From 077cee586eda8b0edcca1ff07e823104eff718e7 Mon Sep 17 00:00:00 2001 From: Pawel Wodnicki Date: Mon, 26 Nov 2012 16:49:56 +0000 Subject: Merging r168186: into the 3.2 release branch. InstructionSimplify should be able to simplify A+B==B+A to 'true' but wasn't due to the same logic bug that caused PR14361. git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_32@168593 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/InstructionSimplify.cpp | 16 ++++++++++++++-- test/Transforms/InstSimplify/compare.ll | 9 +++++++++ 2 files changed, 23 insertions(+), 2 deletions(-) diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index b3d62487fc..c24c18f807 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -2065,8 +2065,20 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, if (A && C && (A == C || A == D || B == C || B == D) && NoLHSWrapProblem && NoRHSWrapProblem) { // Determine Y and Z in the form icmp (X+Y), (X+Z). - Value *Y = (A == C || A == D) ? B : A; - Value *Z = (C == A || C == B) ? D : C; + Value *Y, *Z; + if (A == C) { + Y = B; + Z = D; + } else if (A == D) { + Y = B; + Z = C; + } else if (B == C) { + Y = A; + Z = D; + } else if (B == D) { + Y = A; + Z = C; + } if (Value *V = SimplifyICmpInst(Pred, Y, Z, Q, MaxRecurse-1)) return V; } diff --git a/test/Transforms/InstSimplify/compare.ll b/test/Transforms/InstSimplify/compare.ll index ced74bd4be..ce2bb799c8 100644 --- a/test/Transforms/InstSimplify/compare.ll +++ b/test/Transforms/InstSimplify/compare.ll @@ -266,6 +266,15 @@ define i1 @add5(i32 %x, i32 %y) { ; CHECK: ret i1 true } +define i1 @add6(i64 %A, i64 %B) { +; CHECK: @add6 + %s1 = add i64 %A, %B + %s2 = add i64 %B, %A + %cmp = icmp eq i64 %s1, %s2 + ret i1 %cmp +; CHECK: ret i1 true +} + define i1 @addpowtwo(i32 %x, i32 %y) { ; CHECK: @addpowtwo %l = lshr i32 %x, 1 -- cgit v1.2.3 From bc69dc1d880792c0c2bbea189c3dbb2c39505391 Mon Sep 17 00:00:00 2001 From: Pawel Wodnicki Date: Mon, 26 Nov 2012 16:52:27 +0000 Subject: Merging r168196: into the 3.2 release branch. Make this easier to understand, as suggested by Chandler. git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_32@168594 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Analysis/InstructionSimplify.cpp | 7 ++++++- lib/Transforms/InstCombine/InstCombineCompares.cpp | 7 ++++++- 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp index c24c18f807..a76e5ad1b8 100644 --- a/lib/Analysis/InstructionSimplify.cpp +++ b/lib/Analysis/InstructionSimplify.cpp @@ -2067,15 +2067,20 @@ static Value *SimplifyICmpInst(unsigned Predicate, Value *LHS, Value *RHS, // Determine Y and Z in the form icmp (X+Y), (X+Z). Value *Y, *Z; if (A == C) { + // C + B == C + D -> B == D Y = B; Z = D; } else if (A == D) { + // D + B == C + D -> B == C Y = B; Z = C; } else if (B == C) { + // A + C == C + D -> A == D Y = A; Z = D; - } else if (B == D) { + } else { + assert(B == D); + // A + D == C + D -> A == C Y = A; Z = C; } diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp index e223a049f0..7c3f8fe15d 100644 --- a/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -2358,15 +2358,20 @@ Instruction *InstCombiner::visitICmpInst(ICmpInst &I) { // Determine Y and Z in the form icmp (X+Y), (X+Z). Value *Y, *Z; if (A == C) { + // C + B == C + D -> B == D Y = B; Z = D; } else if (A == D) { + // D + B == C + D -> B == C Y = B; Z = C; } else if (B == C) { + // A + C == C + D -> A == D Y = A; Z = D; - } else if (B == D) { + } else { + assert(B == D); + // A + D == C + D -> A == C Y = A; Z = C; } -- cgit v1.2.3 From 3668de5ba6ce154b365ef2f0b001be155c014e6f Mon Sep 17 00:00:00 2001 From: Pawel Wodnicki Date: Mon, 26 Nov 2012 17:01:12 +0000 Subject: Merging r167912: into the 3.2 release branch. Handle DAG CSE adding new uses during ReplaceAllUsesWith. Fixes PR14333. git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_32@168596 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 13 ++++++++++++- test/CodeGen/X86/pr14333.ll | 12 ++++++++++++ 2 files changed, 24 insertions(+), 1 deletion(-) create mode 100644 test/CodeGen/X86/pr14333.ll diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 5416a5c1d7..37d7731aa1 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -7728,7 +7728,18 @@ bool DAGCombiner::MergeConsecutiveStores(StoreSDNode* St) { if (StoreNodes[i].MemNode == EarliestOp) continue; StoreSDNode *St = cast(StoreNodes[i].MemNode); - DAG.ReplaceAllUsesOfValueWith(SDValue(St, 0), St->getChain()); + // ReplaceAllUsesWith will replace all uses that existed when it was + // called, but graph optimizations may cause new ones to appear. For + // example, the case in pr14333 looks like + // + // St's chain -> St -> another store -> X + // + // And the only difference from St to the other store is the chain. + // When we change it's chain to be St's chain they become identical, + // get CSEed and the net result is that X is now a use of St. + // Since we know that St is redundant, just iterate. + while (!St->use_empty()) + DAG.ReplaceAllUsesWith(SDValue(St, 0), St->getChain()); removeFromWorkList(St); DAG.DeleteNode(St); } diff --git a/test/CodeGen/X86/pr14333.ll b/test/CodeGen/X86/pr14333.ll new file mode 100644 index 0000000000..86c12ef6b5 --- /dev/null +++ b/test/CodeGen/X86/pr14333.ll @@ -0,0 +1,12 @@ +; RUN: llc -mtriple=x86_64-unknown-unknown < %s +%foo = type { i64, i64 } +define void @bar(%foo* %zed) { + %tmp = getelementptr inbounds %foo* %zed, i64 0, i32 0 + store i64 0, i64* %tmp, align 8 + %tmp2 = getelementptr inbounds %foo* %zed, i64 0, i32 1 + store i64 0, i64* %tmp2, align 8 + %tmp3 = bitcast %foo* %zed to i8* + call void @llvm.memset.p0i8.i64(i8* %tmp3, i8 0, i64 16, i32 8, i1 false) + ret void +} +declare void @llvm.memset.p0i8.i64(i8* nocapture, i8, i64, i32, i1) nounwind -- cgit v1.2.3