Author: hans Date: Wed Jul 29 10:38:37 2015 New Revision: 243524 URL: http://llvm.org/viewvc/llvm-project?rev=243524&view=rev Log: Merging r243500: (conflicts resolved manually since the branch doesn't have r243293) ------------------------------------------------------------------------ r243500 | spatel | 2015-07-28 16:28:22 -0700 (Tue, 28 Jul 2015) | 16 lines
ignore duplicate divisor uses when transforming into reciprocal multiplies (PR24141) PR24141: https://llvm.org/bugs/show_bug.cgi?id=24141 contains a test case where we have duplicate entries in a node's uses() list. After r241826, we use CombineTo() to delete dead nodes when combining the uses into reciprocal multiplies, but this fails if we encounter the just-deleted node again in the list. The solution in this patch is to not add duplicate entries to the list of users that we will subsequently iterate over. For the test case, this avoids triggering the combine divisors logic entirely because there really is only one user of the divisor. Differential Revision: http://reviews.llvm.org/D11345 ------------------------------------------------------------------------ Modified: llvm/branches/release_37/ (props changed) llvm/branches/release_37/lib/CodeGen/SelectionDAG/DAGCombiner.cpp llvm/branches/release_37/test/CodeGen/X86/fdiv-combine.ll Propchange: llvm/branches/release_37/ ------------------------------------------------------------------------------ --- svn:mergeinfo (original) +++ svn:mergeinfo Wed Jul 29 10:38:37 2015 @@ -1,3 +1,3 @@ /llvm/branches/Apple/Pertwee:110850,110961 /llvm/branches/type-system-rewrite:133420-134817 -/llvm/trunk:155241,242236,242239,242281,242288,242296,242331,242341,242410,242412,242433-242434,242442,242543,242673,242680,242706,242721-242722,242733-242735,242742,242869,242919,242993,243001,243116,243263,243294,243361 +/llvm/trunk:155241,242236,242239,242281,242288,242296,242331,242341,242410,242412,242433-242434,242442,242543,242673,242680,242706,242721-242722,242733-242735,242742,242869,242919,242993,243001,243116,243263,243294,243361,243500 Modified: llvm/branches/release_37/lib/CodeGen/SelectionDAG/DAGCombiner.cpp URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_37/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=243524&r1=243523&r2=243524&view=diff ============================================================================== --- llvm/branches/release_37/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original) +++ llvm/branches/release_37/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Wed Jul 29 10:38:37 2015 @@ -8365,12 +8365,12 @@ SDValue DAGCombiner::visitFDIV(SDNode *N if (N0CFP && N0CFP->isExactlyValue(1.0)) return SDValue(); - SmallVector<SDNode *, 4> Users; // Find all FDIV users of the same divisor. - for (auto *U : N1->uses()) { + // Use a set because duplicates may be present in the user list. + SetVector<SDNode *> Users; + for (auto *U : N1->uses()) if (U->getOpcode() == ISD::FDIV && U->getOperand(1) == N1) - Users.push_back(U); - } + Users.insert(U); if (TLI.combineRepeatedFPDivisors(Users.size())) { SDValue FPOne = DAG.getConstantFP(1.0, DL, VT); Modified: llvm/branches/release_37/test/CodeGen/X86/fdiv-combine.ll URL: http://llvm.org/viewvc/llvm-project/llvm/branches/release_37/test/CodeGen/X86/fdiv-combine.ll?rev=243524&r1=243523&r2=243524&view=diff ============================================================================== --- llvm/branches/release_37/test/CodeGen/X86/fdiv-combine.ll (original) +++ llvm/branches/release_37/test/CodeGen/X86/fdiv-combine.ll Wed Jul 29 10:38:37 2015 @@ -44,5 +44,24 @@ define double @div3_arcp(double %x, doub ret double %ret } +define void @PR24141() #0 { +; CHECK-LABEL: PR24141: +; CHECK: callq +; CHECK-NEXT: divsd +; CHECK-NEXT: jmp +entry: + br label %while.body + +while.body: + %x.0 = phi double [ undef, %entry ], [ %div, %while.body ] + %call = call { double, double } @g(double %x.0) + %xv0 = extractvalue { double, double } %call, 0 + %xv1 = extractvalue { double, double } %call, 1 + %div = fdiv double %xv0, %xv1 + br label %while.body +} + +declare { double, double } @g(double) + ; FIXME: If the backend understands 'arcp', then this attribute is unnecessary. attributes #0 = { "unsafe-fp-math"="true" } _______________________________________________ llvm-branch-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/llvm-branch-commits
