LoopUses.empty()) {
+ // On the first load/store, just take its TBAA tag.
+ TBAATag = Use->getMetadata(LLVMContext::MD_tbaa);
+ } else if (TBAATag && TBAATag != Use->getMetadata(LLVMContext::MD_tbaa)) {
+ TBAATag = 0;
+ }
+
LoopUses.push_back(Use);
}
}
@@ -841,7 +852,7 @@
SmallVector<PHINode*, 16> NewPHIs;
SSAUpdater SSA(&NewPHIs);
LoopPromoter Promoter(SomePtr, LoopUses, SSA, PointerMustAliases, ExitBlocks,
- InsertPts, *CurAST, DL, Alignment);
+ InsertPts, *CurAST, DL, Alignment, TBAATag);
// Set up the preheader to have a definition of the value. It is the live-out
// value from the preheader that uses in the loop will use.
@@ -850,6 +861,7 @@
Preheader->getTerminator());
PreheaderLoad->setAlignment(Alignment);
PreheaderLoad->setDebugLoc(DL);
+ if (TBAATag) PreheaderLoad->setMetadata(LLVMContext::MD_tbaa, TBAATag);
SSA.AddAvailableValue(Preheader, PreheaderLoad);
// Rewrite all the loads in the loop and remember all the definitions from
Modified: llvm/trunk/test/Transforms/LICM/scalar_promote.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/LICM/scalar_promote.ll?rev=171281&r1=171280&r2=171281&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/LICM/scalar_promote.ll (original)
+++ llvm/trunk/test/Transforms/LICM/scalar_promote.ll Mon Dec 31 02:37:17 2012
@@ -1,4 +1,4 @@
-; RUN: opt < %s -basicaa -licm -S | FileCheck %s
+; RUN: opt < %s -basicaa -tbaa -licm -S | FileCheck %s
target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"
@X = global i32 7 ; <i32*> [#uses=4]
@@ -134,7 +134,7 @@
store i32 %x2, i32* @X
store volatile i32* @X, i32** %P2
-
+
%Next = add i32 %j, 1 ; <i32> [#uses=2]
%cond = icmp eq i32 %Next, 0 ; <i1> [#uses=1]
br i1 %cond, label %Out, label %Loop
@@ -148,3 +148,41 @@
}
+; PR14753 - Preserve TBAA tags when promoting values in a loop.
+define void @test6(i32 %n, float* nocapture %a, i32* %gi) {
+entry:
+ store i32 0, i32* %gi, align 4, !tbaa !0
+ %cmp1 = icmp slt i32 0, %n
+ br i1 %cmp1, label %for.body.lr.ph, label %for.end
+
+for.body.lr.ph: ; preds = %entry
+ br label %for.body
+
+for.body: ; preds = %for.body.lr.ph, %for.body
+ %storemerge2 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.body ]
+ %idxprom = sext i32 %storemerge2 to i64
+ %arrayidx = getelementptr inbounds float* %a, i64 %idxprom
+ store float 0.000000e+00, float* %arrayidx, align 4, !tbaa !3
+ %0 = load i32* %gi, align 4, !tbaa !0
+ %inc = add nsw i32 %0, 1
+ store i32 %inc, i32* %gi, align 4, !tbaa !0
+ %cmp = icmp slt i32 %inc, %n
+ br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge
+
+for.cond.for.end_crit_edge: ; preds = %for.body
+ br label %for.end
+
+for.end: ; preds = %for.cond.for.end_crit_edge, %entry
+ ret void
+
+; CHECK: for.body.lr.ph:
+; CHECK-NEXT: %gi.promoted = load i32* %gi, align 4, !tbaa !0
+; CHECK: for.cond.for.end_crit_edge:
+; CHECK-NEXT: store i32 %inc, i32* %gi, align 4, !tbaa !0
+}
+
+!0 = metadata !{metadata !"int", metadata !1}
+!1 = metadata !{metadata !"omnipotent char", metadata !2}
+!2 = metadata !{metadata !"Simple C/C++ TBAA"}
+!3 = metadata !{metadata !"float", metadata !1}
+
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