From 0e77d72b0ad39fb31d4a435497bd4610e61c586f Mon Sep 17 00:00:00 2001 From: Renato Golin Date: Tue, 10 Nov 2015 18:01:16 +0000 Subject: [PATCH] Revert "Strip metadata when speculatively hoisting instructions" This reverts commit r252604, as it broke all ARM and AArch64 buildbots, as well as some x86, et al. llvm-svn: 252623 --- llvm/lib/Analysis/LoopInfo.cpp | 7 --- llvm/lib/Transforms/Scalar/LICM.cpp | 4 -- llvm/lib/Transforms/Utils/SimplifyCFG.cpp | 5 --- .../Analysis/TypeBasedAliasAnalysis/licm.ll | 2 +- llvm/test/Transforms/LICM/hoist-deref-load.ll | 44 ------------------- .../Transforms/SimplifyCFG/SpeculativeExec.ll | 26 ----------- 6 files changed, 1 insertion(+), 87 deletions(-) diff --git a/llvm/lib/Analysis/LoopInfo.cpp b/llvm/lib/Analysis/LoopInfo.cpp index e679b7ad7b86..9ee72361c92a 100644 --- a/llvm/lib/Analysis/LoopInfo.cpp +++ b/llvm/lib/Analysis/LoopInfo.cpp @@ -120,13 +120,6 @@ bool Loop::makeLoopInvariant(Instruction *I, bool &Changed, // Hoist. I->moveBefore(InsertPt); - - // There is possibility of hoisting this instruction above some arbitrary - // condition. Any metadata defined on it can be control dependent on this - // condition. Conservatively strip it here so that we don't give any wrong - // information to the optimizer. - I->dropUnknownNonDebugMetadata(); - Changed = true; return true; } diff --git a/llvm/lib/Transforms/Scalar/LICM.cpp b/llvm/lib/Transforms/Scalar/LICM.cpp index 6d70cdc3ade2..ba39afd42872 100644 --- a/llvm/lib/Transforms/Scalar/LICM.cpp +++ b/llvm/lib/Transforms/Scalar/LICM.cpp @@ -672,10 +672,6 @@ static bool hoist(Instruction &I, BasicBlock *Preheader) { // Move the new node to the Preheader, before its terminator. I.moveBefore(Preheader->getTerminator()); - // Metadata can be dependent on the condition we are hoisting above. - // Conservatively strip all metadata on the instruction. - I.dropUnknownNonDebugMetadata(); - if (isa(I)) ++NumMovedLoads; else if (isa(I)) ++NumMovedCalls; ++NumHoisted; diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp index ff81e7d5acfd..e0c598f92e2b 100644 --- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp +++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp @@ -1618,11 +1618,6 @@ static bool SpeculativelyExecuteBB(BranchInst *BI, BasicBlock *ThenBB, SpeculatedStore->setOperand(0, S); } - // Metadata can be dependent on the condition we are hoisting above. - // Conservatively strip all metadata on the instruction. - for (auto &I: *ThenBB) - I.dropUnknownNonDebugMetadata(); - // Hoist the instructions. BB->getInstList().splice(BI->getIterator(), ThenBB->getInstList(), ThenBB->begin(), std::prev(ThenBB->end())); diff --git a/llvm/test/Analysis/TypeBasedAliasAnalysis/licm.ll b/llvm/test/Analysis/TypeBasedAliasAnalysis/licm.ll index d2aee58204df..fe07730577e6 100644 --- a/llvm/test/Analysis/TypeBasedAliasAnalysis/licm.ll +++ b/llvm/test/Analysis/TypeBasedAliasAnalysis/licm.ll @@ -5,7 +5,7 @@ ; CHECK: @foo ; CHECK: entry: -; CHECK-NEXT: %tmp3 = load double*, double** @P +; CHECK-NEXT: %tmp3 = load double*, double** @P, !tbaa !0 ; CHECK-NEXT: br label %for.body @P = common global double* null diff --git a/llvm/test/Transforms/LICM/hoist-deref-load.ll b/llvm/test/Transforms/LICM/hoist-deref-load.ll index fd10c5d7503d..c384a858d1e6 100644 --- a/llvm/test/Transforms/LICM/hoist-deref-load.ll +++ b/llvm/test/Transforms/LICM/hoist-deref-load.ll @@ -388,49 +388,5 @@ for.end: ; preds = %for.inc, %entry ret void } -; In this test we should be able to only hoist load from %cptr. We can't hoist -; load from %c because it's dereferenceability can depend on %cmp1 condition. -; By moving it out of the loop we break this dependency and can not rely -; on the dereferenceability anymore. -; In other words this test checks that we strip dereferenceability metadata -; after hoisting an instruction. - -; CHECK-LABEL: @test10 -; CHECK: %c = load i32*, i32** %cptr -; CHECK-NOT: dereferenceable -; CHECK: if.then: -; CHECK: load i32, i32* %c, align 4 - -define void @test10(i32* noalias %a, i32* %b, i32** dereferenceable(8) %cptr, i32 %n) #0 { -entry: - %cmp11 = icmp sgt i32 %n, 0 - br i1 %cmp11, label %for.body, label %for.end - -for.body: ; preds = %entry, %for.inc - %indvars.iv = phi i64 [ %indvars.iv.next, %for.inc ], [ 0, %entry ] - %arrayidx = getelementptr inbounds i32, i32* %a, i64 %indvars.iv - %0 = load i32, i32* %arrayidx, align 4 - %cmp1 = icmp sgt i32 %0, 0 - br i1 %cmp1, label %if.then, label %for.inc - -if.then: ; preds = %for.body - %c = load i32*, i32** %cptr, !dereferenceable !0 - %1 = load i32, i32* %c, align 4 - %arrayidx3 = getelementptr inbounds i32, i32* %b, i64 %indvars.iv - %2 = load i32, i32* %arrayidx3, align 4 - %mul = mul nsw i32 %2, %1 - store i32 %mul, i32* %arrayidx, align 4 - br label %for.inc - -for.inc: ; preds = %for.body, %if.then - %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 - %lftr.wideiv = trunc i64 %indvars.iv.next to i32 - %exitcond = icmp eq i32 %lftr.wideiv, %n - br i1 %exitcond, label %for.end, label %for.body - -for.end: ; preds = %for.inc, %entry - ret void -} - attributes #0 = { nounwind uwtable } !0 = !{i64 4} diff --git a/llvm/test/Transforms/SimplifyCFG/SpeculativeExec.ll b/llvm/test/Transforms/SimplifyCFG/SpeculativeExec.ll index 73f9a0f88aca..c23a96df52ee 100644 --- a/llvm/test/Transforms/SimplifyCFG/SpeculativeExec.ll +++ b/llvm/test/Transforms/SimplifyCFG/SpeculativeExec.ll @@ -69,29 +69,3 @@ end: ret i8* %x10 } - -define i32* @test5(i32 %a, i32 %b, i32 %c, i32* dereferenceable(10) %ptr1, - i32* dereferenceable(10) %ptr2, i32** dereferenceable(10) %ptr3) nounwind { -; CHECK-LABEL: @test5( -entry: - %tmp1 = icmp eq i32 %b, 0 - br i1 %tmp1, label %bb1, label %bb3 - -bb1: ; preds = %entry - %tmp2 = icmp sgt i32 %c, 1 - br i1 %tmp2, label %bb2, label %bb3 -; CHECK: bb1: -; CHECK-NEXT: icmp sgt i32 %c, 1 -; CHECK-NEXT: load i32*, i32** %ptr3 -; CHECK-NOT: dereferenceable -; CHECK-NEXT: select i1 %tmp2, i32* %tmp3, i32* %ptr2 -; CHECK-NEXT: ret i32* %tmp3.ptr2 - -bb2: ; preds = bb1 - %tmp3 = load i32*, i32** %ptr3, !dereferenceable !{i64 10} - br label %bb3 - -bb3: ; preds = %bb2, %entry - %tmp4 = phi i32* [ %ptr1, %entry ], [ %ptr2, %bb1 ], [ %tmp3, %bb2 ] - ret i32* %tmp4 -}