vendor/llvm-project/llvmorg-10.0.1-rc2-0-g77d76b71d7dvendor/llvm-project/llvmorg-10.0.1-0-gef32c611aa2vendor/llvm-project/release-10.x

2 files changed, 28 insertions, 12 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
index 6aed5796acc6a..015b3d99fb0f2 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
@@ -271,8 +271,20 @@ SDValue DAGTypeLegalizer::PromoteIntRes_AtomicCmpSwap(AtomicSDNode *N,
     return Res.getValue(1);
   }
 
-  SDValue Op2 = GetPromotedInteger(N->getOperand(2));
+  // Op2 is used for the comparison and thus must be extended according to the
+  // target's atomic operations. Op3 is merely stored and so can be left alone.
+  SDValue Op2 = N->getOperand(2);
   SDValue Op3 = GetPromotedInteger(N->getOperand(3));
+  if (TLI.getTargetMachine().getTargetTriple().isRISCV()) {
+    // The comparison argument must be sign-extended for RISC-V. This is
+    // abstracted using a new TargetLowering hook in the main LLVM development
+    // branch, but handled here directly in order to fix the codegen bug for
+    // 10.x without breaking the libLLVM.so ABI.
+    Op2 = SExtPromotedInteger(Op2);
+  } else {
+    Op2 = GetPromotedInteger(Op2);
+  }
+
   SDVTList VTs =
       DAG.getVTList(Op2.getValueType(), N->getValueType(1), MVT::Other);
   SDValue Res = DAG.getAtomicCmpSwap(
diff --git a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 24ab65171a179..368e2100031f3 100644
--- a/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -5490,9 +5490,20 @@ char TargetLowering::isNegatibleForFree(SDValue Op, SelectionDAG &DAG,
   EVT VT = Op.getValueType();
   const SDNodeFlags Flags = Op->getFlags();
   const TargetOptions &Options = DAG.getTarget().Options;
-  if (!Op.hasOneUse() && !(Op.getOpcode() == ISD::FP_EXTEND &&
-                           isFPExtFree(VT, Op.getOperand(0).getValueType())))
-    return 0;
+  if (!Op.hasOneUse()) {
+    bool IsFreeExtend = Op.getOpcode() == ISD::FP_EXTEND &&
+                        isFPExtFree(VT, Op.getOperand(0).getValueType());
+
+    // If we already have the use of the negated floating constant, it is free
+    // to negate it even it has multiple uses.
+    bool IsFreeConstant =
+        Op.getOpcode() == ISD::ConstantFP &&
+        !getNegatedExpression(Op, DAG, LegalOperations, ForCodeSize)
+             .use_empty();
+
+    if (!IsFreeExtend && !IsFreeConstant)
+      return 0;
+  }
 
   // Don't recurse exponentially.
   if (Depth > SelectionDAG::MaxRecursionDepth)
@@ -5687,14 +5698,7 @@ SDValue TargetLowering::getNegatedExpression(SDValue Op, SelectionDAG &DAG,
                                  ForCodeSize, Depth + 1);
     char V1 = isNegatibleForFree(Op.getOperand(1), DAG, LegalOperations,
                                  ForCodeSize, Depth + 1);
-    // TODO: This is a hack. It is possible that costs have changed between now
-    //       and the initial calls to isNegatibleForFree(). That is because we
-    //       are rewriting the expression, and that may change the number of
-    //       uses (and therefore the cost) of values. If the negation costs are
-    //       equal, only negate this value if it is a constant. Otherwise, try
-    //       operand 1. A better fix would eliminate uses as a cost factor or
-    //       track the change in uses as we rewrite the expression.
-    if (V0 > V1 || (V0 == V1 && isa<ConstantFPSDNode>(Op.getOperand(0)))) {
+    if (V0 > V1) {
       // fold (fneg (fma X, Y, Z)) -> (fma (fneg X), Y, (fneg Z))
       SDValue Neg0 = getNegatedExpression(
           Op.getOperand(0), DAG, LegalOperations, ForCodeSize, Depth + 1);