vendor/llvm/llvm-release_371-r255217

1 files changed, 13 insertions, 5 deletions

diff --git a/lib/Target/PowerPC/PPCVSXFMAMutate.cpp b/lib/Target/PowerPC/PPCVSXFMAMutate.cpp
index 58d3c3d3fa2ef..46b8d13e47b91 100644
--- a/lib/Target/PowerPC/PPCVSXFMAMutate.cpp
+++ b/lib/Target/PowerPC/PPCVSXFMAMutate.cpp
@@ -103,6 +103,11 @@ protected:
 
         VNInfo *AddendValNo =
           LIS->getInterval(MI->getOperand(1).getReg()).Query(FMAIdx).valueIn();
+        if (!AddendValNo) {
+          // This can be null if the register is undef.
+          continue;
+        }
+
         MachineInstr *AddendMI = LIS->getInstructionFromIndex(AddendValNo->def);
 
         // The addend and this instruction must be in the same block.
@@ -181,11 +186,14 @@ protected:
         if (!KilledProdOp)
           continue;
 
-        // For virtual registers, verify that the addend source register
-        // is live here (as should have been assured above).
-        assert((!TargetRegisterInfo::isVirtualRegister(AddendSrcReg) ||
-                LIS->getInterval(AddendSrcReg).liveAt(FMAIdx)) &&
-               "Addend source register is not live!");
+	// If the addend copy is used only by this MI, then the addend source
+	// register is likely not live here. This could be fixed (based on the
+	// legality checks above, the live range for the addend source register
+	// could be extended), but it seems likely that such a trivial copy can
+	// be coalesced away later, and thus is not worth the effort.
+	if (TargetRegisterInfo::isVirtualRegister(AddendSrcReg) &&
+            !LIS->getInterval(AddendSrcReg).liveAt(FMAIdx))
+          continue;
 
         // Transform: (O2 * O3) + O1 -> (O2 * O1) + O3.